Tag Archives: animals

Understanding squirrel personalities can help us better protect endangered species

Do animals have personalities? We don’t tend to think that they do, but new research brings more evidence that we’ve been too hasty to assume this.

Golden-mantled ground squirrel at a camp-site in Prineville Reservoir State Park, Oregon, USA. Image via Wikimedia.

Researchers at the University of California, Davis have produced the first evidence of personality in golden-mantled ground squirrels (Callospermophilus lateralis), a species whose range includes the western U.S. and certain areas of Canada. While we most likely can’t talk about personalities with the same complexity as those seen in humans, the team explains that at least four main traits — boldness, aggressiveness, sociability, and activity levels — differ among individual squirrels, shaping the way each one interacts with their peers and environment.

Little personalities

“This adds to the small but growing number of studies showing that individuals matter,” said lead author Jaclyn Aliperti, who conducted the study while earning her Ph.D. in ecology at UC Davis. “Accounting for personality in wildlife management may be especially important when predicting wildlife responses to new conditions, such as changes or destruction of habitat due to human activity.”

The species itself is not currently considered threatened from a conservation standpoint, but the findings have value in helping us better protect others that are. The field of animal personality is still young, the team explains, and so is the understanding that these personalities have very real implications for ecological and conservation efforts. How individual animals interact with their environment, their peers, the ways in which they use available space, and feed, are all tied into their particular personalities.

The findings were made possible by research that has been performed at the Rocky Mountain Biological Laboratory in Gothic, Colorado, over the last three decades. For the study, Aliperti and her team used data gathered during these last 30 years, as well as results from experiments they performed with squirrels at the site during the last three years.

Although the study of animal personalities is still in its infancy, there are standardized approaches we can employ to investigate individual critters, the authors explain. In broad lines, they employed four types of tests during their experiments. These were ‘novel environment’ tests, where squirrels are placed in an enclosed box with holes and gridded lines; the ‘mirror’ tests, where squirrels are presented with their mirror image (which they do not recognize as being themselves); the ‘flight initiative’ tests, during which the squirrels are approached slowly in the wild, to check how long they wait before fleeing; and the ‘behavior-in-trap’ tests, where squirrels are caught in a simple and non-dangerous trap, and their initial behavior is recorded.

Beyond ascertaining that different squirrels will, in fact, have different responses or performances during these tests, they were also able to link differences in personality to particular behaviors. For example, bold and active squirrels moved faster than their peers. But squirrels that were bold, active, and more aggressive had an overall better command of their territory — they had higher levels of access to perches (vantage points). This type of access is very important for squirrels, as it allows them to better monitor their surroundings for predators, translating directly into safety.

But this was not the only combination of traits that correlated with greater perch access. More social squirrels also had greater access to these spots compared to their peers.

This is particularly interesting as golden-mantled ground squirrels are considered to be an asocial species. They are small and live short lives, relative to other species of ground squirrels, so they only have limited time to spend with their family units before adulthood, when they move to their own territories. That being said, the team notes that individuals who are more sociable tend to have an advantage over their peers. Being more social, in this particular case, can improve an individual’s chances of survival (through increased perch access). This would improve their chances of reproducing, thus forming a comparative advantage.

“Animal personality is a hard science, but if it makes you relate to animals more, maybe people will be more interested in conserving them,” said Aliperti. “I view [the squirrels] more as individuals. I view them as, ‘Who are you? Where are you going? What are you up to?’ versus on a species level.”

This isn’t the first sign that animals can have unique personalities, although it is the first time it has been reported in squirrels. Cetaceans, fish, chimpanzees, and even spiders have shown they can and do develop personalities. All this (growing) body of evidence points to the fact that the animals around us aren’t simple beasts, and efforts to protect endangered species should take this into account. Individual animals will react to any measures designed to protect them according to their personal traits, so understanding these would definitely help us implement better conservation strategies.

The paper “Bridging animal personality with space use and resource use in a free-ranging population of an asocial ground squirrel” has been published in the journal Animal Behaviour.

Only 2-3% of Earth’s land is ecologically intact, study finds

While wilderness areas are increasingly recognized as important for biodiversity conservation, few areas of the world remain with outstanding ecological integrity. A new study found that only 2.8% of the world’s land surface remains ecologically intact, meaning it still has an undisturbed habitat and populations of all of its original animals.

Image credit: Flickr / Hanming

Wilderness areas were identified as important priorities over 30 years ago, but more recently there have been attempts to be more explicit about what is being measured when referring to wilderness, with a focus on quantifying intact habitat. Previous studies have estimated that 20-40% of Earth’s surface is under low human influence.

Nevertheless, the researchers behind this new study argued that while forests, savannah, and tundra can appear intact from satellite observations, vital species are actually missing on the ground. Elephants, for example, spread seeds and create important clearings in forests, while wolves can control populations of deer and elk.

“Much of what we consider as intact habitat is missing species that have been hunted [and poached] by people, or lost because of invasive species or disease,” Andrew Plumptre, the lead author of the study, told The Guardian. “It’s fairly scary, because it shows how unique places like the Serengeti, which actually have functioning and fully intact ecosystems, are.”

Instead of focusing on human impact, the researchers made a review of the Key Biodiversity Areas (KBA) Criterion for C sites. These state that, in order to be considered as being an intact ecological community, an area must have the full complement of species known to occur in a particular site in their natural abundances, relative to a regionally appropriate benchmark. 

The authors chose the year 1500 as a benchmark, as this is the baseline date for assessing species extinctions within the IUCN Red List of Threatened Species. They assessed habitat intactness, faunal intactness (areas without any loss of biodiversity), and functional intactness (no loss of animal densities below a level that would affect the healthy functioning of an ecosystem).

Applying these three measures of intactness reduced the number of sites that might qualify under KBA Criterion C. Only between 2% and 3% of Earth’s terrestrial surface qualifies if Criterion C is defined as sites that are functionally intact, 10 times lower than previously estimated. Worryingly, only 11% of the analyzed sites are covered by protected areas. 

Many of the identified areas coincide with territories managed by indigenous communities, who play a crucial role in maintaining them. Areas identified as functionally intact included east Siberia and northern Canada for boreal and tundra biomes, parts of the Amazon and Congo basin tropical forests, and the Sahara Desert, according to the authors.

However, it’s not all bad news. Up to 20% of the planet’s land surface could be restored to faunal intactness through reintroductions of a few species into remaining intact habitats, the researchers found. Identifying areas under KBA Criterion C can also help focus attention on these sites for conservation and restoration.

“It has been shown that intact habitat has important benefits for both wildlife and people and as a result needs to be a critical target. Recognition of these special places within intact habitat, where you have full functional intactness, is needed and plans to focus restoration in areas where ecological integrity might be recovered,” said Plumptre in a statement. 

As well as a climate crisis, the world is also facing a biodiversity crisis, with many wildlife species, from lions to insects, struggling because of the destruction of their habitat for farming. Researchers have argued that a sixth mass extinction of life on Earth is beginning, with serious consequences for our sources of food, clean water, and fresh air.

The study was published in the journal Frontiers. 

Want to avoid new pandemics? Preserving biodiversity is step one, research argues

A growing body of evidence is already showing that preventing new pandemics like COVID-19 will require addressing biodiversity loss from human activities such as deforestation and agriculture. Now, a new study has synthesized the current understanding of how biodiversity affects human health and why it’s so important to preserve and protect it. 

Image credit: Flickr / Ali Rajabali.

Felicia Keesing, a Bard College professor and lead author of the paper, says it’s a myth that wild areas with high levels of biodiversity represent hotspots for diseases. The more animal diversity, the more pathogens — the myth goes. But this is plain wrong, Keesing says. Biodiversity itself isn’t a threat, quite the contrary: it protects us from the species that carry pathogens. 

Zoonotic diseases such as Ebola, SARS, and COVID-19 are caused by pathogens that jump to humans from other species. A pathogen might travel from one host to another in droplets or aerosols from coughs or sneezes; through bodily fluids; through fecal material; or by being transferred during the bite of a vector. It’s never easy to figure out how the next virus may jump.

Cross-species transmission results from a complex interplay between the characteristics of the pathogen, the original host’s infection, behavior, and ecology, how the pathogen is shed into and survives in the environment, how humans are exposed to the pathogen, and how susceptible those humans are to infection. So it’s not that more species directly means more risk — it’s more about how we interact with those species, and how they interact with each other.

Natural biodiversity (and its loss) can affect this pathway at multiple points, potentially affecting the probability that a new pathogen will become established in humans. But do diverse communities of host species serve as sources for new pathogens? Recent research seems to suggest that’s not the case.

“Research is mounting that species that thrive in developed and degraded landscapes are often much more efficient at harboring pathogens and transmitting them to people. In less-disturbed landscapes with more animal diversity, these risky reservoirs are less abundant and biodiversity has a protective effect,” Rick Ostfeld, co-author of the paper, said in a statement.

The researchers argued that innate biodiversity can reduce the risk of infectious diseases through a dilution effect, in which species in diverse communities dilute the impact of host species that thrive when diversity declines. This happens when the transmission of a pathogen increases as diversity declines, as has been demonstrated for a number of disease systems.

Despite abundant evidence for the dilution effect, the more general idea that biodiversity can reduce human disease risk has been controversial, in large part because biodiversity was thought to be a source of new zoonotic pathogens via spillover. This is why we need to reconcile the effects of biodiversity on the emergence and ongoing transmission, Ostfeld and Keesing said.

Human impacts like land-use change have been linked to emerging infectious diseases of humans in many studies. When this happens, long-lived and larger-bodied species tend to disappear first, while smaller-bodied species with fast life histories tend to proliferate. Bats, primates and rodents have been highlighted as the ones more likely to transmit pathogens to humans. 

“When we erode biodiversity, we favor species that are more likely to be zoonotic hosts, increasing our risk of spillover events,” Ostfeld said. “Managing this risk will require a better understanding of how things like habitat conversion, climate change, and overharvesting affect zoonotic hosts, and how restoring biodiversity to degraded areas might reduce their abundance.”

The researchers argued we debating the importance of one taxonomic group or another and instead focus on the host attributes linked with diseases transmissions. Getting a better understanding of the features of effective zoonotic hosts such as their habitat preferences and resilience to disturbance will be essential to protect public health, they argued. 

The study was published in the journal PNAS. 

Small but sneaky. These are the world’s 10 smallest mammals

Mammals come in all shapes and sizes, from breathtakingly huge to really tiny. We usually think that bigger is better, but while it does have many advantages, being small can also work out. It means you can squeeze into all sorts of places to hide and escape from predators and hibernate. You also end up needing much less food to survive.

The bumblebee bat, Craseonycteris thonglongyai, is considered the world’s smallest bat and the smallest mammal in the world based on skull size. It weighs less than a penny and has a length of about two centimeters. The name comes from the fact that it’s usually confused for a bumblebee buzzing by your ear in the night – all because of its small size.

However, there are plenty more small mammals worth naming. The world is filled with them, and they’re more than just adorable: they’re excellently adapted to diverse ecosystems. Here’s a list with some of our favorite small mammas — get ready to be surprised by amazing facts and figures regarding their way of living, favorite foods, specific locations, and challenges from other predators and human activities.

The Etruscan shrew

The Etruscan shrew. Image credit: Flickr / Mick Sway

The Etruscan shrew (Suncus etruscus), also known as the Etruscan pygmy shrew or the white-toothed pygmy shrew, is usually considered the smallest known existing mammal by mass – weighing only about 1.8 grams on average and with a body length of four centimeters. Despite its size, it has a huge appetite, eating about twice its body weight every day. Talk about calorie consumption!

The shrew feeds on various small invertebrates and vertebrates, mainly insects, and can hunt individuals of the same size as itself. It prefers warm and damp climates, living in the belt between 10° and 30°N latitude stretching from Europe and North Africa up to Malaysia. While widespread, they are generally uncommon and are endangered in some countries.

Pygmy jerboa

Pygmy jerboas are considered the smallest rodents in the world. Their bodies start at four centimeters and they have tails up to seven centimeters long. Despite their size, they can jump very large distances thanks to their kangaroo-like legs. This helps them move fast over the arid deserts where they mainly live.

They are native to Pakistan and Afghanistan and their habitat includes rolling sand dunes, barren flat gravel, and sandy deserts. They are nocturnal herbivores, feeding on seeds and leaves from the desert. They have highly sensitive hearing, which allows them to detect predators, and mainly live in burrows excavated under small bushes.

Bumblebee bat

We mentioned the Kitti’s hog-nosed bat (also called the bumblebee bat) at the start of the article. At just a few grams, this tiny creatue truly is a wonder of nature.

It can only be found in some selected limestone caves in south-west Thailand. Surveys from 1997 to 2008 counted around 10,000 bats in 44 caves. The single species represents an entire family of bats, which split from the rest about 33 million years ago. It’s just one of around 440 bat species found in Asia — a continent that has more than one-third of the world’s 1,200 bat species.

Mouse lemurs

The Madame Berthe’s mouse lemur. Image credit: Flickr / Allan Hopinks

The adorable mouse lemurs (Microcebus) are considered one of the world’s smallest primates, measuring up to 27 centimeters in length including their tails. There are more than 20 species of mouse lemurs, and several have been identified only in recent years. The smallest species is the Madame Berthe’s mouse lemur, which measures only nine centimeters in length (3.5 inches).

They are forest dwellers that live in female-dominated groups of up to 15 animals. They spend most of their time in trees and can move from branch to branch and tree to tree. They sleep during the day and forage at night for insects, fruit, flowers, and other plants. They store fat in their tails and hind legs, burning it when forage is lean.

Least weasel

Least weasels are very small carnivores in the weasel family (Mustelidae). Males reach 17 centimeters, while females grow to 12 centimeters. Despite their size, they are the worst nightmare of small rodents, as they have a much bigger and ferocious personality than their size might suggest. They have long and slender bodies and short legs.

They are commonly found from Alaska and Canada through the upper Midwest, and portions of Appalachia. populations range from secure in Michigan and South Dakota to vulnerable in Minnesota and Iowa. They can be found in a wide variety of habitats, but prefer forests and woodlands with rocky slopes. They occupy and build nests of grass.

Pygmy possum

Pygmy possums are extremely cute but they’re more than just a pretty face. They range in length between five and seven centimeters and are commonly found in Australia, Papua New Guinea, and Indonesia. The family is divided into two groups, the genus Burramys, and the genus Cercartetu. Burramys only has one surviving species, the Mountain Pygmy Possum.

Pygmy possums are excellently adapted to their environment. They are tree-dwelling marsupials with large eyes, large ears, and long whiskers. Their soft, fur coat is fawn to grey on top and white underneath and, like many marsupials, their long tails swell with extra fat in times of plenty. They use their tails like fifth limbs to climb swiftly and can deftly leap between tall trees. Sky resorts and bush fires have affected parts of the habitats.

African pygmy mouse

Mice are generally known as small creatures, but the African pigmy mouse takes that to the extreme. It measures between two and seven centimeters and it’s considered the world’s smallest mouse. It’s so small that it stays hydrated by licking dew off tiny pebbles that it cleverly stacks in front of its burrow. Some people keep them as pets but they are very fragile.

Their geographical range extends from Central Africa all the way across to Eastern Africa and down to South Africa. They are social species and live in burrows or individual family units. These are constructed under piles of debris or fallen logs. They have a pale belly and their oats are typically red or blue.

Pygmy marmoset

The pigmy marmoset. Image credit: Flickr / BBC

Usually described as “pocket monkeys” as they can fit into your breast pocket, pigmy marmosets are considered the world’s smallest monkeys. They rarely have a length larger than 12 centimeters and, going about the Amazon rainforest in South America, using their sharp teeth and nails to gouge holes in trees and eat the sap, gums, and resins found inside.

These monkeys usually make their home in forests or bamboo thickets near or alongside rivers and floodplains. They prefer living in dense rainforests where there are lots of hiding places among the plants. Each marmoset group has a small home range of less than half an acre. They are orange-brown and their coloration gives them good camouflage.

Long-tailed planigale

The long-tailed planigale is the world’s smallest marsupials, with a length averaging five centimeters – including the tail. Their size and flattened head allow them to squeeze into crevices and cracks any other mammal would find impossible. This enables them to find food in unusual places and hide from predators. They hunt insects and even young mammals.

They belong to the family Dasyuridae, with three subspecies that can be found in northern parts of Australia. They inhabit grasslands, black soil plains, and wooded savannas and face many major threats such as habitat destruction (wildfires and overgrazing) and an increased number of predators. They are widely spread and numerous in the wild.

American shrew mole

The American shrew mole. Image credit: Flickr / Wikipedia Commons

Measuring about 10 centimeters including the tail, the American shrew mole is the smallest species of mole in the world. They are adorable underground dwellers that can be found in the U.S. Northwest and Canada’s British Columbia. They have small front paws than most other moles and travel in groups of 11 or more and spend more time above ground than other moles.

It’s the only living member of the genus Neurotrichus and the tribe Neurotrichini. They are active above ground, foraging in leaf litter for earthworms, insects, snails, and slugs, and can climb bushes to forage for food. They are called shrew mole instead of just shrew or mole because of its fur, a feature of most shrews, its large head and heavy dentition, a feature of moles.


So, there you have it — just some of the smallest mammals out there. Are they cute? Absolutely! But “cute” doesn’t cut it in the animal world. You need to be well-adapted to your environment, otherwise you just won’t make it. So the next time you see one such creature, don’t just think of it as adorable — cherish it as the magnificent creature it truly is.

Animal coronaviruses are roaming much more than we thought

A single virus making the jump from animals to humans can spark disaster, as we’ve seen so well over the past year. If viruses roam freely in animals, this raises the risk of the viruses mutating and ultimately making their way to humans. A new study found that this problem may be much more widespread than we thought — but there are ways we can prepare.

Image via Wikipedia.

The COVID-19 pandemic started when a coronavirus made the jump from an animal (we’re still not 100% certain which one) to humans. At first glance it may seem like it came out of the blue, but the warning signs were there all along — not just with the SARS and MERS outbreaks, but also with studies that highlighted the risk of similar coronavirus outbreaks.

Now, researchers have highlighted another concerning trend, finding that there are at least 11 times more associations between mammalian species and coronavirus strains.

“This means that for every species that we have observed being infected with a specific coronavirus, there are another 11 different sets of wild mammal species and coronavirus infection that we haven’t yet observed. In short, there’s both a lot more and a lot more diverse coronavirus infections in wild mammals than we know about,” said Marcus Blagrove, one of the study authors, to ZME Science.

“We are not suggesting that recombination and production of new coronaviruses is something we should be worried about happening immediately,” Blagrove adds, emphasizing that this is a long-term trend. “This is a more long-term timescale.”

The study’s first author is Maya Wardeh, a specialist in biological data mining. Wardeh, Blagrove, and veterinary epidemiologist Matthew Baylis looked at the potential scale of novel coronavirus generation in both wild and domesticated animals. The goal was to identify likely mammalian hosts where the next coronaviruses may be generated over the next few years or decades, Blagrove explains in an email to ZME Science. If we know what the high-risk species are, we can keep an eye on them and identify potential pandemic viruses before they even jump to humans. This would serve as an effective warning system to either prevent future pandemics or at the very least, give us a headstart to work on effective vaccines and treatments early on.

New coronaviruses can emerge when different strains co-infect an animal, causing the viral genetic material to recombine, so infection patterns can help us understand when and where new coronavirus strains are likely to happen.

The research team looked at 411 strains of coronavirus and 876 potential mammalian host species using a machine-learning approach to predict relationships between the strains and species. They found that some species among the “usual suspects” — species previously associated with coronavirus outbreaks (such as horseshoe bats, palm civets, and pangolins), but also some new ones.

“Many previous and current studies are looking at which existing viruses can ‘jump’ from one species to another. Rather than looking at existing viruses, we look at where new coronaviruses may come from. In the last question, we talk about how new coronaviruses can be produced by viruses exchanging genetic material. We highlight that this can happen in many more mammalian species than we currently realize. Should human-infecting coronaviruses (such as SARS, and SARS-CoV-2) recombine with one of the many non-human coronaviruses, this can generate new viruses, with different diseases, that can affect humans in the future. This is how SARS (and probably SARS-CoV-2, it takes a long time to prove!) emerged.”

This means more species are sharing their viruses, which in turn means individual viruses can likely infect more mammals than expected. For humans, this is not a concern directly, but if these viruses start “meeting each other”, it can become a problem as they become more likely to jump.

“The problem with this is when two different strains of coronavirus meet each other in a host, then can produce new viral strains with attributes from each ‘parent virus’, in a similar way that two animals produce children with genetic material from each parent. This process is called homologous recombination.”

The overall scale of interactions suggests that viruses are coming into direct with each other much more than we realize, and it’s something we should be keeping an eye out for. The researchers predict 40 times more mammalian species can be individually infected with a wide range of coronaviruses than previously believed.

But the study doesn’t only raise an alarm: it also offers some practical solutions, such as keeping potential host species away from each other. Since some of these species are also domestic, protective measures also apply to agriculture, Blagrove concludes.

“Some aspects of animal welfare are particularly relevant to virus spread and, in this case, the generation of new strains. Our work highlights high-risk species of mammal which can be infected with large numbers of different coronaviruses. We would recommend minimizing the chances of these species coming into contact with more of these viruses, for example by minimizing the intensive farming of these animals and keeping them separate from other high-risk species so as to limit virus spread and thus chances for recombination. We also recommend surveillance of the particularly high-risk species to identify any new viruses early.”

The study has been published in Nature Communications.

Like a baby’s bottom: why don’t humans have fur?

Exactly why humans lost their fur is unclear, but our skinny exteriors set us apart from most of our mammalian cousins.

Image via Pixabay.

Still, us shedding our fur had a dramatic effect on the evolution of our species. To understand why, let’s take a look at what body hair does and see what benefits or drawbacks it brings to the table.

First off, what is it?

Each strand of hair is a filament made out of the protein keratin; when hair grows thickly across an animal’s body, we call it fur.

Hair is a hallmark of mammals, but this family doesn’t have a monopoly on hairs. Insects grow hairs too, although theirs are different in structure from our own. Bees, for example, use it to keep them warm, but also as a sensory organ and to carry pollen. Other species of insects, for example, the fruit fly Drosophila, mostly use them as sensors for tactile (touch) and olfactory (smell) input — a fly’s antennas work similarly to our noses, having a pore to allow smell in and neurons at the base of the strands to sense odors.

Some lichens, algae, plants, and a group called protists can grow trichomes, which is like plant-hair. Trichomes serve a wide range of functions including nutrition, the absorption and retention of water, as well as protection from radiation, insects, or larger herbivores.

And now, fur

Fur consists of an undercoat of finer hairs that helps trap heat, and an outer coat (the ‘guard’) that’s oily and keeps out water.

File:Cleaning (2876339550).jpg
Fur isn’t digestible, which is why cats throw up hairballs.
Image via Wikimedia.

The most obvious use of fur is to help you keep warm. Animals that produce their own body heat, most notably mammals, use fur as an energy-saving mechanism. A coat of hair traps air around the animal’s body, which provides insulation. Going without one is like always keeping the window open during winter — you can probably keep the place warm, but your energy bill will skyrocket. Evolution doesn’t like paying bills.

Fur protects against damage from the elements or other threats. A hairless animal on a cold winter night could avoid hypothermia but still develop frostbite (because tissues can’t transfer heat fast enough to prevent freezing). In a pinch, fur can also ward off light scratches or bruises, and some animals have water-repellent coats.

The most obvious drawback of having fur is that it costs energy and nutrients to grow. Hairs are renewed constantly to keep them healthy and efficient, and when you’re covered with them, it adds up fast. A 40kg-sheep for example can produce up to 13.6 kg (30 pounds) of wool per year and eats roughly 1.1 kgs of dry food per day (around 400kgs/year), according to SmilingTreeFarm. Its fleece weighs around 3.4% of its total annual intake of food — another way to look at it is that two weeks out of the year, this hypothetical sheep eats only to grow its fur.

Most other drawbacks of fur are dependent on context. Wet fur is a complete liability as it’s heavy and good at trapping water, which will chill you thoroughly. Dry fur is a good insulator but can also make you overheat in hot climates (most mammals apart from primates don’t sweat). Fur is a great home for parasites and creepy crawlies. Shed hairs can create a scent trail for predators to follow — even human hunters look for hairs in the brush when stalking prey.

Of course, fur can also help you stay hidden if its color is just right.

Hair

The hair on our heads still acts as insulation and offers some degree of protection against solar radiation. A testament to its usefulness is that the follicles on our scalps (these are the ‘foundations’ from which hairs grow) have longer active growth periods than any other on our body. The strands of hair on our head can keep growing for years, whereas most others grow for weeks or a few months.

Image credits Engin Akyurt.

But not all hair grows to keep us warm. Our eyebrows are designed to keep sweat from our eyes, and are thus a product of our lack of fur. We have hair inside our noses, meant to keep out dust and other particles. There are strands of hair inside our ears that allow us to keep balance.

Hair is also meant to help us mate and signal various information to the group. Facial hair for men as well as body and pubic hair for both sexes show maturity. Guys tend to be the hairier of the sexes, and this is a product of testosterone. The most common theory as to why is that it helped keep ancient men warm on those long cold nights out hunting mammoths. But that wouldn’t explain why both sexes have a thin, almost invisible coat of body hair; from experience, I can also vouch that a hairy forearm won’t do much good in winter.

One proposed alternative is that it’s meant to help us feel parasites, and that women tended to favor men who had fewer parasites on them (sounds reasonable). This would have generated an evolutionary pressure for hairier men, as women essentially selected for this trait.

Male pattern baldness, also a product of testosterone, could help signal dominance in the group. Males in other species also signal their position in the group through hair, such as dominant silverback gorillas (whose back hairs grow gray) or black-maned lions.

Finally, many species employ hairs as sensory organs. Whiskers are a prime example. They’re academically known as ‘vibrissae’ and come in two forms: the longer, thicker ‘macrovibirssae’ (that animals can typically move voluntarily) and the smaller, thinner ‘microvibrissae’ (which are typically immobile). Whiskers grow in groups on various parts of an animal’s body, most commonly on their snouts, and are used to sweep a wider area using touch. They vibrate when coming in contact with something, and blood vessels at their roots amplify this vibration for the animal to perceive.

If you’re a cat sticking your head in a dark mouse’s hole, having a good set of whiskers can help you find your meal. Spiders are another great example of hair used as sensing organs. They wear their bones (a chitinous exoskeleton) on their outside. Hairs grow out of this skeleton and help transmit vibrations from the soil or web to the animal, acting similarly to hearing or a long-range sense of touch. Note that while mammals grow their fur from keratin, insects use chitin.

So why don’t we have fur?

r/Animals - A hairless chimp at Tywcross Zoo in England
Mongo, a hairless chimp at Tywcross Zoo in England, who died in 2016.
Image via Reddit.

You might be surprised to hear that humans and other primates have virtually the same density of hair follicles (and thus, hairs) over most of their body. The difference is that ours is ‘vellus hair‘, so short and fine that it’s almost invisible. So it’s not that we lost our body hair, we just changed its type.

We don’t really know why this happened. We have several theories, though.

One of them is that, as our ancestors moved down from the trees, they also discovered seafood. Since wet fur isn’t effective, this could have favored individuals with less fur. However, this isn’t regarded as the likely reason, or at least not the main one.

A more widely-accepted theory is that our ancestors needed to better control their temperature as they switched from living in forests to living in the savannah. No fur meant they could sweat more, preventing heat exhaustion. This may have directly underpinned the success of our species by allowing us to outlast, and thus capture, prey.

Our largest departure from the primate family in regards to our skin comes from our sweat glands. Humans have up to ten times as many eccrine (sweat) glands than chimps or macaques. We also have extremely few apocrine glands, which produce an oil-like substance. Our primate cousins can have equal parts eccrine and apocrine glands and other animals such as dogs will only have apocrine glands on their body and eccrine ones on the pads of their feet or other hairless areas.

The truth is probably somewhere in the middle, and our hairlessness was caused by several factors working together. Environmental pressures and a selective advantage during hunts started the process, and human ingenuity (which means fires and clothes to keep warm) kept it going up to today. However, the heavy presence of sweat glands on our skin suggests that thermoregulation (keeping our bodies’ heat just right) was a major advantage of our hairless outsides.

When?

Keep in mind that there are still many unknowns regarding our hairlessness. But two moments in our evolutionary history could have started this transition.

The first was in our very ancient past, as our furry ancestors climbed down from the trees. Humans have never been too physically imposing, and our ancestors were probably similar in this regard. The theory goes that they focused their activity during the hottest parts of the day in order to avoid predators (who would be hiding from the sun and avoiding activity), which made it advantageous to sweat and made fur impractical. This likely took place around four to seven million years ago. Essentially, in this scenario, it was our efforts to avoid being eaten that lost us our fur.

The second possibility is that humanity needed to shed the hairs in order to be able to hunt. Again, our bodies are very tiny and fragile compared to most wildlife. We’re slower than most animals we’d like to hunt, have no fangs, no claws, and can’t roar. We had tools, maybe spears, to help, but they couldn’t make up all the difference.

However, what our ancestors (and call center operators) can tell you is that you can accomplish a lot if you just tire your competition out. Persistence hunting was one of the few ways our ancestors could acquire large quantities of meat apart from maybe scavenging (which is dangerous and not very lucrative).

Despite our many shortcomings, humans are the best persistence hunters on the planet (or at least among the top ones) simply because we can sweat and cool down even while running. Our ancestors figured out that they didn’t need to fight and stab the antelope; they could just scare it away and chase it, tire it out so that it couldn’t fight back. And then stab it — safely.

This scenario would be more recent — around two million years ago — as hominins like Homo erectus (the first bipedal hominin) started hunting. Bones with tool marks discovered at Homo erectus sites show that they were hunting and butchering large prey regularly. Their bone structures suggest they could walk and run much better than earlier hominins due to longer legs, a foot structure more adapted to walking upright, and larger butt muscles. In this scenario, it was our efforts to catch and eat other animals that cost us our furs.

We may never know for sure why our skin is pink and bare when all our relatives are furry. Personally, I find “because it helped our ancestors survive, somehow” to be a satisfying answer. What I do find more interesting to ponder, however, was whether the way our ancestors wanted to live made fur obsolete, or whether they lost their coats first and then just tried to make the most of it.

Wherever the answers may lie, I’m pretty happy to be a skinny ape; especially as I pick clumps of my cat’s fur from the floor.

The world’s herbivores are in trouble, more so than its predators

Herbivores are facing a greater risk of extinction than predators or omnivores, a new study finds. Megaherbivores (species that grow up to more than 1000 kg) are particularly affected, and their loss will send massive ripples across ecosystems.

Image credits Penny Ash.

The Earth is no stranger to extinction. It’s a natural process, and the rate at which species disappear in the wild is known as the ‘baseline extinction rate’. It’s a bit sad to see species go, obviously, but this process helps remove under-performing actors, or those who can’t adapt, to make room for new ones to evolve.

While this natural extinction rate helps keep the world healthy, human activity is putting immense pressure on the planet, resulting in a greatly accelerated rate of extinction. And it’s disproportionately affecting plant-eaters.

Killing the middleman

“The results were somewhat shocking,” says Trisha Atwood, an Assistant Professor of Watershed Sciences at Utah State and lead author of the study.

“Our highly publicized and fraught relationship with predatory animals such as lions and wolves has led to the unfounded perception that we are losing predators more than any other trophic group.”

This isn’t the first time that human activity has led to the extinction of large herbivorous species. A similar phenomenon took place one million years ago, likely driven by human expansion and hunting, which forever changed the shape of life on our planet.

The disappearance of large herbivores reduced pressure on plantlife, changing growth and population dynamics. This altered fire regimes (there was more fuel, i.e. uneaten plant matter) and impacted nutrient cycling (nutrients are produced by plants and concentrated by herbivores). All in all, such changes lead to the Earth becoming colder — more plants and fewer plant-eaters equals less CO2 in the atmosphere.

The findings suggest that megaherbivores today could experience the same fate, and the consequences of such a change are yet unknown.

The team looked at the diets and threatened status of over 24,500 species of mammals, birds, and reptiles to see which category of animals (herbivores, carnivores, or omnivores) are most at risk of extinction. Their findings indicate that over 25% of today’s herbivore species are faced with extinction, which represents the highest risk margin for any of the studied groups. The team notes that herbivores have been experiencing a disproportionately high rate of extinction since at least the late Pleistocene 11,000-50,000 years ago.

Who needs help the most

The authors say that dispelling misconceptions (such as ‘carnivores are more at risk of extinction than herbivores’) is essential if we’re to fix the issues we’re causing. Different groups of species have different ecological functions, so the loss of each would have a different effect on the balance of nature.

The changes we’re seeing now are similar to those seen 1 million years ago, the authors note: changes to plant species and their population numbers, changes in fire regimes, disruptions in nutrient recycling.

Better management and conservation of herbivores is needed to prevent unpleasant changes in the future, such as dramatic shifts in or complete collapse of natural ecosystems. Since herbivores are a key part of global food webs (both wild and human-run), their loss isn’t an encouraging prospect.

The study highlights that herbivores are faring the worst, but predators aren’t having it easy, either. Scavengers, species that eat the remains of recently deceased animals, and species that primarily eat fish, are also facing a higher risk of extinction.

“Our results enable us to identify specialized diets within the carnivores that are associated with higher extinction risk, and also identify the habitats these species live in,” says Edd Hammill, an assistant professor of watershed sciences at Utah State University and co-author of the study.

“It would appear that seabirds across the globe suffer disproportionately high levels of extinction.”

Understanding the patterns of extinction facing different species groups is only the first step to protecting their health. Next, the team plans to examine what drives these extinctions, so we can focus our efforts on the root of the problem itself.

The paper “Herbivores at the highest risk of extinction among mammals, birds, and reptiles” has been published in the journal Science Advances.

Florida’s birds of prey are full of microplastics

A new study from the University of Central Florida (UCF) has found, for the first time, microplastics in terrestrial and aquatic birds of prey in the state.

Image credits Harry Burgess.

Some of the birds in whose digestive systems the team found microplastics include hawks, ospreys, and owls. The accumulation of such material can lead to starvation and poisoning, either of which can be life-threatening. The findings are particularly worrying because birds of prey are critical to a functioning ecosystem, the authors note.

A bird’s gut view

“Birds of prey are top predators in the ecosystem and by changing the population or health status of the top predator, it completely alters all of the animals, organisms and habitats below them on the food web,” says Julia Carlin, the study’s lead author and a graduate of UCF’s Department of Biology.

Microplastics are pieces of plastic that are under 5 mm in length, produced from the breaking down of larger pieces of plastic such as synthetic clothes, or that are purposely-made for use in industry, or for health and beauty products.

Plastic ingestion by wildlife was first noted in the 1960s, the team explains, adding that microplastic ingestion has come under increased scrutiny since 2010. Since then, microplastics have been found in the guts of fish, marine birds, filter-feeding invertebrates such as oysters, and humans.

Birds of prey, however, have not been studied for microplastic ingestion due to their protected status.

For the study, the team worked with the Audubon Center for Birds of Prey in Maitland, Florida where injured raptor birds are nursed back to health. This gave them a unique opportunity to study the stomach contents of 63 birds found across Florida that were dead when they arrived at the center or died 24 hours after they arrived.

Microplastics were found in the digestive systems of all the examined birds, totalling nearly 1,200 pieces of plastic. The most common microplastics found were microfibers (86%), which come from synthetic ropes and fabrics, and can be released into the environment from clothes-washing.

The most common colors seen were blue and clear, which the team says is likely caused by the birds confusing these colors with prey or materials that would be useful for nesting.

As for solutions, the team says removing plastic waste from open landfills (so birds can’t pick them up), retrofitting water treatment installations to capture microplastics, and switching to natural fibers in the clothing industry could all help.

The paper “Microplastic accumulation in the gastrointestinal tracts in birds of prey in central Florida, USA” has been published in the journal Environmental Pollution.

Big cats test positive for coronavirus at Bronx Zoo

New York City, with over eight million inhabitants, is currently one of the epicenters of the coronavirus pandemic, with over 142,000 cases that tested positive and 11,000 deaths so far.

This has led to many activities being canceled or closed down, such as the Bronx Zoo, one of the largest zoos in the US, closed since early March. Nevertheless, the fact that visitors are no longer welcomed hasn’t reduced the risk for animals at the zoo.

Four more tigers and three lions have recently tested positive for the coronavirus – bringing the total to eight big cats that have come down with COVID-19. Nadia, a four-year-old Malayan tiger, had been the first confirmed case, showing a dry cough and loss of appetite.

Nadia’s diagnosis was “the first time, to our knowledge, that an [wild] animal has gotten sick from COVID-19 from a person,” Paul Calle, the chief veterinarian of the Bronx Zoo, told National Geographic.

The veterinary staff at the zoo collected samples from Nadia’s nose, throat, and respiratory tract while she was under anesthesia. The other animals who developed a cough – three other tigers from the Tiger Mountain section of the zoo and three African lions – were not placed under anesthesia.

The zoo said that all eight cats “continue to do well” and are “behaving normally, eating well, and their coughing is greatly reduced.” Zoo officials said they believe the animals were infected by an asymptomatic staff member who unwittingly passed the virus on to them.

The zoo conducted its analyses of the animals in conjunction with the New York State Diagnostic Laboratory at Cornell University and the Veterinary Diagnostic Lab at the University of Illinois’s College of Veterinary Medicine.

“We tested the tigers and lions out of an abundance of caution and will ensure any knowledge we gain about COVID-19 will contribute to the world’s continuing understanding of this novel coronavirus,” said the zoo officials. “The testing of these cats was done in veterinary laboratories and resources used did not take from those being used for human testing,” they added.

Zoo officials said that none of its snow leopards, cheetahs, clouded leopards, Amur leopards, or pumas were showing any signs of illness. The zoo has put in place “preventive measures” for all staff members caring for animals.

Two pet cats in New York state have also tested positive for coronavirus, becoming the first domestic animal cases detected in the US. Both animals live in different areas of New York state. They have mild respiratory problems and are expected to recover soon.

Both cats and dogs can, in theory, contract the virus — but these are isolated cases. Cats seem more susceptible to dogs, but if a cat gets the virus, it likely gets it from a human. In other words, you’re more likely to give the virus to your cat than the other way around.

The American Veterinary Medical Association and CDC have been recommending that out of an abundance of caution, people ill with the coronavirus should limit contact with animals — advice that the veterinary group reiterated after learning of the tiger’s test result.

While we quarantine, some animals take to the streets, some get lonely, and a panda may get pregnant

As we keep to our homes more and more, wildlife is coming into the city to explore. Luckily for us, there’s always a camera nearby to capture such moments for “d’awws” and “aawws” on social media.

But not all animals are enjoying themselves equally. With zoos shutting their gates to the public, and amid growing concern that staff could unwittingly infect them, some zoo animals are starting to miss getting attention — but they’re also getting busy.

The goats of Llandudno

Wild goats roaming through Llandudno in North Wales by Andrew Stuart, a video producer at Manchester Evening News.
Image via Medium.

“Llandudno has a herd of wild goats, which date back to the 1800s. They do like to come down the hillside, as seen many, many times previously — and documented extensively by my colleagues at North Wales Live and the Daily Post,” Stuart explained for Medium.

“They are still wary of people and human life. Normally, they are put off going much further than the bottom of the Great Orme because of how busy it is (in relative terms — this is still Llandudno after all, and not inner-city Manchester). However, thanks to the Covid-19 lockdown, the goats didn’t have any traffic, people or noise stopping them — so they ventured out.”

The goats do seem to enjoy themselves, as they chew through local shrubbery and gardens, sunbathe in a churchyard, and even “blocked traffic”. However, they are still wary of coming close to humans.

This sleepy fox somewhere in Canada

Image credits SaraReneeRyan / Twitter.

Sara, who is currently pursuing a Ph.D. at Texas Tech, Tweeted that her dad who lives somewhere in Canada “had been sending me and my sister updates [on the fox] all day” and has even named it Nezuko.

It’s not hard to see why.

Foxes are one of the more often-spotted animals in this period, from what I’ve seen so far. There’s a lot of fox photos to enjoy in the replies to Sara’s tweet if that’s your thing (it definitely is mine).

A chill coyote

A coyote spotted in San Francisco.
Image credits beccatravels / Reddit (Becca Cook).

San Francisco is no stranger to coyotes. They live in the woods near the Bay Area and are generally content to stay away from people or ignore them if they meet. This one, however, looks very pleased that the normal hustle and bustle of the city has been curtailed in order do get some peace and quiet with a view.

But while this coyote is enjoying itself, others are hard at work resolving local politics.

“We had coup d’etat if you will,” Presidio Wildlife Ecologist Jonathan Young told ABC News about a fight that broke out in between the animals a few days ago. “A new alpha pair came and took over and kicked out the old alpha pair.”

“Since the COVID shelter-in-place, the winding trails and idle golf course [around the city’s Presidio] have become a go-to refuge for neighbors and more importantly their dogs. For the next few weeks or months, that’s potential trouble.”

The Presidio Trust cautions people that coyotes aren’t typically aggressive, but will regularly be on the hunt or defend themselves from domestic pets. It’s also a pupping season currently, so people would best try to avoid these animals. Sections of the Park Trail and the Bay Area Ridge Trail will be closed to hounds starting April 6 for the next few weeks or months over concerns about safety.

What’s happening in the zoos

We’ve just had our first confirmed case of the coronavirus jumping from a human to a tiger, and zoo staff are understandably worried that they may unwittingly infect their charges. As such, zoos around the world are implementing measures to limit the risk by reducing the animal’s exposure with their handlers and the public.

The US Centers for Disease Control and Prevention (CDC) has since reiterated that there is no evidence yet that pets can spread COVID-19 to people or that they might be a source of infection in the US, but zoos and conservation centers are still being especially careful. For example, the Borneo Orangutan Survival Foundation, a rehabilitation center for orangutans in Borneo, closed its doors to all visitors and asked the caretakers to wear masks and protective gloves when working with the primates, which are burned after the working day is over.

Grosser Panda.JPG
A giant panda at Ocean Park, Hongkong.
Image credits J. Patrick Fischer,

Nathan Hawke from Orana wildlife park in New Zealand told The Guardian that although visitors are no longer permitted, many of the park’s animals continue to come for their daily ‘meet the public’ appointments. Other groups of animals that are accustomed to human presence also seem to miss us, too, although the feeling may be forming through their stomach more than through their hearts.

Privacy, perhaps, was just what some of these species had been missing, however. Staff at the Ocean Park in Hong Kong reported that the 14-year-old resident female and male giant pandas Ying Ying and Le Le have “succeeded in natural mating” two days ago — because there aren’t any rules on panda social distancing.

This is the first success since attempts at natural mating began a decade ago, and the staff is excited for the birth, as the species is currently considered vulnerable in the wild but attempts to breed more giant pandas in captivity have been remarkably frustrating.

Can pets and livestock get infected with the new coronavirus?

Credit: Pixabay.

The novel coronavirus that is sweeping through the world is thought to originate from bats. This is quite typical — most viruses that affect humans have crossed species, often using intermediate species along the way. This begs the question: could this new strain jump from humans to other animals, such as our pets and livestock?

According to Scott Kenney, Associate Professor at the Department of Veterinary Preventive Medicine at Ohio State University, there is little to no research about a potential crossover of the novel coronavirus from humans to other species.

“Viruses are constantly sampling and evolving, trying to find other hosts,” said Kenney in a statement.

There are reports of both cats and dogs testing positive for COVID-19.  However, we have found no evidence so far that they can transmit the disease to other animals or humans.

Bats: the viral reservoir of coronaviruses

Credit: Pixabay.

Scientists who have sequenced and analyzed the genome of SARS-CoV-2 — the novel coronavirus that first surfaced in December 2019 in Wuhan, China — have confirmed that the virus is natural (i.e. not modified in some biolab), originating in bats.

Nothing about this information was surprising to scientists. Coronaviruses are zoonotic viral agents, meaning they all pass from one animal to the next.

The deadly Ebola and rabies viruses, as well as two other types of coronavirus — those that caused SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome — also originated in bats.

There are four coronaviruses that cause common colds in humans — they are known as HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1 — and they all seem to have zoonotic origins.

Bats are sort of natural viral laboratories due to their unique immune system. The only flying mammal has a very high body temperature and high levels of interferon, which signal the activation of antiviral molecules. Scientists believe that the bodies of bats are in a constant state of “fever”, leading to a suppression of their immune system, allowing them to tolerate more viruses.

When a virus infects a host, it can produce billions of copies of itself. Some of these copies contain genetic errors (mutations), most of which are weeded out by natural selection. But some of these mutations are helpful, allowing the virus to spread to more hosts, and are passed down to subsequent generations. When these mutations alter surface proteins allowing the virus to detect and bind to cell receptors belonging to a different species, the virus can officially cross territory into a new species.

However, the novel coronavirus didn’t jump straight from animals to humans. A study published last week in the journal Nature suggests that the endangered pangolin — a scaly anteater and the most illegally traded animal in the world — is the most likely intermediate host of the coronavirus between the coronavirus, bats, and humans.

According to the study, the genetic sequences of the novel coronavirus strain found in pangolins is 85.5% to 92% similar to the one currently infecting people in over 185 countries. SARS moved from bats to civets to humans, while MERS was transferred from bats to camels, before infecting humans.

From humans back to animals

Pangolins are believed to be the intermediate animals that allowed the coronavirus to jump from bats to humans. Credit: Wikimedia Commons.

If coronaviruses can jump from animals to humans, can they jump from humans to other animals, such as our pets or even livestock? Reverse zoonoses are possible, indeed.

In 2009, a 9-year-old chimpanzee at Lincoln Park Zoo in Chicago died of respiratory disease caused by human metapneumovirus. This virus is responsible for approximately 10% of all respiratory tract infections in humans. All seven members of a troop of chimpanzees at the zoo were infected with the virus, but only one became ill.

Elsewhere, at a wildlife sanctuary in Congo, 6 bonobos died after they caught influenza transmitted from humans.

Perhaps the most telling example of reverse zoonosis involves pigs. Many influenza viruses have crossed from humans to pigs causing serious outbreaks.

More recently, in 2009, the H1N1 subtype caused the previous pandemic, infecting millions of people and killing between 151,700 and 575,400 people, 80% of whom were under 65. This pandemic has remained in the public’s consciousness as the ‘swine flu’ because it originated in pigs, which acted as a mixing vessel of genetic segments originating from avian, swine and human strains.

The pigs had it much worse, though. According to a study performed by scientists in the US, at least 49 pandemic H1N1 transmission events from humans to pigs followed the 2009 pandemic — and that is an underestimation.

Swine are very susceptible to contracting viruses from humans. There’s no evidence yet that they can get infected with the new coronavirus, though. Credit: Pixabay.

What about coronaviruses? Again pigs are the prime targets because they share a similar protein with humans that the SARS virus targets. For instance, in 2013, the porcine epidemic diarrhea virus (a member of the coronavirus family) killed millions of pigs in the United States and China, most of which were young. This virus continues to sporadically appear, much to the frustration of farmers.

“I’m not sure anyone really knows why,” Kenney said. “Outside of bats, pigs and humans seem to be infected by the largest numbers of different coronaviruses.”

There’s no mention in the scientific literature yet of the new coronavirus that causes COVID-19 jumping species again, but if it were to happen, the likeliest farm animal to catch it would be pigs. That’s why Kenney advises great caution such that farmers don’t infect their livestock.

“Any time you’re around an animal, you should use good hygiene. There are many illnesses besides coronaviruses in animals that can be passed to humans, and vice versa.

What about pets?

There is no reliable evidence that humans and pets like cats or dogs can infect each other with the novel coronavirus (unless you have a pet pangolin, which you definitely shouldn’t!).

There is one study in China that reported two dogs testing positive for COVID-19. However, the canines didn’t show any symptoms of the disease and the Chinese researchers don’t believe that the dogs transmitted the virus to other people or animals. These were ‘weak-positive’ tests that suggest dogs are poor hosts for the novel coronavirus.

Chinese authorities didn’t take any chances though. TIME reported that all animals living in the homes of people tested positive for COVID-19 were killed as a precaution.

More recently, the Belgian government’s public health department announced that a domestic cat had been infected with COVID-19. According to Dr. Daniel Desmech, a researcher at the Faculty of Veterinary Medicine of Liège, humans and cats share a similar protein on the surfaces of respiratory cells that lets the SARS-CoV-2 virus get inside.

However, Van Gucht stressed that human-to-pet transmission is not a significant path of viral spread. 

During the SARS outbreak (caused by a close cousin of the novel coronavirus) in 2003, eight cats and one dog tested positive for the virus in Hong Kong. But no animal was found to transmit the disease to other animals or humans.

Bottom line: while there is evidence that pets can get infected, there is no evidence to suggest that they can transmit the disease — they might be dead-end viral hosts.

However, pets haven’t been tested for COVID-19 nearly as much as humans. That might have to change in order to form a more accurate picture of both the odds of infection and transmission between humans and various animals.

What precautions should pet owners take?

While a pet might get sick with COVID-19, there’s no evidence to suggest that the infected pet can, in turn, infect other humans. So, there is no need to panic.

Even so, it’s advisable that people who suspect that they have COVID-19 keep a distance from their pets. Perhaps, they can ask someone else to take care of them for some time until they are sure they’re not infected or recover from the illness.

If you are a confirmed case of COVID-19 and live with pets at home, it might be wise to contact your veterinarian for best practices. Some animals might need quarantining, either at home or in a hospital.

As cities quarantine, animals take to the streets

In Venice, the boats and ferries that used to fill up the canals with hundreds of tourists were now replaced by fishes and even ducks, swimming in clear water. In Japan, hungry deer are taking to the streets; and in Thailand, rival gangs of monkeys are squaring it off in cities.

No, it’s not a Hollywood scenario — nature is starting to reclaim quarantined cities.

Credit Wikipedia Commons

Stay at home. That’s the main message by governments across the world to try to stop the spread of the coronavirus. Many cities, especially in the more affected areas, have been virtually shut off. But, as people withdraw from the outer world, animals are coming in.

All journeys in Venice are now forbidden as part of a set of strict rules of self-confinement, with the only exceptions being walking your dog or buying groceries.

This has led to motorboat taxis, transport and even gondolas emptying the cities’ canals, now taken over by wildlife.

“The water is blue and clear,” hotel manager Gloria Beggiato told The Guardian. “It is calm like a pond, because there are no more waves caused by motorized boats transporting day-tripper tourists. And of course, the giant cruise ships have disappeared.”

Image via Facebook.

Venice isn’t the only city where animals are strolling into town.

In the city of Nara, Japan people reported in their social media seeing hungry deer in the streets and subway stations.

Image credits: okadennis / Twitter.

The deer are reportedly eating potted plants due to a lack of tourists to feed them.

The Nara Park, a popular tourist attraction in Japan, has over 1,000 deer that rarely go outside the 1,240 acres of the park. Until now, that is.

Image credits: okadennis / Twitter.

Visitors to the park usually buy rice crackers to feed the deer. Now, with no tourists, the deer began wandering into the city searching for food. Doing so can be risky for them, experts warned, as they can be hit by cars or eat plastic bags, or even get lost.

Credits: Wikipedia Commons

Meanwhile, in Thailand, two gangs of monkeys are reportedly fighting for supremacy in the city’s mostly-empty plaza. In a video that went viral, the monkey groups started a 10minute fight against each other, leaving the few bystanders shocked.

Here too, the cause might be a shortage of food brought in by declining tourist numbers.

The animals live in the Phra Prang Sam Yot monkey temple but they are dealing with a scarcity of food due to the lack of tourists in the area. That has led them to go into the city and try to get some food.

“The fall in tourist numbers because of Covid-19 may have indeed brought about a shortage of food supply for them,” Asmita Sengupta, an ecologist, told The New York Times. “Feeding the monkeys can have detrimental effects. Once they get used to being fed by humans, they become habituated to humans.”

The effect that the lack of tourists to feed the animals will have on the animals remains to be seen. But experts believe that most of them will likely be fine.

“Most animals living in urban environments already have flexible diets, so chances are good that a lot of these animals are going to be OK,” Christopher Schell, an urban ecologist at the University of Washington, told the NYT.

EDIT: There are multiple stories floating around social media about dolphins in Venice and elephants in tea fields. These are not true and are misleading.

Humans aren’t the only animals that get drunk (or worse): here are a few others

Drinking isn’t good for you, but watching parrots get drunk is both healthy and entertaining. Not for the parrots, though.

There’s no day like a weekend day — cause that’s when we get to party. But humans aren’t the only animals that like to abuse their systems with various chemicals. In fact, a lot of animals do it; and get into trouble afterward. We’ve seen the shenanigans that animals go through in love (and lust), some of which are amusingly similar to those we humans cause or experience. So let’s see whether our furry and feathered friends also mirror us in the bad choices we make on a night out on the town (spoiler: they do).

The Darwin Drinking Awards

Northern Australia is the only place on Earth that I know of which has three seasons: a wet season, a dry season, and a drunken parrot season.

Red-collared Lorikeet.
Image via Wikimedia.

Just before the wet season, roughly in mid-to-late December, the local Weeping Boer-bean trees (Schotia brachypetala) are flowering. This brings swarms of red-collared lorikeets to the area to feed on the nectar of the trees’ flowers. However, after a while, some of the birds start to sway a little bit — and then fall out of trees. Darwin locals report that the birds lack coordination and that they seemingly lose their ability to fly and sometimes even to walk. Vets say the birds act similar to drunken people. They also seem to experience disorientation, energy loss, and perhaps headaches, all very familiar hangover symptoms.

While the possibility of a virus affecting these birds hasn’t yet been ruled out, the event may have more to do with the trees — which are also known as the Drunken Parrot Tree, I’ll let you judge for yourself. So far, local animal caretakers and vets provide safe, quiet places for the parrots to recover — which can take months in some rare cases according to National Geographic — while providing sweetened porridge and fresh fruit. The prevailing theory is that the parrots get drunk off their tails on nectar and fruit fermented in the baking Australian heat.

Tripping Reindeers

Reindeer live in Siberia (in North America too, but they’re called caribou there). The hallucinogenic mushroom Amanita muscaria also lives in Siberia, among other places. And the reindeer like to get really, really high on the ‘shrooms during those long and dreary winter months.

Image credits Bernard Spragg. NZ / Flickr.

Reindeer that partake of the mushrooms have been documented to act almost as if drunk, running around aimlessly, making strange noises, and twitching their heads.

“They have a desire to experience altered states of consciousness,” Huffington Post cites researcher Andrew Haynes, who studied the behavior in the wild. “For humans a common side-effect of mushrooms is the feeling of flying, so it’s interesting the legend about Santa’s reindeer is they can fly.”

He also adds that herdsmen drink the reindeer’s urine to get high themselves.

“Fly agaric is found across the northern hemisphere and has long been used by mankind for its psychotropic properties, but its use can be dangerous because it also contains toxic substances,” he explains for the Pharmaceutical Journal.

“Reindeer seem to metabolise these toxic elements without harm, while the main psychoactive constituents remain unmetabolised and are excreted in the urine. Reindeer herders in Europe and Asia long ago learnt to collect the reindeer urine for use as a comparatively safe source of the hallucinogen.”

Sharing, it seems, really is caring.

Popped-up Wallabies

Wallabies are adorable, diminutive kangaroos native to Australia and New Guinea.

They look like this.
Image via Pxfuel.

Opium poppy farmers on Tasmania (an island off the south Australian coast) have reported that wallabies will sometimes break into their fields to dine on the flowers, which are the raw material for prescription painkillers.

Although exactly which species of wallabies are responsible is still unknown, the animals have been seen eating poppies before running around in circles and eventually passing out, according to a BBC report. Lara Giddings, the attorney general for the island state of Tasmania even described the animals as being “high as a kite” and creating crop circles.

“The one interesting bit that I found recently in one of my briefs on the poppy industry was that we have a problem with wallabies entering poppy fields, getting as high as a kite and going around in circles,” Lara Giddings told a parliamentary hearing on security for poppy crops. “Then they crash.”

“We see crop circles in the poppy industry from wallabies that are high.”

Rick Rockliff, a spokesman for poppy producer Tasmanian Alkaloids, told the BBC that these wallaby incursions aren’t very common, although other animals have been spotted “acting unusually” in the poppies.

Australia is a major producer of raw materials for the painkiller industry, supplying around half of the world’s (legally-grown) opium. And, it seems, the main supplier for wallabies as well.

Bees on a binge

Bees keep the world turning, but that doesn’t seem to stop them from functional alcoholism.

https://www.youtube.com/watch?v=ZhUKLsSjUZs

The bee nervous system is similar enough to that of humans for alcohol to have similar effects on them. In fact, researchers sometimes use bee colonies as models to test out the effects of alcohol intoxication in humans and other vertebrates. For example, a team of researchers at Ohio State University routinely gives bees ethanol — drinking alcohol — to see how it affects them. Unsurprisingly, they found that it affected their flying, walking, and grooming.

“Alcohol affects bees and humans in similar ways — it impairs motor functioning along with learning and memory processing,” Dr Julie Mustard, an entomology researcher at the university, explained to the BBC.

But bees seem in no way content to limit their day-drinking to the lab. Just last year, Australian Parliament’s head beekeeper Cormac Farrell explained that the bees, which could be seen sometimes dropping on the ground around the Australian House of Parliament in Canberra, are just really blitzed. Sadly for the bees, they can sometimes drink themselves to death, and the queens aren’t very understanding of them — they will post guards at the entrance of their hives to keep any ‘merry’ bees from getting in.

“As the weather heats up, the nectar in some Australian flowers will ferment, making the foragers drunk,” Farrell told The Canberra Times last year. “Usually this makes them a bit wobbly, and if they come back to the beehive drunk the guards will turn them away until they sober up.”

“The drunk bees are kept out of the hive to stop the honey from fermenting inside, which could hurt the whole colony,” he added.

Only introduced and exotic honeybees seem affected, with Farrell noting that he had not seen any drunk native bees, of which Australia can boast 2000 species.

So, are bees just the victims of excellent work ethic and fermenting sugar? It doesn’t appear that way — bees just seem to enjoy getting smashed hard. Charles Abramson of Ohio State University told Newscientist that while most animals need to be coaxed into drinking alcohol, “we can get [bees] to drink pure ethanol, and I know of no organism that drinks pure ethanol – not even a college student.”

A bee, he adds, will drink the equivalent of a human downing 10 liters of wine in a single sitting. Flawless work ethic indeed!

Puff puff porpoise

Dolphins… like to pass toxic pufferfish around to get high.

The behavior was first reported on by marine biologist Lisa Steiner in 1995. She was studying a group of rough-toothed dolphins roughly in the region of the Azores when she noticed that some of them were pushing an inflated pufferfish around and rubbing their faces against it. Which was an odd sight, as that pufferfish uses one of the most lethal substances on Earth, tetrodotoxin, to protect itself from, among others, dolphins. Later on, Steiner would hypothesize that the dolphins were only exposed to tiny amounts of tetrodotoxin, and this resulted in a high, not death. Which is an ideal outcome in my book.

It’s still unclear whether the dolphins are actually getting a chemical kick out of the pufferfish or if they’re just harassing the poor animal for sport. The main points of contention are that tetrodotoxin isn’t known to cross the brain-blood barrier, and that it’s extremely deadly — one pufferfish contains enough to kill 30 full-grown people. However, in episode two of the BBC One documentary film, “Dolphins: Spy in the Pod,” a group of dolphins was filmed hunting pufferfish and biting into it but not eating it, then sharing the fish with their mates.

So this one is still a bit up in the air. But no matter whether the fish is used as a drug or a simple toy, given how toxic it is, it’s definitely dangerous.

These are a few of the more unusual stories of animals binging, but they’re certainly not the only ones. Jaguars like to chew on the roots of yagé vines — a main component of the hallucinogenic brew ayahuasca — and their diminutive cousins love catnip. And, well, humans are animals too. While it’s definitely a lot of fun reading about their shenanigans, hangovers aren’t, so enjoy your own real-life shenanigans in moderation.

Predators can change their prey’s brains

Killifish in Trinidad that live with predators in their environment grow more brain cells than their less-stressed peers, a new paper found.

Spotfin killifish (Fundulus luciae).
Image credits Scott Smith / ncfishes.

What doesn’t kill you makes you stronger — but it seems they also make you brainier. New research suggests that animals living in predator-heavy environments grow more brain cells than animals that face little to no predation. The findings were made using a group of killifish in a river in Trinidad that is separated into individual populations by waterfalls. These waterfalls block predators from swimming upstream.

Outsmarting the competition

“The killifish living downstream live among predatory fish, while the fish upstream do not,” Josh Corbo, Cancer Research Training Award (CRTA) Fellow at the National Cancer Institute and co-author of the study, told Andrew Concatelli. “Our central question was: how does negative stimuli—predation—in the environment affect the rate of brain cell proliferation?”

“The implication of our research reaches much farther than the Northern Mountain Range of Trinidad. The topic of how the environment we live in affects our health concerns many disciplines, from public health to sociology. Our research draws more attention to our understanding of the relationship we as organisms have with our environment.”

The team writes that while environmental factors are known to influence brain cell proliferation, contributing to brain plasticity and a greater ability to adapt to these factors, there is no research to date on whether environmental factors trump genetic ones in this regard. In other words, on whether the conditions we live in can shape our brain more than our genetics.

To find out, they examined free-living populations of Trinidadian killifish (Rivulus hartii) exposed to very different environmental conditions. Together with Margarita Vergara, now earning a master’s in clinical embryology at the University of Oxford, Corbo sectioned brain tissues used a procedure known as immunohistochemistry to quantify the formation of new brain cells in these animals. The research was carried out while both authors were majoring at Trinity College, Connecticut.

The fish that lived in predatory-heavy areas showed higher rates of brain cell proliferation (roughly twofold higher) and faster brain growth relative to body size than their peers. “Cell proliferation differs among brain regions but is correlated across brain regions,” the authors note, showing that this effect is brain-wide but not necessarily uniform. However, wild-caught fish from predator-heavy areas also had a smaller relative brain size in their early adulthood.

In order to check whether the effect was genetic or environmental in nature, the team also reared a new generation of fish from members in both (predatory-heavy and predatory-free) environments in uniform lab conditions for between 54 and 82 days.

Animals descended from predation-heavy environments also showed a higher rate of brain cell proliferation and faster brain growth compared to those descended from predator-free areas. Furthermore, they found that wild-caught fish had greater cell proliferation in the forebrain than laboratory-reared fish, but very similar everywhere else. This, they explain, suggests that the effect is environmental, not genetic.

“However, both populations showed similar patterns of divergence in the wild and in captivity, indicating that the predator environment per se does not contribute to the enhancement of cell proliferation by the natural habitat,” the team writes.

“The differences in cell proliferation observed across the brain in both the field and [laboratory] studies indicate that the differences are probably genetically based and are mediated by evolutionary shifts in overall brain growth and life-history traits.”

The team says that the observed changes among the two populations could be explained through several different mechanisms. Either individuals are increasing the rate at which they generate new brain cells as a response to predators, or we could be seeing the effects of natural selection at work — in essence, that brainy fish go on to reproduce while the rest get eaten. Alternatively, the presence of predatory fish could improve conditions for the killifish that evade capture, for example by making food more readily available to them through lower competition, which could lead to changes in brain cell proliferation.

The paper “Predation drives the evolution of brain cell proliferation and brain allometry in male Trinidadian killifish, Rivulus hartii” has been published in the journal Royal Society B: Biological Sciences.

Wildlife is doing just fine at the Fukushima Daiichi nuclear disaster site

Wildlife is thriving in the human-free nuclear accident area in Fukushima, Japan.

Image credits IAEA Imagebank / Flickr.

A new study from the University of Georgia reports that populations of wild animals in the nuclear exclusion zone in Fukushima, Japan are blooming. According to the findings, more than 20 species, including wild boar, Japanese hare, macaques, pheasant, fox, and the raccoon dog, make their home in various areas of the landscape.

No humans, more animals

“Our results represent the first evidence that numerous species of wildlife are now abundant throughout the Fukushima Evacuation Zone, despite the presence of radiological contamination,” said UGA associate professor James Beasley.

It’s been nearly a full decade since the nuclear accident at Fukushima. As in other nuclear accidents (such as that at Chernobyl), authorities established a no-go zone around the site of the accident to safeguard public health.

Animals, however, are free to come and go as they please, and both the public and scientific community are curious to see how life gets by in such areas — the answer seems to be ‘better than expected’.

In addition to the team’s past research at Chernobyl, the current paper suggests that quarantined areas can act as safe havens for wild animals, especially species that tend to come into conflict with humans, such as wild boars. These animals were predominantly seen in human-evacuated areas or zones, according to Beasley.

“This suggests these species have increased in abundance following the evacuation of people,” he says.

For the study, the team worked with three zones of interest (established by the government in the Fukushima region after the 2011 accident) and gathered wildlife population figures by using 106 camera sites in these zones. Among the zones, one was completely off-limits for humans due to high levels of radiation contamination, one saw restricted access due to intermediate levels of contamination, and the last one was still open to human access and habitation due to low background levels of radiation.

The uninhabited zone served as the control zone for the research. There is no previous data on wildlife populations in the evacuated areas from which to establish a baseline, but the three areas are in close proximity and have a similar landscape. Thus, the team explains, the human-inhabited area can act as a reliable control.

The cameras captured over 46,000 images of wild boar over 120 days. Around 26,000 were taken in the uninhabited area, approximately 13,000 in the restricted one, and only 7,000 in the inhabited zones. Other species seen in high numbers included raccoons, Japanese marten, and Japanese macaque or monkeys, according to the team.

“This research makes an important contribution because it examines radiological impacts to populations of wildlife, whereas most previous studies have looked for effects to individual animals,” said Hinton.

The team looked at the impact of variables such as distance to road, time of activity (as captured by the cameras’ date-time stamps), vegetation type, and elevation on the wildlife population. They report that the behavioral patterns of most species align with their historically-recorded patterns. Raccoons, for example, a nocturnal species, were more active during the night; pheasants, which are diurnal, were more active during the day. In the meantime, wild boar in the uninhabited area were more active during the day, while boar in human-inhabited areas were more active during the night. The team says this suggests that the species is modifying their behavior in response to humans.

However, the team underscores that these findings refer to whole populations, and doesn’t make any assessments as to the health of individual animals.

“The terrain varies from mountainous to coastal habitats, and we know these habitats support different types of species. To account for these factors, we incorporated habitat and landscape attributes such as elevation into our analysis,” Beasley said.

“Based on these analyses, our results show that level of human activity, elevation and habitat type were the primary factors influencing the abundance of the species evaluated, rather than radiation levels.”

One exception to the general pattern was the Japanese serow, a goat-like mammal, which was most-seen in rural, human-inhabited upland areas. The team believes this comes as a behavioral adjustment to avoid the growing numbers of boar in the evacuated areas.

The paper “Rewilding of Fukushima’s human evacuation zone” has been published in the journal Frontiers in Ecology and the Environment.

Agriculture impacts diets of wild mammals, study shows

Expanding agriculture can not only affect the diversity and abundance of wildlife but also alter the diet and habitat of wild mammals, especially those living in fragmented forest areas near crops or pastures, according to new research.

Image credit: Wikimedia Commons.

The study, published in Proceedings of the National Academy of Sciences (PNAS), analyzed how changes that agriculture affect the diet of wild mammals, proving the hypothesis that deforestation and forest fragmentation are not necessarily the main consequences of expanding crops and cattle.

“Forest remnants and the agricultural matrix aren’t separate. There’s an interface between these areas. It’s hardly news that animals need to find food in plantations, but this practice hadn’t been quantified until now. I should stress that the diet in question isn’t ideal. It’s a matter of survival,” said Marcelo Magioli, the lead author.

Magioli and his fellow researchers looked at stable carbon and nitrogen isotopes in the fur of the animals, a method that allows them to know the kind of food eaten in the last three months. They used hair traps and collection of droppings so as not to alter the animals analyzed, many of them threatened with extinction.

They collected samples in four areas of the Brazilian state of Sao Paulo, two near croplands in Campinas and Botucatu and two in conserved areas in stable carbon and nitrogen isotopes. The samples were from 29 species of mammals and of all the samples taken more than half were from animals living in human-modified areas.

“From previous studies using GPS collars and camera traps, we knew the animals moved through these areas,” Magioli said regarding their research. “However, stable isotope analysis told us where they were feeding and how important each food source was in their diet.”

The results showed that 34.5% of the animals fed only with agricultural resources from human-modified areas, while 67.5% survived on forest resources. Frugivores and insectivores ate the same no matter where they lived, while herbivores and omnivores were the most affected, eating mainly agricultural resources.

Species like the cougar, capybara, brocket deer, ocelot and crab-eating raccoon where some of the ones mentioned in the study for having adapted their diets because of the agricultural expansion. The margays, a small wild cat, for example, eat animals that live near sugarcane plantations.

“Our findings point to the need for more favorable agricultural management to support these animals and underscore the importance of the Brazilian Forest Code and of maintaining legal reserves and permanent conservation areas [APPs],” Katia María Ferraz, co-author, said.

California becomes the first US state to ban animal fur products

Starting in 2023, California will become the first US state to ban the sale and manufacture of new fur products and the third to ban most animals from circus performances, according to a set of bills recently signed by Governor Gavin Newsom.

The law will apply in 2013, as well as a ban to have animals in circus performances
Credit: Wikimedia Commons.

The bill applies to all new clothing, handbags, shoes and other items made with any type of fur. Those who violate the law will be subject to fines and civil penalties. Used fur and taxidermy products are exempt from the ban, along with leather, cowhide, and shearling. Fur products used for religious purposes or by Native American tribes are also exempt from the legislation.

“California is a leader when it comes to animal welfare, and today that leadership includes banning the sale of fur,” Newsom said. “But we are doing more than that. We are making a statement to the world that beautiful wild animals like bears and tigers have no place on trapeze wires or jumping through flames.”

The initiative could mark a significant blow to the fur industry that makes products from animals including mink, chinchillas, rabbits and other animals. The US retail fur industry brought in US$1.5bn in sales in 2014, the most recent data available from the Fur Information Council.

Under California law, there is a fine of up to US$1,000 for multiple violations. Fashion designers including Prada, Versace, Gucci and Giorgio Armani have stopped or have said they plan to stop using fur in the near future — but this will force them to act much sooner.

Animals in fur farms are often subject to gassing, electrocution and other inhumane actions to take their fur, according to animal rights groups. In comparison with other farm animals, species farmed for their fur have been subjected to very little attention. In addition, fur factories are also extremely harmful to soil since producing fur requires pumping waste and the toxic chemicals in to the surrounding environment.

Advocacy group Direct Action Everywhere said it was working with activists to pass similar bills in cities nationwide, including Minneapolis and Portland, Oregon, and was optimistic California’s law would spur action.

“Ordinary people want to see animals protected, not abused,” said Cassie King, an organizer with the Berkeley-based group.

On the other hand, opponents of the legislation have said it could create a black market and be a slippery slope to bans on other products. The ban is part of a “radical vegan agenda using fur as the first step to other bans on what we wear and eat”, Keith Kaplan of the Fur Information Council said in a prior statement. He claimed fake fur was not a renewable or sustainable option.

Several fashion brands have already vowed to keep fur out of the catwalk all around the world, including Prada, Chanel, Burberry, Versace, Stella McCartney, Givenchy, Calvin Klein, and Ralph Lauren.

With the new legislation, California also joins New Jersey and Hawaii in banning most animals from circus performances. The law exempts domesticated dogs, cats, and horses and does not apply to rodeos. Circuses have been declining in popularity for decades. The most well-known act, the Ringling Bros and Barnum & Bailey Circus, closed in 2017.

State officials said at least two circuses that include live animals were scheduled to perform in California this year. At least 18 circuses do not use animals, including Cirque du Soleil. The law includes penalties of up to $25,000 per day for each violation.

The Southwest California Legislative Council opposed the law, saying it would prevent people from being able “to experience the thrill of a circus performance featuring beautiful, well-cared-for animals”.

Pixelated images showcase how close these species are to extinction

As a campaign the World Wildlife Fund ran in 2008 is re-making the rounds on reddit, one Imgur user has created a powerful follow-up.

Image credits JJSmooth44 / Imgur.

Back in 2008, the World Wildlife Fund (WWF) released a striking photo campaign. Called WWF Japan – Population by pixel, the campaign was created by the agency Hakuhodo C&D in Tokyo. It consisted of a set of 4 posters, blurred so that every single pixel in the photo corresponds to one living animal — the poorer-quality the final image is, the worse for wear the species is in the wild.

Since 2008, however, the four species shown in the campaign have been recovering and increasing in numbers in the wild. But those four aren’t the only ones that have been struggling. A collection of 22 new but very similar images recently published on Reddit by user JJSmooth44 showcases just that.

JJSmooth44 claims he “did it as a programming challenge,” using the Python language to obscure these images through pixelation, matching the number of pixels with the number of individuals that species are estimated to still have in the wild. He took the original photos from the Animal Planet endangered animals list.

“The code is very gross,” he says. “I only worried about the final product and not the readability/niceness of the code.”

The rate of species extinction has been picking up recently, and a big part of that is due to us. Species do go extinct through natural mechanisms, but more and more of them are struggling to adapt to ever-more pollution, human encroachment, and habitat devastation. Climate warming is further pushing these species towards extinction.

Work such as the Population by Pixels campaign and JJSmooth44’s work perfectly showcase how vulnerable Earth’s species and ecosystems can be if we do not care for them. Just like a picture losing its pixels, these species run a very real danger of fading away forever.

Jackdaws can distinguish ‘dangerous’ people from friendly ones

The results of a new study suggest that jackdaws, a relative of the crow, can learn which humans are ‘safe’ and which are ‘dangerous’.

Image credits John Haslam / Flickr.

The birds use cues from their fellows to learn which humans are to be seen as a threat, reports a team from the University of Exeter. Furthermore, they are able to recognize individual people and react to them based on their perceived threat level.

Cawing murder

“One of the big challenges for a lot of animals is how to live alongside humans,” said lead author Victoria Lee, a Ph.D. researcher at the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.

“People can provide some benefits, such as the food at bird feeders, but in some cases humans are also a threat.

The crow family of birds, to which the jackdaw (Coloeus monedula) belongs, is known for its intelligence. Crows can make and use tools, recognize our faces, and are quite good with puzzles. According to the Cornell Lab of Ornithology’s allaboutbirds, “crows have more than 20 calls,” with the most common being “a harsh caw” which can take many different meanings depending on its quality or length.

Jackdaws themselves resemble crows but have distinctive gray neck plumage and irises. There are four subspecies of Jackdaw. All are loud, boisterous and live in relatively small groups but are very social. They’re also able to learn from the group which humans to hide from, the findings suggest.

Lee’s team worked on three sites in Cornwall (34 Jackdaw nest boxes) during the 2017 breeding season. One of the researchers put on a mask and came close to their nests while the rest of the team played recordings of either ‘scold calls’ or ‘contact calls’ (the latter of which suggests no threat).

“Scold calls are antipredator vocalizations given by jackdaws to recruit others to mob a predator,” the paper notes.

The second phase of the experiment had the researcher (with the mask) return to the nests after some time, and see if there was a difference in their behavior. There was. The birds that had heard scold calls returned more quickly to their nests than the others.

Jackdaws that were played scold calls when first seeing the masked researcher returned to their nest quicker (in 53% of the initial time), while birds that heard contact calls took relatively longer (63% of the initial time) on average. The team notes that the calls did not appear to influence how long birds took to enter their nest box, or how long they spent inside, only how quickly they returned to them.

“Being able to discriminate between dangerous and harmless people is likely to be beneficial, and in this case we see jackdaws can learn to identify dangerous people without having had a bad experience themselves,” Lee explains.

The paper “Social learning about dangerous people by wild jackdaws” has been published in the journal Royal Society Open Science.

Earliest evidence of milk consumption comes from Stone Age Britain

Researchers, led by archaeologists at the University of York, have found the earliest evidence of milk consumption ever observed in the teeth of prehistoric British farmers.

Image credits Myriam Zilles.

The team identified a milk protein called beta lactoglobulin (BLG) in the mineralized dental plaque of seven individuals who lived around 6,000 years ago. The findings will help improve our understanding of when humans developed lactose persistence (LP), the ability to digest lactose in milk. It’s also the earliest confirmed sighting of the BLG molecule so far.

Luckily they didn’t brush their teeth

“The fact that we found this protein in the dental calculus of individuals from three different Neolithic sites may suggest that dairy consumption was a widespread dietary practice in the past,” says lead author Dr. Sophy Charlton, from the Department of Archaeology at the University of York.

Dental plaque, while not something you want to have, can be used to gain insight into the diets of ancient people. The material traps proteins from food, through saliva, which are then mineralized in plaque or tartar. The samples of dental plaque analyzed in this study are the oldest to be investigated for protein content, the team explains.

The Neolithic period in Britain ran from 4,000 to 2,400 BC and saw the transition from hunter-gatherer communities to farming, mostly revolving around the growing of wheat and barley and the domestication of animals such as cows, sheep, pigs, and goats. This time also saw the emergence of complex cultural practices such as the construction of monumental and burial sites.

The remains used in this study come from three different Neolithic sites in England: Hambledon Hill, Hazleton North (both in the south of England), and Banbury Lane (in the East Midlands). Individuals from all three sites had milk proteins from goats, cows, and sheep, suggesting that multiple domesticated species were reared at the same time.

“It would be a fascinating avenue for further research to look at more individuals and see if we can determine whether there are any patterns as to who was consuming milk in the archaeological past — perhaps the amount of dairy products consumed or the animals utilised varied along the lines of sex, gender, age or social standing,” says Dr. Charlton.

Finding these proteins in the ancient teeth is particularly exciting, as previous genetic work has suggested that people living at the time did not yet have the ability to digest lactose.

Overall, it means that the ancient farmers either consumed milk in small amounts or processed it into foods such as cheese (which removes most of the lactose). Lactose persistence, our ability to consume milk into adulthood, was the result of a mutation in the genes encoding production of lactase, which breaks down lactose. How and why we evolved this ability is of quite some interest to researchers, as milk and dairy products played an important part in past diets, as well as those of today — and this study gives us a better idea of when the mutation occurred, the conditions that helped it appear, and how people dealt with lactose intolerance before it.

“Because drinking any more than very small amounts of milk would have made people from this period really quite ill, these early farmers may have been processing milk, perhaps into foodstuffs such as cheese, to reduce its lactose content,” says Dr. Charlton.

“Identifying more ancient individuals with evidence of BLG in the future may provide further insights into milk consumption and processing in the past, and increase our understanding of how genetics and culture have interacted to produce lactase persistence.

The paper “New insights into Neolithic milk consumption through proteomic analysis of dental calculus” has been published in the journal Archaeological and Anthropological Sciences.