Tag Archives: whale

A lot of “sea serpent sightings” could actually be whale boners

A sailor’s life is rough. You’re up against the weather, the sea, maybe even sea monsters — or so some sailors used to think. Since Ancient Greece, people have been describing sea monsters of various sorts, but according to one study, at least some of those monsters can be explained by something much more mundane: whale penises.

Copperplate engraving of Egede’s great sea monster. The Naturalist’s Library Sir William Jardine (publisher) Wm. Lizars (principal engraver). London & Edinburgh. Hans Egede (a Lutheran missionary) wrote that on 6 July 1734 his ship was off the Greenland coast. Those on board that day “saw a most terrible creature, resembling nothing they saw before.”.

In one of the more famous sea sighting reports, Danish Lutheran missionary Hans Egede wrote that on 6 July 1734, he and those on his ship saw a terrible sight — a “most terrible creature”, resembling nothing they had seen before. The monster, Egede reported, was longer than their whole ship.

“It had a long pointed snout and it blew [spouted] like a whale [it] had broad big flippers and the body seemed to be grown [covered] with carapace and [it] was very wrinkled and uneven [rough] on its skin; it was otherwise created below like a serpent and where it went under the water again threw itself backward and raised thereafter the tail up from the water a whole ship’s length from the body.”

Egede’s account is notable because he was an educated man and had described several whale encounters previously, and as a man who had seen some things in his life, he wouldn’t be one to be easily impressed. So what did Egede and his mates actually see?

Image credits: Paxton et al (2005).

Three researchers took on the challenge of answering that question. The lead author was Charles Paxton, a man familiar with unusual studies. A few years ago, Paxton was awarded the Ig Nobel award for a study on how amorous ostriches attempt to court humans in Britain — yes, really. The Ig Nobel award is offered to research “that cannot, or should not, be reproduced” and that “first makes you laugh, then makes you think”.

Paxton’s whale study was carried out in 2005, and the researchers looked at all the plausible actions that could fit the description. A key part of the description is the “serpent-like” description.

“Although whales are found, and can survive, without flukes (for example grey whales ), serpent-like or eel-like bodies are not usually associated with the rapid thrust that would be required to rear the whole body high out of the water,” Paxton writes.

So it seems like the monster couldn’t have been a whale. But it could have been a whale… part.

“There is an alternative explanation for the serpent-like tail. Many of the large baleen whales have long, snake-like penises. If the animal did indeed fall on its back then its ventral surface would have been uppermost and, if the whale was aroused, the usually retracted penis would have been visible.”

This seems compelling enough, but it still leaves up the matter of size for debate. Whale penises are indeed impressive, but could they have been bigger than the entire boat? Researchers suspect the answer is ‘no’, but there could be an explanation: multiple whales.

“The penises of the North Atlantic right whale and (Pacific) grey whale can be at least 1.8 meters long and 1.7 meters long respectively and could be taken by a naĂŻve witness for a tail. That the tail was seen at one point a ship’s length from the body suggests the presence of more than one male whale,” the study concludes.

To make the whale erection theory even more compelling, a separate incident from 1875 is even more likely to be a whale penis. Sailors aboard the merchant vessel Pauline reported seeing a “whitish pillar” amongst a pod of sperm whales “frantic with excitement” — a description that very well fits the whale penis theory.

Ultimately, we may never know what Egede saw, and probably not all sea serpent sightings are whale penises (though that would be an interesting study), but it seems to happen quite often, and it’s not uncommon for sea serpents to “appear” in the vicinity of whales, often even attached or “battling” a whale.

There’s even a theory that the Loch Ness monster is a whale penis, though there’s a big hole in that theory, in that Loch Ness is a lake and there are no whales in it. But otherwise, a lot of sea serpent sightings could actually be whale penises.

You can read the entire study here.

Who was the Basilosaurus, the ‘king lizard’ that was neither king nor lizard?

Today, we know that the Basilosaurus is the first ancient whale humanity has ever found. But back when it was first described, the animal’s huge proportions earned it the name of ‘king lizard’. And although technically incorrect, the name isn’t undeserved; during its day, the Basilosaurus ruled the waters of Tethys with an iron flipper and a really impressive set of teeth.

Basilosaurus isis skeleton at the Nantes History Museum. Image via Wikimedia.

This creature lived 40 to 35 million years ago, during a part of geologic time known as the late Eocene. The dinosaurs were quite well gone by this time, and mammals were well on the way to dominating the planet. The Basilosaurus was also a mammal — a whale, no less — and could grow up to 60 feet (a bit over 18m) in length. Needless to say, you can’t skip meals and grow so large. But this species likely had no issues getting full, as the Basilosaurus was, by all indications, a formidable apex predator.

It was first described in 1834 from fragments of a skeleton found in the US. Due to the sheer scale of the fossils, their striking similarity in shape and function to marine predatory dinosaurs, poor availability, and the limits of paleontological understanding of the day, the species was initially assumed to have been a dinosaur — and christened the ‘king of the lizards’, Basilosaurus.

How come?

The academic story of this genus starts with B. cetoides, the first ancient whale species ever discovered, which was unearthed in Louisiana around 1830 by Richard Harlan and still serves as the type species of Basilosaurus.

Details from the dig and the wider goings-on around the fossils aren’t very good from the time, but we do know that bones from this dig were sent to the American Philosophical Society by Judge Henry Bry of Ouachita County, Louisiana and Judge John Creagh of Clarke County, Alabama, according to the Encyclopedia of Alabama. Here, they were examined by Richard Harlan, one of the US’s earliest paleontologists and naturalists, who would end up christening the new species.

Upon first examination, Harlan was very excited. Comparing the bones he received to those of Plesiosaurus and Mosasaurus, two species of marine dinosaurs that were already described at the time, he concluded that the new species grew no less than 80–100 ft (24–30 m) long. Still, there were enough structural similarities between its vertebrae and those of Plesiosaurus, as well as between its skull and that of Mosasaurus, for Harlan to assume that the species were related. At the very least, he assumed, they lived around the same time.

The first signs that this name wasn’t really spot-on came when Harlan took his specimens to the UK for consultation with his peers there. Richard Owen, a controversial figure but a superb paleontologist, observed that the animal’s molars were two-rooted. No known fish or reptile at the time showed the same structure, and Owen suggested the animal might have been a whale instead. The two even agreed to rename it Zeuglodon cetoides (“whale-like yoke teeth”).

A few years later the other known species, B. isis, would be described based on fragments of bone recovered from Egypt. Although the first full skeleton of B. isis wouldn’t be unearthed until 2016, the discovery of this species and its fossil association with species that were known to have been whales at the time further suggested that all Basilodons were, in fact, mammals. This was helped by the fact that Basilosaurus fossils actually became quite common over time, so much so that in the 19th century they were even used as andirons, furniture, or decoration.

Over the years, paleontologists have wisened up to the fact and tried to change the genus’ name. However, zoological naming conventions meant that the original name stuck. Today, the Basilosaurus is the state fossil for Alabama and Mississippi.

How did it used to live?

One thing that Harlan got right about the Basilosaurus was that it was large. This whale was bigger even than some predatory dinosaurs that came before it, and it undoubtedly threw its weight around the ancient, lost sea of Tethys.

Another thing it definitely threw around were bites. Unlike most whales today, Basilosaurus didn’t filter feed, it hunted. Its jaws were lined with several types of teeth, including molars and canines, which are specialized for chewing and ripping, respectively. Such teeth are characteristic of meat-eating species.

Two other important characteristics of the species are a skull asymmetry and a relatively low intracranial volume. The first is a trait it shares with modern toothed whales such as orcas. Today, this asymmetry is associated with whales’ ability to produce high-frequency sounds for echolocation; Basilosaurus likely didn’t have this ability, however, and its skull was asymmetrical in order to house a fatty sensory organ meant to help it hear underwater. The lack of room for a big brain inside its skull likely means that Basilosaurus was not a social species, like whales are today, and that it also wasn’t as capable from a cognitive standpoint.

Such traits can be indicative of an evolutionary ‘work-in-progress’. The Basilosaurus seems to have been the first whale species to live entirely underwater, marking the point where the lineage of walking whales finally took the plunge.

It most likely spent its day as a solitary hunter, or at most, one that lived in small groups. Social interactions are extremely demanding, from a cognitive point of view, and Basilosaurus’ brain just seems to have been too small to adequately navigate living in a group.

Still, who needs big brains when you have big brawns? Analysis of fossilized, scarred Dorudon skull bones — this is another genus of prehistoric whale that was the preferred prey of Basilosaurus — suggests that the king of lizards could bite down with 3,600 pounds per square inch (PSI).

To put things into perspective, that’s 233 times more pressure than a fully-loaded M1A2 main battle tank exerts on the ground under its tracks. Most industrial hydraulic presses in use today exert between 1,000 to 3,000 PSI, which is still under the estimated high ofr Basilosaurus. You do not want to get bitten by one of these.

With big bites, however, also comes good manners. Wear patterns on Basilosaurus teeth suggest that the animal bit and then chewed its food, unlike most predators today, whose teeth are specialized in ripping chunks of meat off the bone, that are then gulped up whole. In regards to what they ate, stomach contents seem to indicate that B. cetoides hunted fish and large sharks exclusively, while we know from Dorudon skulls that B. isis would also hunt these. Dorudon was a larger animal, related to today’s dolphins, and B. isis likely focused on delivering a killing blow to its head before tearing it apart while feeding (many Dorudon skeletons, especially those showing signs of predation from Basilosaurus, are found disarticulated).

King no more

The Basilosaur genus went extinct, with our last fossil evidence of them hailing from around 40 million years ago. They didn’t leave behind any direct descendants which, judging from their teeth, isn’t the worst thing to have ever happened.

We’re not entirely sure why they disappeared. Sometime around 40 million years ago, something happened to bring these toothy kings low. However, the fact that other toothed and baleen whales are around today suggests these smaller relatives of the Basilosaurus out-competed them in the end. It might have been their big brains, it might have been their social nature, it could even have been their more modest appetites; for now, it remains a mystery.

Researchers want to use whale song for seismic imaging of the Earth’s crust

An innovative study suggests that songs of fin whales can be used for seismic studies of the oceanic subsurface. This could essentially open up a new avenue for geologic research and even reduce the need for seismic studies in the ocean, which is disturbing and even harmful to whales.

Image credits: Kuna and NĂĄbelek.

Earthquakes are some of nature’s most devastating processes, but in some ways, they can also be useful. Most of what we know about the Earth’s internal structure comes from earthquakes: researchers can analyze vibrations caused by seismic waves and draw conclusions about the Earth’s subsurface — from the near-surface crust to the depths of the mantle and the core.

But seismic waves are essentially just acoustic waves — they don’t need to be tectonic in nature. So researchers had a quirky idea: what if we could use the whales’ deep vocalizations as a ‘seismic’ source. John Nabelek, a professor at Oregon State University’s College of Earth, Ocean, and Atmospheric Sciences and a co-author of the paper explains:

“People in the past have used whale calls to track whales and study whale behavior. We thought maybe we can study the Earth using those calls,” Nabelek said. “What we discovered is that whale calls may serve as a complement to traditional passive seismic research methods.”

The study started as a bit of a chance occurrence. The study’s lead author is Vaclav M. Kuna, who worked on the project as a doctoral student at Oregon State and has since completed his Ph.D. Kuna and Nabelek were studying earthquakes from a network of 54 ocean-bottom seismometers about 1-200 miles from the coast of Oregon when they observed a strange signal. The signal turned out to correlate with whales’ presence in the area.

“After each whale call, if you look closely at the seismometer data, there is a response from the Earth,” Nabelek said.

Fin whales don’t actually “sing” — their calls are more like a series of clicks that go on for hours, two times louder than the loudest concert you’ve ever seen (although sound transmits differently in water). Turns out, the frequency of these clicks are within the range that can be picked up by seismographs. This is what researchers were picking up, so they figured that they could actually use these calls as signals for seismic studies.

It’s a complicated process. The sounds bounce between the surface of the water and the bottom of the ocean, with some of the waves’ energy going through the oceanic crust. Reconstructing this signal is a big challenge, but it can be done; this proof-of-concept study shows it. It’s not clear just how much information can be derived this way, but it could at least be a complement to more conventional seismic surveys.

The approach could also end up helping whales, as conventional seismic surveys can disturb whales.

Journal Reference: VĂĄclav M. Kuna et al, Seismic crustal imaging using fin whale songs, Science (2021). DOI: 10.1126/science.abf3962

They were looking for a beaked whale. Instead, they may have found a new species

In their quest to look for a rare whale, a group of researchers believes they have instead discovered a previously unknown species off the western coast of Mexico. Even though DNA testing hasn’t been confirmed yet, they’re very confident.

Possibly a new species of Beaked whale. Image credit: Sea Shepherd

The researchers, working with the Sea Shepherd Conservation Society, were on board a vessel on November 17 when they observed three beaked whales surfacing in nearby water. The sighting happened 100 miles north of the San Benito Islands, a group of remote islands located 300 miles from the US border.

The expedition’s focus was the study of cetaceans in the waters surrounding the islands, and researchers were particularly hoping to identify a beaked whale species associated with an unidentified acoustic signal. They took photographs and video recordings of the animals and used a microphone to record the acoustic signals.

The beaked whale experts said they are “highly confident” that the photographic and acoustic evidence will reveal the presence of an entirely new whale species. They have already started analyzing the environmental genetic sampling, which they believe will prove the existence of this new species of whale.

“We saw something new. Something that was not expected in this area, something that doesn’t match, either visually or acoustically, anything that is known to exist,” said Dr. Jay Barlow, who was part of the expedition, in a statement. “It just sends chills up and down my spine when I think that we might have accomplished this.”

Back in 2018, scientists recorded an unknown acoustic signal in the waters north of the San Benito Islands. The signal was believed to have been the sound of a species called Perrin’s beaked whale, which is one of 23 known species of beaked whales found in oceans around the world. Still, there have been no live sightings of it.

The animal documented is indeed a beaked whale, but it’s not Perrin’s beaked whale or any other known species, according to the researchers. Initial analysis by the team from Sea Shepherd showed that the physical characteristics and the acoustic recording of the sighted whales don’t match known species of beaked whales.

Perrin’s beaked whale has teeth at the end of the jaw, while in the one the team spotted the teeth were further back. Similar differences were seen regarding their sizes and color patterns. “it really didn’t seem to match any of the other characteristics of described beaked whales,” said Elizabeth Henderson, one of the researchers.

Takashi Fritz Matsuishi, a professor at Hokkaido University’s School of Fisheries Sciences and co-author of a 2019 paper identifying another new species of beaked whale, told Mongabay it’s possible the researchers might have found a new species. But he warned it can’t be identified by DNA analysis or visual observations.

“The external morphology and osteological descriptions are strictly required,” Matsuishi said, referring to the animal’s physical features and skeletal structure. “That is the reason that our Sato’s beaked whale [took] 6 years to be described as a new species since the publication of the paper showing the genetical difference in 2013.”

While they wait for the DNA analysis, the researchers are currently working on a paper to describe the species’ acoustics and morphological characteristics, which they hope to release shortly.

Fossil Friday: huge, ancient dolphin was the first echolocating apex predator

The fossil of a 15-meter-long extinct species of dolphin is helping us better understand how different lineages of marine mammal independently evolved the same characteristics.

Skull and Skeleton of Ankylorhiza tiedemani.
Image credits Robert Boessenecker et al., (2020), Current Biology.

The species, christened Ankylorhiza tiedemani lived about 25 million years ago during the Oligocene in what today is South Carolina. It belonged to a group of large dolphins (Odontoceti) whose best-known modern representative is the orca (killer whale).

The anatomy of this fossil suggests that it was likely a top predator in its day. It shares several features with today’s baleen and toothed whales despite not being directly related to these groups, the authors report. This suggests that these animals evolved their shared swimming adaptations independently from one another, a phenomenon known as parallel evolution.

Like whales in a pod

“The degree to which baleen whales and dolphins independently arrive at the same overall swimming adaptations, rather than these traits evolving once in the common ancestor of both groups, surprised us,” says Robert Boessenecker of the College of Charleston in Charleston, South Carolina, first author of the paper describing this fossil.

“Some examples include the narrowing of the tail stock, increase in the number of tail vertebrae, and shortening of the humerus (upper arm bone) in the flipper.

Comparison with lineages of seals and sea lions reveal that the two families went down very different evolutionary paths as they transitioned from a land- to a marine-based lifestyle. The initial differences between these lineages were slight, the team explains: Ankylorhiza’s ancestors had one extra row of finger bones in their flippers and a “locking elbow joint”. Still, these factors lead to them developing different swimming styles and skeletal structures.

Another thing the authors note is that Ankylorhiza is the first echolocating whale to become an apex predator. According to the team, it was “very clearly preying upon large-bodied prey like a killer whale”. Its extinction cleared an ecological niche that sperm whales and a lineage of shark-toothed dolphins (both extinct) evolved into. Later still, killer whales would evolve into the same niche around 1 or 2 million years ago.

Ankylorhiza was first described from a skull fragment found during dredging of the Wando River, South Carolina, in the 1880s. A nearly-complete skeleton was later unearthed in the 1970s. The one described in this paper was found in the 1990s by commercial paleontologist Mark Havenstein at a building site and donated it to the Mace Brown Museum of Natural History to allow for its study.

“Whales and dolphins have a complicated and long evolutionary history, and at a glance, you may not get that impression from modern species,” Boessenecker says. “The fossil record has really cracked open this long, winding evolutionary path, and fossils like Ankylorhiza help illuminate how this happened.”

Boessenecker says that there are “many other unique and strange early dolphins and baleen whales from Oligocene aged rocks in Charleston, South Carolina,” including fossils of juvenile Ankylorhiza and specimens of related species. Both filter-feeding and echolocation first appeared during the Oligocene, he adds, so these fossils should give us a very good peek into how they came to be.

The paper “Convergent Evolution of Swimming Adaptations in Modern Whales Revealed by a Large Macrophagous Dolphin from the Oligocene of South Carolina” has been published in the journal Current Biology.

Food availability acts as a cap for whales’s maximum size

Whale size may be held in check by the availability of prey, a new study reports. While baleen whales have evolved to leverage size as an advantage while feeding — which put them on an “energetic knife’s edge” — toothed whales instead stand to benefit from being less massive.

Humpback whale and her calf.
Image credits National Marine Sanctuaries.

Growing to more than 100 tons, blue whales are considered to be the largest creatures to have ever roamed the Earth. Seeking to understand why baleen (filter-feeding) whales and toothed whales are so different in body size — and what factors limit their growth — a new study is looking into how much energy the two groups spend when feeding.

Large-scale nomming

“Blue whales and sperm whales are not just kind of big,” said Nicholas Pyenson, curator of fossil marine mammals at the Smithsonian’s National Museum of Natural History and the corresponding author of this study. “They are among the biggest animals ever to have evolved.”

“They rival and, in some cases, exceed the heaviest dinosaurs. That’s pretty spectacular. But why aren’t they bigger?”

Since whales spend most of their time deep underwater, it’s very hard for researchers to actually monitor what they’re doing. The current study, written by an international team of researchers led by Pyenson and Stanford University biologist Jeremy Goldbogen stuck multi-sensor arrays onto the backs of whales, porpoises, and dolphins of various sizes using suction cups.

The sensor arrays were used to track the animals’ underwater activities using accelerometers, pressure sensors, cameras, and hydrophones. Sonar sweeps in the surrounding waters, alongside older records of prey in whale stomachs, were used to estimate the density of prey in the vicinity of each tagged animal. Over 10,000 distinct feeding events were analyzed as part of the study, with the team calculating the energy cost and payoff for each.

“Energy is a key currency for all life, and we wanted to know how energy gain compares to energy use in foraging whales with different body sizes and feeding strategies,” Goldbogen said.

“The ratio of energy gain relative to energy use reveals a whale’s foraging efficiency and that provides clues as to why different whales are big and why they aren’t bigger.”

The net energy return on feeding, they found, largely depended on how each whale fed — i.e. by hunting individual prey (toothed whales) or by filter-feeding (baleen whales). Body size in all whales is limited by this net return of energy.

Less bang for your kill, more bang for your krill

Killer whale.
Image credits Ed Schipul / Flickr.

Filter-feeding whales are the only ones to have evolved a feeding strategy that favors larger body sizes — which turned them into the largest animals to have ever evolved on Earth. Size, they explain, plays right into the feeding style of baleen whales. They feed by straining patches of krill from ocean water — which aren’t particularly smart or able to move out of the way, so catching them is like shooting fish in a barrel. Having a larger body (and mouth) therefore means the whales can generate more calories for the same effort. In other words, their net energy return from feeding increases with the size of the whale.

Toothed whales, in contrast, need to hunt down individual prey, like a cheetah would on land. The whales use echolocation to spot a target and then hunt it down — so they are, in essence, limited to feeding on one target at a time. This hunting process requires a lot of energy, as the prey obviously would rather not be eaten, and does its best to escape. The larger a toothed whale becomes, the more energy it needs to give chase and catch prey. In other words, their feeding strategy favors smaller body sizes.

In some cases, the team reports, larger toothed specimens like sperm whales actually lost energy on some food dives; it simply takes more calories to dive and eat than they get out of what they ate. In effect, energy expenditure related to hunting acts as the hard cap for the size of toothed-whales. There aren’t enough large animals in the ocean for them to grow larger.

“They literally can’t eat enough to achieve a higher energetic payoff before they have to return to the surface and breathe,” Pyenson said.

“Being a sperm whale today is really pushing a serious biological limit.”

Filter-feeding whales, on the other hand, only seek out the densest patches of krill and almost always, the data showed, consume significantly more calories than they expend. The largest whales in this category saw the best energy return rates in the whole study. But they’re also limited in size by prey availability.

Krill population numbers explode but only for short periods of time every year in specific areas of the globe. This seasonal variation is what keeps baleen whale size in check.

Are whales the limit?

“The largest baleen whale species must reap the energy gains of krill patches in only a few of the most productive summer months at high latitudes,” Goldbogen said.

“Highly efficient filter-feeding strategies mean that these whales can build up fat stores that can then power their migrations across ocean basins to breeding grounds at lower latitudes that are leaner and provide much less food.”

While it may seem that filter-feeding whales have it nailed down, Pyenson explains that they’re actually playing a dangerous game here. They’re superbly adapted to take advantage of one resource. It’s an abundant resource, for sure, but if anything were to happen to the supplies of krill, filter-feeding whales have nothing to fall back on. Given their huge bulk, it’s hard to imagine any source of food in the ocean that could serve as a fall-back.

“You have to wonder just how perilous it is for whales living on an energetic knife’s edge,” Pyenson said, noting that climate change, overfishing, and other threats to the oceans are rapidly impacting their food suply.

“If you’re a blue whale and your only prey item is krill, and something causes krill populations to go into decline, then you are at an evolutionary dead end because you would not be able to eat enough to sustain yourself,” he said. “It’s a good reason for us to try to better understand these predator-prey relationships.”

This study identifies food sources as a limiting factor in whale size, but previous research has suggested that it may be biologically impossible for blue whales to grow any larger anyway due to mechanical constraints on their cardiocirculatory systems.

Beyond the immediate value of the findings, the team says it helps us better understand the dynamics between other huge beasts — particularly dinosaurs — and their food source, and how this limited their growth. “We don’t know how badly a herd of sauropod dinosaurs would chomp down on a forest in the Cretaceous period,” Pyenson adds, “but they probably did a number on it.”

The paper “Why whales are big but not bigger: Physiological drivers and ecological limits in the age of ocean giants” has been published in the journal Science.

Ancient whale fossil show how the mammals moved to life in the ocean

A newly-described fossil whale is helping researchers understand how these mammals transitioned from walking on dry land to swimming in the ocean.

Cervical and thoracic vertebrae of the Aegicetus gehennae specimen.
Image credits Gingerich et al., (2019), PLOS ONE.

Whales (infraorder Cetacea) are fully-aquatic creatures — but this wasn’t always the case. Back in the Eocene, a geologic epoch ranging from 56 to 34 million years ago, a group of early whales (protocetids) transitioned from living on land to a semi-aquatic lifestyle. Unlike modern-day whales, they didn’t rely on tails for propulsion but swam and walked around with the same set of limbs.

A study describing a newly-discovered protocetid species, Aegicetus gehennae, is helping researchers piece together how the group started transitioning from an amphibian lifestyle to a fully-aquatic one.

These boots were made for swimming

“Early protocetid whales living 47 to 41 million years ago were foot-powered swimmers, and later basilosaurid and modern whales — starting about 37 million years ago — were tail-powered swimmers,” the study explains.

“The late protocetid Aegicetus was intermediate in time and form, and transitional functionally in having the larger and more powerful vertebral column of a tail-powered swimmer.”

The study, led by Philip Gingerich of the University of Michigan, reports that the new species represents an important link in the evolutionary path of whales and whale locomotion.

Fossils of this species were first discovered in the Wadi Al Hitan World Heritage Site in the Western Desert of Egypt back in 2007. It is the youngest protocetid known so far, dating to around 35 million years ago. It’s also one of the best-preserved species of its family, and the best-preserved early whale fossil — one full skeleton in exceptional condition and a second partial specimen were retrieved from the site in Egypt.

Compared to its more ancient relatives, the team reports, Aegicetus gehennae had a more elongated body and tail, smaller hind legs, and lacked a hard connection between the spinal column and its hind limbs. All of these traits, but the last one more so than the others, are adaptations seen in fully aquatic species.

The shape of its body resembles that of other ancient whales, the authors note, which was likely well-suited for swimming through undulation of the mid-body and tail — pretty much the same swimming style of crocodiles today. This style might represent a transitional stage between foot-powered and tail-powered swimming in modern whales, the team concludes.

The paper “Aegicetus gehennae, a new late Eocene protocetid (Cetacea, Archaeoceti) from Wadi Al Hitan, Egypt, and the transition to tail-powered swimming in whales” has been published in the journal PLOS ONE.

New heart rate measurements suggest that blue whales are about as large as animals can get

Researchers at Stanford University have made the first recording of a wild blue whale’s heart rate to date. The data suggests that the animals’ hearts are operating close to their maximum capacity, which may act as a hard cap on their maximum possible size.

Image credits Thomas Kelley.

The team developed a sensor array which, through the use of four suction cups, can be secured near a whale’s left flipper. This device was used to record the heart rate of a wild blue whale, and offer an explanation as to why they are the largest animal we’ve ever found. The recording points to some unusual features that help whale hearts pump enough blood.

Studying animals that operate “at physiological extremes” can help us better understand biological limits on size, the team explains. Furthermore, such species may also be “particularly susceptible” to environmental changes that disrupt their food supply, since large animals need large meals. All in all, the team hopes that their research will help us design new and better conservation and management schemes for endangered species like blue whales.

Big-hearted

“We had no idea that this would work and we were skeptical even when we saw the initial data. With a very keen eye, Paul Ponganis — our collaborator from the Scripps Institution of Oceanography [Ed. Note also a co-authror of this study] — found the first heart beats,” said Jeremy Goldbogen, assistant professor of biology in the School of Humanities Sciences at Stanford and lead author of the paper.

“There were a lot of high fives and victory laps around the lab.”

The current study draws its roots in some of Goldbogen’s and Ponganis’ previous research, in which they measured the heart rates of diving emperor penguins in McMurdo Sound, Antarctica. The duo wanted to do the same with a blue whale, but there were several issues to overcome: “finding a blue whale, getting the tag in just the right location on the whale, good contact with the whale’s skin and, of course, making sure the tag is working and recording data,” said Goldbogen.

They first tested their sensors on smaller, captive whales, to make sure the technology is sound. However, they didn’t accurately reflect the behavior of wild whales — which aren’t, for example, trained to flip belly-up for a human caretaker. Blue whales also have a wrinkly structure to the skin on their underside that expands during feeding; this could mechanically dislodge the sensor array.

“We had to put these tags out without really knowing whether or not they were going to work,” recalled David Cade, a recent graduate of the Goldbogen Lab who is a co-author of the paper and who placed the tag on the whale.

“The only way to do it was to try it. So we did our best.”

Despite all this, everything went swimmingly with the wild whales, the team reports. Cade managed to fix the tag on his first attempt near the flipper (where it could pick up on signals from the heart).

The recordings showed that when the whale dives, its heart rate slows down to an average of about 4 to 8 beats per minute, although the team did see activity drop down to just 2 beats per minute. At the lowest point of their foraging dives — when the whale needs to swim upwards and catch its prey — heart rate rose to 2.5 times above this minimum value, and then slowly decreased. The highest heart rate was recorded at the surface, between 25 to 37 beats per minute, while the whale was breathing and replenishing its oxygen stocks.

All in all, the team says the findings are very surprising. The upper limit of heart rate was faster than expected, and the lowest ones were about 30-50% slower. The lower-end heart rates seen can be explained by the whale’s elastic aortic arch, which slowly contracts and keeps blood flowing to the body between heartbeats. The highest heart rates seen are likely made possible by small features of the heart’s shape and movement which prevent pressure waves generated during contraction from disrupting blood flow, the team adds.

The blue whale’s heart likely operates near or at the limit of its capacity. The team believes that the energy needs of a larger body would simply outpace the ability of a heart to pump blood, which would explain why no animal has ever outgrown them.

Currently, the team working on improving their sensor array and plan to expand their research to other species such as fin whales, humpbacks and minke whales.

The paper “Extreme bradycardia and tachycardia in the world’s largest animal” has been published in the journal PNAS.

The bottlenose mother, pictured with her adoptive whale calf (which has a short and blunt beak compared to the dolphin's long and slender beak) and biological daughter (bottom). Credit: Pamela Carzon.

Dolphin mother adopts a whale calf — first time this is seen in the wild

The bottlenose mother, pictured with her adoptive whale calf (which has a short and blunt beak compared to the dolphin's long and slender beak) and biological daughter (bottom). Credit: Pamela Carzon.

The bottlenose mother, pictured with her adoptive whale calf (which has a short and blunt beak compared to the dolphin’s long and slender beak) and biological daughter (bottom). Credit: Pamela Carzon.

Bottlenose dolphin mothers are some of the most caring and nurturing moms in the animal kingdom. For years, they will feed, protect, and play with their young. But what even knowing this couldn’t prepare researchers for this unusual behavior: a bottlenose dolphin was spotted caring for an orphan male calf which belongs to a different species and genus of dolphin.

Researchers observed the dolphin mother along the coast of French Polynesia, along with one of her biological calves and an adopted male calf, which was later identified as a melon-headed whale.

Adoption was once thought to be a uniquely human trait. Then, in 2006, primatologists at the University of SĂŁo Paulo were astonished to find a group of capuchins that were caring for a baby marmoset. Along with the bottlenose dolphin (Tursiops truncatus) mother, these are the only two documented cases involving the adoption of an orphan from a different species and genus. Most other adoptions among wild animals — which are very uncommon, to begin with — occur between related members of the same species.

Researchers at the Groupe d’Étude des Mammifères Marins (GEMM) de Polynésie filmed the dual-species family from all angles as part of a broader project designed to study a pod of around 30 bottlenose dolphins, which first began in 2009. After the orphan melon-headed calf (Peponocephala electra) joined the mother and her biological calf, he rarely left her side. The researchers were amazed to see the three of them constantly swimming side by side, an unusual sight since dolphin mothers are known to care for only one young at a time.

What’s more, the adopted calf was also successful at integrating himself in the broader pod. Writing in the journal Ethology, the researchers in French Polynesia said that the melon-headed whale youngster is now behaving like a bottlenose dolphin, regularly surfing and leaping into the waves just like any other dolphin young.

The mother proved to be remarkably committed to her newly adopted calf. The researchers documented how the two were spotted constantly together for nearly three years until the melon-headed whale suddenly disappeared in April 2018 — that’s around the time he would wean. The union lasted far longer than that between the mother and her biological calf, which vanished at one-and-a-half years old. On at least two occasions, the mother was spotted nursing her adopted calf, which is a huge sign of investment. For mammals, making milk is a very costly process so sharing it with not only an unrelated individual but one belonging to an entirely different genus, is truly amazing.

But, if this behavior on the part of the dolphin momma is so costly, why did she go through all of it? One possible explanation is that the orphan calf triggered her maternal instincts. In other words, the calf was in the right place at the right time since the mother was already receptive to forming strong bonds with her own offspring. The dolphin mother also has an accommodating personality, being known for uncanny tolerance for scuba divers in the area.

Lastly, to make the story even more impressive, it seems the melon-headed whale calf himself may have played an important role in the union through sheer, brute determination.

“We argue that the primiparous foster mother’s inexperience and personality may have contributed to factors driving such non‐adaptive behavior. We also propose that the adoptee’s persistence in initiating and maintaining an association with the adult female bottlenose dolphin could have played a major role in the adoption’s ultimate success, as well as the persistence of this cross‐genus adoption after the disappearance of the biological offspring,” the authors argued in their study.

Ancient amphibious whale with four legs and hooves dared to cross the Atlantic

Whales have one of the most fascinating evolutionary stories. Their ancestors adapted to a terrestrial lifestyle and then gradually moved back to the seas — a most unlikely adaptation. Now, paleontologists have caught a creature in this evolutionary act: they’ve discovered traces of a whale ancestor that had legs and hooves. Researchers believe that this unusual creature braved the trip from Africa to South America.

Doesn’t look much like a whale, does it? Artistic reconstruction of newly discovered Peregocetus pacificus. Image credits: Alberto Gennari / Cell Press.

The evolutionary history of cetaceans (the group that includes whales, dolphins, and porpoises) sounds like an elaborate prank. The group which today includes excellent swimmers and the largest organism in our planet’s history (blue whale) emerged from small, deer-like creatures with four toes, each one ending in a small hoof. But the anatomic studies of current creatures and the paleontologic findings leave no room for interpretation.

A particularly interesting missing link found in India suggests that the last whale precursors took to the water in times of danger but came onto land to give birth and eat. Gradually, they transitioned from terrestrial to marine creatures. They tended to spend more and more time in an aquatic environment, but were also capable of terrestrial life — much like beavers and otters today.

Indohyus, an unlikely furry ancestor of modern whales. Image credits: Ghedoghedo / Wiki Commons.

Some 42 million years ago, while it was still capable of walking on land, one such creature undertook a daring trip: from Africa to South America. While back then, the distance between these continents was two times smaller, it was still an amazing feat. Its fossil has now been found on the coastal plains of Peru, which are well known for their rich deposits of ancient marine fossils. The fossil offers new insights into how these amazing creatures adapted to life in the water and expanded from the Indian subcontinent to the rest of the world. Dr. Olivier Lambert, from the Royal Belgian Institute of Natural Sciences, who co-authored the study, describes the finding:

‘This is the first indisputable record of a quadrupedal whale skeleton for the whole Pacific Ocean, probably the oldest for the Americas and the most complete outside India and Pakistan.’

The skeleton shows that the whale would have been at home on the land and in water. Image credits: Lambert et al. / Current Biology.

The newly-discovered creature, called Peregocetus pacificus, was dated to 42.6 million years ago. Its hind legs were only a bit shorter than its front legs and it had tiny hooves on each toe and finger, suggesting it was very much capable of trotting about on land. However, other features indicate it was also well-adapted to aquatic life. Its hind feet bones indicate that despite its hooves, it had webbed feat. It also sports beaver-like tail bones, indicating that the tail was well-adapted to swimming. These biological features, well-suited for both aquatic and terrestrial life, indicate that this is a transitional creature, which makes it very important in understanding whae evolution.

‘The evolution of whales is perhaps the best-documented example of macroevolution that we have, with the group going from small, dog-sized, hoofed mammals to the giants of the ocean we know and love today,’ Travis Park, a postdoctoral fellow studying cetacean evolution, told the Natural History Museum. ‘However, despite having a good fossil record of the different stages involved, there are still questions remaining as to the routes that early whales took when they first spread around the world.’

The finding also indicates that the dispersal of early whales, while steady, was not exactly straightforward. They went from India to North Africa, and then to South America. From there, some individuals (like this one) crossed the continent, while others went on to North America. It took almost 10 million years for whales to colonize the entire planet.

The study “An Amphibious Whale from the Middle Eocene of Peru Reveals Early South Pacific Dispersal of Quadrupedal Cetaceans” has been published in Current Biology.

Japan’s new year resolution: resuming commercial whale hunting

In a largely disappointing move, Japan has announced that it will withdraw from the International Whaling Commission and restart commercial whale hunting in 2019. The move has been blamed by other governments and conservation groups.

Two slaughtered Minke whales are dragged aboard Japan’s Nisshin Maru, the world’s only factory whaling ship. Image credits: Customs and Border Protection Service, Australia.

The International Whaling Commission (IWC) was set up right after World War II, in 1946, to “provide for the proper conservation of whale stocks and thus make possible the orderly development of the whaling industry”. Tokyo representatives complained that the IWC did not allow the “orderly development” of the whaling industry. Simply put, Japan wanted to hunt more whales than it was allowed under the IWC.

“Regrettably, we have reached a decision that it is impossible in the IWC to seek the coexistence of states with different views,” Chief Cabinet Secretary Yoshihide Suga said in a statement.

Japan’s whaling woes are not a new problem. Despite an international ban, Japan basically continued to hunt whales, using a scientific research permit as a cover-up. Despite rising international pressure, the country carried on and threatened that it would exit the IWC — which it now seems determined to do, having failed to convince the IWC to allow hunting campaigns.

“By withdrawing, our nation’s thinking in terms of cooperation with international marine resources management does not change,” Suga said. “We will participate in the IWC as an observer, and while maintaining ties to international organizations our nation will keep contributing to whale resources management based on scientific principles.”

The nearby countries of Australia and New Zealand both expressed strong disagreement with the decision, with Australia saying it is was “extremely disappointed”, while New Zealand called Japanese whaling an “outdated and unnecessary practice.”

Conservation groups have also expressed their disappointment at the announcement.

“By leaving the International Whaling Commission but continuing to kill whales commercially, Japan now becomes a pirate whaling nation killing these ocean leviathans completely outside the bounds of international law,” said Kitty Block, president of Humane Society International.

This essentially highlights a major ideological divide between Japan and other countries. Due to its proximity to the Antarctic, Japan’s whaling practices are considered dangerous to a very vulnerable ecosystem. There’s also a major ethical discussion since most whales are considered to be highly intelligent.

Meanwhile, Japan has historically been unable to ensure food self-sufficiency, now providing only around 40% of its nutritional needs. So the country stockpiles vast quantities of food, including 1.2 million tons of seafood. Out of these, 5,000 tons are whale meat, a food considered traditional by many. However, the demand for whale meat has been steadily declining, and the industry isn’t even sustainable — the Japanese government has had to invest $12 million into the 2008-09 Antarctic whale hunt alone just to break even.

From the outside, whaling seems like a declining and unsustainable industry, but the Japanese government seems determined to push it.

Ichthyosaurs were predatory marine reptiles that swam the world’s oceans while dinosaurs walked the land.

Ichthyosaur may have had blubber, which means the ‘sea monster’ may have been warm-blooded

Researchers have identified a well-preserved ichthyosaur specimen, complete with skin and, most remarkably, a blubber. The incredible discovery suggests that the 180-million-year-old sea creature may have been warm-blooded.

Ichthyosaurs were predatory marine reptiles that swam the world’s oceans while dinosaurs walked the land.

Ichthyosaurs were predatory marine reptiles that swam the world’s oceans while dinosaurs walked the land.

“Ichthyosaurs are interesting because they have many traits in common with dolphins, but are not at all closely related to those sea-dwelling mammals,” said co-author Mary Schweitzer, professor of biological sciences at North Carolina State University and visiting professor at Lund University, Sweden. “We aren’t exactly sure of their biology either. They have many features in common with living marine reptiles like sea turtles, but we know from the fossil record that they gave live birth, which is associated with warm-bloodedness. This study reveals some of those biological mysteries.”

Ichthyosaurus (“fish lizard” in Greek) was a large marine reptile which was perfectly adapted to ocean life. Its dolphin-like body featured a small sail-fin on its back and advanced flippers that allowed the creature to swim at high speeds, perhaps as fast as 33 km per hour (21 mph). The reptile could grow to 1.8 meters (6 feet) in length and weighed around 90 kg (200 pounds).

Paleontologists have been lucky enough to find an abundance of ichthyosaur fossils. Thanks to these findings we’ve come to know that the ancient sea creature had large ear bones that allowed it to locate both prey and predators, or that it used to give birth to live young instead of laying eggs as a fish would. Eventually, Ichthyosaurus was outcompeted by the arrival of better adapted marine animals such as pliosaurs and plesiosaurs.

Some scientists have compared ichthyosaurus with modern toothed whales, based on estimates of their swimming speed, which would imply they were warm-blooded. It seems that they were on to something since a new study, which described a wonderfully preserved specimen, identified a blubber.

The blubber is a thick layer of vascularized adipose tissue under the skin of modern marine mammals, such as cetaceans, pinnipeds, and sirenians. It basically insulates vital organs, keeping them warm while in cold climates. Its discovery in an ichthyosaurus suggests that the ancient marine reptile was also warm-blooded, an extremely rare occurrence among reptiles. Modern leatherback sea turtles also have a blubber, which along with other measures for heat retention and control, allow it to venture into very cold waters.

“This is the first direct, chemical evidence for warm-bloodedness in an ichthyosaur, because blubber is a feature of warm-blooded animals,” Schweitzer says.

The Stenopterygius ichthyosaur specimen was discovered in Holzmaden quarry, Germany. For years it was stored at the Urweltmuseum Hauff in Germany, until researchers at Lund University in Sweden examined it.

Photographic (top) and diagrammatic (bottom) representation of the 85-cm-long fossil (which corresponds to roughly half of the original length of the animal). Credit: Johan Lindgren.

Photographic (top) and diagrammatic (bottom) representation of the 85-cm-long fossil (which corresponds to roughly half of the original length of the animal). Credit: Johan Lindgren.

Besides the blubber, the research team was also able to trace the animal’s flexible skin. Microscopic analysis of this tissue suggests that ichthyosaur was countershaded, meaning it had a dark upper surface and light belly. This camouflage pattern would have helped the animals avoid Jurassic predators such as flying pterosaurs, attacking from above, and pliosaurs from below.

“Both morphologically and chemically, we found that although Stenopterygius would be loosely considered ‘reptiles,’ they lost the scaly skin associated with these animals—just as the modern leatherback sea turtle has,” Schweitzer says. “Losing the scales reduces drag and increases maneuverability underwater.

It’s a bit too early to claim that the Early Jurassic sea creature was warm-blooded, though. But since ichthyosaur fossils are very common, we could have a confirmation once more specimens showing blubber are found.

The findings appeared in the journal Nature.

Sperm whale in Indonesia succumbed with 6 kilos of plastic in its belly

The whale had ingested 115 drinking cups, four plastic bottles, 25 plastic bags and two flip-flops.

Credits: WWF.

A sad reminder of how our pollution affects ecosystems worldwide washed up on the Indonesian shore. The sperm whale, which would normally munch on octopus, fish, and shrimp, had ingested 6 kilograms (13 pounds) of plastic. Its carcass was found in waters near Kapota Island in the Wakatobi National Park.

Given the advanced state of the decay the carcass was in, it’s impossible to say whether the plastic played a direct role in killing it, but it’s not out of the question, and it certainly had a negative effect on the whale.

“Although we have not been able to deduce the cause of death, the facts that we see are truly awful,” Dwi Suprapti, a marine species conservation co-ordinator at WWF Indonesia, was quoted as saying by the Associated Press.

This is just one example of how our plastic pollution is affecting ocean ecosystems. Recent studies have shown the near-ubiquity of plastic pollution in the planet’s oceans, and a team of researchers quantified that extent to over 5 trillion plastic pieces. It has become abundantly clear that we’re filling the oceans with plastic — though there is some good news.

Europe has recently announced a complete ban on single-use plastic, and anti-plastic movements are picking up steam in many parts of the developed world. Whether it’s a plastic tax, a complete ban, or some other initiative, the world is — rather timidly — attempting to address the plastic problem. However, it’s far from being enough.

According to a recent report by environmental campaigner Ocean Conservancy and the McKinsey Center for Business and Environment, five Asian nations (China, Indonesia, the Philippines, Vietnam and Thailand) account for more than half of the plastic waste that ends up in the oceans.

Indonesia, an archipelago of 260 million people, is the world’s second-largest plastic polluter after China. The country is responsible for 1.29 million tons of plastic that end in the ocean each year — though this year, Indonesia seems to have finally gotten serious about its plastic pollution.

The Indonesian government has pledged to reduce marine waste by 70% by 2025 and spend up to $1 billion a year on cleaning up its rivers and seas. The country is also considering a plastic tax, which has done wonders in places like the UK.

Humpback whales stop their song when human vessels make noise

Scientists have found yet another way we’re disrupting wildlife: when cargo ships start producing a lot of noise, humpback whales reduce or even stop their singing.

Image credits: Christopher Michel.

Not only do whales (and other marine mammals) use sounds to communicate, but they’re much more dependent on sounds than land creatures because their other senses are so limited in water. For human ships, meanwhile, sounds are more of a side-effect.

When a ship cuts through the water, its engine working at full power, it’s a huge cacophony of sounds — and in our modern world, there are a lot of ships.

A team of Japanese researchers wanted to see how these ship sounds affect whales. The Ogasawara Whale Watching Association and Hokkaido University in Japan used two underwater recorders to capture whalesong and locations of animals between February and May 2017, in an area around the Ogasawara Islands, where a single ship passed by (more ships would have made the analysis more complicated).

Over the course of the study, only 26 singers were studied in total, but the results were conclusive. The team found that fewer male humpbacks sang in the area within 500 meters of the shipping lane than elsewhere.

“Remarkably, behavioral changes were observed with a ship’s passing except for when a whale was near a shipping line (<500 m),” the study reads. “This result indicates that whales which were under a ship noise exposure continued to sing as usual.”

Furthermore, up to 1,200 meters around the ship, most whales stopped their song, only resuming it 30 minutes after the ship had passed.

“Humpback whales seemed to stop singing temporarily rather than modifying sound characteristics of their song under the noise, generated by a passenger-cargo liner,” the study reads. “Ceasing vocalization, and moving away could be cost-effective adaptations to the fast-moving noise source.”

Researchers note that in the presence of a ship, most whales would rather pause their song rather than change its characteristics (ie frequency). However, in an area with more ships, the response might be quite different. Responses may differ where ship traffic is heavy, because avoiding an approaching ship may be difficult when many sound sources exist. Around crowded ship lines, pausing for 30 minutes every time a ship passes may simply mean you never get to sing your song. For future research, the team wants to see how sound exposure levels in different scenario affect the whales.

The study can only assess the reaction of male humpbacks — because only the males sing. However, there’s no reason to believe that the mothers and calves are spared from the disruption, though the strength of the impact is yet to be assessed.

The study has been published in PLoS.

Researchres found a chain of underwater volcanoes 400 kilometers (250 miles) east of Tasmania. Credit: CSIRO.

Underwater volcano found off Australian coast may act as superhighway for whales

Researchres found a chain of underwater volcanoes 400 kilometers (250 miles) east of Tasmania. Credit: CSIRO.

Researchers found a chain of underwater volcanoes 400 kilometers (250 miles) east of Tasmania. Credit: CSIRO.

Completely by chance, researchers have come across a striking underwater chain of volcanoes rising amid the deep ocean. The ancient, extinct volcanoes tower 3 kilometers (1.9 miles) above the ocean floor, but, despite their massive size, they’ve stayed concealed from our prying eyes due to a 2 km-thick (1.2-mile) layer of water.

Researchers think that this diverse landscape is a perfect breeding ground for all sorts of lifeforms, likely hosting an array of yet-undescribed new species. The seamounts may also act as ‘signposts’ on the migratory highway for humpback whales that move from their winter breeding to summer feeding grounds.

These seamounts are likely the geological remnants of the ancient split off between Australia, Australia, and Tasmania, which took place about 30 million years ago.

Australian researchers at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian National University were responsible for the discovery. The team’s research vessel Investigator was busy monitoring nutrient and phytoplankton levels in the East Australian Current when the ship’s sonar detected unusual contours beneath the ocean, 250 miles (400 kilometers) east of Tasmania.

It didn’t take long for the researchers to realize that the submerged mountains were brimming with life. Right as the ship was sailing above the uncharted terrain, the researchers detected a huge spike in phytoplankton activity — the bottom of the food chain that ensures the livelihoods of

“While we were over the chain of seamounts, the ship was visited by large numbers of humpback and long-finned pilot whales,” said Dr. Eric Woehler from BirdLife Tasmania, who was on the Investigator with a team surveying seabirds and marine mammals.

“We estimated that at least 28 individual humpback whales visited us on one day, followed by a pod of 60-80 long-finned pilot whales the next.

“We also saw large numbers of seabirds in the area including four species of albatross and four species of petrel.”

Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

Investigator will return to the region for two more research voyages in November and December. During these times, they will use deep water cameras to film marine life living on the seamounts. They will also collect rock samples in order to gain a better understanding of the region’s geological origin and evolution.

“We expect that these seamounts will be a biological hotspot year round, and the summer visit will give us another opportunity to uncover the mysteries of the marine life they support,” said Dr. Woehler.

Minke whale.

Whale skulls act like resonance chambers to help them hear underwater

Whales don’t put their back into hearing — but they do put their skull. New research, along with the first-ever full-body CT scan of minke whale show how the sea-borne mammals can pick up low-frequency sounds, from the calls of other whales to the propellers of cargo ships.

Minke whale.

The minke whale specimen inside the industrial CT scanner. To reduce the time required to scan the entire whale, the team cut the specimen in half, scanned both pieces at the same time, and reconstructed the complete specimen afterward in the computer.
Image credits Ted Cranford / San Diego State University.

The gentle giants of the sea often bedazzle and impress with their songs, but… how can they hear each other underwater? New research suggests that it’s possible if you use your head. If you use your head as a huge acoustic antenna, that is.

Can you hear that?

Considering where whales like to hang out and their impressive girths, studying the marine mammals is notoriously difficult. However, one team of determined US researchers wouldn’t let that dissuade them. The duo has developed a new method of determining how baleen whales (parvorder Mysticeti) pick up low-frequency chatter between 10 to 200 Hertz.

“You can imagine that it is nearly impossible to give a hearing test to a whale, one of the largest animals in the world,” said lead researcher Ted W. Cranford, PhD, adjunct professor of research in the department of biology at San Diego State University.

“The techniques we have developed allow us to simulate the biomechanical processes of sound reception and to estimate the audiogram [hearing curve] of a whale by using the details of anatomic geometry.”

Using a computerized tomography (CT) scanner designed for industrial applications (it was originally used to spot structural defects in rockets), the researchers analyzed the internal structure of a minke whale calf (Balaenoptera acutorostrata) and a fin whale calf (B. physalus). Both animals were found stranded along the U.S. coast some years before the study and were preserved after they died during rescue operations.

CT scanners are a type of X-ray detectors that take a cross-sectional picture through objects or organisms. You’re likely quite familiar with them from hospitals or TV shows involving hospitals. The team produced 3D models showing of the calves’ skulls based these scans. Then, they used a method known as finite element modeling (FEM) to combine maps of tissue density from the CT scans with measurements of tissue elasticity. Finally, a supercomputer simulated these combined models’ response to sounds of different frequencies.

The team reports that whales’ skulls surprisingly act as antennae or a resonance chambers: the bones vibrate when impacted by sound, amplifying and transmitting the vibrations to the whales’ ears. The skulls were especially well-tuned to the low-frequency sounds that whales use to communicate. The authors also note that large shipping vessels also produce the same frequencies, a finding that should help industry and policymakers establish new regulation to limit our impact on these gentle giants.

In addition, the team’s models suggest that minke whales hear low-frequency sound best when it arrives from directly ahead of them. This suggests whales have directional hearing that provides cues about the location of sound sources, such as other whales or oncoming ships. Exactly if (and how) whales might boast directional hearing is still a puzzling question, given that low-frequency sounds tend to travel in waves that are longer than the whales themselves.

The findings were presented Monday, April 23rd at the American Association of Anatomists annual meeting during the 2018 Experimental Biology meeting in San Diego.

Beluga whales value culture and family ties

In a detailed study on whale kinship and family ties, researchers report that just like humans, whales also cherish their ancestral roots and family ties.

A while ago, people used to believe that only humans can use tools — but Jane Goodall (and many researchers after her) showed that humans aren’t the only ones to do so. We’ve since found several species that build and use their own tools. Then, many thought that it’s our cultural and family ties that separate us from the animals. Lo and behold, that’s not true either. Several other species, including whales, have shown important cultural behaviors. This new study confirms that. Researchers have found that related whales returned to the same locations year after year, and decade after decade, passing the information from one generation to the next.

Researchers analyzed the structure of the beluga whale society, finding that migratory culture is inherited. Furthermore, this cultural inheritance maintains the family ties of beluga whales. This cultural legacy is so powerful that some travel as far as 6,000 kilometers each year.

“What intrigued us most was whether particular whales returned to where they were born or grew up and if this was an inherited behavior,” said Greg O’Corry-Crowe, Ph.D., lead author and a research professor at FAU’s Harbor Branch. “The only way that we could definitively answer these questions was to find and track close relatives from one year to the next and one decade to the next.”

Researchers also found that beluga whales exhibit an impressively broad range of vocal repertoires and acoustic systems which suggests that they form complex interpersonal relationships. They like to hang out in the thousands nearshore during the summer when the ice melts — which researchers call a whale’s version of an “icebreaker.”

Ultimately, researchers hope that this will not only enable us to better understand these surprisingly complex species but also devise better ways to protect them in the face of a changing environment — the polar regions, where the beluga whales live, are extremely vulnerable to climate change.

“Findings from our study are expanding our understanding of how sophisticated non-primate societies can be and how important culture is for the survival of these species,” said O’Corry-Crowe. “Our findings also will influence our thinking in terms of how populations and species are going to adapt to dramatic environmental changes. There are few places where this is more urgent than in the rapidly changing polar regions.”

Journal Reference: Greg O’Corry-Crowe, Robert Suydam, Lori Quakenbush, Brooke Potgieter, Lois Harwood, Dennis Litovka, Tatiana Ferrer, John Citta, Vladimir Burkanov, Kathy Frost, Barbara Mahoney. Migratory culture, population structure and stock identity in North Pacific beluga whales (Delphinapterus leucas). PLOS ONE, 2018; 13 (3): e0194201 DOI: 10.1371/journal.pone.0194201

Bowhead mother and calf.

“Bowhead [whales] are jazz,” says researcher astonished by the diversity of their songs

Bowhead whales may be the unsung heroes of the musical world.

Bowhead mother and calf.

Bowhead mother and calf.
Image credits NOAA.

Audio recordings taken from 2010 through to 2014, off the coast of Greenland, captured 184 distinct songs from a population of around 300 whales. According to a new paper from the University of Washington (UW), they produce some of the most diverse and complex song patterns of any mammal.

Whale blues

“If humpback whale song is like classical music, bowheads are jazz,” says Kate Stafford, an oceanographer at the UW’s Applied Physics Laboratory and lead author of the study.

“The sound is more freeform. And when we looked through four winters of acoustic data, not only were there never any song types repeated between years, but each season had a new set of songs.”

Bowhead whales are one of the less known species of whale out there, especially compared to their cousins, the humpbacks. In part, this comes down to their neighborhood of choice: they are the only baleen whales that spend all year in the Arctic. It’s also a problem of numbers. Bowhead whales grow to more than 18 meters in length, have thick blubbert, don’t swim very fast, and float after death — so they made prime targets for whalers, which nearly drove them extinct in the mid 19th century.

Luckily for us, in 1977 the International Whaling Commission prohibited the hunting of bowhead whales except for subsistence purposes. If it hadn’t, we would have killed off one of the most creative singers in the natural world, new research shows. The study published the largest set of bowhead whale song recordings, showing the surprisingly diverse repertoire these mammals employ. The recordings — captured year-round from 2010 to 2014 east of Greenland — include 184 different songs in a population of roughly 300 whales. Together with a previous study, which reported that the whales sang continuously during the winter breeding season in 2012, the findings point to a recovering, but healthy population of whales.

“Bowhead whales were singing loudly, 24 hours a day, from November until April. And they were singing many, many different songs,” Stafford recounts of the previous study.

Here are a few samples (not from this study):

The new paper extends on the initial, five-month recording period. The team used hydrophones (underwater microphones) to take roughly 1,000 recordings each season and were surprised to hear just how varied the whales’ songs were over time. The only other whales we know that sing elaborate songs, the humpback whales, share a single song throughout all the males in a community. The tune shifts slightly during the winter breeding season, and each population debuts a new tune in the spring.

Types of songs chart.

The total number of hours and months during which each song type was recorded by year. Most song types were only recorded in one month.
Image credits K. M. Stafford, C. Lydersen, Ø. Wiig, K. M. Kovacs / Biology Letters.

“It was thought that bowhead whales did the same thing, based on limited data from springtime,” Stafford said. “But those 2008 recordings were the first hint, and now this data confirms that bowhead whale songs are completely different from the humpbacks’.”

Animal songs differ from calls in their complexity; they are whole musical compositions that have to be learned. While animals such as birds use songs as a means to signal other individuals, or to draw attention upon themselves (very useful in the mating season), whales also do it out of practicality. Marine mammals rely on sound instead of sight to navigate, hunt for food, and communicate in their often-dark environments.

The findings suggest that bowhead whales are similar to birds such as cowbirds and meadowlarks, learning and improvising a diverse repertoire of songs. We don’t know why they do so, although it’s likely the novelty offers some advantage, perhaps in courting. Then again, it’s possible the whales just like to get creative.

“Bowhead whales do this behavior in the winter, during 24-hour darkness of the polar winter, in 95 to 100 percent sea ice cover. So this is not something that’s easy to figure out,” Stafford said. “We would never have known about this without new acoustic monitoring technology.”

The paper “Extreme diversity in the songs of Spitsbergen’s bowhead whales” has been published in the journal Biology Letters.

416 beached whales send New Zealanders into frantic rescue mission

It is a daunting sight. Hundreds of whales, crying, sighing, and some of them already rotting lay stranded on the beach. In one of the worst whale strandings in history, hundreds of farmers, tourists and teenagers were racing to save the whales, but 275 of the pilot whales didn’t even survive until they arrived. It’s one of the most frantic rescue operations we’ve ever seen.

Stranded pilot whales at Farewell Spit, New Zealand today. Image: Deb Price

Magazine editor Cheree Morrison and photographer Jane Ussher raced out to see what was happening, and they report a disaster.

“It was just red and pink skies and just whales as far as you could see,” Morrison said. “It was really haunting.” At that moment, people didn’t really know what was happening and the story was still unfolding. “Your first instinct was to run to them and help in any way possible,” she said, but they were only three people, completely unprepared.

“There’s nothing you can do,” the guide, who notified authorities, told them.

Official government sources claim that 100 whales were refloated, but there is very little good news. New Zealand’s Department of Conservation staged a massive rescue mission, aided by locals, but success rate was not that high.

“Around 416 pilot whales stranded near the base of Farewell Spit overnight, of which 250 to 300 were already dead when the whales were discovered,” the report states. “A refloat of over 100 whales took place on the high tide around 10.30 am Friday morning. The refloat has been partially successful with around 50 whales out swimming in the bay. The remaining 80 to 90 have re-stranded on the beach.”

“The beached whales will be keep comfortable with the help of volunteers until dark.”

It’s not clear what the chances of the remaining whales are, but it doesn’t look too good. Rescuing whales is a very delicate and even dangerous job, as stressed whales can easily injure humans. They can also carry diseases to volunteers are asked to avoid bodily fluids from whales and avoid getting cuts.

In the meantime, darkness has set in New Zealand, and locals were asked to go home for the night and return in the morning… if any living whales are still left.

“There will be no work done overnight as it would become unsafe for people to be close to the whales in the dark. If necessary, a second attempt to refloat the stranded whales will take place tomorrow around noon on the high tide.”

Every year, up to 2,000 animals beach themselves. About 10 cetacean species frequently display mass beachings, with 10 more rarely doing so. Pilot whales are among those more likely to get stranded.

megalodon.

Megalodon extinction paved the way for whale development

Megalodon is quite possibly the most dangerous predator to ever live in the Earth’s waters in the recent geological history – roaming the seas between 28 to 1-3 million years ago. We’re still not sure why it went extinct, but a recent study suggests that its extinction paved the way for whales to grow more and more, reaching the enormous sizes we see today.

Today’s biggest whales. Credit: Smithsonian Institution

The blue whale is the largest creature ever on Earth. At 30 metres (98 ft) in length and 170 tonnes, it is also the heaviest. But it’s not the only huge whale around – the finback can measure over 24 meters (80 feet), while the sperm whale and the right whale can both reach 18 meters (60 feet). But why are whales so big, especially in a geological period where life forms tend to be smaller than what was going around in the Jurassic, for example? Paleontologists believe this has a lot to do with the Megalodon.

The Megalodon was the largest shark to have ever lived, reaching a maximum length of 18 meters (60 feet), and having 18 cm long teeth (7 inches)! It was one of the most powerful and robust predators in vertebrate history, shaping basically entire ecosystems around it. Megalodon had enough adaptability to inhabit a wide range of marine environments (i.e. coastal shallow waters, coastal upwelling, swampy coastal lagoons, sandy littorals and offshore deep water environments), and exhibited a transient lifestyle. Throughout its existence as a species, it faced an incredibly competitive environment, but it was no doubt on top of the food chain for over 20 million years. Juvenile Megalodon preferred habitats where small cetaceans were abundant, and adult Megalodon preferred habitats where large cetaceans were abundant – in other words, the Megalodon’s preferred food was whale.

megalodon.

Megalodon relative size. Image via Wiki Commons.

In a new study published in the journal PLOS One on Oct. 22, researchers looked at the records of 42 of the most recent fossils of the ancient shark and employed a technique known as Optimal Linear Estimation (OLE) to determine when this animal went extinct. What they found was that Megalodon was contemporary to some of today’s whales; they also found that as Megalodon went extinct, whales started to grow more and more, reaching the dimensions we see today.

This makes a lot of sense. A 18 meter long Megalodon could easily eat a bigger whale, even one much larger than it. The size of the whale would have actually made it a more desirable prey, so whales had no reason to grow more and more.

“Our results suggest that C. megalodon went extinct around 2.6 Ma.,” the researchers wrote. “Furthermore, when contrasting our results with known ecological and macro-evolutionary trends in marine mammals, it became evident that the modern composition and function of modern gigantic filter-feeding whales was established after the extinction of C. megalodon.”

The thing is, we still don’t know why the shark went extinct (and this goes for several other top predators), and this research might help us paint a picture of what happened.

“When you remove large sharks, then small sharks are very abundant and they consume more of the invertebrates that we humans eat,” Pimiento said. “Recent estimations show that large-bodied, shallow-water species of sharks are at greatest risk among marine animals, and the overall risk of shark extinction is substantially higher than for most other vertebrates.”

Journal Reference: Catalina Pimiento, Christopher F. Clements. When Did Carcharocles megalodon Become Extinct? A New Analysis of the Fossil Record. DOI: 10.1371/journal.pone.0111086