Tag Archives: Cetaceans

Scientists around the world call on governments to protect cetaceans or risk seeing them go extinct

Scientists and conservationists from 40 countries have signed an open letter calling for global action to protect cetaceans (whales, dolphins, and porpoises) from extinction. Half of all species are of conservation concern, with two on the edge of extinction according to the researchers, who called for urgent action.

Credit Flickr Isaac Kohane

“Let this be a historic moment when realizing that whales are in danger sparks a powerful wave of action from everyone: regulators, scientists, politicians and the public to save our oceans,” Mark Simmonds, a visiting research fellow at the University of Bristol who coordinated the letter, told the BBC.

Of the 90 living species of cetaceans, more than half now have a concerning conservation status according to the International Union for Conservation of Nature (IUCN). Thirteen species listed as “Critically Endangered” or “Endangered,”, seven as “Vulnerable” and seven as “Near Threatened,” whilst 24 species are “Data Deficient”. Additionally, there are 32 subspecies and other distinct cetacean populations that are presently either Endangered or Critically Endangered. With ongoing research, scientists are recognizing more populations of cetaceans that are discrete and require conservation action, the letter reads.

Environmentalists came up with the “save the whales” slogan in the 1970s, which spread around the world and created a movement to end commercial whaling. Although disturbed populations in most parts of the world have had a chance to recover from organized hunting, they are now facing myriad threats from human actions.

Cetacean populations are adversely affected by many interacting factors, including chemical and noise pollution, loss of habitat and prey, climate change, and ship-strikes. For many, foremost among these threats is fishing. An estimated 300,000 cetaceans are killed because of fishing every year.

This has raised the alarm among scientists, who argued we are moving closer to a number of preventable extinctions. And unless we take action now, future generations won’t experience a large number of these creatures. They recalled the decline of the North Atlantic right whale and the vaquita, a porpoise species with only 10 surviving individuals. And these will be followed by the inevitable decline of the baiji or Chinese river dolphin.

The baiji was identified as ‘Possibly Extinct’ by the IUCN in 2017 and, regrettably, there is little hope for this species, the scientists argued. In all cases, enough was known over the decline but there was a lack of political action.

Speaking with the BBC, Susan Lieberman of the Wildlife Conservation Society said she signed the letter to help scientists raise these issues more widely. “It is critical that governments develop, fund, and implement additional needed actions to better protect and save these iconic species – so they don’t end going the way of the baiji,” she said.

The scientists called on countries with cetaceans in their waters to take precautionary action to ensure these species and populations are adequately protected from human activities. This includes implementing appropriate and fully resourced monitoring. Improved technologies now offer new opportunities to observe and address problematic activities at sea.

At the same time, they asked all nations to work with and strengthen the relevant international bodies that seek to address threats to cetaceans. This mainly refers to the International Whaling Commission and the Convention for the Conservation of Migratory Species of Wild Animals. Both are generating important conservation initiatives, they argued.

“Whales, dolphins and porpoises are seen and enjoyed all over the world, and are valued as sentient, intelligent, social and inspiring species; we should not deny future generations the opportunity to experience them. They are also sentinels of the health of our seas, oceans and, in some cases, major river systems,” the letter concludes.

Whale toy.

Big-brained cetaceans have “marine-based cultures” similar to those of humans, study reveals

A new study links the size of whale and dolphin brains to the complexity of the species’ cultural and social behavior. The research could help us better understand the interplay between our own brains and social development.

Whale toy.

Image via Pixabay.

Whales and their smaller relatives, dolphins, have vibrant social lives. They form closely-knit social groups based on complex personal relationships and language that seems to include regional dialects (both dolphins and whales). Obviously, a certain degree of cerebral finesse would help to successfully maintain and navigate such communities, so a team led by Dr Keran Fox, a postdoc research fellow at Stanford University’s Department of Neurology and Neurological Sciences, set out to see how brain size relates to social complexity in different cetacean species.

The research team included scientists from the University of Manchester, the University of British Columbia, Canada, the London School of Economics and Political Science (LSE) and Stanford University, United States.

Bigger, better, brains

The paper presents the first large databank of cetacean brain sizes and social behaviors. The team compiled information on 90 different species of dolphins, whales, and porpoises, and overall found ample evidence that cetaceans exhibit complex social and cooperative behaviors similar to those seen in human culture and other primates. The list included traits such as:

  • complex alliance relationships – working together for mutual benefit
  • social transfer of hunting techniques – teaching how to hunt and using tools
  • cooperative hunting
  • complex vocalizations, including regional group dialects – ‘talking’ to each other
  • vocal mimicry and ‘signature whistles’ unique to individuals – using ‘name’ recognition
  • interspecific cooperation with humans and other species – working with different species
  • alloparenting – looking after youngsters that aren’t their own
  • social play

Furthermore, it establishes a strong link between these characteristics, brain size, and encephalization (an increase in the relative complexity of the brain). Their next step was to test the social brain hypotheses (SBH) and cultural brain hypothesis (CBH), two evolutionary theories that try to explain why some land species have developed unusually large brains, against the dataset. In broad lines, both hypotheses argue that certain species selected for bigger brains to navigate information-rich environments — such as living in a group and cooperation.

Dr Fox explains that although behavior exhibited by cetaceans is similar to that of certain land species, their brains are wired differently. This has led some researchers to believe they aren’t capable of higher cognitive processes, including social behavior. This was the first time either hypothesis had been tested against such a large database on marine mammals.

“I think our research shows that this is clearly not the case,” Dr Fox says.

The apparent co-evolution of cetaceans’ brains, their social structure, and cooperation behaviors represents a “striking parallel” to the hyper-social nature of humans and other primates on land, Shultz explains. This doesn’t mean we’re on the cusp of seeing a cetacean civilization brewing in the oceans “because they didn’t evolve opposable thumbs,” she adds.

“As humans, our ability to socially interact and cultivate relationships has allowed us to colonise almost every ecosystem and environment on the planet,” says Dr Susanne Shultz, an evolutionary biologist in Manchester’s School of Earth and Environmental Sciences and coresponding author of the paper. “We know whales and dolphins also have exceptionally large and anatomically sophisticated brains and, therefore, have created a similar marine based culture.”

“A new question emerges,” Dr Fox concludes. “How can very diverse patterns of brain structure in very different species nonetheless give rise to highly similar cognitive and social behaviours?”

The research gives us a more accurate image of the intelligence levels of whales and dolphins, but it also helps further our understanding of ourselves. In order to create a more general theory of why humans behave the way they do, we need to understand what sets us apart from other animals, says Dr Michael Muthukrishna, paper co-author and Assistant Professor of Economic Psychology at LSE.

“And to do this, we need a control group. Compared to primates, cetaceans are a more “alien” control group,” he concluded.

The full paper “The social and cultural roots of whale and dolphin brains” has been published in the journal Nature Ecology & Evolution.