Humpback Bubble Feeding And The Importance Of Animal Culture

Humpbacks are high on my list of fascinating animals, in part because of this sort of spectacular and complex behavior, filmed by drone in Alaska’s Prince William Sound:

For the uninitiated, I09 describes what is going on:

Typically, humpback whales lunge into a shoal of prey, but as described in Arkive, they also herd their prey using a “bubble net” to trap them in quantity:

During this process, a number of whales will circle underwater emitting a continuous stream of air which traps fish in the centre of the ring, the whales then surface up through their ‘net’ gorging on the contents within. During the summer months, humpbacks must feed intensely as they do not feed again during either the migration or the time spent in tropical breeding grounds.

The fact that many species have developed unique and distinctive behaviors gives credence to the idea that animals have “cultures,” that both define them and help them survive. Increasingly, conservationists are arguing that understanding and incorporating those cultures into conservation strategies is a key to success. Last month, delegates at the UN Convention on Migratory Species passed a resolution (PDF) that calls on conservationists to acknowledge and incorporate animal cultures into conservation thinking.

This is a key evolution in thinking about the animal world and its future. Philippa Brakes of Whale And Dolphin Conservation explains:

In 1975 sociobiologist E. O. Wilson noted the influence of social structure on fitness, gene flow and spatial patterns in some species. Deeper understanding only started to emerge in the past decade, and wildlife policy has been slow to catch up.

The new resolution recognises both positive and negative consequences of non-human culture. Individuals passing on knowledge may increase population viability by allowing the rapid spread of innovations amid environmental challenges, which could mean more-resilient social groups. On the other hand, the effects of human-induced threats may be amplified by the presence of non-human culture.

How so? The type of threat and the type of society is important. For example, orca societies are often conservative and so may be reluctant to adopt an innovation in response to a new threat, like the depletion of a food source. The distinct cultures of different groups also lead orcas to behave in different ways, and this can make one group more vulnerable than another. So they should be assessed as cultural groups, rather than by absolute population numbers.

In African elephants, older matriarchs are thought to act as “repositories of social knowledge”, holding information important to the survival and fitness of their social group, such as the location of food or water. Their removal may have impacts beyond the loss of one elephant.

There is also evidence that baleen whale calves learn migratory routes from their mothers and that hunting two species – southern right and humpback whales – meant that critical knowledge was lost.

I would add another benefit. Understanding the distinctive cultures of animals opens the door to empathy. A mother elephant or whale who has knowledge and plays the same role that your own mother might is more than just a whale or elephant. She is inherently valuable and her protection is inherently important.

That makes a difference. It shouldn’t, in my view. But unfortunately humans care more when they can see parallels to their own lives and social structures. So the more awed and compelled we are by any cultural behavior, like bubble-feeding, the better.

The Graphic Reality Of Extinction

The journal Nature sums up the threat of the Sixth Great Extinction in one mindblowing graphic (click here, or on graphic for zoomable  version):

Here’s the data and thinking that are behind the graphic:

Studies that try to tally the number of species of animals, plants and fungi alive right now produce estimates that swing from less than 2 million to more than 50 million. The problem is that researchers have so far sampled only a sliver of Earth’s biodiversity, and most of the unknown groups inhabit small regions of the world, often in habitats that are rapidly being destroyed.

The International Union for Conservation of Nature (IUCN) highlighted the uncertainty in the latest version of its Red List of Threatened Species, which was released in November. The report evaluated more than 76,000 species, a big increase over earlier editions. But that is just 4% of the more than 1.7 million species that have been described by scientists, making it impossible to offer any reliable threat level for groups that have not been adequately assessed, such as fish, reptiles and insects.

Recognizing these caveats, Nature pulled together the most reliable available data to provide a graphic status report of life on Earth (see ‘Life under threat’). Among the groups that can be assessed, amphibians stand out as the most imperilled: 41% face the threat of extinction, in part because of devastating epidemics caused by chytrid fungi. Large fractions of mammals and birds face significant threats because of habitat loss and degradation, as well as activities such as hunting.

Looking forward, the picture gets less certain. The effects of climate change, which are hard to forecast in terms of pace and pattern, will probably accelerate extinctions in as-yet unknown ways. One simple way to project into the future would be to assume that the rate of extinction will be constant; it is currently estimated to range from 0.01% to 0.7% of all existing species a year. “There is a huge uncertainty in projecting future extinction rates,” says Henrique Pereira, an ecologist at the German Centre for Integrative Biodiversity Research in Leipzig.

At the upper rate, thousands of species are disappearing each year. If that trend continues, it could lead to a mass extinction — defined as a loss of 75% of species — over the next few centuries.

I find it hard to believe that this is not screaming headline news every day. The media, like the public, simply doesn’t know what to do with the catastrophic implications of climate change and human impact on the planet. That is not good.

(H/T The Dodo–very appropriate, no?)