Avian Adaptation

Study of 8,600 species reveals how 5 crafty birds turn adversity into an advantage

As humans push into the natural world, these five avian innovators are not just surviving the pressure. They are thriving.

Wael Zahran / EyeEm/EyeEm/Getty Images

Forget the early bird. In an increasingly human-dominated natural environment, it’s the crafty bird who wins big.

Birds that devise creative ways to adapt to their surroundings are more likely to have a stable or even increasing population, compared to less flexible birds. That's the upshot of a huge new study of 8,600 bird species from around the world. The findings reveal how innovation and adaptability add up to resilience against pressure stemming from human incursions into their natural habitats.

Researchers compared thousands of birds abilities to innovate against each species’ risk of going extinct. They discovered that those species that could find new sources of food, develop new feeding strategies, or even switch up their flying techniques were rewarded for their innovation with higher populations or lower chances of extinction.

These strategies are all examples of "behavioral plasticity" — which means the ability to change behavior based on external forces.

Five species in particular stand out from the results:

  • Great egrets:

These majestic birds are known as pescatarians, but given the opportunity, they will also prey on other birds, namely common sparrows, according to the research.

Great egrets may pose a threat to more than fish, according to the new study.Wong Yung Pang / EyeEm/EyeEm/Getty Images
  • Carrion crows:

These clever corvids were observed engaging in a novel feeding strategy by researchers — kleptoparasiting. This means becoming a parasitic species via the act of theft. In this case, the victims of the robbery were common starlings, which had been observed feeding in a waste dump in Spain.

  • Himalayan griffons:

Like the carrion crows, Himalayan griffons are also known carrion-eaters. But in the absence of their preferred rotten carcass meal, they will turn omnivore and eat pine needles, according to observations made in India.

  • Yellow-rumped warblers:

During a cold spell in Canada's Saskatchewan region, these bright-bottomed birds were observed picking off dormant flies hiding out in a heated building at a dairy farm.

Yellow-rumped warblers are using human habitats to help themselves to their prey, the new study suggests.Linda Krueger / 500px/500Px Plus/Getty Images
  • Great cormorants:

These sassy sea birds were observed at a wharf in New Zealand capitalizing on commercial ferries in a curious way. Rather than avoid the boat traffic, the birds timed their fishing trips with the boats setting off, “using the strong currents generated by the propellers to catch confused fish,” the authors write.

Differences in birds’ rates of innovation vary across species, with the changes reflected in extinction risk and population trends. Points represent mean innovation rate and bars show the corresponding 95% confidence interval, for vulnerable (VU), endangered (EN), and critically endangered (CR) species.Ducatez et. al.

The findings were published Monday in the journal Nature Ecology & Evolution.

Other research shows that being intelligent gives birds a major advantage when it comes to navigating areas where humans run rampant, like cities.

Being able to learn and adapt is just one of two key strategies that help birds manage life alongside us, according to a study published in March in the journal Frontiers in Ecology and Evolution. The second strategy, employed by pigeons everywhere, is having lots of babies.

Good news?The findings offer some hope for birds species' survival amid a slew of studies that suggest these creatures are particularly vulnerable to anthropogenic pressure and other environmental stresses.

Humans moving into wildlife habitats changes animals’ behavior and exposes local animals to invasive species. As a result, globally, about 13 percent of all bird species are under threat.

In North America alone, 3 million birds — one in four birds — have disappeared over the past fifty years, according to research published in September 2019.

The lead author of that study, Ken Rosenberg, a conservation scientist at the Cornell Lab of Ornithology, told Inverse at the time that the fate of birds is important because birds indicate the overall health of an ecosystem.

“By studying birds, we can understand how the natural world has changed over time, and is continuing to change,” Rosenberg said.

Declining bird populations point to more widespread biodiversity loss.

“Habitat loss, climate change, unregulated harvest, and other forms of human-caused mortality have contributed to a thousand-fold increase in global extinctions,” wrote Rosenberg and their colleagues in the paper.

Humans invading natural spaces can have “profound effects on ecosystem functioning and services,” the researchers write.

The new research suggests that the animals which can best adapt to these widespread changes are the most likely to survive in the long run.

Animals that adaptThere's evidence from around the animal kingdom that other creatures besides birds are innovating to stay alive, too.

Fish and reptiles also adapt their behavior based on humans, and new predators.

An image from the paper shows examples of dolphins, juncos, anoles that are adapting successfully. Simon Ducatez, Samuel Bressler, Oriol Lapiedra

For example, in Shark Bay, Western Australia, bottlenose dolphins use sponges as foraging tools, making them more likely to survive after heatwaves than non-tool users.

In San Diego, California, dark-eyed juncos have shifted to off-ground nesting, helping them navigate the urban environment.

In the Bahaman Islands, brown anole lizards with local predators spend less time exploring on the ground than those on islands without predators.

As humans push deeper into once-untouched areas, animals coming up with their own creative solutions may be a key method of preserving the future of the planet’s biodiversity.

Abstract: Behavioural plasticity is believed to reduce species vulnerability to extinction, yet global evidence supporting this hypothesis is lacking. We address this gap by quantifying the extent to which birds are observed behaving in novel ways to obtain food in the wild; based on a unique dataset of >3,800 novel behaviours, we show that species with a higher propensity to innovate are at a lower risk of global extinction and are more likely to have increasing or stable populations than less innovative birds. These results mainly reflect a higher tolerance of innovative species to habitat destruction, the main threat for birds.
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