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(GIST OF SCIENCE REPORTER) Diving birds are more prone to extinction, says new study

(September-2023)

Diving birds are more prone to extinction, says new study

Diving birds like penguins, puffins and cormorants may be more prone to extinction than non-diving birds, according to a new study by the Milner Centre for Evolution at the University of Bath.
The authors suggest this is because they are highly specialised and therefore less able to adapt to changing environments than other birds.

Key findings:

The ability to dive is quite rare in birds, with less than a third of the 727 species of water birds using this way of hunting for food.
Evolutionary scientists Joshua Tyler and Dr Jane Younger studied the evolution of diving in modern waterbirds to investigate how diving impacted: the physical characteristics of the birds (morphology); how the species evolved to increase diversity (rate of speciation); and how prone the species were to extinction.
The study, published in Proceedings of the Royal Society B, found that diving evolved independently 14 times and that once a group had evolved the ability to dive, subsequent evolution didn’t reverse this trait.
The researchers found that body size amongst the diving birds had evolved differently depending on the type of diving they did.
Wing divers, such as penguins and puffins, use their wings to propel themselves through the water. These birds tend to have larger body sizes adapted for swimming.
Birds that “foot dive”, such as cormorants, kick their feet to swim and are similarly larger in body size to the wing divers.
In contrast, so-called “Plunge divers”, such as gulls and gannets, dive vertically from the air to catch their prey. The researchers found these species tended to be more constrained in their body size, as they were better adapted for flying than swimming.
Whilst the research found no significant difference in speciation rate for diving birds versus non-diving species, they also found that many diving birds appeared to be more prone to extinction than non-diving species.
The techniques used by the researchers could be used to help conservationists predict which species are most at risk of extinction from an evolutionary perspective.