In new research, ornithologists from the Field Museum and elsewhere analyzed the whole genomes of 30 diverse kingfisher species to identify the genomic signatures associated with convergent feeding behaviors and the ability to dive without sustaining brain damage.
“The type of diving that kingfishers do — what we call ‘plunge-diving’ — is an aeronautic feat,” said Dr. Chad Eliason, a researcher at the Field Museum.
“It’s a high-speed dive from air to water, and it’s done by very few bird species. But it’s a behavior that’s potentially risky.”
“For kingfishers to dive headfirst the way they do, they must have evolved other traits to keep them from hurting their brains,” added Dr. Shannon Hackett, associate curator of birds at the Field Museum.
Not all kingfishers actually fish. Many species of these birds eat land-dwelling prey like insects, lizards, and even other kingfishers.
Previously, the authors found that the groups of kingfishers that eat fish aren’t each others’ closest relatives within the kingfisher family tree.
That means that kingfishers evolved their fishy diets — and the diving abilities to procure them — a number of separate times, rather than all evolving from one common fish-eating ancestor.
“The fact that there are so many transitions to diving is what makes this group both fascinating and powerful, from a scientific research perspective,” Dr. Hackett said.
“If a trait evolves a multitude of different times independently, that means you have power to find an overarching explanation for why that is.”
In the study, the researchers examined the DNA of 30 species of kingfishers, both fish-eating and not.
They found that the fish-eating birds had several modified genes associated with diet and brain structure.
For instance, they found mutations in the birds’ AGT gene, which has been associated with dietary flexibility in other species, and the MAPT gene, which codes for tau proteins that relate to…
Read the full article here