January 22, 2019,
A study, led by the University of Bristol, has shed some new light on how the beaks of birds have adapted over time.
The observation that Galapagos finch species possessed different beak shapes to obtain different foods was central to the theory of evolution by natural selection, and it has been assumed that this form-function relationship holds true across all species of bird.
However, a new study published in the journal Evolution suggests the beaks of are not as adapted to the food types they feed on as it is generally believed.
An international team of scientists from the United Kingdom, Spain and the US used computational and mathematical techniques to better understand the connection between beak shapes and functions in living birds.
By measuring beak shape in a wide range of modern bird species from museum collections and looking at information about how the beak is used by different species to eat different foods, the team were able to assess the link between beak shape and feeding behaviour.
Professor Emily Rayfield, from the University of Bristol's School of Earth Sciences, and senior author of the study, said: "This is, to our knowledge, the first approach to test a long-standing principle in biology: that the beak shape and function of birds is tightly linked to their feeding ecologies."
Guillermo Navalón, lead author of the study and a final year Ph.D. student at Bristol's School of Earth Sciences, added: "The connection between beak shapes and feeding ecology in birds was much weaker and more complex than we expected and that while there is definitely a relationship there, many species with similarly shaped beaks forage in entirely different ways and on entirely different kinds of food.
"This is something that has been shown in other animal groups, but in birds this relationship was always assumed to be stronger."