About This Project

Birds of prey, or raptors, are composed of three unrelated lineages of birds which converged on very similar body plans. Characteristic to all raptors are patterns in the shortening of specific bones in the foot which indicate several complex trends. We will decipher the mechanical driving forces that prey type and ecological niche has on foot morphology, tracking predatory behavior through the evolution of birds. This study also has notable implications for raptorial behavior in some dinosaurs.

Ask the Scientists

What is the context of this research?

The birds of prey have historically been an understudied group. Scientists have long noted that raptors (unified by their carnivorous niches) appear to be very similar in form, but they have noted equally as long that the group is polyphyletic (a conglomeration of several unrelated groups, not a true group). Confusion was abound with which groups were true groups and what their closest relatives were, which led most ornithologists to only halfheartedly tackle the convergent evolution of birds of prey. In the last four years, genetic research (Jetz 2012, Prum 2015) has confidently resolved the avian family tree. We can now finally analyze the evolution of raptors and interpret the bio-mechanical, ecological, and dietary stresses which developed the raptorial characteristics we see today.

What is the significance of this project?

Of all of the features which unite raptors, their feet are one of the most telling. Raptors have derived the behavior of manipulating their environment via their feet, not their mouths (as is primitive): understanding the morphology of their feet is vital to understanding functional stresses. We can therefore interpret the biology and diet of fossil raptors and better interpret past ecosystems. We aim to relate this study to dinosaur biomechanics in two future studies. Some Oviraptor feet possess abbreviation which is very similar to the raptorial foot pattern, suggesting a raptor-like footing behavior for capturing prey as suggested by Fowler 2011. Also, the hands of dromaeosaurs (like Velociraptor) show a similar pattern- can the biomechanics of bird feet be applied to dinosaur hands?

What are the goals of the project?

This project will boil down to four topics.

What shortening, or abbreviation, patterns are a prerequisite for all raptors?

What abbreviation patterns are unique to each group of raptor? The three groups evolved independently and might have had their take on abbreviation patterns.

What abbreviation patterns are common to dietary/ecological niches? This is the most promising question. Across clades, raptor foot morphology seem to shift the most with respect to ecological niches: how does fishing vs hunting large mammals vs the aerial catching other birds affect abbreviation via mechanical stresses?

When and in what order did the morphologies we see today originate? We will be using fossilized birds to help form a timeline sequencing the occurrence of abbreviated elements.