Studying New Hawk Communities Through Genetics and Collections 

Ornithologists carefully and strategically collect samples for the Academy’s collections from all over the world; work that often involves support from conservation organizations and even local community members. Every part of the specimen, big or small, will help tell the story of the bird’s species — its place in the family tree, their particular eating habits and hosted parasites, the health and ecology of their habitat and even changes in the region’s biodiversity over time. 

We reached out to Therese Catanach, PhD, a postdoctoral researcher in Ornithology who primarily studies hawks and their parasitic lice, but also analyzes genetic data for other researchers studying birds, insects and viruses, to learn more about the importance of the collection for genetics and discoveries, especially for hawks. 

 Tell us about your work with birds of prey. 

I have spent most of my life in close proximity to birds of prey. In high school, I volunteered at a raptor rehabilitation center near Dallas, TX, and during my undergrad I worked for the Peregrine Fund’s Aplomado Falcon restoration project for three summers. I have also been a falconer in Texas for about 15 years. Between these opportunities, I have spent tens of thousands of hours observing birds of prey. 

I’ve also learned what types of traps are best to use in which situation. Once a bird is trapped, I will use a falconry hood to cover their eyes (which reduces stress) and then collect my samples. If the bird is to be released as soon as we have finished processing it, we take the hood off and let it fly off.  

Birds of prey are heavily regulated by laws and treaties around the world so all of our work requires specific permits to collect our samples. Locally, many of our samples come from birds that are found dead by members of the public or turned into rehabbers. We also work with other museums around the world and conservation groups such as the Peregrine Fund to get samples for our analysis. In some instances, we will directly collect birds of prey in the wild. 

What is so special about hawks? 

They are extremely charismatic and virtually everyone has a story about a diurnal bird of prey.  However, we know surprisingly little about how they are related to each other. Many populations live in extremely isolated areas and are known from only a few individuals, and so are likely of conservation concern.   

Our ability to conserve them is hampered because historically these populations have been treated as members of widespread species and so given limited protection. However, genetic work we have done at the Academy has often shown that these populations are actually species that require population management. 

Through this genetic work, we also found that the louse relationships loosely mirror the hawk relationships. This was really interesting because at first glance they did not mirror each other at all, but it turns out it was the hawk relationships, not the louse ones, that were initially wrong. 

How does this data collection help us better understand these birds of prey?  

Once we know how the hawks are really related, we can ask a bunch of different questions. One group of hawks, for example, the genus Accipiter, is made up of almost 50 species. Virtually anywhere you go in the world you will find multiple species of Accipiter that are all different sizes living in the same area.  

Using samples we have collected, I am trying to determine how these species came to be — did a single species of Accipiter arrive in the location and then diversify into several species (so all the Accipiter in the place are closely related), or, over extended periods of time did multiple species colonize the area (so the Accipiters are distantly related).  

These patterns help us to learn how communities are assembled, and our study is one of the first to attempt this work on a globally distributed group of animals.   

I also hope to determine how many species are actually in the genus of Accipiter. Based on some preliminary sequencing work and genetic mapping, we expect there are many instances where single species that are thought to have extremely large ranges (occuring across several continents or islands) are actually multiple different species. And, in order to identify whether certain hawk species are of conservation concern, we must first know what exactly the species are!