For thousands of years migratory birds have made annual journeys from their breeding to wintering grounds, following the seasonal availability of resources. While topographic features like mountain ranges and oceans shape migration routes and destinations, geopolitical boundaries like countries are of little consequence to birds. This inherent international nature of long-distance migratory birds means that studying them takes large-scale international collaboration and cooperation.
American Kestrels are widespread across the Americas, breeding in much of Canada and the U.S. and wintering in the U.S, Mexico, and Central America. Fortunately, because of this widespread distribution and charismatic and conspicuous nature, many professional and citizen scientists are studying them across their range. This large network has allowed groups like ourselves and the American Kestrel Partnership to examine large-scale patterns and variation.
Over the past two years, the Full Cycle Phenology project has had the incredible opportunity to conduct kestrel field research with amazing collaborators in Canada, the United States, and most recently, Mexico, making our work feel truly international.
We had such a phenomenal experience in Mexico this past winter, that we wanted to share some highlights here. Our mission was to capture kestrels wintering in Mexico to attach identifying bands, take genetic (feathers) and isotopic (claw clips) samples, take measurements, and potentially attach gps transmitters. Through this combination of methods we hope to understand more about the breeding origin and migratory status of these birds.
We began our work in the state of Veracruz, where lush tropical forests, beaches and wetlands along the Gulf coast were interspersed with colorful rural mountain towns and sugar cane crops on the verge of harvest. While on our previous travels, we were used to seeing kestrels conspicuously perched on power lines along open fields, here they were tough to spot through the dense vegetation, not to mention the lack of power lines in many areas! Despite these challenges, we were able to capture 8 kestrels in Veracruz.
Crossing over the Sierra Madre mountains into the state of Puebla, the landscape and climate changed dramatically, from lush greenery to dry, arid desert. The wide open fields, and availability of power lines, made it much easier to spot birds. Now our main challenge was battling the stifling dry heat, and trying to keep our low-clearance minivan from disaster on the rough dirt roads with no shoulders. We captured another 8 kestrels on the west side of the mountains, including one in view of an active volcano! (Popocatépetl)
In addition to kestrels, Veracruz and Puebla were rife with stunning wildlife! We saw three other falcon species: Bat falcons, Laughing falcons, and Aplomado falcons, as well as numerous other bird species!
As is always evident on these trips, American Kestrels are potentially a highly adaptable species, found in many geographic and climatic regions, with a variety of migratory strategies. Understanding whether genetic traits/plasticity, and climate are influencing shifts in phenology will be important in predicting effects of global change on this species, and others.
Although the birds were our main focus, it was just as important that we got to spend time working with and learning from researchers in another country. We got to exchange knowledge about how ornithological research and conservation works in our respective countries, practice common banding and field terminology in both english and spanish, and plan future collaboration. This tri-national team: myself (a Canadian biologist working for Boise State University), Jesse Watson (an American biologist working for Hawkwatch International), and Kashmir Wolf and Dayan Espinosa (Mexican biologists working for Pronatura Veracruz) truly exemplified the relationships between people and organizations across borders that are vital to conducting research on migratory species and global change ecology.
¡Muchas gracias a nuestros maravillosos anfitriones Kashmir y Dayan por esta experiencia única en la vida!
Post by Anjolene Hunt
Full Cycle Phenology 