Learning on the fly: Studying migratory swallows in Chile
Translated from the original text written by Red de Observadores de Aves y Vida Silvestre de Chile (ROC)
We rarely think twice when we see a swallow flying through the sky, but these aerial acrobats are key members of our ecosystems. They rely mainly on insects that they catch mid-flight for food, so the abundance of swallow populations are a good reflection of the health of an ecosystem. Worryingly, over the last fifty years, populations of aerial insectivores that breed in North America have decreased by ~ 32% (Rosenberg et al. 2019). Current evidence suggests that there are multiple factors during their life cycle, both in breeding and wintering areas, that have influenced this decline. Among them are the decrease in the quantity and quality of their prey, linked to the use of pesticides, climate change and the loss of habitat (Spiller and Dettmers, 2019).
One of the important information gaps that persists is what happens during the non-reproductive period when swallows migrate to Latin America. To help us gain a better understanding of the patterns and behaviors related to this migration, The GAAP, together with Red de Observadores de Aves y Vida Silvestre de Chile (ROC), is collaborating on an international project, led by Environment and Climate Change Canada, which seeks to improve our knowledge about the distribution of these swallows in the non-reproductive season and the association they have with different habitats in Latin America.
Barn swallow in Ecuador, photo by Luis Calapi
During the summer of 2020/2021, Chilean observers, all along the length of this long and skinny country, carried out censuses registering the Barn Swallows (Hirundo rustica), Cliff Swallows (Petrochelidon pyrrhonota) and Bank Swallow (Riparia riparia) in a gradient of the ecoregions of the country. We completed 15 transects (the vast majority with 3 replicas) in 5 ecoregions (Atacama Desert, Chilean Matorral, Southern Andean Steppe, Valdivian Forest and Patagonian Steppe). In total, 484 individuals were registered (all Barn Swallows). Of these, 99 were recorded in the Atacama Desert, 344 in the Chilean Matorral and 41 in the Patagonian Steppe. Similar efforts were carried out by groups in Argentina, Uruguay, Paraguay, Colombia, and Ecuador. These data will be used in studies to learn about swallow occupancy and habitat use.
This international collaboration unites the efforts of many passionate bird researchers throughout the Americas to contribute to the knowledge that can help the conservation of swallows. But it also underscores, for those of us in Chile, how little we know about the populations of our resident swallows. What are the important characteristics and behaviors of our resident species of swallows, such as the Chilean swallow (Tachycineta leucopyga), blue-and-white swallow (Notiochelidon cyanoleuca) and the Andean swallow (Haplochelidon andecola)? The changes in ecosystems that have resulted in the decline of populations of aerial insectivores in North America are also present in Chile and throughout Latin America and it is urgent to study the status of resident swallow populations as indicators of ecosystem health. This research effort is just one of many needed to tackle this pending challenge for Chilean ornithology
Cliff swallow, photo by Dorian Anderson, Macaulay Library, June 2, 2017
Finally, we would like to warmly thank the census takers who collaborated in this project in Chile: Ronny Peredo, Marcelo Olivares, Nelson Contardo, Laura Portugal, Heraldo Norambuena, Ricardo Matus, and Erik Sandvig, as well as ROC’s Executive Director Ivo Tejada. A special thanks to the driver of this effort, Kevin Kardynal, of ECCC, for allowing The GAAP to oversee the completion of this international project. We are grateful for his investment in this project and the funding from ECCC that made this research possible. Stay tuned to our social media to learn more about the results of this collaborative project!
Sources:
Rosenberg, K. V., Dokter, A. M., Blancher, P. J., Sauer, J. R., Smith, A. C., Smith, P. A., … & Marra, P. P. (2019). Decline of the North American avifauna. Science, 366(6461), 120-124.
Spiller, K. J., & Dettmers, R. (2019). Evidence for multiple drivers of aerial insectivore declines in North America. The Condor, 121(2), duz010.