Since 2010, we have been studying the evolution and ecology of the fascinating endemic avifauna of Guadalupe, a volcanic oceanic island off the coast of Baja California, in Mexico. After field expeditions in 2010, 2011 and 2014, we have been able to obtain samples from various species, and have active projects studying the genetics and ecology of three of them: the Island Junco (Junco insularis), the Guadalupe House Finch (Hemorrhous mexicanus amplus), and Guadalupe Anna’s Hummingbird (Calypte anna). All three are portrayed in the photographs below. We are doing this work in collaboration with the NGO Grupo de Ecología y Conservación de Islas (GECI) in Ensenada, México (www.islas.org.mx), working closely with Julio Hernández Montoya, the coordinator of GECI’s Guadalupe Island Project. Several students have been involved in studying Guadalupe’s avifauna. Pau Aleixandre did his master’s project on the junco, which resulted in a publication (see Related Publications below) and very importantly, in the recognition of Junco insularis as a new species by the American Ornithologists’ Union! Jatziri Calderón, from the Universidad Nacional Autónoma de México (UNAM) studied the house finch for her Honors Thesis, focusing on the phenotypic differentiation of this subspecies in terms of plumage color, morphology and song. More recently, Alvar Veiga focused on the genetics of the finch and we now know that it is genetically differentiated from the mainland subspecies. Alba Aparicio and María Rojo (master students from Universidad Complutense de Madrid) are doing their master’s projects on the genetics of Anna’s hummingbird using samples collected by Alvar during his one-month stay on the island in 2014. These species are providing us with valuable insight into the mechanisms of speciation on islands, and how species change their phenotypes and ecologies once they become isolated in an insular environment with limited resources and social dynamics that change patterns of natural and sexual selection. More soon on these active and fruitful projects!
A few images of Guadalupe Island from our expedition in 2010, in collaboration with Ellen Ketterson and Jonathan Atwell, Indiana University, long-term collaborators on our research of the Junco radiation across North America. Other members of that expedition were Marlenne Rodríguez, Steve Burns, and Christie Bergeon Burns (Photos by Borja Milá).
Guadalupe Island is also home to other endemic species, like the cypress Cupressus guadalupensis, or the Guadalupe Sea Lion (Arctophoca philippii townsendi). The island also hosts a colony of Laysan’s Albatross (Phoebastria immutabilis) (Photos by Borja Milá)
Related publications:
Aleixandre, P., J. Hérnandez-Montoya, B. Milá. 2013. Speciation on oceanic islands: rapid adaptive divergence vs. cryptic speciation in a Guadalupe Island songbird (Aves: Junco). PLOS ONE, 8(5): e63242.
Milá, B., P. Aleixandre, S. Alvarez and John McCormack. In press. “More than meets the eye: lineage diversity and evolutionary history of dark-eyed and yellow-eyed juncos.” In Integrative approaches to understanding evolutionary diversity in the avian genus Junco. Ellen D. Ketterson and Jonathan W. Atwell (Editors), Chicago University Press, Chicago.
