Blue-footed booby nesting on San Jerónimo Island.
Observation: The first record of a blue-footed booby (Sula nebouxii) nest (a pair of adults with two chicks) in San Jeronimo Island was made (Figures 1 and 2). The blue-footed booby is distributed and nests in lower latitudes, in warmer areas. This represents a new, but also the northernmost, nesting site for this species.
Marine birds expert: Indeed, this is the first record of this kind in the Baja California Pacific Islands. Blue-footed booby sightings are rare in both the Pacific and inland in California, as well as southeast Arizona, as it's commonly distributed in the Gulf of California [1]. This species is native to the Tropical Pacific, with nestings recorded in the Gulf of California islands [2], such as Roca Consag and San Jorge Island, San Pedro Mártir, San Ildefonso and Isabela. It has also been reported in Marietas Islands, Tres Marías and Clarión Island (in the Pacific), as well as other South american islands [3] (Figure 3).
The confirmed nesting of this species in San Jerónimo Island, in front of the Baja California Peninsula coasts, is of great relevance given that it can be inferred that it's related to climate change, being an entirely tropical species and is starting its nesting in warm waters on the Pacific side. It's important to mention that the blue-footed booby does not represent a threat to the ecosystem or to the local communities; it is not an invasive species, nor is it aggressive with native species. It is, however, a species indicative of the health of the ecosystem and its changes.
At present, the Grupo de Ecología y Conservación de Islas A.C. (GECI), is following this topic within their project: Restoration of Seabirds of the Baja California Pacific Islands, which includes monitoring and follow-up activities.
References:
Dunn, J. L. y J. Alderfer. 2011. Field Guide to the Birds of North America. Sixth Edition. National Geographic. 574 pp.
Kaufman, K. 2000. Field Guide to Birds of North America. Hillstar Editions L.C. 391pp.
Velarde-González, M. E. 2008. Ficha técnica de Sula nebouxii. En: Escalante-Pliego, P. (compilador). Fichas sobre las especies de Aves incluidas en el Proyecto de Norma Oficial Mexicana PROY-NOM-ECOL-2000. Parte 2. Instituto de Biología, Universidad Nacional Autónoma de México. Bases de datos SNIB-CONABIO. Proyecto No. W042. México. D. F.