El Grupo Cerúleo: Collaboration to assess nonbreeding range of Cerulean Warbler in South America
Cerulean Warbler (Dendroica cerulea. Parulidae) has been listed as a vulnerable species by the International Union for the Conservation of Nature because of recent population declines. An international, proactive approach to Cerulean Warbler conservation, the Cerulean Warbler Technical Group, was founded in 2001. One of its subcommittees, El Grupo Cerúleo, addresses nonbreeding season issues to promote the protection of this bird through habitat conservation, field research on Cerulean Warbler winter ecology, public awareness, and the development of a predictive model to allow for assessment and monitoring of Cerulean Warbler. Most of the recent efforts of this group have been devoted to studying and understanding the spatial distribution of the Cerulean Warbler in South America through predictive models as a highly necessary strategy to elucidating the bird's occurrence, and thereby to identify and locate important nonbreeding habitats and areas of concentration in the Neotropics. To address this issue, members of EI Grupo Cerúleo developed five hypothetical models of potential distribution of the bird in the northern Andes based on existing historical records and surveys conducted by EI Grupo members. In order to validate the model output, we selected locations to verify the occurrence of the species, based on a stratified-random design, using locations where the Cerulean Warbler was predicted to occur by all five models. We elaborated field protocols to survey these locations. Resulting data will be structured for analysis using the techniques of occupancy modeling. Basic survey designs to carry out the fieldwork as well as preliminary results of the first year's fieldwork are presented. Accepted 5 December 2007.