Occupancy Rates and Migratory Connectivity of Cerulean Warbler

 

Status – in progress since 2016

Overview

The Cerulean Warbler is a rapidly declining Nearctic-Neotropical migratory bird that breeds in North America and migrates to South America during its non-breeding period. In South America the species winters in the tropical Andes of Venezuela, Colombia, Ecuador and Peru across a variety of habitats including pre-montane forests and shaded agroforestry systems. The tropical Andes have experienced and continue to experience high rates of deforestation, having lost up to 90% of their original vegetation cover. In Colombia, for example, 69% of Andean forests were converted to grazing and agricultural land by 1998. In addition, agroforestry systems such as shade coffee plantations, a habitat widely used by Cerulean Warblers, have been rapidly disappearing with more than 60% of shade coffee being converted to sun coffee by 1990 in Colombia alone. Given the widespread transformation of known Cerulean Warbler wintering habitats, the loss of winter habitat has been cited as one of the potential drivers of declines in this species.

Recent and historic records of Cerulean Warblers projected on a map of priority areas for three migratory warblers in Colombia.

Despite the importance of Andean habitats to Cerulean Warblers, few studies have attempted to determine how abundance or habitat quality varies across habitats and elevations or how populations from different Andean regions are connected to North American breeding populations. Both these questions are key to defining conservation priorities that directly address the needs of this flagship species.

In this collaborative project SELVA will work alongside Gabriel Colorado (U. Nacional de Colombia), Arkansas State University, University of Tennessee, Indiana University of Pennsylvania and the American Bird Conservancy to determine how occupancy rates vary between habitats and elevations in Colombia and to tag between Cerulean Warblers with geolocators to determine connectivity.

Key Findings and Achievements

  • Santa María, Boyacá, was selected as one of the study sites in Colombia, due to the high abundance of Ceruleans in the region
  • In February 2017 SELVA completed 160 transects for Cerulean Warblers in and around Santa Maria.
  • More birds were recorded in shade cacao plantations, followed by forest, with fewest in forest remnants in a matrix of cattle pastures.
  • During 12 days of captures with canopy nets in Santa María in 2017, 13 male Cerulean Warblers were captured and fitted with geolocators.

Double-paneled canopy net (left) and a Cerulean Warbler fitted with a geolocator 

Documents for download / Publications

None to date.

Donors

American Bird Conservancy https://abcbirds.org/
Contact: Wendy Willis wwillis@abcbirds.org
Geolocators: US Fish and Wildlife Service

Project Team

Project directors in Colombia – Nicholas Bayly and Gabriel Colorado
Researchers SELVA – Yuly Caicedo, Angela Caguazango

Alliances

This project is only possible through collaborations with the following institutions and researchers: AES Chivor (access to forest reserve in Santa María), Gabriel Colorado (U. Nacional de Colombia), Than Boves (Arkansas State University), David  Buehler & Doug Raybuck (University of Tennessee) and Jeff Larkin (Indiana University of Pennsylvania).

The Andean foothills of Boyacá – an important region for Cerulean Warblers