Distribution, diversity, abundance, and richness of Grenadian birds, including endemic and restricted-range species.
Grenada is host to 35 documented species of resident terrestrial passerine birds including the Endangered Grenada Hook-billed Kite, the critically endangered Grenada Dove, the near-endemic Grenada flycatcher, and regional endemic Lesser Antillean Tanager and Lesser Antillean Bullfinch. However, the island lacks detailed studies surveying all land birds, and very little is known about the actual conservation status of restricted-range and some endemic species. The island is currently undergoing rapid developmental changes that may affect the conservation status of Grenada’s birds. This study, therefore, aimed to identify birds or bird habitat in Grenada of conservation concern, to help develop proper management plans for existing protected areas, to help identify habitat types and requirements for similar avian species across the Caribbean, and to collect baseline data for future research in Grenada. As such, we collected data on the main islands (Grenada, Carriacou, and Petite Martinique), and three offshore islands (Ronde, Caille, and Hog Islands). We used the dependent double-observer method of identification to conduct point count bird surveys, employing single observer methods only when research volunteers were unavailable. A total of 488 point-counts were conducted across 54 field sites (8 point-counts per site) across the islands at dusk or dawn. We recorded the habitat types and land-use at each point. Sufficient habitat types and land-use data were obtained to analyze 21 species. We calculated the density, abundance, and richness of each species across the islands and compared them to the main island, Grenada. We also evaluated and compared species richness and habitat use by individual bird species on Grenada in natural and human-modified habitats.
Chris De Ruyck
Moult, life-cycle phenology, and diet of birds living in agroforests on Grenada, Lesser Antilles
We are using bird banding, surveys, and DNA bar-coding to study the life-cycle phenology and diet of bird species living in Grenada's agroforests. We are interested in understanding how the health, moult patterns, and breeding timing of different species varies among habitats to determine the important drivers of adaptation and evolution are for this unique bird community, and identify beneficial land use practices. This information can then contribute towards the development of effective conservation and land-use practices. We are also interested in helping to establish educational resources for children, landowners, and policy-makers to expand our knowledge of natural history and biodiversity conservation issues in Grenada, help improve the perceived value of biodiversity conservation within local agro-forestry and eco-tourism industries, and instill pride in Grenada's unique natural and agricultural heritage.
Morphology of Grenada House Wrens
On islands, songbird morphology tends towards longer legs, shorter wings and bigger bodies when compared to mainland conspecifics. This is linked to low interspecific competition and predation pressures on island ecosystems. House wrens are found all over south, central and north America as well as several Caribbean islands, making them a good species for studying morphology. For my research, we captured House Wrens on Grenada and collected morphological data. We compared their morphology to a database of other House wren subspecies. Preliminary results indicate that they have longer legs, larger bills and longer wings than all mainland subspecies. They are most similar morphologically to House wrens found on St. Vincent.
With this morphological work, plus recent genetic analyses, the Grenada House wren is likely unique enough to be considered it's own subspecies and possibly it's own species.