Bird communities of contrasting semi-natural habitats of Lac Bay, Bonaire, during the fall migration season, 2011
Species richness is highest in Lac’s mangrove thickets and salt flats. They have a two-fold higher total species richness and a fourfold higher migrant species richness compared to woodland habitats.
The coastal barrens habitats have the lowest number of species.
Composition of bird communities
63 species were recorded. 38% were resident species; 10% had resident populations but also potentially occurred as migrants, 49% were migrants and 3% were migrants that are known to possibly or irregularly breed on Bonaire.
Significant differences were found in the bird communities of the five habitats studied.
- Migrant species are significantly more abundant among the waterbirds (herons, flamingo, waders).
- The highest concentration of migrant birds is in the mangrove thickets and salt flat habitats
- Migratory shorebirds and waders dominate the bird communities of Lac’s salt flat habitat.
- The bird communities of Lac’s woodland habitats are dominated by breeding resident species.
- Migratory passerines are not a major component of Lac’s bird fauna.
Significance of Lac
Lac Bay may be of local significance as a breeding and foraging site to the globally Near-Threatened Reddish Egret, Egretta rufescens.
Lac Bay’s mangroves seem to be of local significance as a nesting and roosting habitat for the Scaly-naped Pigeon, Patagioenas squamosa.
The Yellow-shouldered Amazon no longer uses Lac’s mangrove thickets as a roosting area. Probable causes are decrease in persecution and increase in the quality of the woodlands in many areas of Bonaire.
The Caribbean Coot is not present in Lac’s salt flat habitat. It prefers a number of freshwater locations around the island.
Lac’s number of West Indian flamingo, Phoenicopterus ruber, has grown significantly. This suggests a wider ecological shift taking place within the bay (growth of stagnant backwaters and salt flats behind the mangroves) which threatens Lac’s premier values as a mangrove and seagrass nursery area.
Further observations to document potential egret breeding activity at Lac.