Winter bird communities in pine woodland vs. broadleaf forest on Abaco
- Author(s): Franklin, Janet
- Steadman, David W
- et al.
We assessed the relative abundance of winter resident birds (species that breed in North America but spend the winter in The Bahamas) through 115 point counts conducted during December and January 2007–2012 on Abaco, The Bahamas. We also analyzed structure and composition of the woody vegetation in Abaco’s two widespread terrestrial habitats: Pineland, an open woodland of Pinus caribaea var. bahamensis (Bahamas Pine) that covers most of the island; and Coppice, a broadleaf, relatively diverse forest that covers <10% of Abaco. Winter resident birds were more abundant in Pineland (8.61 individuals/point) than in Coppice (2.28 individuals/point). Setophaga palmarum (Palm Warbler) and S. coronata (Yellow-rumped Warbler) dominated the winter bird communities in Pineland (44.6% and 37.4% of all detected individuals, respectively), with the next three most common species (S. discolor [Prairie Warbler], Dumetella carolinensis [Gray Catbird], and Geothlypis trichas [Common Yellowthroat]) ranging from 6.5 to 2.0%. The winter species composition in Coppice was more even than in Pineland, featuring S. ruticilla [American Redstart] (39.8%), Prairie Warbler (16.2%), Gray Catbird (13.1%), and the next five most common species (S. americana [Northern Parula], Seiurus aurocapillus [Ovenbird], S. caerulescens [Black-throated Blue Warbler], Mnio- tilta varia [Black-and-white Warbler], and S. citrina [Hooded Warbler]) ranging from 7.3 to 3.1%. In Pineland, bird community composition varied with overstory cover and height, understory cover and type, and ground cover. In contrast, patterns of bird community composition in Coppice were not associated strongly with variation in habitat structure or forest composition. This may reflect that Coppice, experiencing frequent hurricane disturbance, has considerable small-scale heterogeneity in the availability of food for winter resident birds. Comparing our data with those from previous surveys of winter birds conducted 5–40 years earlier in the northern Bahamas, we see little evidence of major changes in this bird community.