Habitat selection on the wintering grounds and stop-over areas is crucial for migratory bird survival and for a successful migration. Vegetation features can influence resource availability for birds, an important factor affecting habitat selection. In this research we evaluated the use of secondary dry forest by both migratory and resident birds. We surveyed three sites in and outsite Jobos Bay National Estuarine Research Reserve (JBNERR) with distinct degrees of disturbance and successional stages, from mature to novel, from protected to abandoned pasture. The abundance and diversity of avian communities was surveyed in relation to the characteristics of each site, between seasons: wet migratory, dry migratory and non-migratory. For this, fixed-radius point counts and mist netting were used in order to quantify bird presence and fitness (body condition index, BCI). For site characterization, plant identification, relative density, frequency, and dominance were assessed using point-centered quarter methods (PCQM); arthropod sampling was also included, focused on canopy macro-arthropod communities. Special focus was placed on resident Bananaquits (Coereba flaveola), a sedentary nesting resident species (known to roost in their foraging habitat) used to assess body condition and interactions within habitat.
Results/Conclusions
Potential relationships between habitat structure and vegetative composition (or tree dominance) and avian species richness and body condition were evaluated. We discovered there was no significant difference in species richness and abundance between sites, only diminishing during non-migratory season. For several species, site was greatly significant (e.g. Ovenbirds, S. aurocapilla - p value=0.004); in some cases, endemic species (Adelaide’s Warblers, S. adelaide) selected novel sites, not under the protection of the JBNERR. Other relationships between sites and the avian community are being evaluated using ordination analysis (NMS, MRPP).With this information, habitat use can be evaluated so as to establish better conservation plans for migratory and resident birds, bringing additional information for the restoration and conservation of favorable spaces.