Raptor communities in French Guiana: Distribution, habitat selection, and conservation

French Guiana still has a full gradient of natural habitats, from coastal mangroves, marshes, and savannas (ca. 3700 km(2)), to swamp and terra fume lowland primary rain forest (ca. 80 000 km2). Thirty-two study sites, >2000 ha each, were surveyed throughout the country, including all major vegetation types from 1981 to 2003 during >5472 hr of effective daylight raptor searches. Census techniques took into account the behavior and detectability of every species to assess their abundance and habitat associations. The French Guiana raptor community included 27 forest species, five species restricted to forest edges and large gaps, five species of wetlands and mangroves, eight coastal grassland specialists, four nearctic migrants, and seven occasional taxa of unconfirmed status. In the 19 undisturbed primary forest sites, the most common raptor was the Lined Forest-Falcon (Micrastur gilvicollis). Many species were rare or patchily distributed: 15% of all species were found in only 5-11% of the 32 localities sampled and <30% were present in almost all of them. The abundance index was correlated with site occupancy frequency. There was no significant difference in species richness among parts of the country. Some taxa widespread in Latin America (Cathartes, Accipiter, Micrastur) were comparatively rare and local in French Guiana, where more typical Amazonian species were present. Mean abundance of forest vultures, eagles, and caracaras decreased with hunting and logging activities. Country-wide population estimates of forest species ranged from fewer than 100 pairs for habitat specialists such as Orange-breasted Falcon (Falco deiroleucus) and Black Caracara (Daptrius aler) and 400-500 pairs for the largest and widespread Harpy (Harpia harpyja) and Crested (Morphnus guianensis) eagles, to >10 000 pairs for the common Lined Forest-Falcon.