Area Requirements for the Conservation of Rain Forest Raptors and Game Birds in French Guiana

Abstrack: The distribution and density of diurnal raptors and large game birds were studied in the vast unbroken rain forest of French Guiana to bring some concrete data to the design of a national park Mainly by mapping the movements of raptors displaying over the canopy and estimating densities on understory strip transects, I tried to assess the species composition of I 1 2,500–ha plots of primary forest then to determine the actual population of a 10,000–ha area including all the major forest habitats Among 27 primary forest raptors 7 were recorded in all plots and 4 in only I or 2 plots. There was a near doubling of species with a tenfold increase in area but no 10,000–ha area and few 100,000–ha quadrats would include the full regional set of forest raptors A 10,000–ha plot included less than 100 pairs of diurnal raptors and only 23 species, 21 of which were represented by a mere I to 8 pairs. The three rarest species (harpy eagle, black caracara and orange‐breasted falcon) have extremely low densities and patchy distributions (on average 1 pair for 10,000 to 300,000‐ha), but narrow habitat selection or specialized diet are not the sole correlates of rarity. The dispute o w the best conservation strategy cannot be settled without a knowledge of the species' ecology that is currently lacking. Local patchiness and low dispersal ability usually argue for single large reserves, whereas some widely scattered species may be better protected in a network of smaller reserves According to the results and the (still unsupported) minimum size estimates of a viable population, the smallest Guianan rain forest reserve including a complete bird community should be somewhere between I and 10 million hectares Moreover, the large game birds were found to be high sensitive to hunting pressure even when it occurs around the protected area. Their seasonal movements make them especially vulnerable.