Demography and Populations

Why can’t Pearly-eyed Thrasher compete on larger islands, or more specifically, in species-rich avian communities? Part of the answer is diffuse competition. To its disadvantage, the pearly-eye is a "jack-of-all-trades, master-of-none" generalist. Within insular habitats, a high density of small, avian specialists makes it impossible for this larger generalist to exist. Interspecific competitive pressures are among the key factors keeping the pearly-eye from gaining a foothold on the large islands of Hispaniola, Cuba, and Jamaica, as well as the continents. On Puerto Rico, a smaller island with fewer frugivorous species, the pearly-eye can compete in species-poor habitats. The pearly-eye’s future depends on its ability to adapt to the ever-changing conditions in natural and anthropogenic environments. It is unlikely that the Pearly-eyed Thrasher will ever expand its range onto the continents, at least in the near future.