A New Species of Warbler (Parulidae) from Puerto Rico

THE West Indies are among the best known of the world's tropical regions, and our knowledge of the distribution of indigenous land birds in the Greater Antilles has been thought to be nearly complete (Bond, 1956). The last new species from the Antilles were described in 19'27, the results of work in the Zapata Swamp of Cuba (Barbour and Peters, 1927) and the isolated Morne de la Selle in Haiti (Wetmore, 1927). No new species has been found in Puerto Rico in this century, and it would seem unlikely that a bird could escape detection on the island, which has a human population density now approaching 320 per square km, and less than 3,300 ha (0.4 percent of land area) of virgin forest remaining (Wadsworth, 1949). Nevertheless the discovery of extant populations of the Puerto Rican Whip-poor-will (Caprimulgus no.ctitherus) by Reynard (1962) and the Puerto Rican Plain Pigeon (Columba inornata wetmorel) by Leopold (1963), both previously presumed extinct (Bond, 1956, 1961), indicated that the inventory of the Puerto Rican avifauna might be incomplete. The largest remaining forest in Puerto Rico is in the Sierra de Luquillo at the island's eastern end. In September 1968 the senior author and his wife established residence within the forest at an elevation of 770 m, and began intensive studies of the Puerto Rican Parrot (Amazona vittata) and the Puerto Rican Tody (Todus mexicanus). These studies included a series of census routes through the forest to assess easonal and altitudinal distribution a d abundance of these and other species (Kepler and Kepler, 1970). Two census routes were established in Elfin Woodland (Figure 1), a distinctive forest type confined to the higher peaks and ridges. In this forest they occasionally noticed a warbler of peculiar appearance, but were unsure of its identity because of the difficulty of seeing small birds in this habitat. The bird (see Frontispiece) showed similarities both to the Blackand-white Warbler (Mniotilta varia), a common North American migrant to Puerto Rico, and the Arrow-headed Warbler (Den•oica pharetra), a