The diversity of cloud forest birds on the eastern and western slopes of the Ecuadorian Andes: a latitudinal and comparative analysis with implications for conservation

We studied the avifaunas of five cloud forest localities at 3000–3350 mas1 on the eastern slope of the Andes of Ecuador A method standardised for area, altitude and effort was the basis for obtaining data on species richness and abundances Richness and abundances (diversity) were unchanged along the limned latitudinal gradient (530 km) studied, whereas there was a considerable turnover in community structure between localities This result has important implications for ranking conservation priorities the total community richness and the dominance/evenness component of diversity does not provide a basis for making priorities along this limited latitudinal gradient Instead, species compositions and species referred to threatened categories (e g, endemics, restricted–range, IUCN threatened/near–threatened, CITES) will be the most meaningful data for making priorities for conservation We compared our results with similar results from the Andean western slope of Ecuador, obtained with the same method and standardised for time of the year The number of species was significantly higher on the eastern slope than on the western slope, a characteristic that can be explained from differences in extension of adjacent source areas and geohistory However, because the species compositions on the two slopes are rather different, it is not recommended to use the difference in richness to rank conservation priorities Abundances were quite similar on both sides of the Andes Contrary to the general belief, the montane avifaunas investigated have tropical and not temperate species richness which agrees with the tropical clutch sizes found among montane birds The avian richness found on the eastern slope of Ecuador near the Equator is definitely among the highest m the world for this altitude