Variation in tropical bird survival across longitude and guilds: a case study from the Amazon

Abstract

Survival estimates of tropical birds have been used to examine life‐history variation across latitudes and dietary guilds. Here, we provide apparent survival estimates of 31 rainforest species from central Amazonian Brazil and compare our results with estimates from Ecuador, Peru (western Amazonia) and French Guiana (eastern Amazonia) to examine geographic variation in demography. Our averaged annual survival estimate for central Amazonian species (ϕ= 0.59, SE = 0.10) was concordant with previously published estimates from the western Amazon (ϕ= 0.58, SE = 0.02), and eastern Amazon (ϕ= 0.63, SE = 0.06). Two predominate demographic patterns were detected across the study areas: within species, survival was highest or lowest in eastern or western Amazonia, but rarely in central Amazonia. The most striking demographic variation was exhibited by Pithys albifrons, for which apparent survival estimates were nearly twice as high in eastern Amazonia (ϕ= 0.80, SE = 0.06) than in western Amazonia (ϕ= 0.42, SE = 0.06) but intermediate in central Amazonia (ϕ= 0.54, SE = 0.04). Although variation in survival may be associated with differences in life history characteristics, our analysis of flocking guild, body size, and nest architecture revealed only moderate differences in survival associated with nest architecture. These results suggest that geographic variation in population processes may be significant for widespread Amazonian species.