Nesting is a particularly sensitive period during which birds are highly vulnerable to predation, parasitism, and other natural events resulting in high mortality rates. Some factors can increase nesting success, such as habitat selection. In general, only female hummingbirds build nests, incubate eggs, and provide nestling care until chicks can feed independently. The purpose of our study was to describe nests (shape, size, and construction materials), nest survival, and habitat use of 3 resident hummingbirds in western Mexico: Cinnamon Hummingbird (Amazilia rutila), Golden-crowned Emerald (Cynanthus auriceps; a Mexican endemic), and Broad-billed Hummingbird (C. latirostris). In all 3 species, the nest is an open cup built with plant material and bound together with spider web. All 3 species used the same materials (silk cotton, wood, and grass) for nest construction. However, Cinnamon Hummingbird was the only one that used lichens at its outer surface, whereas Broad-billed Hummingbird used only seeds. We did not find interspecific differences among the materials used and their quantities. A low nest survival (26%) can be explained by the high rate of predation but also by the occurrence of natural events such as hurricanes. All 3 species showed preference for nesting in semi-deciduous forests but chose different nest placement sites that differed in (1) nest height, (2) the height of trees or shrubs where nests were built, and (3) the diameter of the supporting branch within a shrub or tree. Other factors, such as distance to the nearest stream, and distance to nesting-branch tip or trunk, did not differ among species.
The Wilson Journal of Ornithology
Vol. 133 • No. 2
Vol. 133 • No. 2