INFLUENCE OF HABITAT VARIATION, NEST-SITE SELECTION, AND PARENTAL BEHAVIOR ON BREEDING SUCCESS OF RUDDY-CAPPED NIGHTINGALE THRUSHES (CATHARUS FRANTZII) IN CHIAPAS, MEXICO

Abstract

We examined the influence of ecological and behavioral factors on breeding success of Ruddy-capped Nightingale Thrushes (Catharus frantzii) in contiguous primary- and secondary-forest habitats during the 2000–2003 breeding seasons in the Central Highlands of Chiapas, Mexico. Breeding density was higher in primary, undisturbed forest than in secondary forest with less understory vegetation. Nest-site selection was related to nest-concealment attributes (visibility, canopy cover, and shrub density) at the nest-site and patch levels. Nest-site selection was stronger in secondary forest, which indicates that preferred nest-site attributes were more limited in that habitat. Overall success per breeding attempt varied annually from 20% to 35%, with a higher mean annual success in primary forest (42%) than in secondary forest (19%). Daily nest survival rates were higher in primary than in secondary forest and varied with nest cover, lateral visibility, and density of ground epiphytes. The number of parental visits to nests was higher in primary than in secondary forest and lower for successful than for failed nests during incubation but did not vary with habitat or fate during the nestling stage. Female nest-attentiveness was higher in primary forest than in secondary forest throughout the nesting attempt and was higher for successful nests during the nestling stage only. Thus, Ruddy-capped Nightingale Thrushes showed habitat-specific breeding performance, with the primary-forest habitats (cloud forest, riparian) supporting higher densities and nesting success than secondary, disturbed habitats.