Foraging patterns of breeding Chimney Swifts (Chaetura pelagica) in relation to urban landscape features.

摘要

Declines in abundance and quality of food resources (i.e., flying insects) are strongly linked to population declines in Chimney Swifts (Chaetura pelagica). Recovery of this aerially-foraging insectivore requires a greater understanding of how swifts use their habitat while foraging during times of high metabolic demand, such as during nesting. I used radio telemetry to track the daily movements of breeding Chimney Swifts to identify foraging preferences for different areas in an urban environment. Water had a negative or neutral influence on habitat use in all cases. Those areas that are traditionally considered important to urban wildlife, namely forests and semi-natural greenspace, occasionally had a modest positive effect on habitat use. Though only observed in four birds, industrial areas had the strongest positive relationship with foraging behaviours. As industrial areas are unlikely to be substantial sources of aerial insects, the prey concentrated in these areas likely arrived as "aerial plankton": by thermal convection over developed areas. Thus, chimney swift foraging habitat is multi-scaled; their foraging patterns depend on local landscape features that host or coalesce prey produced in other areas.;Keywords: foraging habitat, Chimney Swift, Chaetura pelagica, radio telemetry, aerial insectivore, resource selection function.