LE3 .A278 2017

2017

Shutler, Dave

Acadia University

Bachelor of Science

Honours

Biology

Biology

Nest-site selection is an important determinant of fitness because of its potential influence on reproductive success. To reduce metabolic costs of thermoregulation and limit predation risks, adult birds must identify nest-sites with favorable habitat characteristics. I quantified habitat preferences in Tree Swallows (Tachycineta bicolor), acavity-nesting species. These birds readily accept nest-boxes, which facilitates manipulation of box design, lateral vegetation density, and vertical vegetation cover (hereafter, canopy cover). If avoiding predators influences habitat selection, adults may favor nest-boxes with small entrance holes that make clutches and broods less accessible to predators. Nest-boxes with sparse lateral vegetation density and canopy cover may be favored because birds can better detect and escape predators. However, adults may also favor nest-boxes with dense lateral vegetation and canopy cover to make clutches less conspicuous to predators. I measured habitat surrounding 43 occupied and 136 unoccupied Tree Swallow nest-boxes in Port Williams, Nova Scotia. Lateral vegetation density did not differ between occupied and unoccupied nest-boxes. However, occupied nest-boxes had significantly less canopy cover and smaller entrance hole diameters than unoccupied nest-boxes. Studies identifying habitat factors that influence nest-site selection may allow for conservation and management of suitable habitats and consequently, higher reproductive success for populations at risk

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https://scholar.acadiau.ca/islandora/object/theses:2078