Jon Atwood, PhD
Department of Environmental Studies
As secondary cavity nesters, Tree Swallows (Tachycienta bicolor) will readily accept and use man-made nest boxes for their breeding sites. This allows for easy study of nesting success of pairs using the boxes. Knowing the factors that may affect the success and survivorship of these nests can provide improved management techniques that will enhance the success of the species in managed areas. This study focused on a population of Tree Swallows using 9.3 hectares of open field habitat containing 58 pairs of nest boxes. The study was conducted over a two-year period in 2001 and 2001. Factors such as timing of nest initiation, field management procedures, age and nest site fidelity were evaluated to determine if they might affect nesting success. Results showed a significant different in the number of young fledged at different periods of the nesting season, with the later portion of the season displaying a significant lower success rate. This was in contrast to mean clutch and brood sizes, which did not differ significantly at different periods of the season. A marginally significant difference was found between the average clutch size of pairs with one-year-old banded birds and pairs consisting of birds of unknown ages; however there was no significant difference in average brood size or the average number of young fledged.