Nest-Site Characteristics, Reproductive Success and Cavity Availability for Tree Swallows Breeding in Natural Cavities

Abstract

We examined 10 characteristics of natural cavities and their influence on reproductive success of Tree Swallows (Tachycineta bicolor) nesting in dead trees in beaver ponds. Large ranges were found for entrance height and area, cavity volume, and nearness to shore of nest sites. Other characteristics were less variable: 46% of cavities were less than 2 m above the pond surface, and 48% had entrance widths of 4-5 cm. Tree Swallow nest sites were uniformly dispersed in the ponds. Two cavity characteristics, cavity height and floor area, influenced reproductive success: Lower nest sites were more frequently preyed on and females laid larger clutches in cavities with a large floor area. Five species larger than Tree Swallows used cavities during the study. Girth of the snag at the base and at the cavity, entrance width, and cavity volume were significantly greater at sites used by these species than those used by Tree Swallows. Nest sites suitable for breeding did not appear to be limiting to Tree Swallows, because characteristics of unused cavities did not differ from those used by Tree Swallows and other species. Intraspecific territoriality was likely responsible for the large number of unused cavities in our populations. Other factors influencing cavity availability in our sites include interspecific competition, predation, snag fall, and continuing woodpecker excavation.

Lophozonia tree cavities used for nesting by Slender-billed Parakeets (Enicognathus leptorhynchus) in the central valley of southern Chile: a potentially vanishing keystone resource

“…>300 cm 2 ) cavities. Alatalo et al (1988) reported similar findings for Pied Flycatchers (Ficedula hypoleuca), as did Rendell and Robertson (1989) for Tree Swallows (Tachycineta bicolor). In our case, some caveats to this assertion include our small sample sizes and high variability (Table 1), which also may have reduced the likelihood of detecting the effect of the internal area of a cavity on clutch size, if any (see Purcell et al 1997).…”

“…Because of suggested potential relationships between clutch and/or brood size and internal cavity dimensions (e.g. Karlsson and Nilsson 1977;Gustafsson and Nilsson 1985;Rendell and Robertson 1989;but see Pitts 1988;Bortolotti 1994) we also used simple linear regressions to test for relationships between SBP clutch size and the internal ellipse of cavities (a surrogate for floor area), cavity depth and cavity volume after log-transforming these cavity variables for normality (Sokal and Rohlf 1981). Because of small sample sizes, we considered tests significant at p ≤ 0.10 to minimize Type II error (Sokal and Rohlf 1981).…”

Successional stage effect on the availability of tree cavities for cavity-nesting birds in an Atlantic Forest park from the state of São Paulo, Brazil

“…We have defined a cavity as a depression in a woody tree (living or dead), which had a plateau to support an oologic chamber and had a closed cover. Cavities that were up to 7 m high were accessed using ladder for biometric analyses (Rendell & Robertson 1989, Kerpz & Smith 1990). Measurements included: tree diameter at cavity height, smaller entrance diameter, internal diameter, and depth (Marini et al 2002, Remm et al 2006, Tamungang et al 2016.…”

Nest-site Characteristics of Hole-Nesting Birds in a Primeval Boreal Forest of Mongolia

“…In the United States, the nest niche of the introduced European Starling and House Sparrow Passer domesticus overlapped with native Bluebirds Sialia spp., and caused great decline of their populations (Erskine & McLaren 1976, Sedgwick 1997. The competition with the Starling also limited the Tree Swallow Tachycineta bicolor to smaller holes and nest sites farther from woodland edges (Rendell & Robertson 1989, Dobkin et al 1995. The aggressiveness of the Starling could exert selection on other species to shift their nesting phenology and behaviour (Koenig 2003).…”