Main content area

Not all nesting guild members are alike: nest predators and conspecific abundance differentially influence nest survival in the ground-nesting Ovenbird (Seiurus aurocapilla) and Veery (Catharus fuscescens)

Kelly, Janice K., Schmidt, Kenneth A., Ostfeld, Richard S.
The Wilson journal of ornithology 2017 v.129 no.1 pp. 112-121
Catharus, Seiurus aurocapilla, Tamias, breeding season, models, nesting, predation, predators, risk, rodents, songbirds, sympatry, vocalization, New York
At the nest guild level, nest predation is a major cause of failure for many passerines. Species differ in behaviors that influence nest predation risk, presenting a challenge to nest survival analyses at the nest guild level. At our study site in southeastern New York, previous findings have suggested rodent nest predator abundance strongly drives daily nest survival of the Veery (Catharus fuscescens), a ground or low shrub-nesting songbird. In cue playback experiments, the sympatric ground-nesting Ovenbird (Seiurus aurocapilla) shows a greater aversion to chipmunk vocalizations than Veeries. These behavioral differences suggest these two sympatric ground-nesters may be driven by different ecological mechanisms despite similarity in their nesting niche. We examined how nest predator abundance, regional songbird abundance, and timing of nest activity during the breeding season influence nest survival in two songbirds from the same nest guild by building competitive models for determining the extrinsic drivers of daily nest survival. Ovenbird nest survival was best described by nest activity date, where nest survival decreased later in the breeding season, and was positively influenced by conspecific density. Nest survival of Veeries was strongly and negatively influenced by both nest predator abundance and regional abundance of Veeries. Thus, the strong relationship between nest predator abundance and nest survival observed in Veeries does not extend to Ovenbirds. These sympatric ground-nesting songbirds differ in how nest predators influence nest survival, therefore highlighting the importance of considering species-specific differences within nesting guilds to better understand nest survival at multiple ecological levels.