Upper Midwest Environmental Sciences Center
Comparing the effects of local, landscape, and temporal factors on forest bird nest survival using logistic-exposure models
Knutson, M. G., Gray, B. R., and Meier, M. S., 2007, Comparing the effects of local, landscape, and temporal factors on forest bird nest survival using logistic-exposure models, Studies in Avian Biology, v. 34, p. 105-116
We studied the bird communities of Mississippi River floodplain and adjacent upland forests to identify factors associated with nest survival. We estimated daily nest survival for forest-nesting birds using competing logistic-exposure models, that will allow a comparison of multiple possible factors associated with nest survival, measured at different spatial or temporal scales. We compared models representing landscape (upland vs. fl oodplain and forest cover), edge (nest distance to edge and forest edge density), nest-site (nest height, canopy cover, nest concealment, and shrub density), Brown-headed Cowbird (Molothrus ater; parasitism rate and cowbird abundance), and temporal effects (year, nest stage, and Julian date of observations). We found that the temporal effects model had the strongest support, followed by the landscape effects model for most species. Nest survival tended to be highest early in the nesting season (May-June) and late in the nest cycle (nestling stage). For Eastern Wood-Pewees (Contopus virens) and Prothonotary Warblers (Protonotaria citrea), higher nest survival was associated with lower proportions of forest surrounding the plot. Significant effects of nest placement in upland vs. floodplain locations were not observed for any species. Models representing edge, nest-site, and cowbird effects had less statistical support, although higher nest survival was sometimes associated with dense shrubs and more concealment around the nest. Management implications may include timing management disturbances to avoid the early nesting season (May and June). For shrub nesting species, management to open the canopy and allow the shrub layer to develop may be beneficial.
Brown-headed Cowbird, demographic monitoring, floodplain forest, informationtheoretic, landbird, landscape, logistic-exposure model, Mississippi River, nest-site, nest survival.