Program and Agenda

Abstract

A MULTI-SCALE ANALYSIS OF RUSTY BLACKBIRD NEST SURVIVAL AND NEST PREDATORS IN NEW ENGLAND

Our objectives were to identify the mechanisms by which a previously hypothesized ecological trap for Rusty Blackbirds (Euphagus carolinus) may be operating in New England through a multi-scale analysis of nest survival, predator identification and quantification. We monitored 65 Rusty Blackbird nests in Maine and New Hampshire in 2011 and 2012 and related nest survival to habitat characteristics at the nest patch (0.008 ha) and home range (785 ha) scale using an information-theoretic approach. At the nest patch scale, we found that nest survival increased with increasing total basal area, and we recommend land managers maintain areas of densely stocked seedling/sapling spruce (Picea spp.) and fir (Abies spp.) to enhance Rusty Blackbird nesting habitat. At the home range scale, nests that were closer to the road were less successful in 2011, but not in 2012. It was difficult to robustly assess the effect of timber management on nest survival because we had so few nests in unharvested areas (n = 8), but we did not find clear support for an ecological trap caused by timber harvesting. We documented eight predation events and identified four predator species, including white-tailed deer (Odocoileus virginianus), an Accipiter sp., Blue Jay (Cyanocitta cristata) and red squirrel (Tamiasciurus hudsonicus). Red squirrels were the most frequent predator of Rusty Blackbird nests (n = 4), but only in 2012, when they were generally abundant relative to 2011. Abundance of spruce and fir cones was high in 2011 and low in 2012. Fluctuating predator populations mediated through cone mast likely influence Rusty Blackbird nest survival more than timber harvesting.

Authors

Luepold, S. B., SUNY College of Environmental Science and Forestry, USA, shbuck01@syr.edu

Hodgman, T. P., Maine Department of Inland Fisheries and Wildlife, USA, tom.hodgman@maine.gov

McNulty, S. A., SUNY College of Environmental Science and Forestry, USA, smcnulty@esf.edu

Cohen, J., SUNY College of Environmental Science and Forestry, USA, jcohen14@esf.edu

Foss, C. R., New Hampshire Audubon, USA, cfoss@nhaudubon.org

Details

Oral presentation

Session #:S15
Date: 9/27/2014
Time: 14:00
Location: Longs Peak - Diamond East

Presentation is given by student: No