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Environmental Health and Protection

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Environmental Studies Faculty Publications

Vermont

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Nestling Sex Ratios Do Not Support Long-Term Parity In Two Species With Different Life-History Strategies, Noah G. Perlut, Steven E. Travis, Catherine A. Dunbar, Allan M. Strong, Derek M. Wright Mar 2014

Nestling Sex Ratios Do Not Support Long-Term Parity In Two Species With Different Life-History Strategies, Noah G. Perlut, Steven E. Travis, Catherine A. Dunbar, Allan M. Strong, Derek M. Wright

Environmental Studies Faculty Publications

To maximize fitness, breeding adults may respond to environmental processes by adjusting their progeny’s sex ratios. R. A. Fisher in 1930 hypothesized that frequency-dependent selection would result in equal investment in sons and daughters over the long term, yielding a balanced sex ratio if the costs of raising a son and daughter are equal. Diverse hypotheses have tried to explain population and brood-by-brood deviations from this mean as well as annual variation by focusing on adult sex ratios, resources, abiotic conditions, and female and male quality. We collected data in 2002-2010 to explore population-level variation in nestling sex ratios in …


Minor Fitness Benefits For Edge Avoidance In Nesting Grassland Birds In The Northeastern United States, David G. Perkins, Noah G. Perlut, Allan M. Strong Jul 2013

Minor Fitness Benefits For Edge Avoidance In Nesting Grassland Birds In The Northeastern United States, David G. Perkins, Noah G. Perlut, Allan M. Strong

Environmental Studies Faculty Publications

Grassland birds are often affected negatively by habitat fragmentation. Outcomes include greater nest predation and brood parasitism, decreased colonization rates of small, isolated patches, and greater nest density in remnant core habitats. These effects have been well documented in the Midwest, but little is known about fragmentation and edge effects on grassland birds in the fragmented agricultural fields within the forested landscapes of the northeastern United States. From 2002 to 2010, we assessed how edges and edge types affected nest-site location and daily nest survival (DNS) of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) breeding …


Grassland Songbirds In A Dynamic Management Landscape: Behavioral Responses And Management Strategies, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley Dec 2006

Grassland Songbirds In A Dynamic Management Landscape: Behavioral Responses And Management Strategies, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley

Environmental Studies Faculty Publications

In recent decades, earlier and more frequent harvests of agricultural grasslands have been implicated as a major cause of population declines in grassland songbirds. From 2002 to 2005, in the Champlain Valley of Vermont and New York, USA, we studied the reproductive success of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- to mid-July; (2) middle-hayed fields cut once between 21 June and 10 July; (3) late-hayed fields cut after 1 August; and (4) rotationally grazed pastures. Both the number of …