Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Environmental Health and Protection

Seismic Surveys And Marine Turtles: An Underestimated Global Threat?, Sarah E. Nelms, Wendy Dow Piniak, Caroline R. Weir, Brendan J. Godley Nov 2015

Seismic Surveys And Marine Turtles: An Underestimated Global Threat?, Sarah E. Nelms, Wendy Dow Piniak, Caroline R. Weir, Brendan J. Godley

Environmental Studies Faculty Publications

Seismic surveys are widely used in marine geophysical oil and gas exploration, employing airguns to produce sound-waves capable of penetrating the sea floor. In recent years, concerns have been raised over the biological impacts of this activity, particularly for marine mammals. While exploration occurs in the waters of at least fifty countries where marine turtles are present, the degree of threat posed by seismic surveys is almost entirely unknown. To investigate this issue, a mixed-methods approach involving a systematic review, policy comparison and stakeholder analysis was employed and recommendations for future research were identified. This study found that turtles have …


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 …


Evaluating The Roles Of Visual Openness And Edge Effects On Nest-Site Selection And Reproductive Success In Grassland Birds, Alexander C. Keyel, Allan M. Strong, Noah G. Perlut, J. Michael Reed Jan 2013

Evaluating The Roles Of Visual Openness And Edge Effects On Nest-Site Selection And Reproductive Success In Grassland Birds, Alexander C. Keyel, Allan M. Strong, Noah G. Perlut, J. Michael Reed

Environmental Studies Faculty Publications

In some species, habitat edges (ecotones) affect nest-site selection and nesting success. Openness, or how visually open a habitat is, has recently been shown to influence grassland bird density and may affect nest-site selection, possibly by reducing the risk of predation on adults, nests, or both. Because edge and openness are correlated, it is possible that effects of openness have been overlooked or inappropriately ascribed to edge effects. We tested the roles of edges and visual openness in nest-site selection and nesting success of two grassland passerines, the Bobolink (Dolichonyx oryzivorus) and Savannah Sparrow (Passerculus sandwichensis), …


The Functions And Values Of Fringing Salt Marshes In Northern New England, Usa, Pamela A. Morgan, David M. Burdick, Frederick T. Short Feb 2009

The Functions And Values Of Fringing Salt Marshes In Northern New England, Usa, Pamela A. Morgan, David M. Burdick, Frederick T. Short

Environmental Studies Faculty Publications

Although large salt marshes of the northeastern United States have been studied extensively, very little is known about the smaller, fringing marshes in this area, despite the fact that they are a common habitat type. We compared the functions and values of five fringing salt marshes (FM) to those of five meadow marshes (MM) along the southern Maine/New Hampshire coast. Specifically we compared their primary production, soil organic matter content, plant diversity, sediment trapping ability and wave dampening properties. Also explored were the relationships between these functions and several physical characteristics at each site, including soil salinity, percent surface slope, …


Grassland Songbird Survival And Recruitment In Agricultural Landscapes: Implications For Source-Sink Demography, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley Jul 2008

Grassland Songbird Survival And Recruitment In Agricultural Landscapes: Implications For Source-Sink Demography, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley

Environmental Studies Faculty Publications

Population growth and decline are particularly sensitive to changes in three key life-history parameters: annual productivity, juvenile survival, and adult survival. However, for many species these parameters remain unknown. For example, although grassland songbirds are imperiled throughout North America, for this guild, only a small number of studies have assessed these parameters. From 2002 to 2006, in the agricultural landscape of the Champlain Valley of Vermont and New York, USA, we studied Savannah Sparrow (Passerculus sandwichensis) and Bobolink (Dolichonyx oryzivorus) demography on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- …


A Comprehensive Wetland Program For Fringing Salt Marshes In The York River, Maine, Pamela A. Morgan, Jeremy Miller, Christopher Cayce Dalton, Michele Dionne May 2007

A Comprehensive Wetland Program For Fringing Salt Marshes In The York River, Maine, Pamela A. Morgan, Jeremy Miller, Christopher Cayce Dalton, Michele Dionne

Environmental Studies Faculty Publications

The overall goal of this project was to assist the Town of York, Maine, in its efforts to monitor and protect the fringing salt marshes along the York River. In particular, the project focused on potential impacts to the marshes due to shoreline development pressures. Specific objectives included (1) gathering baseline data about the marshes (2) developing a set of indicators to be used in future monitoring, and (3) generating management recommendations.


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 …


Assessing The Health Of Fringing Salt Marshes Along The Fore River And Its Tributaries, Pamela A. Morgan, Lucas Curci, Cayce Dalton, Jeremy Miller Aug 2005

Assessing The Health Of Fringing Salt Marshes Along The Fore River And Its Tributaries, Pamela A. Morgan, Lucas Curci, Cayce Dalton, Jeremy Miller

Environmental Studies Faculty Publications

Casco Bay has experienced two significant oil spills in recent history - the Tamano Tanker spill in 1972 and the Julie N spill in 1996. In addition, the Fore River and its tributaries have experienced numerous small spills over the years, including the August 2002 fuel oil spill (2,900 gallons) and the April 2003 jet fuel spill (6,000 gallons). The impacts of these spills on the fringing salt marshes that line the edges of the Fore River and its tributaries are not well understood. Are these salt marshes resilient enough to withstand these impacts and still act as healthy marshes …


Ecological Functions And Values Of Fringing Salt Marshes Susceptible To Oil Spills In Casco Bay, Maine, Pamela A. Morgan, Michele Dionne, Richard Mackenzie, Lucas Curci Feb 2005

Ecological Functions And Values Of Fringing Salt Marshes Susceptible To Oil Spills In Casco Bay, Maine, Pamela A. Morgan, Michele Dionne, Richard Mackenzie, Lucas Curci

Environmental Studies Faculty Publications

Casco Bay is the largest oil port in Maine and northern New England, handling over 20 million tons of crude oil and oil products annually. The susceptibility of the Bay’s estuarine habitats, especially its fringing salt marshes, to potential spill events was the impetus for this study. Although much has been learned to date about the effects of oil spills on estuarine habitats around the world, there is a real need for site-specific knowledge of the structures and functions of local habitats so that resource managers can be prepared in the event of a spill. Our study focused specifically on …