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Full-Text Articles in Physical Sciences and Mathematics

The Traits That Predict The Magnitude And Spatial Scale Of Forest Bird Responses To Urbanization Intensity, Grant D. Paton, Alexandra V. Shoffner, Andrew M. Wilson, Sara A. Gagné Jul 2019

The Traits That Predict The Magnitude And Spatial Scale Of Forest Bird Responses To Urbanization Intensity, Grant D. Paton, Alexandra V. Shoffner, Andrew M. Wilson, Sara A. Gagné

Environmental Studies Faculty Publications

As humans continue moving to urban areas, there is a growing need to understand the effects of urban intensification on native wildlife populations. Forest species in remnant habitat are particularly vulnerable to urban intensification, but the mechanisms behind these effects are poorly understood. An understanding of how species traits, as proxies for mechanisms, mediate the effects of urban intensification on forest species can help fill this knowledge gap. Using a large point count dataset from the Second Pennsylvania Breeding Bird Atlas, we tested for the effects of species traits on the magnitude and spatial scale of the responses of 58 …


The Relative Effects Of Forest Amount, Forest Configuration, And Urban Matrix Quality On Forest Breeding Birds, Alexandra V. Shoffner, Andrew M. Wilson, Wenwu Tang, Sara A. Gagné Nov 2018

The Relative Effects Of Forest Amount, Forest Configuration, And Urban Matrix Quality On Forest Breeding Birds, Alexandra V. Shoffner, Andrew M. Wilson, Wenwu Tang, Sara A. Gagné

Environmental Studies Faculty Publications

Urbanization modifies landscape structure in three major ways that impact avian diversity in remnant habitat: habitat amount is reduced and habitat configuration and matrix quality are altered. The relative effects of these three components of landscape structure are relatively well-studied in agricultural landscapes, but little is known about the relative effect of urban matrix quality. We addressed this gap by investigating the relative effects of forest amount, forest configuration, and matrix quality, indicated by degree of urbanization and agriculture amount, on the diversity of three guilds of forest birds using data from 13,763 point counts from Pennsylvania, USA. Forest amount …


Geographic Variation Of Cirques On Iceland: Factors Influencing Cirque Morphology, Heather A. Ipsen, Rachael E. Grube, Jessica F. Lee, Sarah M. Principato Mar 2017

Geographic Variation Of Cirques On Iceland: Factors Influencing Cirque Morphology, Heather A. Ipsen, Rachael E. Grube, Jessica F. Lee, Sarah M. Principato

Environmental Studies Faculty Publications

Cirques are one of the most common glacial landforms in alpine settings. They also provide important paleoclimate information (e.g. Meierding 1984; Evans 2006). The purpose of this study is to fill in gaps in the climate record of Iceland by conducting a quantitative analysis of cirques in three regions in Iceland: Tröllaskagi, the East Fjords, and Vestfirðir. Iceland, located in the center of the North Atlantic Ocean, contains many small glaciers, in addition to large ice caps. The glaciers on Iceland are particularly sensitive to variations in oceanic and atmospheric circulation (Andresen et al. 2005; Geirsdóttir et al., 2009; Ólafsdóttir …


Hearing In The Juvenile Green Sea Turtle (Chelonia Mydas): A Comparison Of Underwater And Aerial Hearing Using Auditory Evoked Potentials, Wendy Dow Piniak, David A. Mann, Craig A. Harms, T. Todd Jones, Scott A. Eckert Oct 2016

Hearing In The Juvenile Green Sea Turtle (Chelonia Mydas): A Comparison Of Underwater And Aerial Hearing Using Auditory Evoked Potentials, Wendy Dow Piniak, David A. Mann, Craig A. Harms, T. Todd Jones, Scott A. Eckert

Environmental Studies Faculty Publications

Sea turtles spend much of their life in aquatic environments, but critical portions of their life cycle, such as nesting and hatching, occur in terrestrial environments, suggesting that it may be important for them to detect sounds in both air and water. In this study we compared underwater and aerial hearing sensitivities in five juvenile green sea turtles (Chelonia mydas) by measuring auditory evoked potential responses to tone pip stimuli. Green sea turtles detected acoustic stimuli in both media, responding to underwater stimuli between 50 and 1600 Hz and aerial stimuli between 50 and 800 Hz, with maximum …


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), …


Natal And Breeding Dispersal Of Bobolinks (Dolichonyx Oryzivorus) And Savannah Sparrows (Passerculus Sandwichensis) In An Agricultural Landscape, Natalia Fajardo, Allan M. Strong, Noah G. Perlut, Neil J. Buckley Apr 2009

Natal And Breeding Dispersal Of Bobolinks (Dolichonyx Oryzivorus) And Savannah Sparrows (Passerculus Sandwichensis) In An Agricultural Landscape, Natalia Fajardo, Allan M. Strong, Noah G. Perlut, Neil J. Buckley

Environmental Studies Faculty Publications

Dispersal is a key process in the metapopulation dynamics and genetic structure of spatially segregated populations. However, our knowledge of avian dispersal, particularly in migratory passerines, remains limited. We studied dispersal of Bobolinks (Dolichonyx oryzivorus) and Savannah Sparrows (Passerculus sandwichensis) to determine whether agricultural management practices affected dispersal patterns and habitat selection. From 2002 to 2006, we banded adults and nestlings on six focal hay fields and two pastures in the Champlain Valley of Vermont and New York and searched for banded birds within 1.5 km of Vermont field sites during two years. Natal dispersal distances were …


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 …


A Comparison Of Aviris And Landsat For Land Use Classification At The Urban Fringe, Rutherford V. Platt, Alexander F.H. Goetz Jan 2004

A Comparison Of Aviris And Landsat For Land Use Classification At The Urban Fringe, Rutherford V. Platt, Alexander F.H. Goetz

Environmental Studies Faculty Publications

In this study we tested whether AVIRIS data allowed for improved land use classification over synthetic Landsat ETM+ data for a location on the urban-rural fringe of Colorado. After processing the AVIRIS image and creating a synthetic Landsat image, we used standard classification and post-classification procedures to compare the data sources for land use mapping. We found that, for this location, AVIRIS holds modest, but real, advantages over Landsat for the classification of heterogeneous and vegetated land uses. Furthermore, this advantage comes almost entirely from the large number of sensor spectral bands rather than the high Signal-to-Noise Ratio (SNR).


Polinices Predation Patterns And Mercenaria Morphology Models, John A. Commito Mar 1987

Polinices Predation Patterns And Mercenaria Morphology Models, John A. Commito

Environmental Studies Faculty Publications

DeAngelis et al. (1985) have described a model of the evolutionary response of bivalve prey to size-selective naticid snail predation. The model analyzed "the allocation of bivalve energy among reproduction, overall growth in size, and supplementary growth in shell thickness" (p. 818). Using parameter values for Polinices duplicatus as the predator and Mercenaria mercenaria as the prey, the model predicted three optimal strategies for bivalves faced with naticid predation: (1) delayed reproduction with energy diverted into rapid growth in order to reach a size refuge; (2) early reproduction, possibly with some extra shell thickness; and (3) greatly increased shell thickness …