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Winter diets of immature green turtles (Chelonia mydas) on a northern feeding ground: integrating stomach contents and stable isotope analyses Winter diets of immature green turtles (Chelonia mydas) on a northern feeding ground: integrating stomach contents and stable isotope analyses

The foraging ecology and diet of the green turtle, Chelonia mydas, remain understudied, particularly in peripheral areas of its distribution. We assessed the diet of an aggregation of juvenile green turtles at the northern edge of its range during winter months using two approaches. Stomach content analyses provide a single time sample, and stable isotope analyses integrate diet over a...
Authors
Natalie C. Williams, Karen A. Bjorndal, Margaret M. Lamont, Raymond R. Carthy

Screening native botanicals for bioactivity: an interdisciplinary approach Screening native botanicals for bioactivity: an interdisciplinary approach

Objective: Plant-based therapies have been used in medicine throughout recorded history. Information about the therapeutic properties of plants often can be found in local cultures as folk medicine is communicated from one generation to the next. The aim of this study was to identify native Louisiana plants from Creole folk medicine as a potential source of therapeutic compounds for the...
Authors
Anik Boudreau, Diana M. Cheng, Carmen Ruiz, David Ribnicky, Larry K. Allain, C. Ray Brassieur, D. Phil Turnipseed, William T. Cefalu, Z. Elizabeth Floyd

Aboveground allometric models for freeze-affected black mangroves (Avicennia germinans): Equations for a climate sensitive mangrove-marsh ecotone Aboveground allometric models for freeze-affected black mangroves (Avicennia germinans): Equations for a climate sensitive mangrove-marsh ecotone

Across the globe, species distributions are changing in response to climate change and land use change. In parts of the southeastern United States, climate change is expected to result in the poleward range expansion of black mangroves (Avicennia germinans) at the expense of some salt marsh vegetation. The morphology of A. germinans at its northern range limit is more shrub-like than in...
Authors
Michael J. Osland, Richard H. Day, Jack C. Larriviere, Andrew S. From

Grass carp in the Great Lakes region: establishment potential, expert perceptions, and re-evaluation of experimental evidence of ecological impact Grass carp in the Great Lakes region: establishment potential, expert perceptions, and re-evaluation of experimental evidence of ecological impact

Intentional introductions of nonindigenous fishes are increasing globally. While benefits of these introductions are easily quantified, assessments to understand the negative impacts to ecosystems are often difficult, incomplete, or absent. Grass carp (Ctenopharyngodon idella) was originally introduced to the United States as a biocontrol agent, and recent observations of wild, diploid...
Authors
Marion E. Wittmann, Christopher L. Jerde, Jennifer G. Howeth, Sean P. Maher, Andrew M. Deines, Jill A. Jenkins, Gregory W. Whitledge, Sarah B. Burbank, William L. Chadderton, Andrew R. Mahon, Jeffrey T. Tyson, Crysta A. Gantz, Reuben P. Keller, John M. Drake, David M. Lodge

Wetlands: Tidal Wetlands: Tidal

Tidal wetlands are some of the most dynamic areas of the Earth and are found at the interface between the land and sea. Salinity, regular tidal flooding, and infrequent catastrophic flooding due to storm events result in complex interactions among biotic and abiotic factors. The complexity of these interactions, along with the uncertainty of where one draws the line between tidal and...
Authors
William H. Conner, Ken W. Krauss, Andrew H. Baldwin, Stephen Hutchinson

Forcing functions governing salt transport processes in coastal navigation canals and connectivity to surrounding marshes in South Louisiana using Houma Navigation Canal as a surrogate Forcing functions governing salt transport processes in coastal navigation canals and connectivity to surrounding marshes in South Louisiana using Houma Navigation Canal as a surrogate

Understanding how circulation and mixing processes in coastal navigation canals influence the exchange of salt between marshes and coastal ocean, and how those processes are modulated by external physical processes, is critical to anticipating effects of future actions and circumstance. Examples of such circumstances include deepening the channel, placement of locks in the channel...
Authors
Gregg Snedden

Assessing effects of variation in global climate data sets on spatial predictions from climate envelope models Assessing effects of variation in global climate data sets on spatial predictions from climate envelope models

Climate change poses new challenges for natural resource managers. Predictive modeling of species–environment relationships using climate envelope models can enhance our understanding of climate change effects on biodiversity, assist in assessment of invasion risk by exotic organisms, and inform life-history understanding of individual species. While increasing interest has focused on...
Authors
Stephanie S. Romanach, James I. Watling, Robert J. Fletcher, Carolina Speroterra, David N. Bucklin, Laura A. Brandt, Leonard G. Pearlstine, Yesenia Escribano, Frank J. Mazzotti

Connecting the dots: a collaborative USGS-NPS effort to expand the utility of monitoring data Connecting the dots: a collaborative USGS-NPS effort to expand the utility of monitoring data

The Natural Resource Challenge (National Park Service 1999) was a call to action. It constituted a mandate for monitoring based on the twin premises that (1) natural resources in national parks require active management and stewardship if we are to protect them from gradual degradation, and (2) we cannot protect what we do not understand. The intent of the challenge was embodied in its
Authors
James B. Grace, Donald R. Schoolmaster, E. William Schweiger, Brian R. Mitchell, Kathryn Miller, Glenn R. Guntenspergen

Regional differentiation among populations of the Diamondback terrapin (Malaclemys terrapin) Regional differentiation among populations of the Diamondback terrapin (Malaclemys terrapin)

The Diamondback terrapin (Malaclemys terrapin) is a brackish-water turtle species whose populations have been fragmented due to anthropogenic activity such as development of coastal habitat and entrapment in commercial blue crab (Callinectes sapidus) fishing gear. Genetic analyses can improve conservation efforts for the long-term protection of the species. We used microsatellite DNA...
Authors
Kristen M. Hart, Margaret E. Hunter, Tim L. King

Spatial distribution of loggerhead turtle (Caretta caretta) emergences along a highly dynamic beach in the northern Gulf of Mexico Spatial distribution of loggerhead turtle (Caretta caretta) emergences along a highly dynamic beach in the northern Gulf of Mexico

As coastlines change due to sea level rise and an increasing human presence, understanding how species, such as marine turtles, respond to alterations in habitat is necessary for proper management and conservation. Survey data from a major nesting beach in the northern Gulf of Mexico, where a revetment was installed, was used to assess spatial distribution of loggerhead emergences...
Authors
Margaret M. Lamont, Chris Houser

Tailoring point counts for inference about avian density: dealing with nondetection and availability Tailoring point counts for inference about avian density: dealing with nondetection and availability

Point counts are commonly used for bird surveys, but interpretation is ambiguous unless there is an accounting for the imperfect detection of individuals. We show how repeated point counts, supplemented by observation distances, can account for two aspects of the counting process: (1) detection of birds conditional on being available for observation and (2) the availability of birds for...
Authors
Fred A. Johnson, Robert M. Dorazio, Traci D. Castellon, Julien Martin, Jay O. Garcia, James D. Nichols
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