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Articles 1 - 11 of 11

Full-Text Articles in Ecology and Evolutionary Biology

Perilous Choices: Landscapes Of Fear For Adult Birds Reduces Nestling Condition Across An Urban Gradient, Aaron M. Grade, Susannah B. Lerman, Paige S. Warren Jan 2021

Perilous Choices: Landscapes Of Fear For Adult Birds Reduces Nestling Condition Across An Urban Gradient, Aaron M. Grade, Susannah B. Lerman, Paige S. Warren

Environmental Conservation Faculty Publication Series

Predator fear effects influence reproductive outcomes in many species. In non-urban systems, passerines often respond to predator cues by reducing parental investment, resulting in smaller and lighter nestlings. Since trophic interactions in urban areas are highly altered, it is unclear how passerines respond to fear effects in human-altered landscapes. Nestlings of passerines in urban areas also tend to be smaller and lighter than their rural counterparts and are often exposed to high densities of potential predators yet experience lower per capita predation-the predation paradox. We suggest fear effects in urban habitats could be a significant mechanism influencing nestling condition in …


Large-Scale Patterns Of Green Turtle Trophic Ecology In The Eastern Pacific Oceans, Jeffery A. Seminoff, Lisa M. Komoroske, Diego Amorocho, Randall Arauz, Didiher Chacón-Chaverrí, Nelly De Paz, Peter H. Dutton, Miguel Donoso, Maike Heidemeyer, Gabriel Hoeffer Jan 2021

Large-Scale Patterns Of Green Turtle Trophic Ecology In The Eastern Pacific Oceans, Jeffery A. Seminoff, Lisa M. Komoroske, Diego Amorocho, Randall Arauz, Didiher Chacón-Chaverrí, Nelly De Paz, Peter H. Dutton, Miguel Donoso, Maike Heidemeyer, Gabriel Hoeffer

Environmental Conservation Faculty Publication Series

Trophic position and niche width are fundamental components of a species' ecology, reflecting resource use, and influencing key demographic parameters such as somatic growth, maturation, and survival. Concepts about a species' trophic niche space have important implications for local management and habitat protection, and can shed light about resilience to changing climate for species occurring over broad spatial scales. For elusive marine animals such as sea turtles, trophic niche is challenging to study, and researchers often rely on other metrics, such as isotopic niche, as a proxy. Here, stable isotope analysis (delta C-13 and delta N-15 values) was conducted on …


Annual Winter Water-Level Drawdowns Influence Physical Habitat Structure And Macrophytes In Massachusetts, Usa, Lakes, Jason R. Carmignani, Allison H. Roy Jan 2021

Annual Winter Water-Level Drawdowns Influence Physical Habitat Structure And Macrophytes In Massachusetts, Usa, Lakes, Jason R. Carmignani, Allison H. Roy

Environmental Conservation Faculty Publication Series

Annual wintertime water-level drawdowns are a common management strategy in recreational lakes; however, few studies have estimated their relative impact on lake littoral habitat among a set of typically co-occurring anthropogenic stressors including lakeshore development and herbicide application. Within 21 Massachusetts, USA lakes that represented a drawdown magnitude gradient (0.07-2.26 m), we assessed depth-specific littoral habitat (coarse wood, sediment, macrophytes) at two sites adjacent to forested or developed shorelines. Using generalized linear mixed models, we found coarse wood abundance and branching complexity was not correlated with drawdown magnitude but was primarily explained by the presence of lakeshore development. Drawdown magnitude …


The Value Of Considering Demographic Contributions To Connectivity: A Review, Joseph Drake, Xavier Lambin, Chris Sutherland Jan 2021

The Value Of Considering Demographic Contributions To Connectivity: A Review, Joseph Drake, Xavier Lambin, Chris Sutherland

Environmental Conservation Faculty Publication Series

Connectivity is a central concept in ecology, wildlife management, and conservation science. Understanding the role of connectivity in determining species persistence is increasingly important in the face of escalating anthropogenic impacts on climate and habitat. These connectivity augmenting processes can severely impact species distributions and community and ecosystem functioning. One general definition of connectivity is that it is an emergent process arising from a set of spatial interdependencies between individuals or populations, and increasingly realistic representations of connectivity are being sought. Generally, connectivity consists of a structural component, relating to the distribution of suitable and unsuitable habitat, and a functional …


The Motion Of Trees In The Wind: A Data Synthesis, Toby D. Jackson, Sarab Sethi, Ebba Dellwik, Nikolas Angelou, Amanda Bunce, Tim Van Emmerick, Marine Duperat, Jean-Claude Ruel, Axel Wellpott, Brian Kane Jan 2021

The Motion Of Trees In The Wind: A Data Synthesis, Toby D. Jackson, Sarab Sethi, Ebba Dellwik, Nikolas Angelou, Amanda Bunce, Tim Van Emmerick, Marine Duperat, Jean-Claude Ruel, Axel Wellpott, Brian Kane

Environmental Conservation Faculty Publication Series

Interactions between wind and trees control energy exchanges between the atmosphere and forest canopies. This energy exchange can lead to the widespread damage of trees, and wind is a key disturbance agent in many of the world's forests. However, most research on this topic has focused on conifer plantations, where risk management is economically important, rather than broadleaf forests, which dominate the forest carbon cycle. This study brings together tree motion time-series data to systematically evaluate the factors influencing tree responses to wind loading, including data from both broadleaf and coniferous trees in forests and open environments. We found that …


Hatching Date Influences Winter Habitat Occupancy: Examining Seasonal Interactions Across The Full Annual Cycle In A Migratory Songbird, Michael E. Akresh, David I. King, Peter P. Marra Jan 2021

Hatching Date Influences Winter Habitat Occupancy: Examining Seasonal Interactions Across The Full Annual Cycle In A Migratory Songbird, Michael E. Akresh, David I. King, Peter P. Marra

Environmental Conservation Faculty Publication Series

Birds experience a sequence of critical events during their life cycle, and past events can subsequently determine future performance via carry-over effects. Events during the non-breeding season may influence breeding season phenology or productivity. Less is understood about how events during the breeding season affect individuals subsequently in their life cycle. Using stable carbon isotopes, we examined carry-over effects throughout the annual cycle of prairie warblers (Setophaga discolor), a declining Nearctic-Neotropical migratory passerine bird. In drier winters, juvenile males that hatched earlier at our study site in Massachusetts, USA, occupied wetter, better-quality winter habitat in the Caribbean, as indicated by …


Spatial Capture–Recapture Models Allowing Markovian Transience Or Dispersal, J. Royle, Angela Fuller, Chris Sutherland Jan 2016

Spatial Capture–Recapture Models Allowing Markovian Transience Or Dispersal, J. Royle, Angela Fuller, Chris Sutherland

Environmental Conservation Faculty Publication Series

Spatial capture–recapture (SCR) models are a relatively recent development in quantitative ecology, and they are becoming widely used to model density in studies of animal populations using camera traps, DNA sampling and other methods which produce spatially explicit individual encounter information. One of the core assumptions of SCR models is that individuals possess home ranges that are spatially stationary during the sampling period. For many species, this assumption is unlikely to be met and, even for species that are typically territorial, individuals may disperse or exhibit transience at some life stages. In this paper we first conduct a simulation study …


Quantifying The Human Influence On Fire Ignition Across The Western Usa, Emily J. Fusco, John T. Abatzoglou, Jennifer K. Balch, John T. Finn, Bethany Bradley Jan 2016

Quantifying The Human Influence On Fire Ignition Across The Western Usa, Emily J. Fusco, John T. Abatzoglou, Jennifer K. Balch, John T. Finn, Bethany Bradley

Environmental Conservation Faculty Publication Series

Humans have a profound effect on fire regimes by increasing the frequency of ignitions. Although ignition is an integral component of understanding and predicting fire, to date fire models have not been able to isolate the ignition location, leading to inconsistent use of anthropogenic ignition proxies. Here, we identified fire ignitions from the Moderate Resolution Imaging Spectrometer (MODIS) Burned Area Product (2000–2012) to create the first remotely sensed, consistently derived, and regionally comprehensive fire ignition data set for the western United States. We quantified the spatial relationships between several anthropogenic land-use/disturbance features and ignition for ecoregions within the study area …


Continent-Wide Survey Reveals Massive Decline In African Savannah Elephants, Michael J. Chase, Scott Schlossberg, Curtice R. Griffin, Philippe J.C. Bouché, Sintayehu W. Djene, Paul W. Elkan, Sam Ferreira, Falk Grossman, Edward Mtarima Kohi, Kelly Landen, Patrick Omondi, Alexis Peltier, S.A. Jeanetta Selier, Robert Sutcliffe Jan 2016

Continent-Wide Survey Reveals Massive Decline In African Savannah Elephants, Michael J. Chase, Scott Schlossberg, Curtice R. Griffin, Philippe J.C. Bouché, Sintayehu W. Djene, Paul W. Elkan, Sam Ferreira, Falk Grossman, Edward Mtarima Kohi, Kelly Landen, Patrick Omondi, Alexis Peltier, S.A. Jeanetta Selier, Robert Sutcliffe

Environmental Conservation Faculty Publication Series

African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah …


Spatial Capture–Recapture: A Promising Method For Analyzing Data Collected Using Artificial Cover Objects, Chris Sutherland, David Mun'oz, David Miller, Evan Grant Jan 2016

Spatial Capture–Recapture: A Promising Method For Analyzing Data Collected Using Artificial Cover Objects, Chris Sutherland, David Mun'oz, David Miller, Evan Grant

Environmental Conservation Faculty Publication Series

Spatial capture–recapture (SCR) is a relatively recent development in ecological statistics that provides a spatial context for estimating abundance and space use patterns, and improves inference about absolute population density. SCR has been applied to individual encounter data collected noninvasively using methods such as camera traps, hair snares, and scat surveys. Despite the widespread use of capture based surveys to monitor amphibians and reptiles, there are few applications of SCR in the herpetological literature. We demonstrate the utility of the application of SCR for studies of reptiles and amphibians by analyzing capture–recapture data from Red-Backed Salamanders, Plethodon cinereus, collected using …


Modelling Non-Euclideanmovement And Landscape Connectivity In Highly Structured Ecological Networks, Chris Sutherland, Angela Fuller, J. Royle Dec 2014

Modelling Non-Euclideanmovement And Landscape Connectivity In Highly Structured Ecological Networks, Chris Sutherland, Angela Fuller, J. Royle

Environmental Conservation Faculty Publication Series

1. Movement is influenced by landscape structure, configuration and geometry, but measuring distance as perceived by animals poses technical and logistical challenges. Instead, movement is typically measured using Euclidean distance, irrespective of location or landscape structure, or is based on arbitrary cost surfaces. Arecently proposed extension of spatial capture-recapture (SCR)models resolves this issue using spatial encounterhistories of individuals to calculate least-cost paths (ecological distance: Ecology, 94, 2013, 287) thereby relaxingthe Euclidean assumption. We evaluate the consequences of not accounting for movement heterogeneity whenestimating abundance in highly structured landscapes, and demonstrate the value of this approach for estimatingbiologically realistic space-use patterns …