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Full-Text Articles in Life Sciences

Aggressive Signaling In New World Warblers, David Hof Nov 2014

Aggressive Signaling In New World Warblers, David Hof

Doctoral Dissertations

In many animal species, communication can enable individuals to resolve conflict without the high potential costs involved in direct fighting. During contests, animals may exchange information about their aggressive motivational state. A central question throughout the study of animal communication research has been whether animal signals convey reliable information, and this question has been particularly relevant to communication during conflicts where the evolutionary interests of competitors directly oppose. Deceptive signaling of aggressive motivation would be highly favored by natural selection because it could allow individuals to gain access to resources they might not gain through direct combat. However, selection should ...


Integrated Modeling Of Land Use And Climate Change Impacts On Multiscale Ecosystems Of Central African Watersheds, Simon Nampindo Nov 2014

Integrated Modeling Of Land Use And Climate Change Impacts On Multiscale Ecosystems Of Central African Watersheds, Simon Nampindo

Doctoral Dissertations

Assessment and management of ecosystem services demands diverse knowledge of the system components. Land use change occurring mainly through deforestation, expansion of agriculture and unregulated extraction of natural resources are the greatest challenges of the Congo basin and yet is central to supporting over 100 million people. This study undertook to implement an integrated modeling of multiscale ecosystems of central African watersheds and model the impact of anthropogenic factors on elephant population in Greater Virunga landscape. The study was conducted at varied scales, regional, landscape, and community. Regional study included watershed analysis and hydrological assessment using remotely sensed data implemented ...


Turning Up The Heat On The Little Things That Run The World: Evaluating The Impacts Of Climate Change On Ant Biodiversity In The Temperate Forest Communities Of The Northeastern United States, Israel Del Toro Nov 2014

Turning Up The Heat On The Little Things That Run The World: Evaluating The Impacts Of Climate Change On Ant Biodiversity In The Temperate Forest Communities Of The Northeastern United States, Israel Del Toro

Doctoral Dissertations

Climatic change threatens biodiversity worldwide. In the forests of the northeastern United States, climate change is expected to increase mean annual temperatures by up to 4.5˚C and change precipitation seasonality. These changes in climate are likely to have impacts on the biodiversity of the region. In order to better understand the impacts of climate change on biodiversity, I used ants, an indicator taxonomic group, to predict how ant communities and ant-mediated ecosystem processes change as the climate warms. In the first chapter of this dissertation, I review the major ecosystem processes and services mediated by ants using the ...


Assessing Wild Canid Distribution Using Camera Traps In The Pioneer Valley Of Western Massachusetts, Eric G. Leflore Nov 2014

Assessing Wild Canid Distribution Using Camera Traps In The Pioneer Valley Of Western Massachusetts, Eric G. Leflore

Masters Theses

With the ever-increasing human population, more people reside in urban areas than ever before; this is having marked effects on the landscape and in turn, wildlife. This study uses automatically triggered wildlife cameras to assess the distribution of three carnivore species (coyotes, Canis latrans; red foxes, Vulpes vulpes; and gray foxes, Urocyon cinereoargenteus) around the Pioneer Valley of Massachusetts in relation to a gradient of human development. Cameras were placed at 141 locations within the 320-km2 study area over the course of three field seasons (3,052 trap nights). Relative abundances for fourteen other species and site characteristics (e ...


The Effects Of Suburbanization On Nest Ectoparasites And Nest Defense Behavior In The Wood Thrush, Evan N. Dalton Nov 2014

The Effects Of Suburbanization On Nest Ectoparasites And Nest Defense Behavior In The Wood Thrush, Evan N. Dalton

Masters Theses

The Wood Thrush (Hylocichla mustelina) is declining throughout its range, yet is capable of persisting in both contiguous forests and small forest patches surrounded by human suburban development. Thus, it is an ideal species for gaining insight into the effects of suburbanization on migrant songbirds. I investigated two aspects of Wood Thrush nesting ecology: nest ectoparasites and nest defense behavior in order to determine if suburbanization influences either aspect. Nests from suburban forests had fewer haematophagous mites, though the abundance of haematophagous blowfly larvae did not differ between suburban and contiguous forests. There was no relationship between the abundance of ...


Spatio-Temporal Factors Affecting Human-Black Bear Interactions In Great Smoky Mountains National Park, Nathan Buckhout Nov 2014

Spatio-Temporal Factors Affecting Human-Black Bear Interactions In Great Smoky Mountains National Park, Nathan Buckhout

Masters Theses

Wildlife managers use models to aid in predicting high risk areas for human and black bear (Ursus americanus) interactions (HBI). These tools help managers implement management strategies to minimize HBI. Over 3,000 incidents of HBI were compiled from management reports at Great Smoky Mountains National Park (GSMNP) during 1998-2011, a park with 9-10.2 million visitors per year and a black bear population of about 1,600 bears.

We used data from bear management reports along with annual visitor use, mast and bear abundance data to develop a series of generalized linear models to assess the spatial and temporal ...


Were Neandertal Humeri Adapted For Spear Thrusting Or Throwing? A Finite Element Study, Michael Anthony Berthaume Nov 2014

Were Neandertal Humeri Adapted For Spear Thrusting Or Throwing? A Finite Element Study, Michael Anthony Berthaume

Masters Theses

An ongoing debate concerning Neandertal ecology is whether or not they utilized long range weaponry. The anteroposteriorly expanded cross-section of Neandertal humeri have led some to argue they thrusted their weapons, while the rounder cross-section of Late Upper Paleolithic modern human humeri suggests they threw their weapons. We test the hypothesis that Neandertal humeri were built to resist strains engendered by thrusting rather than throwing using finite element models of one Neandertal, one Early Upper Paleolithic (EUP) human and three recent human humeri, representing a range of cross-sectional shapes and sizes. Electromyography and kinematic data and articulated skeletons were used ...


Functional And Comparative Morphology Of The Nasal Cavity In Phyllostomid Bats, Thomas P. Eiting Aug 2014

Functional And Comparative Morphology Of The Nasal Cavity In Phyllostomid Bats, Thomas P. Eiting

Doctoral Dissertations

The functional morphology and evolution of the nasal cavity is poorly understood. The New World Leaf-nosed bats of the family Phyllostomidae are an excellent group of mammals in which to study the evolution of the nose and nasal cavity. Phyllostomids span a wide dietary diversity, which is correlated both with the shape of the rostrum as well as with reliance on olfaction, one of the key functions mediated by the nose and the focus of my dissertation. How does dietary diversity relate to differences in the olfactory anatomy of phyllostomids?

I examined three neurological features thought to relate to olfactory ...


Vocal Performance In Songbirds: Territorial Defense And The Development Of Male Song And Female Mating Preferences, Dana L. Moseley Apr 2014

Vocal Performance In Songbirds: Territorial Defense And The Development Of Male Song And Female Mating Preferences, Dana L. Moseley

Doctoral Dissertations

The evolution of sexually selected signals has been a major topic of scientific research since Darwin. In recent years, scientists have focused on how elaborate signals can indicate honest information about the quality of their bearers, as predicted by reliability theory. A key concept relating to how mating displays could reliably reveal quality is "performance." Animals face limits in display production, and producing high-­‐performance displays depends on the adept coordination of multiple motor systems. Thus, by observing motor performance, signal-­‐receivers can assess the quality of signalers. Birdsong is a prime example of a display that involves motor challenges ...