Ecology and Evolutionary Biology Commons^™

Generating Best Management Practices For Avian Conservation In A Land-Sparing Agriculture System, And The Habitat-Specific Survival Of A Priority Migrant, Jeffrey D. Ritterson

Masters Theses

A large amount of the world’s biodiversity is located in a disproportionately small amount of area, namely the tropics. Many of these areas are experiencing rapid landscape changes, mainly in the form of deforestation for agricultural practices. Current conservation efforts are focused on agricultural areas and their ability to provide habitat. The conservation value of a novel land-sparing agroforestry system, known as Integrated Open Canopy (IOC), was recently demonstrated on the study site when applied to coffee. IOC coffee supports forest species that are uncommon or absent in shade grown coffee. I generated best management practices for IOC farms relative …

Density-Dependent Survival In The Larval Stage Of An Invasive Insect: Dispersal Vs. Predation, Adam A. Pepi

Masters Theses

1. The success of invasive species is often thought to be due to release from natural enemies. This hypothesis relies on the assumption that species are regulated by top-down forces in their native range and implies that species are likely to be regulated by bottom-up forces in the invasive range. Neither of these assumptions has been consistently supported with insects, a group which include many highly destructive invasive pest species.

2. Winter moth (Operophtera brumata) is an invasive defoliator in North America that appears to be regulated by mortality in the larval stage in its invasive range. To …

Complex Effects Of Ungulate Browsers On Tree Recruitment And Herbaceous Layers In New England Temperate Forests, Edward K. Faison

Doctoral Dissertations

Browsing by ungulates is a leading biotic disturbance in northern forest ecosystems and an important determinant of habitat, biodiversity, and ecosystem services. A large body of work has revealed that white-tailed deer (Odocoileus virginianus) at high densities alter forest understories in strong and predictable ways; however, less is known about how lower densities of deer and the combined effects of multiple herbivores influence forest understory vegetation, particularly in stands following canopy disturbance. Using fenced exclosures, remote cameras and other field observations, I explored the foraging response and browsing effects of low densities of deer and moose (Alces …

Behavioral And Neural Mechanisms Of Impulsive Choice, Jesse Mcclure

Doctoral Dissertations

Impulsive choice is defined as the preference for a small immediate reward over a larger delayed reward. Individual variablity in impulsive choice correlates with many socially relevant behaviors. Although forms of impulsive choice have been studied in both behavioral ecology and psychology, the exchange of knowledge between these fields is just beginning. Drawing from both of these fields will improve our research methods allowing for a more detailed understanding of this complex behavior. Existing tasks to measure impulsive choice conflate the delay and quantity of the reward. To address this, I have drawn from foraging research to establish a method …

The Effectiveness And Applicability Of Amphibians As Indicator Species For Long-Term Monitoring Of Ecological Changes In New England Forests, Ahmed Siddig

Doctoral Dissertations

The objective of this study is to assess the potential of two amphibians species, Eastern Red-backed Salamander (Plethodon cinereus (Green)) and Eastern Red-spotted Newt (Notopthalmus viridescens viridescens Rafinesque), as indicator species of forest disturbances at Harvard Forest, located in Petersham, Massachusetts, United States. Specifically, I 1) assess the impacts of these focal species to decline of hemlock forests in Harvard Forest; 2) calibrate abundance indices of P. cinereus based on artificial and natural objects surveys with a population size estimator based on depletion sampling; and 3) assess the potential of these salamanders as indicator species by developing an …

Experimental Test Of Genetic Rescue In Isolated Populations Of Brook Trout, Zachary L. Robinson

Masters Theses

Translocations are an important aspect of the management of natural populations in an increasingly fragmented landscape. Maintaining connectivity and gene flow is beneficial for both contemporary fitness and adaptive potential in the face of environmental change. Genetic rescue (GR) can alleviate inbreeding depression, genetic load, and increase adaptive potential of populations. Here, I have translocated 10 (5 of each sex) brook trout (Salvelinus fontinalis) to four geographically proximate and environmentally similar fragmented stream-dwelling populations of brook trout in Virginia to test for genetic rescue. The translocated brook trout contributed to more families than would be expected under neutral …

Experimental Tests Of Road Passage Systems For Reducing Road Mortalities Of Freshwater Turtles, Derek T. Yorks

Masters Theses

Roadways are a pervasive feature of northeastern landscapes and can be a significant source of mortality for turtles. Until recently, little has been known about the design requirements for successful under-road passages for turtles and other wildlife to move safely between bisected habitat patches. At outdoor laboratories, using a factorial experimental design, we examined movements in response to varying light levels, and barrier opacity for painted turtles (Chrysemys picta, n=833), Blanding’s turtles (Emydoidea blandingii, n=49), and spotted turtles (Clemmys guttata, n=49). Additionally, we examined tunnel size, tunnel entrance design, and artificial lighting for painted …

Trends In Human-Wildlife Interactions As Related To Land Use And Human Density In Massachusetts, Michael A. Huguenin Jr

Masters Theses

We conducted a study of human-wildlife interactions in Massachusetts, USA between April 2010 and May 2012. Our objectives were to (1) compile and summarize public-generated reports on human-wildlife interactions across Massachusetts; (2) evaluate reports based on species, public concerns, and seasonal distribution; and (3) evaluate public perceptions of human-wildlife interactions. We collected unsolicited reports of human-wildlife interaction submitted to the Massachusetts Division of Fisheries and Wildlife (MDFW) through phone calls, emails, and face-to-face communications from the public. We received 2,730 reports from 332 of 351 towns in Massachusetts regarding 76 different wildlife species ranging from moose (Alces alces) …

Ant (Hymenoptera: Formicidae) Assemblages In Three New York Pine Barrens And The Impacts Of Hiking Trails, Grace W. Barber

Masters Theses

Ants are ecologically important, environmentally sensitive, widespread, and abundant, yet ant assemblages of many habitats remain poorly understood. Ants in inland barrens of New York State (NY) barely have been studied, but the limited data suggest such habitats are likely to support uncommon ant species and high species density for the region. To increase knowledge of these assemblages, I systematically collected ants from three inland barrens systems in NY, to create species lists and measure species density. I also investigated how hiking trails — a common man-made disturbance — may be impacting ant assemblages in these early-successional, disturbance-dependent ecosystems. My …

The Effect Of Thermoregulation And Roads On The Movements And Habitat Selection Of Moose In Massachusetts, David W. Wattles

Doctoral Dissertations

Massachusetts, U.S.A. is located along the southern boundary of the geographic range of moose (Alces alces) in North America. This is an atypical environment for moose, because of its extremely high levels of human development and high year-round temperatures, which are possibly at the limits of moose physiological tolerances. I investigated the role of these two factors on moose movements and habitat selection to determine how human development of the landscape and temperature influence moose occupation of this extreme environment. In addition, the response of moose to these factors provides insights into the influence of development and temperature …