Animal Sciences Commons^™

Niche Evolution Along A Gradient Of Ecological Specialization, Meaghan Conway

Electronic Theses and Dissertations

The concept of the ecological niche is fundamental to understanding constraints on species distributions in space and time, and in explaining the origin and maintenance of biodiversity. A niche can be broadly defined to include all of the biotic and abiotic conditions that a species requires to persist. Niche breadth, or the degree of specialization, may influence how labile a species niche is, which can have broad implications for species ability to adapt to environmental change, and for explaining patterns of diversification. I investigated mechanism that facilitate or constrain niche evolution at multiple scales. First, I developed an index of …

Repeat Disturbances Have Cumulative Impacts On Stream Communities, Jessica M. Haghkerdar, Jack R. Mclachlan, Alexis Ireland, Hamish S. Greig

Biology and Ecology Faculty Scholarship

1. Climate change has altered disturbance regimes in many ecosystems, and predictions show that these trends are likely to continue. The frequency of disturbance events plays a particularly important role in communities by selecting for disturbance -tolerant taxa.

2. However, ecologists have yet to disentangle the influence of disturbance frequency per se and time since last disturbance, because more frequently disturbed systems have also usually been disturbed more recently. Our understanding of the effects of repeated disturbances is therefore confounded by differences in successional processes.

3. We used in -situ stream mesocosms to isolate and examine the effect of disturbance …

Associations Between Avian Spruce-Fir Species, Harvest Treatments, Vegetation, And Edges, Brian W. Rolek

Electronic Theses and Dissertations

Habitat loss is the primary cause of species loss and declines of global biodiversity. Several birds associated with the spruce-fir forest type (hereafter spruce-fir birds) have declining populations across the continent in the Atlantic Northern Forest, and the extent of coniferous forest has declined in some areas. This region is extensively and intensively managed for timber products.

To investigate the influence from harvest treatments on the spruce-fir bird assemblage during the breeding and post-breeding period in lowland conifer and mixed-wood forests, we used avian point count detection data to test for associations between avian assemblages and seven common harvest treatments. …

Wildlife Use Of Vernal Pools In An Urbanizing Landscape With A Focus On Population Vitality Of Vernal Pool-Breeding Amphibians, Carly Jasmine Eakin Phd

Electronic Theses and Dissertations

Vernal pools in the northeastern United States provide essential habitat for pool-breeding amphibians and provide resources for other forest-dwelling wildlife. These pools and pool-breeding amphibians in particular are threatened by land conversion associated with urbanization and urban-associated factors. The responses of these amphibians and of birds and mammals using vernal pools to intermediate levels of urban development are largely unknown. I used field observations and lab experiments to study the amphibians, birds, and mammals associated with vernal pools along an urban development gradient in greater Bangor, Maine.

In Chapter 1, I examined bird and mammal use and assemblage composition at …

Connecting Rivers For Healthy Ocean Fisheries, Catherine Schmitt

Maine Sea Grant Publications

Across Maine, communities and land owners are reconnecting rivers and streams by improving road crossings, fixing broken culverts, and removing dams and other barriers. There are many reasons for doing this work, including preventing costly repairs associated with flooding and washouts, enhancing water quality, increasing wildlife habitat, and restoring fish populations. Connecting Rivers explores some of the ways that streams connect inland lakes and forests and the sea. This first fact sheet in the series focuses on connections between populations of migratory river fish (alewives and blueback herring) and groundfish (e.g., cod).

Mammals Of Maine, Ralph S. Palmer

Honors College

The present paper was undertaken in order that the compiler might gain a slight knowledge of Maine mammals and the literature pertaining to this branch of zoology. It was undertaken as a "major honors" course at the University of Maine for the school year of 1936-1937. It is possible that a perusal of this paper will reveal to others the striking scarcity of information on many of our mammalian forms. All the endemic forms known to have occurred in Maine within historic times are listed. Some of these forms are extirpated at the present time. Introduced species are not treated.