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You searched for +publisher:"University of Maine" +contributor:("Thomas P. Hodgman"). Showing records 1 – 2 of 2 total matches.

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University of Maine

1. Ruskin, Katharine J. Intra- and Interspecific Variation in Demographic Rates and Niche Across the Range of a Species, the Saltmarsh Sparrow (Ammodramus caudacutus).

Degree: PhD, Ecology and Environmental Sciences, 2015, University of Maine

In this project, we examined various hypotheses that address one of the fundamental questions in ecology and evolution: what determines the range of a species? We used demographic data for saltmarsh sparrows (Ammodramus caudacutus) collected over the majority of the global breeding range. Saltmarsh sparrows are considered threatened by climate change, specifically sea level rise, which is predicted to result in loss of the tidal marsh habitat where saltmarsh sparrows live across their entire life cycle. For my dissertation, I investigated the reproductive biology of saltmarsh sparrows both to provide vital information for wildlife managers and to explore broad questions in ecological and evolutionary theory. We examined the spatial variation in risks to fecundity, vital rates, and niches across the global range of a species. We were thus able to investigate some of the most fundamental concepts in ecology, the drivers of species’ distributions and spatial and temporal variation in niches. Specifically, I 1) explored competing risks to saltmarsh sparrow fecundity across their global range; 2) quantified saltmarsh sparrow fecundity across the range and tested whether fecundity decreases from the range center to its periphery; 3) characterized the nesting niche of saltmarsh sparrows across a large spatial scale to determine whether niche conservatism holds in this system; and 4) investigated differences in nesting niches between saltmarsh and sympatric Nelson’s sparrows and the fitness consequences of those differences. The results of these chapters suggest that though saltmarsh sparrow fecundity is influenced by large-scale factors such as global predation gradients, the saltmarsh sparrow range is not determined by large-scale trends in demographic rates or habitat marginality with latitude or between sister species. Advisors/Committee Members: Brian J. Olsen, Thomas P. Hodgman, Matthew Etterson.

Subjects/Keywords: latitudinal gradients; fecundity; birds; Ammodramus caudacutus; biogeography; saltmarsh; Ecology and Evolutionary Biology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ruskin, K. J. (2015). Intra- and Interspecific Variation in Demographic Rates and Niche Across the Range of a Species, the Saltmarsh Sparrow (Ammodramus caudacutus). (Doctoral Dissertation). University of Maine. Retrieved from https://digitalcommons.library.umaine.edu/etd/2333

Chicago Manual of Style (16th Edition):

Ruskin, Katharine J. “Intra- and Interspecific Variation in Demographic Rates and Niche Across the Range of a Species, the Saltmarsh Sparrow (Ammodramus caudacutus).” 2015. Doctoral Dissertation, University of Maine. Accessed January 19, 2020. https://digitalcommons.library.umaine.edu/etd/2333.

MLA Handbook (7th Edition):

Ruskin, Katharine J. “Intra- and Interspecific Variation in Demographic Rates and Niche Across the Range of a Species, the Saltmarsh Sparrow (Ammodramus caudacutus).” 2015. Web. 19 Jan 2020.

Vancouver:

Ruskin KJ. Intra- and Interspecific Variation in Demographic Rates and Niche Across the Range of a Species, the Saltmarsh Sparrow (Ammodramus caudacutus). [Internet] [Doctoral dissertation]. University of Maine; 2015. [cited 2020 Jan 19]. Available from: https://digitalcommons.library.umaine.edu/etd/2333.

Council of Science Editors:

Ruskin KJ. Intra- and Interspecific Variation in Demographic Rates and Niche Across the Range of a Species, the Saltmarsh Sparrow (Ammodramus caudacutus). [Doctoral Dissertation]. University of Maine; 2015. Available from: https://digitalcommons.library.umaine.edu/etd/2333


University of Maine

2. Correll, Maureen D. Biogeography and Conservation of Tidal Marsh Bird Communities Across a Changing Landscape.

Degree: PhD, Ecology and Environmental Sciences, 2015, University of Maine

Given the current mass extinction crisis and continued fragmentation of resources worldwide, the outlook is dire for global biodiversity. Rising global temperature, sea levels, and storm frequency all create environmental conditions that can drive change in species abundance and distribution across a landscape. Those species reliant upon a single type of habitat and resource for survival, termed “specialists”, are particularly vulnerable to change due to their inability to utilize a variety of resources well. As a result, specialism is now considered one of the dominant factors determining extinction of species. In this dissertation I explore the effects of disturbance on habitat specialist birds in tidal marshes of the northeastern United States. This ecosystem is important due to the significant ecosystem services it provides to humans, and supports several specialist species including the saltmarsh sparrow (Ammodramus caudacutus). I examine this specialist bird community across scales of space, time, and ecological organization to A) evaluate the impacts of disturbance on tidal marsh communities and B) provide findings and management recommendations for long-term maintenance and conservation of coastal marsh ecosystems, specifically as they pertain to salt-marsh specialist birds. In Chapter 1 I introduce my study system and give background for the current conservation status of tidal marsh birds. In Chapter 2 I generate population trends in the five species particularly specialized to tidal marsh using a database of historical records, and explore potential drivers for population change through local and regional habitat disturbance. In Chapter 3 I expand upon patterns in Chapter 2 ad quantify life history strategy in marsh birds across a gradient of habitat specialization to explore how this metric explains species persistence in tidal marshes. In Chapter 4 I test several theoretical hypotheses from disturbance ecology empirically using traditional and novel community metrics. Finally, in Chapter 5 I respond to research needs identified in Chapter 4 to develop a method for quantification of high-marsh habitat using remote sensing methods. I hope the findings presented here contribute towards understanding of the mechanisms driving biodiversity patterns on our planet and help inform conservation priorities within the changing tidal marsh landscapes. Advisors/Committee Members: Brian J. Olsen, Thomas P. Hodgman, Brian J. McGill.

Subjects/Keywords: Mass extinction; Biodiversity; Specialism; Saltmarsh sparrow; Environmental Sciences; Terrestrial and Aquatic Ecology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Correll, M. D. (2015). Biogeography and Conservation of Tidal Marsh Bird Communities Across a Changing Landscape. (Doctoral Dissertation). University of Maine. Retrieved from https://digitalcommons.library.umaine.edu/etd/2405

Chicago Manual of Style (16th Edition):

Correll, Maureen D. “Biogeography and Conservation of Tidal Marsh Bird Communities Across a Changing Landscape.” 2015. Doctoral Dissertation, University of Maine. Accessed January 19, 2020. https://digitalcommons.library.umaine.edu/etd/2405.

MLA Handbook (7th Edition):

Correll, Maureen D. “Biogeography and Conservation of Tidal Marsh Bird Communities Across a Changing Landscape.” 2015. Web. 19 Jan 2020.

Vancouver:

Correll MD. Biogeography and Conservation of Tidal Marsh Bird Communities Across a Changing Landscape. [Internet] [Doctoral dissertation]. University of Maine; 2015. [cited 2020 Jan 19]. Available from: https://digitalcommons.library.umaine.edu/etd/2405.

Council of Science Editors:

Correll MD. Biogeography and Conservation of Tidal Marsh Bird Communities Across a Changing Landscape. [Doctoral Dissertation]. University of Maine; 2015. Available from: https://digitalcommons.library.umaine.edu/etd/2405

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