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You searched for subject:(Ammodramus caudacutus). 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 (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 24, 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. 24 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 24]. 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 Connecticut

2. Meiman, Susan T. Modeling Saltmarsh Sparrow Distribution in Connecticut.

Degree: MS, Ecology and Evolutionary Biology, 2011, University of Connecticut

To develop a map that would predict where saltmarsh sparrows live and reproduce in Connecticut, I compared models to test a) whether field data or remote-sensing data most effectively characterized within-marsh conditions that relate to sparrow occurrence, and b) whether including landscape-level variables improved model fit.  The best sparrow presence model used a variable derived from raw spectral reflectance values associated with plots where sparrows did not occur, while the best nest presence model used a combination of vegetation structure descriptions.   A second nest model, built using high resolution remote sensing data that organized marsh characteristics into high and low marsh categories, had enough support for state-wide application. When the models were tested using new data, model performance, assessed by determining the area under a receiver operating curve and the model deviance, was significantly better than expected by chance alone.  A large proportion of the saltmarsh area in Connecticut was predicted to have a high probability of being occupied by sparrows, yet a much smaller proportion of marsh was predicted to have a high probability of having nests.  While detailed delineation of plant communities in the marsh provided good predictions of sparrow nesting, they poorly predicted presence.  On the other hand, because areas of nesting activity are not well-identified by species presence models, a distribution model that describes only species presence would provide misleading information about where the most important areas for reproduction lie.  Advisors/Committee Members: Daniel L. Civco, Kent E. Holsinger, Chris S. Elphick.

Subjects/Keywords: Ammodramus caudacutus; Bayesian hierarchical models; habitat use; occupancy modeling; remote sensing; salt marsh; saltmarsh sparrow

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

APA (6th Edition):

Meiman, S. T. (2011). Modeling Saltmarsh Sparrow Distribution in Connecticut. (Masters Thesis). University of Connecticut. Retrieved from https://opencommons.uconn.edu/gs_theses/72

Chicago Manual of Style (16th Edition):

Meiman, Susan T. “Modeling Saltmarsh Sparrow Distribution in Connecticut.” 2011. Masters Thesis, University of Connecticut. Accessed January 24, 2020. https://opencommons.uconn.edu/gs_theses/72.

MLA Handbook (7th Edition):

Meiman, Susan T. “Modeling Saltmarsh Sparrow Distribution in Connecticut.” 2011. Web. 24 Jan 2020.

Vancouver:

Meiman ST. Modeling Saltmarsh Sparrow Distribution in Connecticut. [Internet] [Masters thesis]. University of Connecticut; 2011. [cited 2020 Jan 24]. Available from: https://opencommons.uconn.edu/gs_theses/72.

Council of Science Editors:

Meiman ST. Modeling Saltmarsh Sparrow Distribution in Connecticut. [Masters Thesis]. University of Connecticut; 2011. Available from: https://opencommons.uconn.edu/gs_theses/72

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