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Full-Text Articles in Ecology and Evolutionary Biology

Exploring Red-Tailed Hawk Migration Using Stable Isotope Analysis And Dna Sexing Techniques, Kara Clare Donohue Dec 2009

Exploring Red-Tailed Hawk Migration Using Stable Isotope Analysis And Dna Sexing Techniques, Kara Clare Donohue

Boise State University Theses and Dissertations

Understanding the movements of migratory birds and connecting the different stages of their annual cycle is necessary for the conservation and management of migratory bird species. Stable isotope technology has the potential to shed light on the movements of migratory species and to help us better understand their population dynamics. Several studies use stable hydrogen isotopes in particular to predict origins of birds sampled during migration or in winter. However, recent work on stable hydrogen isotopes in feathers (δDf) draws into question the utility of this technology in estimating origins of migrants. My objective was to determine whether …


Temporal Shifts In Demography And Life History Of An Anadromous Alewife Population In Connecticut, Justin P. Davis, Eric T. Schultz May 2009

Temporal Shifts In Demography And Life History Of An Anadromous Alewife Population In Connecticut, Justin P. Davis, Eric T. Schultz

EEB Articles

Populations of anadromous alewives (Alosa pseudoharengus) are declining throughout much of their range, particularly in southern New England where fishery moratoriums have recently been instituted in three states. The alewife run at Bride Brook, a coastal stream in East Lyme, Connecticut, was studied from 2003-06 to assess shifts in demography and life history. Annual censuses of abundance, along with sampling for size, age, and spawning history structure were conducted. These data were compared to similar data in 1966-67 at this site. Recent alewife runs at Bride Brook featured lower abundance and younger, smaller fish that were less likely to be …


Investigating Raptor Migration Behavior Using Orientation Cages And Wing Measurements: A Comparison Of The Flammulated Owl And Northern Saw-Whet Owl In Southwestern Idaho, Rhonda F. Smith May 2009

Investigating Raptor Migration Behavior Using Orientation Cages And Wing Measurements: A Comparison Of The Flammulated Owl And Northern Saw-Whet Owl In Southwestern Idaho, Rhonda F. Smith

Boise State University Theses and Dissertations

Flammulated Owls (Otus flammeolus) are long-distance migrants, while Northern Saw-whet Owls (Aegolius acadicus) exhibit more variable migration tendencies. I investigated the migratory behavior of these species using orientation cages and tested hypotheses concerning (1) the presence of migratory restlessness and orientation, (2) inter-specific differences in migratory restlessness and orientation, and (3) correlates of migratory restlessness and orientation. Only four of 16 Flammulated Owls displayed activity consistent with migratory restlessness although all four owls exhibited significant directionality in their movements. Alternatively, 59 of 97 Northern Saw-whet Owls exhibited activity consistent with migratory restlessness with most of these 59 owls showing preferred …