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Stopover On Galapagos During Autumn Migration Of Bobolinks (Dolichonyx Oryzivorus), Noah G. Perlut, Rosalind Renfrew
Stopover On Galapagos During Autumn Migration Of Bobolinks (Dolichonyx Oryzivorus), Noah G. Perlut, Rosalind Renfrew
Environmental Studies Faculty Publications
The Bobolink (Dolichonyx oryzivorus) is the only landbird species that is known to stop every year in Galapagos while migrating; however, its stopover ecology while on the islands is unknown. In October 2015, we searched for and captured Bobolinks in the highlands of San Cristóbal. We found Bobolinks in two fields, separated by 9.15 km, at ∼425 m elevation. Average daily counts of Bobolinks on these two fields were 3.2 ± 1.8 and 4.8 ± 2.3 individuals. We caught nine individuals; body mass and fat reserves varied from 22.5–40.0 g and no fat reserves to 50–100% reserves, respectively. …
Why Come Back Home? Investigating The Proximate Factors That Influence Natal Philopatry In Migratory Passerines, Jenna A. Cava, Noah G. Perlut, Steven E. Travis
Why Come Back Home? Investigating The Proximate Factors That Influence Natal Philopatry In Migratory Passerines, Jenna A. Cava, Noah G. Perlut, Steven E. Travis
Environmental Studies Faculty Publications
Knowledge of which cues attract birds back to natal areas is important for conservation because the cues could be manipulated to attract breeders to source habitat or discourage breeders from settling in sink habitat. We examined the influence of intrinsic and extrinsic variables on natal philopatry using two metrics, short-distance natal dispersal and the probability of philopatry to the natal field, in two obligate-grassland bird species breeding in an agricultural landscape: the bobolink, Dolichonyx oryzivorus, and the Savannah sparrow, Passerculus sandwichensis. During 2002–2014, we detected 90 locally hatched Savannah sparrows and 129 locally hatched bobolinks breeding as adults …
Local Parasite Lineage Sharing In Temperate Grassland Birds Provides Clues About Potential Origins Of Galapagos Avian Plasmodium, Iris I. Levin, Rachel E. Colborn, Daniel Kim, Noah G. Perlut, Rosalind B. Renfrew, Patricia G. Parker
Local Parasite Lineage Sharing In Temperate Grassland Birds Provides Clues About Potential Origins Of Galapagos Avian Plasmodium, Iris I. Levin, Rachel E. Colborn, Daniel Kim, Noah G. Perlut, Rosalind B. Renfrew, Patricia G. Parker
Environmental Studies Faculty Publications
Oceanic archipelagos are vulnerable to natural introduction of parasites via migratory birds. Our aim was to characterize the geographic origins of two Plasmodium parasite lineages detected in the Galapagos Islands and in North American breeding bobolinks (Dolichonyx oryzivorus) that regularly stop in Galapagos during migration to their South American overwintering sites. We used samples from a grassland breeding bird assemblage in Nebraska, United States, and parasite DNA sequences from the Galapagos Islands, Ecuador, to compare to global data in a DNA sequence registry. Homologous DNA sequences from parasites detected in bobolinks and more sedentary birds (e.g., brown-headed cowbirds …
Nestling Sex Ratios Do Not Support Long-Term Parity In Two Species With Different Life-History Strategies, Noah G. Perlut, Steven E. Travis, Catherine A. Dunbar, Allan M. Strong, Derek M. Wright
Nestling Sex Ratios Do Not Support Long-Term Parity In Two Species With Different Life-History Strategies, Noah G. Perlut, Steven E. Travis, Catherine A. Dunbar, Allan M. Strong, Derek M. Wright
Environmental Studies Faculty Publications
To maximize fitness, breeding adults may respond to environmental processes by adjusting their progeny’s sex ratios. R. A. Fisher in 1930 hypothesized that frequency-dependent selection would result in equal investment in sons and daughters over the long term, yielding a balanced sex ratio if the costs of raising a son and daughter are equal. Diverse hypotheses have tried to explain population and brood-by-brood deviations from this mean as well as annual variation by focusing on adult sex ratios, resources, abiotic conditions, and female and male quality. We collected data in 2002-2010 to explore population-level variation in nestling sex ratios in …
Minor Fitness Benefits For Edge Avoidance In Nesting Grassland Birds In The Northeastern United States, David G. Perkins, Noah G. Perlut, Allan M. Strong
Minor Fitness Benefits For Edge Avoidance In Nesting Grassland Birds In The Northeastern United States, David G. Perkins, Noah G. Perlut, Allan M. Strong
Environmental Studies Faculty Publications
Grassland birds are often affected negatively by habitat fragmentation. Outcomes include greater nest predation and brood parasitism, decreased colonization rates of small, isolated patches, and greater nest density in remnant core habitats. These effects have been well documented in the Midwest, but little is known about fragmentation and edge effects on grassland birds in the fragmented agricultural fields within the forested landscapes of the northeastern United States. From 2002 to 2010, we assessed how edges and edge types affected nest-site location and daily nest survival (DNS) of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) breeding …
Evaluating The Roles Of Visual Openness And Edge Effects On Nest-Site Selection And Reproductive Success In Grassland Birds, Alexander C. Keyel, Allan M. Strong, Noah G. Perlut, J. Michael Reed
Evaluating The Roles Of Visual Openness And Edge Effects On Nest-Site Selection And Reproductive Success In Grassland Birds, Alexander C. Keyel, Allan M. Strong, Noah G. Perlut, J. Michael Reed
Environmental Studies Faculty Publications
In some species, habitat edges (ecotones) affect nest-site selection and nesting success. Openness, or how visually open a habitat is, has recently been shown to influence grassland bird density and may affect nest-site selection, possibly by reducing the risk of predation on adults, nests, or both. Because edge and openness are correlated, it is possible that effects of openness have been overlooked or inappropriately ascribed to edge effects. We tested the roles of edges and visual openness in nest-site selection and nesting success of two grassland passerines, the Bobolink (Dolichonyx oryzivorus) and Savannah Sparrow (Passerculus sandwichensis), …
Natal And Breeding Dispersal Of Bobolinks (Dolichonyx Oryzivorus) And Savannah Sparrows (Passerculus Sandwichensis) In An Agricultural Landscape, Natalia Fajardo, Allan M. Strong, Noah G. Perlut, Neil J. Buckley
Natal And Breeding Dispersal Of Bobolinks (Dolichonyx Oryzivorus) And Savannah Sparrows (Passerculus Sandwichensis) In An Agricultural Landscape, Natalia Fajardo, Allan M. Strong, Noah G. Perlut, Neil J. Buckley
Environmental Studies Faculty Publications
Dispersal is a key process in the metapopulation dynamics and genetic structure of spatially segregated populations. However, our knowledge of avian dispersal, particularly in migratory passerines, remains limited. We studied dispersal of Bobolinks (Dolichonyx oryzivorus) and Savannah Sparrows (Passerculus sandwichensis) to determine whether agricultural management practices affected dispersal patterns and habitat selection. From 2002 to 2006, we banded adults and nestlings on six focal hay fields and two pastures in the Champlain Valley of Vermont and New York and searched for banded birds within 1.5 km of Vermont field sites during two years. Natal dispersal distances were …
Grassland Songbird Survival And Recruitment In Agricultural Landscapes: Implications For Source-Sink Demography, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley
Grassland Songbird Survival And Recruitment In Agricultural Landscapes: Implications For Source-Sink Demography, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley
Environmental Studies Faculty Publications
Population growth and decline are particularly sensitive to changes in three key life-history parameters: annual productivity, juvenile survival, and adult survival. However, for many species these parameters remain unknown. For example, although grassland songbirds are imperiled throughout North America, for this guild, only a small number of studies have assessed these parameters. From 2002 to 2006, in the agricultural landscape of the Champlain Valley of Vermont and New York, USA, we studied Savannah Sparrow (Passerculus sandwichensis) and Bobolink (Dolichonyx oryzivorus) demography on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- …
Grassland Songbirds In A Dynamic Management Landscape: Behavioral Responses And Management Strategies, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley
Grassland Songbirds In A Dynamic Management Landscape: Behavioral Responses And Management Strategies, Noah G. Perlut, Allan M. Strong, Therese M. Donovan, Neil J. Buckley
Environmental Studies Faculty Publications
In recent decades, earlier and more frequent harvests of agricultural grasslands have been implicated as a major cause of population declines in grassland songbirds. From 2002 to 2005, in the Champlain Valley of Vermont and New York, USA, we studied the reproductive success of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- to mid-July; (2) middle-hayed fields cut once between 21 June and 10 July; (3) late-hayed fields cut after 1 August; and (4) rotationally grazed pastures. Both the number of …