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Peter P Marra - One of the best experts on this subject based on the ideXlab platform.
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ARTICLE Relationships
2016Co-Authors: Matthew M. Osmond, Peter P Marra, Matthew W Reudink, Peter T Boag, Ryan R. Germain, Joseph J. Nocera, Laurene M RatcliffeAbstract:between carotenoid-based female plumage and age, reproduction, and mate colour in the American Redstart (Setophaga ruticilla
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Winter habitat quality but not long-distance dispersal influences apparent reproductive success in a migratory bird.
Ecology, 2015Co-Authors: Clark S. Rushing, Peter P Marra, Michele R. DudashAbstract:Long-distance breeding and natal dispersal play central roles in many ecological and evolutionary processes, including gene flow, population dynamics, range expansion, and individual responses to fluctuating biotic and abiotic conditions. However, the relative contribution of long-distance dispersal to these processes depends on the ability of dispersing individuals to successfully reproduce in their new environment. Unfortunately, due to the difficulties associated with tracking dispersal in the field, relatively little is known about its reproductive consequences. Furthermore, because reproductive success is influenced by a variety of processes, disentangling the influence of each of these processes is critical to understanding the direct consequences of dispersal. In this study, we used stable hydrogen and carbon isotopes to estimate long-distance dispersal and winter territory quality in a migratory bird, the American Redstart (Setophaga ruticilla). We then applied Aster life-history models to quantify the strength of influence of these factors on apparent reproductive success. We found no evidence that male or female reproductive success was lower for long-distance dispersers relative to non-dispersing individuals. In contrast, carry-over effects from the winter season did influence male, but not female, reproductive success. Use of Aster models further revealed that for adult males, winter territory quality influenced the number of offspring produced whereas for yearling males, high-quality winter territories were associated with higher mating and nesting success. These results suggest that although long-distance natal and breeding dispersal carry no immediate reproductive cost for American Redstarts, reproductive success in this species may ultimately be limited by the quality of winter habitat.
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Habitat and body condition influence American Redstart foraging behavior during the non-breeding season
Journal of Field Ornithology, 2015Co-Authors: Luke L. Powell, Robert C. Dobbs, Peter P MarraAbstract:Insectivorous birds may adjust their foraging strategies to exploit changes in resource distributions. Arthropod prey strongly influence habitat-specific persistence of long-distance migrant passerines in their wintering areas, and arthropods are strongly affected by rainfall. However, the effect of drought on the dynamics of avian foraging ecology as resources shift is not well understood. We captured female American Redstarts (Setophaga ruticilla) and studied their foraging behavior in high-quality (evergreen black mangrove) and low-quality (deciduous scrub) habitat in Jamaica during the winter of 1995–1996. As is typical in southwestern Jamaica, conditions became drier as spring approached and many trees in scrub lost most of their leaves; mangrove trees maintained most of their leaf cover. Birds in scrub lost more mass than those in mangrove, and scrub birds shifted to using more aerial (and fewer near-perch) maneuvers. In scrub, but not in mangrove, the proportion of wing-powered movements and aerial foraging maneuvers was positively correlated with mass corrected by body size. In both habitats, attack rate was negatively correlated with body condition. Therefore, Redstarts in scrub that maintained body condition were likely better able to use energetically expensive aerial maneuvers and wing-powered search movements to exploit large, calorie-rich flying arthropods. As the scrub dried over the course of the winter, the shift in foraging tactic may have allowed some birds to forage more efficiently (i.e., lower attack rate), likely facilitating maintenance of good body condition. RESUMEN El habitat y la condicion corporal influye sobre la conducta de forrajeo de Setophaga ruticilla durante el periodo no-reproductivo Las aves insectivoras pueden ajustar sus estrategias de forrajeo para explotar los cambios que puedan ocurrir en la distribucion de recursos. La disponibilidad de artropodos utilizados como presas, en donde la presencia y cantidad de estos puede ser afectada por las lluvias, influye grandemente sobre la persistencia de paserinos migratorios invernales, que vuelan largas distancias, a habitats especificos invernales. Sin embargo, el efecto de sequias y la dinamica de la ecologia de forrajeo, en habitats diferentes, con referencia a cambios en la disponibilidad de recursos no es del todo bien entendido. Capturamos hembras de la Reinita candelita (Setophaga ruticilla), y estudiamos su conducta de forrajeo en un habitat de alta calidad (mangle negro) y un habitat pobre (matorral deciduo) durante el invierno del 1995–1996 en Jamaica. Como es tipico del suroeste de Jamaica, las condiciones fueron mas secas segun se acerco la primavera y muchos arboles y arbustos perdieron las hojas, pero el mangle negro mantuvo gran parte de su follaje. Las aves en el matorral perdieron mas masa que las aves en el manglar y hubo un cambio en utilizar mas capturas a vuelos que alimentarse en perchas. En el matorral, pero no asi en el mangle, la proporcion de movimientos propulsados por las alas y uso de forrajeo por aire, estuvo correlacionado positivamente con el tamano del cuerpo. En ambos habitats, la tasa de ataque aereo estuvo negativamente correlacionada con la condicion corporal. Por tanto, las reinitas en habitat de matorral que pudieron mantener su condicion corporal fueron mas propensas a utilizar forrajeo aereo, de mayor gasto energetico, y a utilizar artropodos voladores de gran valor calorico. Segun fue secandose el matorral a lo largo del invierno, el cambio en tacticas de forrajeo, puede haberle permitido a algunas aves a forrajear de forma mas eficiente (ej. una tasa menor de ataques aereos), facilitando el mantenimiento de una buena condicion corporal.
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age related change in carotenoid based plumage of the American Redstart setophaga ruticilla
Journal of Ornithology, 2015Co-Authors: Kristen L D Marini, Peter P Marra, Laurene M Ratcliffe, Ann E. Mckellar, Matthew W ReudinkAbstract:Plumage colouration serves a variety of functions for birds, including conspecific signalling, crypsis, and predator–prey interactions. Though much research has been conducted on colour changes in species with delayed plumage maturation, where birds do not exhibit definitive adult plumage until their second breeding season or later, relatively few studies have examined how plumage colour changes once definitive adult plumage has been attained. In this study on male and female American Redstarts (Setophaga ruticilla), which exhibit male delayed plumage maturation, we used reflectance spectrometry to evaluate carotenoid-based tail colour changes over 11 breeding seasons, examining both within-individual and population-level changes. At a population level, males in their first breeding season in definitive adult plumage had a feather hue that was more orange-shifted than birds in their second year in adult plumage, and marginally, but not significantly, more orange-shifted than birds in their third year in adult plumage. Within-individual analysis of males recaptured in subsequent seasons also revealed a shift away from orange towards a more yellow feather hue as individuals aged. Within individuals, red chroma was highest for males in their second year in adult plumage, but it showed no population-level effects. At the population level, female Redstarts in their first breeding season displayed plumage with a higher red chroma and a lower brightness than birds in their second breeding season, potentially as a result of differences in the timing and conditions of moult (first-year bird tail feathers were grown in the nest). For adult males and females, there was no difference in plumage colouration between birds that returned to the study site compared to those that failed to return. Together, our results suggest that within-individual change rather than differential survival best explains our findings. We suggest that studies examining age-related colour changes are critical for understanding the evolution of complex signalling systems, such as that of American Redstarts.
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Optimal Conservation of Migratory Species
2014Co-Authors: Tara G. Martin, Peter P Marra, Peter Arcese, Hugh P. Possingham, Ryan D NorrisAbstract:Background. Migratory animals comprise a significant portion of biodiversity worldwide with annual investment for their conservation exceeding several billion dollars. Designing effective conservation plans presents enormous challenges. Migratory species are influenced by multiple events across land and sea–regions that are often separated by thousands of kilometres and span international borders. To date, conservation strategies for migratory species fail to take into account how migratory animals are spatially connected between different periods of the annual cycle (i.e. migratory connectivity) bringing into question the utility and efficiency of current conservation efforts. Methodology/Principal Findings. Here, we report the first framework for determining an optimal conservation strategy for a migratory species. Employing a decision theoretic approach using dynamic optimization, we address the problem of how to allocate resources for habitat conservation for a Neotropical-Nearctic migratory bird, the American Redstart Setophaga ruticilla, whose winter habitat is under threat. Our first conservation strategy used the acquisition of winter habitat based on land cost, relative bird density, and the rate of habitat loss to maximize the abundance of birds on the wintering grounds. Our second strategy maximized bird abundance across the entire range of the species by adding the constraint of maintaining a minimum percentage of birds within each breeding region in North America using information on migratory connectivity as estimated from stable-hydrogen isotopes in feathers. We show that failure to take into account migratory connectivity may doom some regional populations to extinction, wherea
Laurene M Ratcliffe - One of the best experts on this subject based on the ideXlab platform.
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ARTICLE Relationships
2016Co-Authors: Matthew M. Osmond, Peter P Marra, Matthew W Reudink, Peter T Boag, Ryan R. Germain, Joseph J. Nocera, Laurene M RatcliffeAbstract:between carotenoid-based female plumage and age, reproduction, and mate colour in the American Redstart (Setophaga ruticilla
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age related change in carotenoid based plumage of the American Redstart setophaga ruticilla
Journal of Ornithology, 2015Co-Authors: Kristen L D Marini, Peter P Marra, Laurene M Ratcliffe, Ann E. Mckellar, Matthew W ReudinkAbstract:Plumage colouration serves a variety of functions for birds, including conspecific signalling, crypsis, and predator–prey interactions. Though much research has been conducted on colour changes in species with delayed plumage maturation, where birds do not exhibit definitive adult plumage until their second breeding season or later, relatively few studies have examined how plumage colour changes once definitive adult plumage has been attained. In this study on male and female American Redstarts (Setophaga ruticilla), which exhibit male delayed plumage maturation, we used reflectance spectrometry to evaluate carotenoid-based tail colour changes over 11 breeding seasons, examining both within-individual and population-level changes. At a population level, males in their first breeding season in definitive adult plumage had a feather hue that was more orange-shifted than birds in their second year in adult plumage, and marginally, but not significantly, more orange-shifted than birds in their third year in adult plumage. Within-individual analysis of males recaptured in subsequent seasons also revealed a shift away from orange towards a more yellow feather hue as individuals aged. Within individuals, red chroma was highest for males in their second year in adult plumage, but it showed no population-level effects. At the population level, female Redstarts in their first breeding season displayed plumage with a higher red chroma and a lower brightness than birds in their second breeding season, potentially as a result of differences in the timing and conditions of moult (first-year bird tail feathers were grown in the nest). For adult males and females, there was no difference in plumage colouration between birds that returned to the study site compared to those that failed to return. Together, our results suggest that within-individual change rather than differential survival best explains our findings. We suggest that studies examining age-related colour changes are critical for understanding the evolution of complex signalling systems, such as that of American Redstarts.
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Inter-annual variation in American Redstart (Setophaga ruticilla) plumage colour is associated with rainfall and temperature during moult: an 11-year study.
Oecologia, 2014Co-Authors: Matthew W Reudink, Peter P Marra, Ann E. Mckellar, Kristen L D Marini, Sarah L. Mcarthur, Laurene M RatcliffeAbstract:Carotenoid-based colouration plays an important role in sexual signaling in animals as an honest indicator of individual quality during mate choice and competitive interactions. However, few studies have examined how natural variation in weather conditions influences inter-annual variation in the expression of ornamentation, potentially through affecting the dietary availability of carotenoids. In this study, we examine variation in the expression of carotenoid-based plumage colouration in relation to temperature and rainfall during the pre-moulting and moulting period over 11 years in a population of American Redstarts, Setophaga ruticilla, breeding in eastern Canada. We used reflectance spectrometry of tail feathers collected from male and female Redstarts to relate feather colour with weather conditions the previous breeding season during the months over which Redstarts are likely to moult (June–September). At a population level, birds expressed feathers with higher red chroma and lower brightness in years following high July rainfall and low August temperature. The pattern was stronger in males, but was generally consistent across ages and sexes. Analyses of feathers from repeatedly captured birds indicated that the above patterns could be explained by individual change in feather colour. We suggest that higher rainfall during the moulting period may increase insect abundance and the availability of dietary carotenoids. This is among the first studies to show effects of weather conditions on a sexual signalling trait, which may have important consequences for sexual selection, mate choice, and the reliability of putative signals.
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Relationships between carotenoid-based female plumage and age, reproduction, and mate colour in the American Redstart (Setophaga ruticilla)
Canadian Journal of Zoology, 2013Co-Authors: Matthew M. Osmond, Peter P Marra, Matthew W Reudink, Peter T Boag, Ryan R. Germain, Joseph J. Nocera, Laurene M RatcliffeAbstract:Most studies investigating the function and evolution of ornaments have focused on males. Variation in ornaments may also reflect individual quality and convey information in females. We examined correlations between female plumage colour and reproductive variables in the sexually dichromatic songbird, the American Redstart (Setophaga ruticilla (L., 1758)). Female American Redstarts display yellow, carotenoid-based plumage patches on their tails, wings, and flanks. Using reflectance spectrometry, we quantified brightness (feather structure) and "yellowness" (hue and chroma) of tail and flank feathers to examine whether female plumage colour varies with age, reproductive success, parental care, and the plumage colour of mates. Female plumage varied with age, with adult (after-second-year) females having brighter tail feathers than first-year females. We failed to find a relationship between female plumage colour and pairing or first-egg dates. However, adult females with brighter tails visited their nests less frequently and first-year females with brighter tails fledged fewer offspring. Adult females with brighter tails also mated with males who provided less care. In addition, adult females with yellower flanks paired with males with brighter flanks and with males who provided less parental care. We suggest that plumage colouration in female American Redstarts can act as a signal of individual age and quality. Resume : La plupart des etudes sur la fonction et l'evolution des ornements se sont interessees aux mâles. Les variations des ornements des femelles pourraient egalement refleter la qualite des individus et transmettre de l'information. Nous avons examine les correlations entre la couleur du plumage des femelles et des variables relatives ala reproduction chez la paruline flamboyante (Setophaga ruticilla (L., 1758)), un oiseau chanteur caracterise par un dichroisme sexuel. Les femelles de cette espece presentent des zones de plumage jaune abase de carotenoide sur leur queue, leurs ailes et leurs flancs. Nous avons quantifie la clarte (structure de la plume) et le caractere jaune (tonalite et saturation) de plumes de queue et de flanc par spectrometrie par reflectance afin de determiner si la couleur du plumage des femelles varie selon l'âge, le succes de reproduction, le soin parental et la couleur du plumage du compagnon. Le plumage des femelles variait selon l'âge, les femelles adultes (apres la deuxieme annee) presentant des plumes de queue plus claires que les femelles d'un an. Nous n'avons trouve aucun lien entre la couleur du plumage des femelles et le moment de l'appariement ou des premiers œufs. Toutefois, les femelles adultes presentant une queue plus claire visitaient leur nid moins frequemment et les femelles d'un an presentant une queue plus claire produisaient moins d'oisillons envoles. Les femelles adultes avec une queue plus claire s'accouplaient egalement avec des mâles faisant preuve de moins de soin parental. En outre, les femelles adultes presentant des flancs plus jaunes s'accouplaient avec des mâles avec des flancs plus clairs et des mâles faisant preuve de moins de soin parental. Nous postulons que la coloration du plumage des femelles de la paruline flamboyante peut constituer un indice de l'âge et de la qualite individuels. (Traduit par la Redaction) Mots-cles : paruline flamboyante, carotenoide, couleur, ornement de la femelle, plumage, Setophaga ruticilla, selection sexuelle.
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Carotenoid-based Male Plumage Predicts Parental Investment in the American Redstart
The Wilson Journal of Ornithology, 2010Co-Authors: Ryan R. Germain, Peter P Marra, Matthew W Reudink, Laurene M RatcliffeAbstract:Abstract We examined whether male plumage coloration signals parental quality in the American Redstart (Setophaga ruticilla), a highly ornamented, migratory warbler. We measured the relationship between both adult male arrival date and phenotype (morphology, melanin- and carotenoid-based plumage), and parental care levels of both parents. Males with brighter flank feathers made more visits to the nest and spent more time at the nest, consistent with the ‘good-parent hypothesis’. Female parental care (number of visits) was negatively correlated with intensity of red of her mate's tail feathers and positively associated with her mate's parental effort. These data indicate offspring of brighter males receive more care from both parents. Our results suggest carotenoid-based plumage traits of male American Redstarts may have an important role in intersexual signaling, and add to our understanding of the evolution of multiple ornaments.
Thomas W. Sherry - One of the best experts on this subject based on the ideXlab platform.
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Sherry et al annual covariate data
2016Co-Authors: Thomas W. Sherry, Scott Wilson, Sarah Hunter, Richard T. HolmesAbstract:Text file containing annual covariates (1983-1995) for analyzing American Redstart nesting success in Hubbard Brook Experimental Forest, NH, USA. Besides year, covariates in file include Redstart population density, predator index, May temperature, May rainfall, June temperature, June rainfall
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Sherry et al nest survival data
2016Co-Authors: Thomas W. Sherry, Scott Wilson, Sarah Hunter, Richard T. HolmesAbstract:Text file containing nest survival data for American Redstart in MARK format for the years 1983-1995, Hubbard Brook Experimental Forest, NH, USA. Covariates (besides nest year and ID number) are date found, date nest last alive, date nest last checked, nest fate, encounter history, nest height above ground, nest status as to whether baffled against scansorial predators or not, nest tree DBH, and age status of nest
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Combining survey methods to estimate abundance and transience of migratory birds among tropical nonbreeding habitats
The Auk, 2015Co-Authors: Ashley M. Peele, Peter M. Marra, T. Scott Sillett, Thomas W. SherryAbstract:ABSTRACT Estimating population abundance for territorial species is challenging because individuals often differ in behavior (e.g., transience, multiterritoriality), and thus in detectability. How well prevailing methods detect and quantify individuals using multiple strategies is rarely addressed. In our effort to efficiently quantify avian abundance and transience among diverse nonbreeding habitats, we combined ‘unmarked' (distance sampling) with traditional ‘marked' (territory mapping) survey methods using a migratory passerine, the American Redstart (Setophaga ruticilla), wintering in 3 habitats in Jamaica from 2010 to 2012. We predicted that the ‘unmarked' survey method would detect not only all known (marked) territorial individuals, but also individuals that were transient or nonterritorial in the same habitats. Comparisons of abundance estimates generated by our best distance sampling (unmarked) model with territory mapping data identified high proportions of transient individuals (up to 50%) in 2...
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Assessing habitat quality for a migratory songbird wintering in natural and agricultural habitats
Conservation Biology, 2006Co-Authors: Matthew D. Johnson, Thomas W. Sherry, Richard T. Holmes, Peter P MarraAbstract:As tropical forests are cleared, a greater proportion of migratory songbirds are forced to winter in agricultural and disturbed habitats, which, if poorer in quality than natural forests, could contribute to population declines. We compared demographic indicators of habitat quality for a focal species, the American Redstart (Setophaga ruticilla), wintering in Jamaican citrus orchards and shade coffee plantations with those in four natural habitats: mangrove, coastal scrub, coastal palm, and dry limestone forests. Demographic measures of habitat quality included density, age and sex ratio, apparent survival, and changes in body mass. Measures of habitat quality for Redstarts in citrus and coffee habitats were generally intermediate between the highest (mangrove) and lowest (dry limestone) measurements from natural habitats. The decline in mean body mass over the winter period was a strong predictor of annual survival rate among habitats, and we suggest that measures of body condition coupled with survival data provide the best measures of habitat quality for nonbreeding songbirds. Density, which is far easier to estimate, was correlated with these more labor-intensive measures, particularly in the late winter when food is likely most limiting. Thus, local density may be useful as an approximation of habitat quality for wintering migrant warblers. Our findings bolster those of previous studies based on bird abundance that suggest arboreal agricultural habitats in the tropics can be useful for the conservation of generalist, insectivorous birds, including many migratory passerines such as Redstarts.
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SINGING BEHAVIOR VARIES WITH BREEDING STATUS OF American RedstartS (SETOPHAGA RUTICILLA)
The Wilson Journal of Ornithology, 2006Co-Authors: Cynthia A. Staicer, Victoria Ingalls, Thomas W. SherryAbstract:Abstract We examined the relationship between singing behavior and breeding status in the American Redstart (Setophaga ruticilla) by analyzing song rates, singing mode (Repeat or Serial), and variability of song delivery in relation to the age and breeding status of 129 males in the Hubbard Brook Experimental Forest, New Hampshire. Unpaired males spent most of their time (>90%) after dawn singing in Repeat mode, whereas paired males sang sporadically, in Serial as well as Repeat mode (51% of their singing time). Males who lost their mates sang in Repeat mode at rates indistinguishable from males who had not yet obtained a mate. Overall, unpaired males sang in Repeat mode at significantly higher and less variable rates than did paired males. Although a larger proportion of second-year males were unpaired than after-second-year males, we found no evidence that age affected singing behavior. We also assessed the effect of pairing status on male detectability in song-based monitoring surveys (e.g., point coun...
Richard T. Holmes - One of the best experts on this subject based on the ideXlab platform.
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Sherry et al annual covariate data
2016Co-Authors: Thomas W. Sherry, Scott Wilson, Sarah Hunter, Richard T. HolmesAbstract:Text file containing annual covariates (1983-1995) for analyzing American Redstart nesting success in Hubbard Brook Experimental Forest, NH, USA. Besides year, covariates in file include Redstart population density, predator index, May temperature, May rainfall, June temperature, June rainfall
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Sherry et al nest survival data
2016Co-Authors: Thomas W. Sherry, Scott Wilson, Sarah Hunter, Richard T. HolmesAbstract:Text file containing nest survival data for American Redstart in MARK format for the years 1983-1995, Hubbard Brook Experimental Forest, NH, USA. Covariates (besides nest year and ID number) are date found, date nest last alive, date nest last checked, nest fate, encounter history, nest height above ground, nest status as to whether baffled against scansorial predators or not, nest tree DBH, and age status of nest
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Assessing habitat quality for a migratory songbird wintering in natural and agricultural habitats
Conservation Biology, 2006Co-Authors: Matthew D. Johnson, Thomas W. Sherry, Richard T. Holmes, Peter P MarraAbstract:As tropical forests are cleared, a greater proportion of migratory songbirds are forced to winter in agricultural and disturbed habitats, which, if poorer in quality than natural forests, could contribute to population declines. We compared demographic indicators of habitat quality for a focal species, the American Redstart (Setophaga ruticilla), wintering in Jamaican citrus orchards and shade coffee plantations with those in four natural habitats: mangrove, coastal scrub, coastal palm, and dry limestone forests. Demographic measures of habitat quality included density, age and sex ratio, apparent survival, and changes in body mass. Measures of habitat quality for Redstarts in citrus and coffee habitats were generally intermediate between the highest (mangrove) and lowest (dry limestone) measurements from natural habitats. The decline in mean body mass over the winter period was a strong predictor of annual survival rate among habitats, and we suggest that measures of body condition coupled with survival data provide the best measures of habitat quality for nonbreeding songbirds. Density, which is far easier to estimate, was correlated with these more labor-intensive measures, particularly in the late winter when food is likely most limiting. Thus, local density may be useful as an approximation of habitat quality for wintering migrant warblers. Our findings bolster those of previous studies based on bird abundance that suggest arboreal agricultural habitats in the tropics can be useful for the conservation of generalist, insectivorous birds, including many migratory passerines such as Redstarts.
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CONSEQUENCES OF DOMINANCE-MEDIATED HABITAT SEGREGATION IN American RedstartS DURING THE NONBREEDING SEASON
The Auk, 2001Co-Authors: Peter P Marra, Richard T. HolmesAbstract:Abstract Several species of migratory songbirds exhibit a distinct form of habitat segregation while on their Neotropical wintering grounds in which males and females occupy different habitat types. In the American Redstart (Setophaga ruticilla), that sexual habitat segregation is a result of behavioral dominance of older males. In that study, we examined whether such dominance behavior and the resulting differential habitat segregation has consequences for the condition or survival of excluded individuals. We quantified the physical condition and survival of Redstarts (both males and females) occupying two habitat types that differed in the proportion of males and females present in Jamaica. Both sexes of Redstarts occupying female-biased habitat lost significantly more mass over-winter and had lower annual survival and longevity compared to individuals in male-biased habitat. These results suggest that nonbreeding habitats differed in suitability, with the least suitable habitat being occupied predomina...
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Consequences of Dominance-Mediated Habitat Segregation in American Redstarts During the Nonbreeding Season
The Auk, 2001Co-Authors: Peter P Marra, Richard T. HolmesAbstract:AbstractSeveral species of migratory songbirds exhibit a distinct form of habitat segregation while on their Neotropical wintering grounds in which males and females occupy different habitat types. In the American Redstart (Setophaga ruticilla), that sexual habitat segregation is a result of behavioral dominance of older males. In that study, we examined whether such dominance behavior and the resulting differential habitat segregation has consequences for the condition or survival of excluded individuals. We quantified the physical condition and survival of Redstarts (both males and females) occupying two habitat types that differed in the proportion of males and females present in Jamaica. Both sexes of Redstarts occupying female-biased habitat lost significantly more mass over-winter and had lower annual survival and longevity compared to individuals in male-biased habitat. These results suggest that nonbreeding habitats differed in suitability, with the least suitable habitat being occupied predominately by females. Because most female Redstarts are forced to over-winter in these kinds of habitats, they may often be in poor physiological condition prior to departing on spring migration for the breeding grounds. This in turn may influence dynamics of the breeding period by determining their condition and perhaps reproductive success. Furthermore, because winter habitat segregation appears to lower female survivorship, it may also limit the number and availability of breeding females. These results implicate events that occur during the nonbreeding period as playing a critical role in the annual dynamics of this migratory species.
Marra, Peter P. - One of the best experts on this subject based on the ideXlab platform.
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The Strength of Migratory Connectivity for Birds En Route to Breeding Through the Gulf of Mexico
'Wiley', 2019Co-Authors: Cohen, Emily B., Moore, Frank R., Rushing, Clark R., Hallworth, Michael T., Hostetler, Jeffrey A., Ramirez, Mariamar Gutierrez, Marra, Peter P.Abstract:The strength of migratory connectivity is a measure of the cohesion of populations among phases of the annual cycle, including breeding, migration, and wintering. Many Nearctic‐Neotropical species have strong migratory connectivity between breeding and wintering phases of the annual cycle. It is less clear if this strength persists during migration when multiple endogenous and exogenous factors may decrease the cohesion of populations among routes or through time along the same routes. We sampled three bird species, American Redstart Setophaga ruticilla, ovenbird Seiurus aurocapilla, and wood thrush Hylocichla mustelina, during spring migration through the Gulf of Mexico region to test if breeding populations differentiate spatially among migration routes or temporally along the same migration routes and the extent to which within‐population timing is a function of sex, age, and carry‐over from winter habitat, as measured by stable carbon isotope values in claws (δ13C). To make quantitative comparisons of migratory connectivity possible, we developed and used new methodology to estimate the strength of migratory connectivity (MC) from probabilistic origin assignments identified using stable hydrogen isotopes in feathers (δ2H). We found support for spatial differentiation among routes by American Redstarts and ovenbirds and temporal differentiation along routes by American Redstarts. After controlling for breeding origin, the timing of American Redstart migration differed among ages and sexes and ovenbird migration timing was influenced by carry‐over from winter habitat. The strength of migratory connectivity did not differ among the three species, with each showing weak breeding‐to‐spring migration MC relative to prior assessments of breeding‐wintering connectivity. Our work begins to fill an essential gap in methodology and understanding of the extent to which populations remain together during migration, information critical for a full annual cycle perspective on the population dynamics and conservation of migratory animals
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Data from: Extra-pair offspring are less heterozygous than within-pair offspring in American Redstarts (Setophaga ruticilla)
2019Co-Authors: Hajdasz Adrianne, Marra, Peter P., Mckellar, Ann E., Ratcliffe, Laurene M., Boag, Peter T., Reudink, Matthew W.Abstract:The vast majority of bird species are socially monogamous; however, extra-pair paternity is nearly ubiquitous and a number of theories have been proposed to explain the prevalence of this mixed mating strategy. Here, we test the genetic compatibility hypothesis—the idea that females that are genetically similar to their social partners will mate with extra-pair males that are genetically dissimilar to produce offspring that are more heterozygous. For this study, we examined eight years of paternity data (2004-2011) from a Nearctic-Neotropical migratory bird, the American Redstart (Setophaga ruticilla), breeding in southeastern Ontario, Canada. We predicted that females paired with genetically similar males (higher relatedness) would be more likely to produce extra-pair offspring and that extra-pair offspring would have higher levels of heterozygosity than within-pair offspring. Alternatively, because this population experiences high levels of immigration, females may produce extra-pair offspring with more genetically similar males because of the potential for outbreeding depression. Using five highly variable microsatellite markers, we examined patterns of relatedness among social pairs as well as measures of offspring heterozygosity. In contrast to our predictions, we found no difference in relatedness between social pairs where the females produced extra-pair offspring and social pairs where the females produced only within-pair offspring. However, extra-pair offspring were significantly less heterozygous than within-pair offspring. Together, these findings suggest that females a) are not engaging in extra-pair fertilizations based on relatedness to their social mate and b) appear to be mating with extra-pair males that are more genetically similar to themselves. We suggest there may be benefits for females to mate with genetically similar extra-pair males in highly outbred populations with high rates of immigration, such as for maintaining co-adapted gene complexes or genes coding for local adaptations
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Data from: The strength of migratory connectivity for birds en route to breeding through the Gulf of Mexico
2018Co-Authors: Cohen, Emily B., Moore, Frank R., Rushing, Clark R., Hallworth, Michael T., Hostetler, Jeffrey A., Ramirez, Mariamar Gutierrez, Marra, Peter P.Abstract:The strength of migratory connectivity is a measure of the cohesion of populations among phases of the annual cycle, including breeding, migration, and wintering. Many Nearctic-Neotropical species have strong migratory connectivity between breeding and wintering phases of the annual cycle. It is less clear if this strength persists during migration when multiple endogenous and exogenous factors may decrease the cohesion of populations among routes or through time along the same routes. We sampled three bird species, American Redstart (Setophaga ruticilla), ovenbird (Seiurus aurocapilla), and wood thrush (Hylocichla mustelina), during spring migration through the Gulf of Mexico region to test if breeding populations differentiate spatially among migration routes or temporally along the same migration routes and the extent to which within-population timing is a function of sex, age, and carry-over from winter habitat, as measured by stable carbon isotope values in claws (δ13C). To make quantitative comparisons of migratory connectivity possible, we developed and used new methodology to estimate the strength of migratory connectivity (MC) from probabilistic origin assignments identified using stable hydrogen isotopes in feathers (δ2H). We found support for spatial differentiation among routes by American Redstarts and ovenbirds and temporal differentiation along routes by American Redstarts. After controlling for breeding origin, the timing of American Redstart migration differed among ages and sexes and ovenbird migration timing was influenced by carry-over from winter habitat. The strength of migratory connectivity did not differ among the three species, with each showing weak breeding-to-spring migration MC relative to prior assessments of breeding-wintering connectivity. Our work begins to fill an essential gap in methodology and understanding of the extent to which populations remain together during migration, information critical for a full annual cycle perspective on the population dynamics and conservation of migratory animals
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Winter Habitat Quality but not Long- distance Dispersal Influences Apparent Reproductive Success in a Migratory Bird
Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange, 2016Co-Authors: Rushing, Clark S., Marra, Peter P., Dudash, Michele R.Abstract:Long- distance breeding and natal dispersal play central roles in many ecological and evolutionary processes, including gene flow, population dynamics, range expansion, and individual responses to fluctuating biotic and abiotic conditions. However, the relative contribution of long- distance dispersal to these processes depends on the ability of dispersing individuals to successfully reproduce in their new environment. Unfortunately, due to the difficulties associated with tracking dispersal in the field, relatively little is known about its reproductive consequences. Furthermore, because reproductive success is influenced by a variety of processes, disentangling the influence of each of these processes is critical to understanding the direct consequences of dispersal. In this study, we used stable hydrogen and carbon isotopes to estimate long- distance dispersal and winter territory quality in a migratory bird, the American Redstart (Setophaga ruticilla). We then applied Aster life-history models to quantify the strength of influence of these factors on apparent reproductive success. We found no evidence that male or female reproductive success was lower for long- distance dispersers relative to non- dispersing individuals. In contrast, carry- over effects from the winter season did influence male, but not female, reproductive success. Use of Aster models further revealed that for adult males, winter territory quality influenced the number of offspring produced whereas for yearling males, high- quality winter territories were associated with higher mating and nesting success. These results suggest that although long- distance natal and breeding dispersal carry no immediate reproductive cost for American Redstarts, reproductive success in this species may ultimately be limited by the quality of winter habitat
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Data from: Habitat features and long-distance dispersal modify the use of social information by a long-distance migratory bird
2015Co-Authors: Rushing, Clark S., Dudash, Michele R., Marra, Peter P.Abstract:1. The processes by which individuals select breeding sites have important consequences for individual tness as well as population- and community-dynamics. Although there is increasing evidence that many animal species use information acquired from conspecics to assess the suitability of potential breeding sites, little is known about how the use of this social information is modified by biotic and abiotic conditions. 2. We used an automated playback experiment to simulate two types of social information, post-breeding public information and pre-breeding location cues, to determine the relative importance of these cues for breeding site selection by a migratory songbird, the American Redstart (Setophaga ruticilla). In addition, we used stable hydrogen isotopes to determine the dispersal status of individuals that responded to our experimental treatments and quantify whether long-distance dispersers use different social cues to select breeding sites compared to philopatric individuals. 3. We found that points that received pre-breeding location cue treatments were signi cantly more likely to be settled by Redstarts than control points that received no playback. However, we found no evidence the Redstarts used post-breeding public information gathered during one season to select breeding sites the following year. Breeding site habitat structure was also a strong predictor of settlement probability, indicating that Redstarts modi ed the use of social information based on habitat cues. Furthermore, stable hydrogen isotope signatures from individuals that responded to location cue treatments suggest that long-distance dispersers may rely more heavily on these cues than local recruits. 4. Collectively, these results indicate that Redstarts use multiple sources of information to select breeding sites, which could buffer individuals from selecting suboptimal sites when they breed in unfamiliar locations or when habitat quality becomes decoupled from social cues
