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Full-Text Articles in Life Sciences

Parent-Offspring Resemblance In Colony-Specific Adult Survival Of Cliff Swallows, Charles R. Brown, Erin A. Roche, Mary Bomberger Brown Jul 2015

Parent-Offspring Resemblance In Colony-Specific Adult Survival Of Cliff Swallows, Charles R. Brown, Erin A. Roche, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Survival is a key component of fitness. Species that occupy discrete breeding colonies with different characteristics are often exposed to varying costs and benefits associated with group size or environmental conditions, and survival is an integrative net measure of these effects. We investigated the extent to which survival probability of adult (≥ 1-year old) cliff swallows (Petrochelidon pyrrhonota) occupying different colonies resembled that of their parental cohort and thus whether the natal colony had long-term effects on individuals. Individuals were cross-fostered between colonies soon after hatching and their presence as breeders monitored at colonies in the western Nebraska …


Ectoparasitism Shortens The Breeding Season In A Colonial Bird, Charles R. Brown, Mary Bomberger Brown Feb 2015

Ectoparasitism Shortens The Breeding Season In A Colonial Bird, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

When blood-feeding parasites increase seasonally, their deleterious effects may prevent some host species, especially those living in large groups where parasites are numerous, from reproducing later in the summer. Yet the role of parasites in regulating the length of a host’s breeding season—and thus the host’s opportunity for multiple brooding—has not been systematically investigated. The highly colonial cliff swallow (Petrochelidon pyrrhonota), a temperate-latitude migratory songbird in the western Great Plains, USA, typically has a relatively short (eight to nine week) breeding season, with birds rarely nesting late in the summer. Colonies at which ectoparasitic swallow bugs (Oeciacus vicarius) were experimentally …


The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown Dec 2014

The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

Episodes of food deprivation may change how nestling birds allocate energy to the growth of skeletal and feather morphological traits during development. Cliff swallows (Petrochelidon pyrrhonota) are colonial, insectivorous birds that regu­larly experience brief periods of severe weather–induced food deprivation during the nesting season which may affect offspring development. We investigated how annual variation in timing of rearing and weather were associated with length of wing and tail, skeletal traits, and body mass in juvenile cliff swallows reared in southwestern Nebraska during 2001–2006. As predicted under conditions of food deprivation, nestling skeletal and feather measurements were generally smaller …


Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown Oct 2014

Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Global climate change is altering the breeding phenology of many organisms, and one reported consequence of warmer average temperatures is earlier breeding times in migratory songbirds of north temperate latitudes. Less studied are the potential interactions between earlier breeding and social behavior in colonial species. We investigated how breeding time, as measured by colony initiation dates across the entire summer, in Cliff Swallows (Petrochelidon pyrrhonota) of southwestern Nebraska, USA, changed over a 30-year period and could be predicted by climatic variables, year, and colony size. Mean colony initiation date became earlier over the study, with variation best predicted …


Variation In Age Composition Among Colony Sizes In Cliff Swallows, Charles R. Brown, Erin A. Roche, Mary Bomberger Brown Jan 2014

Variation In Age Composition Among Colony Sizes In Cliff Swallows, Charles R. Brown, Erin A. Roche, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Variation in group size is characteristic of most social species. The extent to which individuals sort among group sizes based on age may yield insight into why groups vary in size and the age-specific costs and benefits of different social environments. We investigated the age composition of Cliff Swallow (Petrochelidon pyrrhonota) colonies of different sizes over 18 yr at a long-term study site in western Nebraska, USA. Using years elapsed since banding as a relative measure of age for over 194,000 birds, we found that the proportion of age-class-1 swallows (birds banded as nestlings or juveniles or adults in the …


Fluctuating Viability Selection On Morphology Of Cliff Swallows Is Driven By Climate, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche May 2013

Fluctuating Viability Selection On Morphology Of Cliff Swallows Is Driven By Climate, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche

School of Natural Resources: Faculty Publications

The extent to which fluctuating selection can maintain evolutionary stasis in most populations remains an unresolved question in evolutionary biology. Climate has been hypothesized to drive reversals in the direction of selection among different time periods and may also be responsible for intense episodic selection caused by rare weather events. We measured viability selection associated with morphological traits in cliff swallows (Petrochelidon pyrrhonota) in western Nebraska, USA, over a 14-year period following a rare climatic event. We used mark-recapture to estimate the annual apparent survival of over 26 000 individuals whose wing, tail, tarsus, and bill had been …


Heritable Choice Of Colony Size In Cliff Swallows: Does Experience Trump Genetics In Older Birds?, Erin A. Roche, Charles R. Brown, Mary Bomberger Brown Dec 2011

Heritable Choice Of Colony Size In Cliff Swallows: Does Experience Trump Genetics In Older Birds?, Erin A. Roche, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

The variation in breeding colony size seen in populations of most colonial birds may reflect heritable choices made by individuals that are phenotypically specialized for particular social environments. Although a few studies have reported evidence for genetically based choice of group sizes in birds, we know relatively little about the extent to which animals potentially rely on experience versus innate preferences in deciding how many conspecifics to settle with at different times of their lives. We conducted a cross-fostering experiment in 1997–1998 on cliff swallows, Petrochelidon pyrrhonota, in southwestern Nebraska, USA, in which some individuals were reared in colonies …


Winter Ecology Of Buggy Creek Virus (Togaviridae, Alphavirus) In The Central Great Plains, Charles R. Brown, Stephanie A. Strickler, Amy T. Moore, Sarah A. Knutie, Abinash Padhi, Mary Bomberger Brown, Ginger R. Young, Valerie A. O'Brien, Jerome E. Foster, Nicholas Komar May 2010

Winter Ecology Of Buggy Creek Virus (Togaviridae, Alphavirus) In The Central Great Plains, Charles R. Brown, Stephanie A. Strickler, Amy T. Moore, Sarah A. Knutie, Abinash Padhi, Mary Bomberger Brown, Ginger R. Young, Valerie A. O'Brien, Jerome E. Foster, Nicholas Komar

School of Natural Resources: Faculty Publications

A largely unanswered question in the study of arboviruses is the extent to which virus can overwinter in adult vectors during the cold winter months and resume the transmission cycle in summer. Buggy Creek virus (BCRV; Togaviridae, Alphavirus) is an unusual arbovirus that is vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) and amplified by the ectoparasitic bug’s main avian hosts, the migratory cliff swallow (Petrochelidon pyrrhonota) and resident house sparrow (Passer domesticus). Bugs are sedentary and overwinter in the swallows’ mud nests. We evaluated the prevalence of BCRV and extent of …


Familiarity With Breeding Habitat Improves Daily Survival In Colonial Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Kathleen R. Brazeal Oct 2008

Familiarity With Breeding Habitat Improves Daily Survival In Colonial Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Kathleen R. Brazeal

School of Natural Resources: Faculty Publications

One probable cost of dispersing to a new breeding habitat is unfamiliarity with local conditions such as the whereabouts of food or the habits of local predators, and consequently immigrants may have lower probabilities of survival than more experienced residents. Within a breeding season, estimated daily survival probabilities of cliff swallows, Petrochelidon pyrrhonota, at colonies in southwestern Nebraska, USA, were highest for birds that had always nested at the same site, followed by those for birds that had nested there in some (but not all) past years. Daily survival probabilities were lowest for birds that were naive immigrants to …


Bird Movement Predicts Buggy Creek Virus Infection In Insect Vectors, Charles R. Brown, Mary Bomberger Brown, Amy T. Moore, Nicholas Komar Jan 2007

Bird Movement Predicts Buggy Creek Virus Infection In Insect Vectors, Charles R. Brown, Mary Bomberger Brown, Amy T. Moore, Nicholas Komar

School of Natural Resources: Faculty Publications

Predicting the spatial foci of zoonotic diseases is a major challenge for epidemiologists and disease ecologists. Migratory birds are often thought to be responsible for introducing some aviozoonotic pathogens such as West Nile and avian influenza viruses to a local area, but most information on how bird movement correlates with virus prevalence is anecdotal or indirect. We report that the prevalence of Buggy Creek virus (BCRV) infection in cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, was directly associated with the likelihood of movement by cliff swallows (Petrochelidon pyrrhonota), an amplifying host …