1,005 research outputs found

    Heritable Choice of Colony Size in Cliff Swallows: Does Experience Trump Genetics in Older Birds?

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    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 that differed in size from those in which they were born. Breeding colony sizes chosen by this cohort of birds were monitored by mark-recapture throughout their lives. A multistate mark-recapture analysis revealed that birds in their first breeding year chose colony sizes similar to those of their birth, regardless of their rearing environment, confirming a previous analysis. Beyond the first breeding year, however, cliff swallows’ choice of colony size was less dependent on the size of the colony in which they were born. Birds born in small colonies and reared in large colonies showed evidence of a delayed rearing effect, with these birds overwhelmingly choosing large colonies in later years. Heritabilities suggested strong genetic effects on colony choice in the first year but not in later years. Cliff swallows’ genetically based colony size preferences their first year could be a way to ensure matching of their phenotype to an appropriate social environment as yearlings. In later years, familiarity with particular colony sites and available information on site quality may override innate group size preferences when birds choose colonies

    The Effect of Weather during Rearing on Morphometric Traits of Juvenile Cliff Swallows

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    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 in cooler years. However, variability explained by weather was small, suggesting that morphometric traits of juvenile cliff swallows were not highly sensitive to weather conditions experienced during this study. Measurements of juvenile morphological traits were positively correlated with measurements taken as adults, meaning that any variation among juveniles in response to rearing conditions showed evidence of persisting into a bird’s first breeding season. Our results show that body size in this species is phenotypically plastic and influ­enced, in part, by weather variables

    Heritable Choice of Colony Size in Cliff Swallows: Does Experience Trump Genetics in Older Birds?

    Get PDF
    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 that differed in size from those in which they were born. Breeding colony sizes chosen by this cohort of birds were monitored by mark-recapture throughout their lives. A multistate mark-recapture analysis revealed that birds in their first breeding year chose colony sizes similar to those of their birth, regardless of their rearing environment, confirming a previous analysis. Beyond the first breeding year, however, cliff swallows’ choice of colony size was less dependent on the size of the colony in which they were born. Birds born in small colonies and reared in large colonies showed evidence of a delayed rearing effect, with these birds overwhelmingly choosing large colonies in later years. Heritabilities suggested strong genetic effects on colony choice in the first year but not in later years. Cliff swallows’ genetically based colony size preferences their first year could be a way to ensure matching of their phenotype to an appropriate social environment as yearlings. In later years, familiarity with particular colony sites and available information on site quality may override innate group size preferences when birds choose colonies

    Fluctuating Viability Selection on Morphology of Cliff Swallows Is Driven by Climate

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    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 measured. The fitness functions associated with tarsus length and bill dimensions fluctuated depending on annual climate conditions on the birds’ breeding grounds. The oscillating yearly patterns may have slowed and occasionally reversed directional change in trait trajectories, although there was a trend over time for all traits except tarsus to increase in size. The net positive directional selection on some traits, despite periodic climate-associated fluctuations, suggests that cliff swallow morphology in the population is likely to keep changing and supports recent work contending that selection in general does not fluctuate enough to be an effective driver of stasis

    The Effect of Weather during Rearing on Morphometric Traits of Juvenile Cliff Swallows

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    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 in cooler years. However, variability explained by weather was small, suggesting that morphometric traits of juvenile cliff swallows were not highly sensitive to weather conditions experienced during this study. Measurements of juvenile morphological traits were positively correlated with measurements taken as adults, meaning that any variation among juveniles in response to rearing conditions showed evidence of persisting into a bird’s first breeding season. Our results show that body size in this species is phenotypically plastic and influ­enced, in part, by weather variables

    Parent-Offspring Resemblance in Colony-Specific Adult Survival of Cliff Swallows

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    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 study area for the subsequent decade. Colony-specific adult survival probabilities of offspring born and reared in the same colony, and those cross-fostered away from their natal colony soon after birth, were positively and significantly related to subsequent adult survival of the parental cohort from the natal colony. This result held when controlling for the effect of natal colony size and the age composition of the parental cohort. In contrast, colony-specific adult survival of offspring cross-fostered to a site was unrelated to that of their foster parent cohort or to the cohort of non-fostered offspring with whom they were reared. Adult survival at a colony varied inversely with fecundity, as measured by mean brood size, providing evidence for a survival-fecundity trade-off in this species. The results suggest some heritable variation in adult survival, likely maintained by negative correlations between fitness components. The study provides additional evidence that colonies represent nonrandom collections of individuals

    A Glimpse at Interdisciplinary Studies

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    This panel strives to draw attention to the field of interdisciplinary research and its implications for research dealing with literature. Using many unrelated fields such as, chemistry, geography, and psychology, and a bit of strong determination, the panel members have coaxed out new meaning from seemingly “dead” pieces of literature. Paper one will explore the short story, “Videotape” by Don DeLillo by widening the perspective from which it is read from strictly literary to psychological and scientific, using the principle of Schadenfreude and the Heisenburg Uncertainty Principle which gives readers a better understanding of character motivation resulting in deeper meaning from the text. Paper two is a interdisciplinary literary cartography project that explores F. Scott Fitzgerald’s “The Ice Palace” through a geographic lens. Literary cartography deepens readers understanding of the geographical and cultural differences between the main characters in the story. Paper three applies the techniques of literary cartography to the fictional work “In the Land of the Free” by Sui Sin Far in order to develop a greater sense of its context and background. Together, the panel aims to uncover the process of interdisciplinary research and its applications to literature

    Recapture Heterogeneity in Cliff Swallows: Increased Exposure to Mist Nets Leads to Net Avoidance

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    Ecologists often use mark-recapture to estimate demographic variables such as abundance, growth rate, or survival for samples of wild animal populations. A common assumption underlying mark-recapture is that all animals have an equal probability of detection, and failure to meet or correct for this assumption–as when certain members of the population are either easier or more difficult to capture than other animals–can lead to biased and inaccurate demographic estimates. We built within-year and among-years Cormack-Jolly-Seber recaptures-only models to identify causes of capture heterogeneity for a population of colonially nesting cliff swallows (Petrochelidon pyrrhonota) caught using mist-netting as a part of a 20- year mark-recapture study in southwestern Nebraska, U.S.A. Daily detection of cliff swallows caught in stationary mist nets at their colony sites declined as the birds got older and as the frequency of netting at a site within a season increased. Experienced birds’ avoidance of the net could be countered by sudden disturbances that startled them into a net, such as when we dropped a net over the side of a bridge or flushed nesting cliff swallows into a stationary net positioned at a colony entrance. Our results support the widely held, but seldom tested, belief that birds learn to avoid stationary mist nets over time, but also show that modifications of traditional field methods can reduce this source of recapture heterogeneity

    Improving patient education about tobacco withdrawal and nicotine gum use by registered nurses in inpatient psychiatry: A feasibility study

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    IntroductionTobacco use is prohibited in most psychiatric facilities in the United States, yet many psychiatric inpatients are tobacco users. Psychiatric nurses have reported inadequate education about best practices for managing tobacco dependence.AimTo explore the feasibility of an educational intervention for psychiatric nurses designed to improve their ability to educate patients about best practices for managing tobacco dependence, as well as effective use of nicotine gum.MethodFourteen nurses on a psychiatric inpatient unit at a community hospital were educated about the targeted topics. Chart reviews of nonequivalent pre‐intervention and post‐intervention patient groups were conducted to explore the outcomes of the intervention.ResultsPatients received more teaching, and used nicotine gum more often, following the intervention. However, no statistically significant differences between the pre‐intervention and post‐intervention patient groups were found.DiscussionEducating nurses about best practices for managing tobacco withdrawal symptoms may have positive outcomes. Existing research suggests that such interventions may be most effective when support and structure are provided to ensure long‐term practice changes.Implications for practiceThis feasibility study demonstrates that a brief nurse education intervention has the potential to improve the experience of tobacco withdrawal for psychiatric inpatients. Future research that expands upon the current project is warranted.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146317/1/jpm12495.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146317/2/jpm12495_am.pd

    A PRELIMINARY FEASIBILITY FOR ESTABLISHING A MULTI-SPECIES MEAT PROCESSING PLANT IN SOUTHWESTERN NORTH DAKOTA

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    The number of small commodity livestock slaughter plants in the Upper Northern Plains region continues to decline. Significant factors contributing to this decline include: 1) pressure to consolidate, thereby capturing economies of scale; 2) relatively stringent federal inspection specifications, along with; 3) HACCP (Hazardous Analysis Critical Control Points) requirements. At the same time, consumer demand (markets) for specialty, selected, and exotic meats appears to be growing. For example, the recent market successes in Europe evidenced by the North American Bison Cooperative based in New Rockford, North Dakota. Several alternative livestock producer groups have emerged which include lamb, ratite, elk, deer, goat, poultry, rabbit, specialty beef, and organic livestock. These groups have expressed a need for slaughter and processing facilities to meet market demand. The economic question which then becomes foremost to developing a viable business enterprise is: "What is the critical threshold volume (CTV) of product required to succeed in terms of economic profit?" Specialty livestock is relatively new and production volume small in comparison to established commodity livestock such as cattle or hogs. This fact led researchers to consider the preliminary feasibility of a multi-species processing facility as a means of addressing the expressed need.multi-species, specialty meats, specialty livestock, alternative livestock, economies of scale, HACCP (Hazardous Analysis Critical Control Points), slaughter plants, processing plants, Community/Rural/Urban Development, Agribusiness,
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