2,769 research outputs found

    A protected area influences genotype-specific survival and the structure of a Canis hybrid zone

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    It is widely recognized that protected areas can strongly influence ecological systems and that hybridization is an important conservation issue. However, previous studies have not explicitly considered the influence of protected areas on hybridization dynamics. Eastern wolves are a species of special concern and their distribution is largely restricted to a protected population in Algonquin Provincial Park (APP), Ontario, Canada, where they are the numerically dominant canid. We studied intrinsic and extrinsic factors influencing survival and cause-specific mortality of hybrid and parental canids in the three-species hybrid zone between eastern wolves, eastern coyotes, and gray wolves in and adjacent to APP. Mortality risk for eastern wolves in areas adjacent to APP was significantly higher than for other sympatric Canis types outside of APP, and for eastern wolves and other canids within APP. Outside of APP, the annual mortality rate of all canids by harvest (24%) was higher than for other causes of death (4–7%). Furthermore, eastern wolves (hazard ratio ¼ 3.5) and nonresidents (transients and dispersing animals, hazard ratio ¼ 2.7) were more likely to die from harvest relative to other Canis types and residents, respectively. Thus, eastern wolves dispersing from APP were especially vulnerable to harvest mortality. For residents, eastern wolf survival was more negatively influenced by increased road density than for other Canis types, further highlighting the sensitivity of eastern wolves to human disturbance. A cycle of dispersal from APP followed by high rates of mortality and hybridization appears to maintain eastern wolves at low density adjacent to APP, limiting the potential for expansion beyond the protected area. However, high survival and numerical dominance of eastern wolves within APP suggest that protected areas can allow rare hybridizing species to persist even if their demographic performance is compromised and barriers to hybridization are largely absent in the adjacent matrix

    Roost Use and Movements of Northern Long-Eared Bats in a Southeast Nebraska Agricultural Landscape

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    Bats are important bio-indicators of ecosystem health and provide a number of ecosystem services. White-nose Syndrome and habitat loss have led to the decline of many bat species in eastern North America, including the federally threatened northern long-eared bat, Myotis septentrionalis. White-nose Syndrome was only recently found in Nebraska, which lies on the western extent of this species geographic range. To better understand how this forest-dependent species persists in an agriculturally dominated landscape amid a growing number of pressures, we investigated the roosting habits of this bat at the Homestead National Monument of America, located in southeast Nebraska. We mist-netted bats on eight nights in 2019 (16 August–26 August) and caught 55 bats across five species, including five juvenile northern long-eared bats. We located five unique roosts between two juvenile radio-tracked bats; most of the female roosts were in anthropogenic structures and tree cavities within 0.23 km of capture, while most of the male roosts were in snags and tree cavities as far as 2.73 km from the capture site. Fence cavities were also used by other undocumented northern long-eared bats. We recorded three radio-tagged bats that commuted between roosting sites and capture sites within hours after sunset. Our results provide evidence that at the distributional edge for this species, wooded areas, riparian zones, and human-built structures in an intensively managed agricultural landscape are used by this imperiled species

    Resource selection at homesites by wolves and eastern coyotes in a \u3ci\u3eCanis\u3c/i\u3e hybrid zone

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    We modeled resource selection by wolves (Canis spp.), eastern coyotes (C. latrans), and admixed canids during the pup-rearing season at den and rendezvous sites (collectively, homesites) within a largely unprotected landscape proposed as the recovery zone for federally and provincially threatened eastern wolves (C. lycaon) in Ontario, Canada. Overall, canids selected wetlands, while avoiding secondary roads and open-structure rock-grass habitat patches. Packs with greater wolf ancestry selected wetlands and tertiary roads more strongly, while avoiding mixed conifer-hardwood forests. Contrary to our prediction, canids with greater coyote ancestry did not establish homesites closer to roads, which likely mitigated their risk of human-caused mortality during pup-rearing. Packs exhibited increased selection of wetlands within territories as a function of increasing availability of wetlands. Packs with abundant access to wetlands may prioritize this habitat type to exploit beavers, a valuable prey species during pup-rearing. Packs with higher pup survival selected hardwood forests and avoided conifer forests more than packs with lower pup survival. This is consistent with our understanding of habitat relations of the main prey species for canids in central Ontario and suggests that selecting prey-rich habitat types at homesites increases fitness. A proposed goal of eastern wolf recovery is numerical and geographical expansion outside of the population core in Algonquin Provincial Park. Thus, our results provide valuable information for conservation by quantifying resource selection of wolves, coyotes, and hybrids during pup-rearing and identifying links between fitness and homesite selection

    Individual and Population Level Resource Selection Patterns of Mountain Lions Preying on Mule Deer along an Urban-Wildland Gradient

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    Understanding population and individual-level behavioral responses of large carnivores to human disturbance is important for conserving top predators in fragmented landscapes. However, previous research has not investigated resource selection at predation sites of mountain lions in highly urbanized areas. We quantified selection of natural and anthropogenic landscape features by mountain lions at sites where they consumed their primary prey, mule deer (Odocoileus hemionus), in and adjacent to urban, suburban, and rural areas in greater Los Angeles. We documented intersexual and individual-level variation in the environmental conditions present at mule deer feeding sites relative to their availability across home ranges. Males selected riparian woodlands and areas closer to water more than females, whereas females selected developed areas marginally more than males. Females fed on mule deer closer to developed areas and farther from riparian woodlands than expected based on the availability of these features across their home ranges.We suggest that mortality risk for females and their offspring associated with encounters with males may have influenced the different resource selection patterns between sexes. Males appeared to select mule deer feeding sites mainly in response to natural landscape features, while females may have made kills closer to developed areas in part because these are alternative sites where deer are abundant. Individual mountain lions of both sexes selected developed areas more strongly within home ranges where development occurred less frequently. Thus, areas near development may represent a trade-off for mountain lions such that they may benefit from foraging near development because of abundant prey, but as the landscape becomes highly urbanized these benefits may be outweighed by human disturbance

    Measurement of the Parallax of PSR B0950+08 Using the VLBA

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    A new technique has been developed to remove the ionosphere's distorting effects from low frequency VLBI data. By fitting dispersive and non-dispersive components to the phases of multi-frequency data, the ionosphere can be effectively removed from the data without the use of {\em a priori} calibration information. This technique, along with the new gating capability of the VLBA correlator, was used to perform accurate astrometry on pulsar B0950+08, resulting in a much improved measurement of this pulsar's proper motion (μα=1.6±0.4\mu_{\alpha} = -1.6 \pm 0.4 mas/yr, μδ=29.5±0.5\mu_{\delta} = 29.5 \pm 0.5 mas/yr) and parallax (π=3.6±0.3\pi = 3.6 \pm 0.3 mas). This puts the pulsar at a distance of 280±25280 \pm 25 parsecs, about twice as far as previous estimates, but in good agreement with models of the electron density in the local bubble.Comment: 5 pages, Latex with AASTEX. Accepted for publication in Ap

    Habitat fragmentation reduces survival and drives source–sink dynamics for a large carnivore

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    Rigorous understanding of how environmental conditions impact population dynamics is essential for species conservation, especially in mixed-use landscapes where source–sink dynamics may be at play. Conservation of large carnivore populations in fragmented, human-dominated landscapes is critical for their long-term persistence. However, living in human-dominated landscapes comes with myriad costs, including direct anthropogenic mortality and sublethal energetic costs. How these costs impact individual fitness and population dynamics are not fully understood, partly due to the difficulty in collecting long-term demographic data for these species. Here, we analyzed an 11-year dataset on puma (Puma concolor) space use, mortality, and reproduction in the Santa Cruz Mountains, California, USA, to quantify how living in a fragmented landscape impacts individual survival and population dynamics. Long-term exposure to housing density drove mortality risk for female pumas, resulting in an 18-percentage-point reduction in annual survival for females in exurban versus remote areas. While the overall population growth rate appeared stable, reduced female survival in more developed areas resulted in source–sink dynamics across the study area, with 42.1% of the Santa Cruz Mountains exhibiting estimated population growth rates \u3c1. Since habitat selection is often used as a proxy for habitat quality, we also assessed whether puma habitat selection predicted source and sink areas. Patterns of daytime puma habitat selection predicted source areas, while time-of-day-independent habitat selection performed less well as a proxy. These results illuminate the individual- and population-level consequences of habitat fragmentation for large carnivores, illustrating that habitat fragmentation can produce source– sink dynamics that may not be apparent from other metrics of habitat quality. Locally, conserving high-quality source habitat within the Santa Cruz Mountains is necessary to support long-term puma population persistence. More broadly, source–sink dynamics may at play for other carnivore populations in similar fragmented systems, and linking landscape condition

    Attitudes of medical students to medical leadership and management: a systematic review to inform curriculum development.

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    BACKGROUND: There is a growing acknowledgement that doctors need to develop leadership and management competences to become more actively involved in the planning, delivery and transformation of patient services. We undertook a systematic review of what is known concerning the knowledge, skills and attitudes of medical students regarding leadership and management. Here we report the results pertaining to the attitudes of students to provide evidence to inform curriculum development in this developing field of medical education. METHODS: We searched major electronic databases and citation indexes within the disciplines of medicine, education, social science and management. We undertook hand searching of major journals, and reference and citation tracking. We accessed websites of UK medical institutions and contacted individuals working within the field. RESULTS: 26 studies were included. Most were conducted in the USA, using mainly quantitative methods. We used inductive analysis of the topics addressed by each study to identity five main content areas: Quality Improvement; Managed Care, Use of Resources and Costs; General Leadership and Management; Role of the Doctor, and Patient Safety. Students have positive attitudes to clinical practice guidelines, quality improvement techniques and multidisciplinary teamwork, but mixed attitudes to managed care, cost containment and medical error. Education interventions had variable effects on students' attitudes. Medical students perceive a need for leadership and management education but identified lack of curriculum time and disinterest in some activities as potential barriers to implementation. CONCLUSIONS: The findings from our review may reflect the relatively little emphasis given to leadership and management in medical curricula. However, students recognise a need to develop leadership and management competences. Although further work needs to be undertaken, using rigorous methods, to identify the most effective and cost-effective curriculum innovations, this review offers the only currently available summary of work examining the attitudes of students to this important area of development for future doctors.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Stability of empathy among undergraduate medical students: a longitudinal study at one UK medical school.

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    BACKGROUND: Empathy is important to patient care. The prevailing view is that empathy declines during university medical education. The significance of that decline has been debated.This paper reports the findings in respect of two questions relating to university medical education: 1. Do men and women medical students differ in empathy? 2. Does empathy change amongst men and women over time? METHODS: The medical course at the University of Cambridge comprises two components: Core Science (Years 1-3) and Clinical (Years 4-6). Data were obtained from repeated questionnaire surveys of medical students from each component over a period of four years: 2007-2010. Participation in the study was voluntary.Empathy was measured using two subscales of the Interpersonal Reactivity Index: IRI-EC (affective empathy) and IRI-PT (cognitive empathy). We analysed data separately for men and women from the Core Science and Clinical components. We undertook missing value analyses using logistic regression separately, for each measure of empathy, to examine non-response bias. We used Student's t-tests to examine gender differences and linear mixed effects regression analyses to examine changes over time. To assess the influence of outliers, we repeated the linear mixed effects regression analyses having excluded them. RESULTS: Women displayed statistically significant higher mean scores than men for affective empathy in all 6 years of medical training and for cognitive empathy in 4 out of 6 years - Years 1 and 2 (Core Science component) and Years 4 and 5 (Clinical component).Amongst men, affective empathy declined slightly during both Core Science and Clinical components. Although statistically significant, both of these changes were extremely small. Cognitive empathy was unchanged during either component. Amongst women, neither affective empathy nor cognitive empathy changed during either component of the course.Analysis following removal of outliers showed a statistically significant slight increase in men's cognitive empathy during the Core Science component and slight decline in women's affective empathy during the Clinical component. Again, although statistically significant, these changes were extremely small and do not influence the study's overall conclusions. CONCLUSIONS: Amongst medical students at the University of Cambridge, women are more empathetic than men (a generally observed phenomenon). Men's affective empathy declined slightly across the course overall, whilst women's affective empathy showed no change. Neither men nor women showed any change in cognitive empathy during the course. Although statistically significant, the size of such changes as occurred makes their practical significance questionable. Neither men nor women appear to become meaningfully less empathetic during their medical education at the University of Cambridge.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Evolutionary and Practical Implications of Pseudo-Estrus Behavior in Florida Panthers (Puma Concolor Coryi)

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    Estrus behavior by females for reasons other than reproduction (pseudo-estrus) has been reported in species of primates and felids, and alternative hypotheses have been put forth to explain its evolution and function. We observed 3 separate cases of pseudo-estrus behavior by 2 Puma concolor coryi (Florida Panther) females while they were nursing young (old) kittens. We used VHF and GPS telemetry data, genetic pedigree analysis, and visual observations to provide insight into the evolutionary and practical implications of this behavior for Panthers. We suggest that female Panthers likely consort with males while nursing kittens to maintain amicable relations with these males to prevent infanticide. For studies monitoring Puma dens with radio-telemetry, pseudo-estrus events may be confused with litter abandonment, and thus our observations are useful to fi eld biologists who may consider removing kittens from the wild following presumed abandonment events to prevent kitten mortality
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