41 research outputs found

    Home Ranges of Rusty Blackbirds Breeding in Wetlands: How Much Would Buffers from Timber Harvest Protect Habitat?

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    We calculated the home ranges and core areas of 13 adult Rusty Blackbirds (Euphagus carolinus) in Maine to determine (1) the area requirements of breeding adults, (2) whether area requirements of the sexes and of colonial and noncolonial individuals differ, and (3) the proportion of the home range and core area that would be protected by a buffer of no logging of 50–100 m around occupied wetlands. Mean home ranges (37.5 ± 12.6 ha) and core areas (11.1 ± 2.8 ha) were large in comparison to those of other breeding icterids, and adults often foraged in multiple unconnected wetlands. Rusty Blackbirds that were part of a loose colony had home ranges and core areas three times larger than those of pairs that nested solitarily, which we speculate may be due to adults following one other to feed on unpredictable emergences of aquatic insects. Home ranges and core areas included a surprisingly small amount of wetland habitat, only 12% and 19% respectively, but adults often foraged in small wet patches (\u3c16 m2) in otherwise upland habitat. The 75-m buffers around wetlands that we recommended in a concurrent study may help protect the Rusty Blackbird\u27s nesting habitat, but such buffers contained less than half the average home range, suggesting that they may be of only limited benefit as a conservation strategy for protecting foraging habitat

    Assessment and Choice: An Operant Simulation of Foraging in Patches

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    Pigeons were presented with an operant simulation of two prey patches using concurrent random ratio schedules of reinforcement. An unstable patch offered a higher initial reinforcement probability, which then declined unpredictably to a zero reinforcement probability in each session. A stable patch offered a low but unvarying reinforcement probability. When the reinforcement probability declined to zero in a single step, the birds displayed shorter giving-up times in the unstable patch when the ratio between the initial reinforcement probabilities in the unstable and stable patches was greater and when the combined magnitude of the reinforcement probabilities in the two patches was greater. When the unstable patch declined in two steps, the birds behaved as if their giving-up times were influenced heavily by events encountered during the most recent step of the double-step change. This effect was observed, however, only when the reinforcement probability in that step was .04, not when it was .06. All of these data agree with the predictions of a capture-probability model based on a comparison of the estimated probability of receiving a reinforcer in the current patch with that in alternative patches

    Habitat occupancy of Rusty Blackbirds (Euphagus carolinus) breeding in northern New England, USA

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    The Rusty Blackbird (Euphagus carolinus), an uncommon songbird often associated with northern coniferous wetlands, has experienced a precipitous population decline since at least the early 20th century. Here, we provide the first analysis of breeding-habitat occupancy at the wetland scale and make recommendations for streamlined monitoring. We modeled occupancy and detectability as a function of site (i.e. habitat-based) and sampling (i.e. visit-specific) variables collected at 546 wetlands in northern New England, USA. Wetland occupancy (mean 6 SE ÂŒ 0.07 6 0.02 in randomly selected wetlands, and 0.12 6 0.02 in all wetlands surveyed) was best explained by variables describing Rusty Blackbird foraging habitat (PUDDLES: a proxy for shallow water), nesting habitat (coniferous adjacent uplands), and evidence of beavers. In contrast to Rusty Blackbirds’ selection of pole-stage conifers at the nest-site scale, stand age did not affect occupancy at the wetland scale. It appears that most wetlands in northern coniferous forest landscapes, regardless of stand age, offer dense conifer patches nearby and provide suitable breeding habitat if quality foraging sites (e.g., areas of shallow water) also are available. Detectability (0.29 6 0.04) decreased with increasing wind speed, and decreased about fourfold over the course of the breeding season. Rusty Blackbirds responded to broadcast of conspecific vocalizations by flying toward the observer and perching more often than prior to broadcast, demonstrating that broadcasts can be a useful tool to enhance visual detectability. Given our results, observers can now focus site selection on wetlands and sampling conditions most likely to maximize detections of Rusty Blackbirds

    Nest-Site Selection and Nest Survival of the Rusty Blackbird: Does Timber Management Adjacent to Wetlands Create Ecological Traps?

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    Animals are subject to ecological traps when anthropogenic changes create habitat that appears suitable but when selected results in decreased fitness. The Rusty Blackbird (Euphagus carolinus) breeds in boreal wetlands and has declined by 85–95% over the last half century. We studied nest-site selection and daily nest survival rate (DSR) of 43 Rusty Blackbird nests in northern New England and evaluated whether regenerating logged areas adjacent to wetlands created ecological traps. Although nesting adults avoided high-canopied forests and selected areas with dense balsam fir (Abies balasmea) 1 to 3 m high, those characteristics were not associated with DSR. Conversely, the frequency of speckled alder (Alnus incana) and sedges (Cyperaceae) in the nest plot varied with DSR, suggesting that the risk of predation of nests within wetlands was lower. DSR also varied with past logging; nests in plots not harvested recently were 2.3x more likely to fledge young than nests in plots harvested within 20 years. When logging extends to the edges of or into wetlands, the subsequent dense regenerating conifers appear to attract Rusty Blackbirds to nest closer to or within these human-altered uplands, exposing their nests to increased predation not typical of unaltered wetlands. Three surrogates for habitat preference did not differ by timber-management history, suggesting that the birds do not prefer habitats that increase their fitness. Rusty Blackbirds nesting in harvested wetlands may be subject to “equal preference” ecological traps, and we suggest that buffers 75 m wide around the perimeter of suitable wetlands should increase DSR

    A four-year, systems-wide intervention promoting interprofessional collaboration

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    Background: A four-year action research study was conducted across the Australian Capital Territory health system to strengthen interprofessional collaboration (IPC) through multiple intervention activities. Methods: We developed 272 substantial IPC intervention activities involving 2,407 face-to-face encounters with health system personnel. Staff attitudes toward IPC were surveyed yearly using Heinemann et al’s Attitudes toward Health Care Teams and Parsell and Bligh’s Readiness for Interprofessional Learning scales (RIPLS). At study’s end staff assessed whether project goals were achieved. Results: Of the improvement projects, 76 exhibited progress, and 57 made considerable gains in IPC. Educational workshops and feedback sessions were well received and stimulated interprofessional activities. Over time staff scores on Heinemann’s Quality of Interprofessional Care subscale did not change significantly and scores on the Doctor Centrality subscale increased, contrary to predictions. Scores on the RIPLS subscales of Teamwork & Collaboration and Professional Identity did not alter. On average for the assessment items 33% of staff agreed that goals had been achieved, 10% disagreed, and 57% checked ‘neutral’. There was most agreement that the study had resulted in increased sharing of knowledge between professions and improved quality of patient care, and least agreement that between-professional rivalries had lessened and communication and trust between professions improved. Conclusions: Our longitudinal interventional study of IPC involving multiple activities supporting increased IPC achieved many project-specific goals, but improvements in attitudes over time were not demonstrated and neutral assessments predominated, highlighting the difficulties faced by studies targeting change at the systems level and over extended periods

    Sense of Coherence and Gambling: Exploring the Relationship Between Sense of Coherence, Gambling Behaviour and Gambling-Related Harm

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    Understanding why some people experience problems with gambling whilst others are able to restrict gambling to recreational levels is still largely unexplained. One potential explanation is through salutogenesis, which is a health promotion approach of understanding factors which move people towards health rather than disease. An important aspect of salutogenesis is sense of coherence. Individuals with stronger sense of coherence perceive their environment as comprehensible, manageable and meaningful. The present study examined the relationship of individuals’ sense of coherence on their gambling behaviour and experience of gambling related harm. This exploratory study utilised an archival dataset (n = 1236) from an online, cross sectional survey of people who had experienced negative consequences from gambling. In general, a stronger sense of coherence was related to lower problem gambling severity. When gambling behaviour was controlled for, sense of coherence was significantly related to the experience of individual gambling harms. A strong sense of coherence can be seen as a protective factor against problematic gambling behaviour, and subsequent gambling related harms. These findings support the value of both primary and tertiary prevention strategies that strengthen sense of coherence as a harm minimisation strategy. The present study demonstrates the potential value of, and provides clear direction for, considering sense of coherence in order to understand gambling-related issues.This study was funded by the Victorian Responsible Gambling Foundation, Grant VRGF1-13

    Vertical Integration and Media Regulation in the New Economy

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    Notes on Bolivian mammals. 7, A new species of Abrocoma (Rodentia) and relationships of the Abrocomidae. American Museum novitates ; no. 2991

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    32 p. : ill. ; 26 cm.Includes bibliographical references (p. 29-31

    Habitat occupancy of Rusty Blackbirds ( Euphagus carolinus

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    The Rusty Blackbird (Euphagus carolinus), an uncommon songbird often associated with northern coniferous wetlands, has experienced a precipitous population decline since at least the early 20th century. Here, we provide the first analysis of breeding-habitat occupancy at the wetland scale and make recommendations for streamlined monitoring. We modeled occupancy and detectability as a function of site (i.e. habitat-based) and sampling (i.e. visit-specific) variables collected at 546 wetlands in northern New England, USA. Wetland occupancy (mean 6 SE ÂŒ 0.07 6 0.02 in randomly selected wetlands, and 0.12 6 0.02 in all wetlands surveyed) was best explained by variables describing Rusty Blackbird foraging habitat (PUDDLES: a proxy for shallow water), nesting habitat (coniferous adjacent uplands), and evidence of beavers. In contrast to Rusty Blackbirds’ selection of pole-stage conifers at the nest-site scale, stand age did not affect occupancy at the wetland scale. It appears that most wetlands in northern coniferous forest landscapes, regardless of stand age, offer dense conifer patches nearby and provide suitable breeding habitat if quality foraging sites (e.g., areas of shallow water) also are available. Detectability (0.29 6 0.04) decreased with increasing wind speed, and decreased about fourfold over the course of the breeding season. Rusty Blackbirds responded to broadcast of conspecific vocalizations by flying toward the observer and perching more often than prior to broadcast, demonstrating that broadcasts can be a useful tool to enhance visual detectability. Given our results, observers can now focus site selection on wetlands and sampling conditions most likely to maximize detections of Rusty Blackbirds
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