33 research outputs found

    Review of \u3ci\u3eAppreciating Your Feathered Neighbors\u3c/i\u3e, by Dana Gardner and Nancy Overcott

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    Fifty Common Birds of the Upper Midwest. Watercolors by Dana Gardner; text by Nancy Overcott. 2006. University of Iowa Press, Iowa City, Iowa. 106 pages. $34.95 (cloth). What\u27s the best way to interest a friend in bird watching? Buy them a field guide, a CD of bird songs, or take them out bird watching? All of these ideas might work, but another approach is to tell personal stories and draw pictures of common birds in yards, parks, and natural areas where they live; help them get to know their neighbors with feathers. That\u27s exactly what Dana Gardner and Nancy Overcott did in their recent book about common birds of the Upper Midwestern United States. The authors\u27 decision to focus on common birds will be appealing to people who feed or watch birds casually; they will likely be familiar with some of these birds. The book is a self-described set of stories and paintings about birds; the authors express their hope in the introduction that these stories will inspire interest in habitat preservation

    Use of Artificial Enclosures to Determine the Survival of Rana pipiens Larvae in Upper Midwestern Agricultural Ponds

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    Amphibians in the upper Midwest use agricultural ponds for breeding. Unfortunately, the risks (both direct and indirect) associated with using these ponds are poorly understood in both amphibian adults and larvae. In order to quantify these risks, we performed a comparison of larval survival rates between agricultural and natural ponds in southeastern Minnesota during the spring and summer of 2001. During this time, larval survival was observed in Rana pipiens tadpoles raised through metamorphosis in enclosures placed in agricultural and natural ponds. In addition, we measured the levels of nutrients commonly linked with agricultural ponds (i.e., ammonia, total phosphorous, and total nitrogen), and whether or not nutrient concentration was associated with larval survival. No differences were detected in nutrient levels or survival of larvae reared in agricultural and natural ponds. Furthermore, neither nutrient levels nor pond type significantly predicted larval survival. Our data were highly variable, making the interpretation of our results difficult. The enclosures used to rear tadpoles were highly effective and can be easily incorporated into future studies

    Flow Cytometry Used to Assess Genetic Damage in Frogs from Farm Ponds

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    Flow cytometry (FC) is a laboratory method used to detect genetic damage induced by environmental contaminants and other stressors in animals, including amphibians. We tested FC methods on three species of ranid frogs collected from farm ponds and natural wetlands in southeastern Minnesota. We compared FC metrics for Rana clamitans between ponds with direct exposure to agricultural contaminants and reference (unexposed) ponds. Concentrations of atrazine in water from our farm ponds ranged from 0.04 to 0.55 ppb. We found that R. clamitans from exposed ponds had DNA content similar to frogs from unexposed ponds. Pond-averaged C-values (a measure of DNA content) ranged from 6.53 to 7.08 for R. pipiens (n = 13), 6.55 to 6.60 for R. clamitans (n = 40) and 6.74 for R. palustris (n = 5). Among all species, the mean sample CVs ranged from 1.91 (R. palustris) to 6.31 (R. pipiens). Deformities were observed in only 2 of 796 individuals among all species and occurred in both reference and exposed ponds. Although we did not detect evidence of DNA damage associated with agriculture in our study, we demonstrated the potential of FC for screening amphibian populations for genetic damage. Metrics from a variety of amphibian species and locations as well as laboratory studies are needed to further assess the value of FC for monitoring amphibian genetic integrity in contaminated sites

    Landscape Associations of Frog and Toad Species in Iowa and Wisconsin, U.S.A.

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    Landscape habitat associations of frogs and toads in Iowa and Wisconsin were tested to determine whether they support or refute previous general habitat classifications. We examined which Midwestern species shared similar habitats to see if these associations were consistent across large geographic areas (states). Rana sylvatica (wood frog), Hyla versicolor (eastern gray treefrog), Pseudacris crucifer (spring peeper), and Acris crepitans (cricket frog) were identified as forest species, P. triseriata (chorus frog), H. chrysoscelis (Cope\u27s gray treefrog), R. pipiens (leopard frog), and Bufo americanus (American toad) as grassland species, and R. catesbeiana (bullfrog), R. clamitans (green frog), R. palustris (pickerel frog), and R. septentrionalis (mink frog) as lake or stream species. The best candidates to serve as bioindicators of habitat quality were the forest species R. sylvatica, H. versicolor, and P. crucifer, the grassland species R. pipiens and P. triseriata, and a cold water wetland species, R. palustris. Declines of P. crucifer, R. pipiens, and R. palustris populations in one or both states may reflect changes in habitat quality. Habitat and community associations of some species differed between states, indicating that these relationships may change across the range of a species. Acris crepitans may have shifted its habitat affinities from open habitats, recorded historically, to the more forested habitat associations we recorded. We suggest contaminants deserve more investigation regarding the abrupt and widespread declines of this species. Interspersion of different habitat types was positively associated with several species. A larger number of wetland patches may increase breeding opportunities and increase the probability of at least one site being suitable. We noted consistently negative associations between anuran species and urban development. Given the current trend of urban growth and increasing density of the human population, declines of amphibian populations are likely to continue

    Detecting spatial regimes in ecosystems

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    Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change

    A road map for designing and implementing a biological monitoring program

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    Designing and implementing natural resource monitoring is a challenging endeavor undertaken by many agencies, NGOs, and citizen groups worldwide. Yet many monitoring programs fail to deliver useful information for a variety of administrative (staffing, documentation, and funding) or technical (sampling design and data analysis) reasons. Programs risk failure if they lack a clear motivating problem or question, explicit objectives linked to this problem or question, and a comprehensive conceptual model of the system under study. Designers must consider what “success” looks like from a resource management perspective, how desired outcomes translate to appropriate attributes to monitor, and how they will be measured. All such efforts should be filtered through the question “Why is this important?” Failing to address these considerations will produce a program that fails to deliver the desired information. We addressed these issues through creation of a “road map” for designing and implementing a monitoring program, synthesizing multiple aspects of a monitoring program into a single, overarching framework. The road map emphasizes linkages among core decisions to ensure alignment of all components, from problem framing through technical details of data collection and analysis, to program administration. Following this framework will help avoid common pitfalls, keep projects on track and budgets realistic, and aid in program evaluations. The road map has proved useful for monitoring by individuals and teams, those planning new monitoring, and those reviewing existing monitoring and for staff with a wide range of technical and scientific skills

    Appendix A. Environmental covariates considered for hierarchical models of Cerulean Warbler habitat associations in the prairie–hardwood transition.

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    Environmental covariates considered for hierarchical models of Cerulean Warbler habitat associations in the prairie–hardwood transition

    Appendix B. Point counts from 17 locations within the prairie–hardwood transition, used in evaluating hierarchical count models.

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    Point counts from 17 locations within the prairie–hardwood transition, used in evaluating hierarchical count models

    Supplement 1. WinBUGS code for modeling relative Cerulean Warbler abundance in the upper midwestern United States.

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    <h2>File List</h2><blockquote> <p><a href="Thogmartin_WinBUGS_code.txt">Thogmartin_WinBUGS_code.txt</a> - WinBUGS code </p> <p> </p></blockquote><h2>Description</h2><blockquote> <p>The file "Thogmartin_WinBUGS_code.txt" contains code for fitting a hierarchical spatial count model. To execute the code, the text must be pasted into a document window in WinBugs.</p> </blockquote> <p> </p

    The Distribution and Role of Functional Abundance in Cross‐Scale Resilience

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    The cross-scale resilience model suggests that system-level ecological resilience emerges from the distribution of species’ functions within and across the spatial and temporal scales of a system. It has provided a quantitative method for calculating the resilience of a given system and so has been a valuable contribution to a largely qualitative field. As it is currently laid out, the model accounts for the spatial and temporal scales at which environmental resources and species are present and the functional roles species play but does not inform us about how much resource is present or how much function is provided. In short, it does not account for abundance in the distribution of species and their functional roles within and across the scales of a system. We detail the ways in which we would expect species’ abundance to be relevant to the cross-scale resilience model based on the extensive abundance literature in ecology. We also put forward a series of testable hypotheses that would improve our ability to anticipate and quantify how resilience is generated, and how ecosystems will (or will not) buffer recent rapid global changes. This stream of research may provide an improved foundation for the quantitative evaluation of ecological resilience
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