24 research outputs found

    Assessing wolves and cougars as conservation surrogates

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    Large carnivores have been posited as potential conservation surrogates to inform the design and prioritization of conservation planning. We show that wolves Canis lupus and cougars Puma concolor may have potential to serve as a surrogate suite for conserving landscape heterogeneity, hypothesized to be a determinant of biodiversity in some landscapes. We examined habitat and landscape features associated with the spatial distribution of wolf- and cougar-killed prey in the basin of the North Fork of the Flathead River in Montana. The spatial distribution of wolf-killed prey was driven largely by cover type, whereas physiographic characteristics were the primary driver of the distribution of cougar-killed prey. Spatial templates, generated using \u3e0.66 probability quantiles from spatially explicit models of kill site distribution, estimated over three times as much high-quality habitat for wolves (1005 km2) than for cougars (381 km2). While there were only minor differences in the proportional representation of land cover types between the wolf and cougar templates, 40% of the cougar template fell outside the wolf template, and the former contained over three times more rugged terrain than the latter. The use of a combined wolf–cougar spatial template resulted in a 15% increase in total area and 91% increase in the amount of rugged terrain identified. Based on our models, the advantage of using both wolves and cougars as a focal suite in north-west Montana is the ability to identify a greater area of high-quality habitat, and capture landscape heterogeneity that may be important to conserving biodiversity

    Estimation of the Bottleneck Size in Florida Panthers

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    We have estimated the extent of genetic variation in museum (1890s) and contemporary (1980s) samples of Florida panthers Puma concolor coryi for both nuclear loci and mtDNA. The microsatellite heterozygosity in the contemporary sample was only 0.325 that in the museum samples although our sample size and number of loci are limited. Support for this estimate is provided by a sample of 84 microsatellite loci in contemporary Florida panthers and Idaho pumas Puma concolor hippolestes in which the contemporary Florida panther sample had only 0.442 the heterozygosity of Idaho pumas. The estimated diversities in mtDNA in the museum and contemporary samples were 0.600 and 0.000, respectively. Using a population genetics approach, we have estimated that to reduce either the microsatellite heterozygosity or the mtDNA diversity this much (in a period of c. 80 years during the 20th century when the numbers were thought to be low) that a very small bottleneck size of c. 2 for several generations and a small effective population size in other generations is necessary. Using demographic data from Yellowstone pumas, we estimated the ratio of effective to census population size to be 0.315. Using this ratio, the census population size in the Florida panthers necessary to explain the loss of microsatellite variation was c. 41 for the non-bottleneck generations and 6.2 for the two bottleneck generations. These low bottleneck population sizes and the concomitant reduced effectiveness of selection are probably responsible for the high frequency of several detrimental traits in Florida panthers, namely undescended testicles and poor sperm quality. The recent intensive monitoring both before and after the introduction of Texas pumas in 1995 will make the recovery and genetic restoration of Florida panthers a classic study of an endangered species. Our estimates of the bottleneck size responsible for the loss of genetic variation in the Florida panther completes an unknown aspect of this account

    Assessing wolves and cougars as conservation surrogates

    No full text
    Abstract Large carnivores have been posited as potential conservation surrogates to inform the design and prioritization of conservation planning. We show that wolves Canis lupus and cougars Puma concolor may have potential to serve as a surrogate suite for conserving landscape heterogeneity, hypothesized to be a determinant of biodiversity in some landscapes. We examined habitat and landscape features associated with the spatial distribution of wolf-and cougar-killed prey in the basin of the North Fork of the Flathead River in Montana. The spatial distribution of wolf-killed prey was driven largely by cover type, whereas physiographic characteristics were the primary driver of the distribution of cougar-killed prey. Spatial templates, generated using >0.66 probability quantiles from spatially explicit models of kill site distribution, estimated over three times as much high-quality habitat for wolves (1005 km 2 ) than for cougars (381 km 2 ). While there were only minor differences in the proportional representation of land cover types between the wolf and cougar templates, 40% of the cougar template fell outside the wolf template, and the former contained over three times more rugged terrain than the latter. The use of a combined wolf-cougar spatial template resulted in a 15% increase in total area and 91% increase in the amount of rugged terrain identified. Based on our models, the advantage of using both wolves and cougars as a focal suite in north-west Montana is the ability to identify a greater area of high-quality habitat, and capture landscape heterogeneity that may be important to conserving biodiversity
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