We describe methods for the preservation, extraction and amplification of DNA from faeces that facilitate field applications of faecal DNA technology. Mitochondrial, protein encoding and microsatellite nuclear DNA extracted and amplified from faeces of Malayan sun bears and North American black bears is shown to be identical to that extracted and amplified from the same individual's tissue or blood. A simple drying agent, silica beads, is shown to be a particularly effective preservative, allowing easy and safe transport of samples from the field. Methods are also developed to eliminate the risk of faecal DNA contamination from hair present in faeces.
Abstract. Many wildlife species are managed based on the compensatory mortality hypothesis, which predicts that harvest mortality (especially adult male mortality) will trigger density-dependent responses in reproduction, survival, and population growth caused via reduced competition for resources. We tested the compensatory mortality hypothesis on two cougar (Puma concolor) populations in Washington, USA (one heavily hunted and one lightly hunted). We estimated population growth, density, survival, and reproduction to determine the effects of hunting on cougar population demography based on data collected from 2002 to 2007. In the heavily hunted population, the total hunting mortality rate (mean 6 SD) was 0.24 6 0.05 (0.35 6 0.08 for males, 0.16 6 0.05 for females). In the lightly hunted population, the total hunting mortality rate was 0.11 6 0.04 (0.16 6 0.06 for males, 0.07 6 0.05 for females). The compensatory mortality hypothesis predicts that higher mortality will result in higher maternity, kitten survival, reproductive success, and lower natural mortality. We found no differences in rates of maternity or natural mortality between study areas, and kitten survival was lower in the heavily hunted population. We rejected the compensatory mortality hypothesis because vital rates did not compensate for hunting mortality. Heavy harvest corresponded with increased immigration, reduced kitten survival, reduced female population growth, and a younger overall age structure. Light harvest corresponded with increased emigration, higher kitten survival, increased female population growth, and an older overall age structure. Managers should not assume the existence of compensatory mortality when developing harvest prescriptions for cougars.
Lynx (Lynx canadensis) and snowshoe hare (Lepus americanus) population characteristics and use of habitats were studied during 1985–1987 in north central Washington. Lynx used areas above 1463 m elevation that were dominated by lodgepole pine (Pinus contorta) and Engelmann spruce – subalpine fir (Picea engelmannii – Abies lasiocarpa) cover types. Snowshoe hares were the most common prey of lynx, with remains of snowshoe hare occurring in 23 of 29 scats. Counts of tracks and pellets showed snowshoe hares to be most abundant in 20-year-old lodgepole pine stands. Fire suppression and natural fire frequencies in the past 5 decades has limited the amount of these early successional forests, which are important as habitat for snowshoe hares. Marginal habitat conditions for snowshoe hares probably resulted in a scarcity of prey in the study area and may explain the relatively large home ranges of lynx (69 ± 28 km2 for five males and 39 ± 2 km2 for two females), low density of adults (2.3 lynx/100 km2), and high kitten mortality rates (88% for eight kittens in three litters). Demographic characteristics of lynx in the study area may be representative of lynx populations along the southern periphery of their range where habitat conditions are marginal for lynx and snowshoe hares.
Wildlife agencies typically attempt to manage carnivore numbers in localized game management units through hunting, and do not always consider the potential influences of immigration and emigration on the outcome of those hunting practices. However, such a closed population structure may not be an appropriate model for management of carnivore populations where immigration and emigration are important population parameters. The closed population hypothesis predicts that high hunting mortality will reduce numbers and densities of carnivores and that low hunting mortality will increase numbers and densities. By contrast, the open population hypothesis predicts that high hunting mortality may not reduce carnivore densities because of compensatory immigration, and low hunting mortality may not result in more carnivores because of compensatory emigration. Previous research supported the open population hypothesis with high immigration rates in a heavily hunted (hunting mortality rate = 0.24) cougar population in northern Washington. We test the open population hypothesis and high emigration rates in a lightly hunted (hunting mortality rate = 0.11) cougar population in central Washington by monitoring demography from 2002 to 2007. We used a dual sex survival/fecundity Leslie matrix to estimate closed population growth and annual census counts to estimate open population growth. The observed open population growth rate of 0.98 was lower than the closed survival/ fecundity growth rates of 1.13 (deterministic) and 1.10 (stochastic), and suggests a 12-15% annual emigration rate. Our data support the open population hypothesis for lightly hunted populations of carnivores. Low hunting mortality did not result in increased numbers and densities of cougars, as commonly believed because of compensatory emigration.
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