The conservation of large carnivores is a formidable challenge for biodiversity conservation. Using a data set on the past and current status of brown bears (Ursus arctos), Eurasian lynx (Lynx lynx), gray wolves (Canis lupus), and wolverines (Gulo gulo) in European countries, we show that roughly one-third of mainland Europe hosts at least one large carnivore species, with stable or increasing abundance in most cases in 21st-century records. The reasons for this overall conservation success include protective legislation, supportive public opinion, and a variety of practices making coexistence between large carnivores and people possible. The European situation reveals that large carnivores and people can share the same landscape.
Summary1. The effects of harvest on the annual and seasonal survival of willow ptarmigan Lagopus lagopus L. were tested in a large-scale harvest experiment. Management units were randomly assigned to one of three experimental treatments: 0%, 15% or 30% harvest. Seasonal quotas were based on the experimental treatment and estimates of bird density before the hunting season. Survival rates and hazard functions for radio-marked ptarmigan were then estimated under the competing risks of harvest and natural mortality. 2. The partially compensatory mortality hypothesis was supported: annual survival of ptarmigan was 0AE54 ± 0AE08 SE under 0% harvest, 0AE47 ± 0AE06 under 15% harvest, and was reduced to 0AE30 ± 0AE05 under 30% harvest. Harvest mortality increased linearly from 0AE08 ± 0AE05, 0AE27 ± 0AE05 and 0AE42 ± 0AE06 from 0% to 30% harvest, whereas natural mortality was 0AE38 ± 0AE08, 0AE25 ± 0AE05 and 0AE28 ± 0AE06 under the same treatments. 3. Realized risk of harvest mortality was 0AE08-0AE12 points higher than our set harvest treatments of 0-30% because birds were exposed to risk if they moved out of protected areas. The superadditive hypothesis was supported because birds in the 30% harvest treatment had higher natural mortality during winter after the hunting season. 4. Natural mortality was mainly because of raptor predation, with two seasonal peaks in fall and spring. Natural and harvest mortality coincided during early autumn with little potential for compensation during winter months. Peak risk of harvest mortality was 5· higher than natural mortality. Low natural mortality during winter suggests that most late season harvest would be additive mortality. 5. Environmental correlates of natural mortality of ptarmigan included seasonal changes in snow cover, onset of juvenile dispersal, and periods of territorial activity. Natural mortality of ptarmigan was highest during autumn movements and nesting by gyrfalcons Falco rusticolus L. Mortality was low when gyrfalcons had departed for coastal wintering sites, and during summer when ptarmigan were attending nests and broods. 6. Our experimental results have important implications for harvest management of upland gamebirds. Seasonal quotas based on proportional harvest were effective and should be set at £15% of August populations for regional management plans. Under threshold harvest of a reproductive surplus, 15% harvest would be sustainable at productivity rates ‡2AE5 young per pair. Impacts of winter harvest could be minimized by closing the hunting season in early November or by reducing late season quotas.
The ongoing recovery of terrestrial large carnivores in North America and Europe is accompanied by intense controversy. On the one hand, reestablishment of large carnivores entails a recovery of their most important ecological role, predation. On the other hand, societies are struggling to relearn how to live with apex predators that kill livestock, compete for game species, and occasionally injure or kill people. Those responsible for managing these species and mitigating conflict often lack fundamental information due to a long-standing challenge in ecology: How do we draw robust population-level inferences for elusive animals spread over immense areas? Here we showcase the application of an effective tool for spatially explicit tracking and forecasting of wildlife population dynamics at scales that are relevant to management and conservation. We analyzed the world’s largest dataset on carnivores comprising more than 35,000 noninvasively obtained DNA samples from over 6,000 individual brown bears (Ursus arctos), gray wolves (Canis lupus), and wolverines (Gulo gulo). Our analyses took into account that not all individuals are detected and, even if detected, their fates are not always known. We show unequivocal quantitative evidence of large carnivore recovery in northern Europe, juxtaposed with the finding that humans are the single-most important factor driving the dynamics of these apex predators. We present maps and forecasts of the spatiotemporal dynamics of large carnivore populations, transcending national boundaries and management regimes.
Theoretical analyses have shown that the spatial scaling of environmental autocorrelation, strength of density regulation, and the dispersal of individuals determine the scaling of synchrony in population fluctuations. By modeling the separate effects of density regulation, environmental stochasticity, and demographic stochasticity, we estimate the spatial scaling of the component that is due to environmental stochasticity in the population dynamics of roe deer (Capreolus capreolus) in Norway.The estimated spatial scaling of the environmental noise was ϳ200 km. An examination of how different weather variables influenced the scaling indicated that snow depth was the major weather variable affecting the scaling of synchrony in population fluctuations, and was negatively related to population growth rates in 97.4% of the 151 populations included in the study. A large-scale climatic phenomenon, the North Atlantic Oscillation, was positively related to population growth rates in 94.7% of the populations but did not significantly affect the pattern of synchrony among populations.We used newly developed theoretical results of the contribution of environmental noise and dispersal to the spatial scale of synchrony to show that the spatial scaling estimated in this study could not be explained by dispersal. This suggests that common environmental noise operating mainly during the winter is able to synchronize population fluctuations of roe deer over large distances.
The southern Norwegian wolverine (Gulo gulo) population was considered functionally extinct in the 1960s but has partly recovered in recent years. Proper management of this population is highly dependent on reliable estimates of critical population parameters such as population size, sex ratio, immigration rate, and reproductive contribution from immigrants. We report on a large-scale population monitoring project assessing these parameters through genetic tagging of individuals, with feces as the source of DNA. Sixty-eight different individuals were detected among 147 successfully genotyped samples collected in 2000 and 2001. Sixty of these individuals were represented in the 2001 sample, which may be considered a minimum estimate of the population size. Almost 50% of these animals were sampled only once, however, indicating that the true population size may be markedly higher. Accordingly, a capture-recapture estimate based on the observed resampling rates suggested a population size of 89 wolverines (95% confidence interval [CI] = 74-104), which is approximately 35% higher than an estimate of 64 obtained from the number of active natal dens (95% CI = 46-95; p = 0.08). Indirect estimates of dispersal distances inferred from mother-offspring relationships suggested that wolverine males have the ability to disperse up to 500 km, a distance exceeding anything previously reported in the literature. Dispersal distances of more than 100 km were detected for females. Bayesian clustering analysis and subsequent assessment of individual relationships suggest that immigrants from northern Scandinavia have contributed and still contribute to the southern Norwegian gene pool, counteracting genetic erosion and reducing the risk of inbreeding depression. Additional sampling efforts will be undertaken during the coming years to allow for observations of population trends, immigration rate, and reproductive variance among individuals. Such data will provide an important basis for the design of an appropriate conservation plan for this small and vulnerable population. Historia de Colonización y Monitoreo No Invasivo de una Población Reestablecida de Gulo gulo Resumen: La población sureña de Gulo gulo se consideraba funcionalmente extinta en la década de 1960 pero se ha recuperado parcialmente en años recientes. El manejo adecuado de esta población depende, en gran medida, de estimaciones confiables de parámetros poblacionales críticos como por ejemplo el tamaño poblacional, la proporción de sexos, la tasa de inmigración y la contribución reproductiva de inmigrantes. Reportamos un proyecto de monitoreo poblacional a gran escala que evaluó estos parámetros por medio del marcaje genético de individuos, con heces como la fuente de ADN. Se detectaron 68 individuos diferentes entre 147 muestras de genotipos identificados exitosamente y colectadas en 2000 y 2001. Sesenta de estos individuos estuvieron representados en la muestra de 2001, lo que puede considerarse como una estimación §Current Noninvasive Monitoring of Wolverines 677 ...
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