The difficulty of obtaining pedigrees for wild populations has hampered the possibility of demonstrating inbreeding depression in nature. In a small, naturally restored, wild population of grey wolves in Scandinavia, founded in 1983, we constructed a pedigree for 24 of the 28 breeding pairs established in the period 1983–2002. Ancestry for the breeding animals was determined through a combination of field data (snow tracking and radio telemetry) and DNA microsatellite analysis. The population was founded by only three individuals. The inbreeding coefficient F varied between 0.00 and 0.41 for wolves born during the study period. The number of surviving pups per litter during their first winter after birth was strongly correlated with inbreeding coefficients of pups ( R 2 =0.39, p <0.001). This inbreeding depression was recalculated to match standard estimates of lethal equivalents (2B), corresponding to 6.04 (2.58–9.48, 95% CI) litter-size-reducing equivalents in this wolf population.

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.

So far the vast majority of studies on large carnivore predation, including kill rates and consumption, have been based on winter studies. Because large carnivores relying on ungulates as prey often show a preference for juveniles, kill rates may be both higher and more variable during the summer season than during the rest of the year leading to serious underestimates of the total annual predation rate. This study is the first to present detailed empirical data on kill rates and prey selection in a wolf-moose system during summer (June-September) as obtained by applying modern Global Positioning System-collar techniques on individual wolves (Canis lupus) in Scandinavia. Moose (Alces alces) was the dominant prey species both by number (74.4%) and biomass (95.6%); 89.9% of all moose killed were juveniles, representing 76.0% of the biomass consumed by wolves. Kill rate in terms of the kilogram biomass/kilogram wolf per day averaged 0.20 (range: 0.07-0.32) among wolf territories and was above, or well above, the daily minimum food requirements in most territories. The average number of days between moose kills across wolf territories and study periods was 1.71 days, but increased with time and size of growing moose calves during summer. Over the entire summer (June-September, 122 days), a group (from two to nine) of wolves killed a total of 66 (confidence interval 95%; 56-81) moose. Incorporation of body growth functions of moose calves and yearlings and wolf pups over the summer period showed that wolves adjusted their kill rate on moose, so the amount of biomass/kilogram wolf was relatively constant or increased. The kill rate was much higher (94-116%) than estimated from the winter period. As a consequence, projecting winter kill rates to obtain annual estimates of predation in similar predator-prey systems may result in a significant underestimation of the total number of prey killed.

Recent analyses have questioned the usefulness of heterozygosity estimates as measures of the inbreeding coefficient (f), a finding that may have dramatic consequences for the management of endangered populations. We confirm that f and heterozygosity is poorly correlated in a wild and highly inbred wolf population. Yet, our data show that for each level of f, it was the most heterozygous wolves that established themselves as breeders, a selection process that seems to have decelerated the loss of heterozygosity in the population despite a steady increase of f. The markers contributing to the positive relationship between heterozygosity and breeding success were found to be located on different chromosomes, but there was a substantial amount of linkage disequilibrium in the population, indicating that the markers are reflecting heterozygosity over relatively wide genomic regions. Following our results we recommend that management programs of endangered populations include estimates of both f and heterozygosity, as they may contribute with complementary information about population viability.

We document a new record dispersal for wolves worldwide. The natal straight‐line dispersal distance of a Global Positioning System‐collared female wolf from the Scandinavian population was 1,092 km from southeast Norway to northeast Finland, with a multistage actual travel distance of >10,000 km. Natural gene flow to the isolated, inbred Scandinavian wolf population may occur if survival of dispersers is improved.

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Summary1. Global positioning systems (GPS) were used to track hunters in an area of central Norway where willow ptarmigan Lagopus lagopus were contemporaneously radio-tracked. A geographical information system (GIS) was then used to study spatiotemporal interactions between hunters and game. 2. Recording hunting activity with the GPS produced accurate and unbiased information about the behaviour and eort of hunters. When GPS tracking nine hunters during 50 hunter-days, data were lost for an estimated time of 30 h 45 min, which constituted about 10% of the total hunting time. 3. Willow ptarmigan hunters walked on average 16´2 km daily at a speed of 2´8 km h ±1 , and they hunted for 9 h each day, of which almost 6 h was active hunting time. During 50 hunter-days they had 295 h of active hunting, covered a distance of 818 km and harvested 20% of the willow ptarmigan population in the area. 4. The spatial distribution of hunting pressure was strongly dependent on the starting point of the hunters, and areas close to the base cabin were subject to most hunting activity. Areas furthest away, towards the border of the hunting area, experienced little hunting activity. 5. Logistic regression showed that survival probability of ptarmigan was best predicted by distance from the cabin. Shot radio-tagged birds lived closer to the cabin, and had twice as high hunting pressure in their home range, compared with surviving radio-tagged birds. 6. This method of obtaining quantitative data about human eort will have application in other studies when there is a need to quantify and analyse human eort on temporal and spatial scales.

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