We investigated the long-term effect of fitting back-mounted radio tags to nestling tawny owls Strix aluco in northern England by comparing apparent survival rates of radio-tagged and non radio-tagged nestlings from two cohorts using capture-mark-recapture methodology. If radio tags had no effect, apparent survival rates should not have differed between the two groups of birds. Overall, juvenile survival was much lower than adult survival and yearling breeding probability much lower than adult breeding probability. Radios had no significant effect on yearling breeding probability, but they did have a significant negative effect on juvenile survival. Overall, just one bird (1.8%) was recruited from the radio-tagged group of 55 birds, whereas 14 (16%) were recruited from the control group of 89 birds. There was no significant difference in the distribution of sexes between groups that could account for these differences in apparent survival rates. Moreover, food supply and breeding performance of broods in the two groups did not differ significantly, indicating that differences in rearing conditions were not responsible for the disparity in survival rates. Based on our results, and those from other studies of tawny and spotted owls Strix occidentalis, we recommend that back-mounted radio tags should not be used on nestling or recently fledged Strix species.

Mountain hare Lepus timidus populations show unstable dynamics with regular 7–10 year fluctuations in abundance. We tested the hypothesis that parasites destabilise hare dynamics by experimentally reducing parasite burdens and recording female body condition and fecundity. We trapped and radio tagged 42 female hares in April 2000 and 2001 in the Central Highlands of Scotland. Of these, 23 were treated with Ivermectin to remove intestinal parasites and 19 were left untreated as controls. The treated and untreated hares were killed in October together with a second control group of 19 unhandled hares. Treatment with Ivermectin reduced the abundance of the parasite Trichostrongylus retortaeformis and increased the body condition of hares. There was a trend for increased fecundity in treated hares, but this was not statistically significant. Our study demonstrates that parasites can reduce mountain hare condition and may affect their fecundity. We conclude that a host-parasite interaction is a possible mechanism for destabilising mountain hare dynamics.

The literature on cheetah Acinonyx jubatus ecology is dominated by studies on the Serengeti Plains (SNP) in East Africa. Because of this and the cheetah's hunting strategy it is generally considered to be a predator that prefers open grassland plains. However, cheetahs also inhabit a range of bush, scrub and woodland habitats. A field study using direct observations of radio-collared individuals in the woodland savanna habitat of the Kruger National Park (KNP), South Africa, and a literature review of studies across savanna habitats examined cheetah predation, hunting behaviour and habitat use in relation to prey composition, cover availability and kleptoparasitism. The cheetah's main prey is medium-sized herbivores, with a bias towards male prey. The group size and sex of the hunting cheetah may influence the results of prey selection studies as male coalitions tend to take larger prey than females. Cheetahs initiated more hunts and had a higher success rate in the open woodland savanna of the KNP compared to other available habitats with thicker bush, and in other wooded savanna areas they also prefer more open habitat for hunting. Although they appear to have shorter chase distances in more wooded habitats, hunting success appears to be slightly higher in open grassland habitat. Woody vegetation appears to obstruct the cheetah's high-speed hunting strategy, thereby lowering hunting success. However, cheetahs use cover for stalking prey and open habitats with bordering woodlands, or patches of cover are considered preferred cheetah habitats. In these habitats, cheetahs can stalk closer to their prey using available cover, but also successfully pursue their prey into available open spaces. Across African savanna ecosystems, cheetahs appear to be kleptoparasitised less in more wooded habitats. Therefore they may also prefer these habitats because they provide greater concealment from kleptoparasites. Our study suggests that the cheetah is more adaptable to habitat variability than is often thought and is not only a successful hunter on open grassland plains.

When hunting species in which the sexes differ substantially in value, sex-selective harvesting can increase income dramatically. In some hunted species, for example the red deer Cervus elaphus in Scotland, there are also marked ecological differences between the sexes. In red deer, stag mortality and dispersal rates are substantially higher when hind densities are high. Hence, there is a trade-off between having enough hinds to produce valuable stags, but keeping densities low enough to minimise losses from dispersal and stag mortality. We develop a model, parameterised for red deer on Rum, to explore these trade-offs. This stochastic, age and sex-structured model includes two neighbouring estates with differing harvesting policies. Due to stag dispersal, estates with low hunting levels act as sources of stags for neighbouring estates that harvest more heavily. The optimal harvesting strategy depends on the actions of neighbours, but keeps hinds below 50% of carrying capacity and imposes heavy hunting pressure on stags. Scottish deer estates aim to harvest fewer stags and more hinds than the model suggests as optimal, which could lead to substantially reduced incomes. We explore the reasons for this mismatch between predicted optimal behaviour and actual harvesting strategies by incorporating realistic levels of uncertainty, bias and infrequent population counts into our model. We show that the estates' harvesting strategies lead to approximately optimal hind harvesting, because hind numbers are generally underestimated in counts, whereas the uncertainty surrounding population sizes leads to a lower than optimal stag harvest. The most effective method of improving incomes is to increase count frequency. This modelling approach is broadly applicable, both for the management of hunted species under uncertainty and for spatially explicit conservation policies such as no-take areas.

Determining the factors causing variation in traffic accidents both in space and time are important for management, as it can help in designing mitigation efforts. The annual harvest of red deer Cervus elaphus in Norway has increased from 2,695 in 1971 to 23,597 in 2001, while the number of car-killed red deer increased from 27 to 443 over the same period. I analysed how the temporal variation in the annual number of car-killed red deer along the west coast of Norway varied with population density and climate. The increase in the number of car-killed red deer was mainly an effect of increasing population size (as evidenced from harvest records). The parameter estimate for the population size effect was 1.722 and 1.025, respectively, before and after adding the (non-significant) effect of ‘year‘ (as a continuous term). An increase in population size therefore led to an increase in the proportion of the number of car-killed red deer only when excluding the year effect which was likely due to an increase in traffic volume. Spring conditions, as measured by the March–May value of the North Atlantic Oscillation (NAO), correlated with the number of car-killed red deer, but winter, summer or autumn NAO did not. I argue that the consequences of an increasing number of car-deer collisions with increasing population density should be incorporated into future modelling of harvesting strategies if the aim is to maximise the economic outcome at a national scale.

Landowners in southeast Norway have supplied moose Alces alces with ensilaged bales of hay for up to eight winters. The incentive has been to limit migratory movements into heavily trafficated winter areas and away from young forest plantations. In this article, we report on landscape characteristics that increase the use of feeding stations, and on how browsing activity on Scots pine Pinus sylvestris twigs as well as leader stems of both pine and Norway spruce Picea abies was associated with distance to feeding stations at two different spatial scales: 1) at a local scale we sampled data from 50 m² observational plots up to 200 m from the feeding stations, and 2) at a regional scale we sampled data at all available young forest plantations up to 7 km from a feeding station. The probability that a feeding station was used increased towards the bottom of side valleys. The frequency of use of feeding stations increased annually, with increasing distance to other feeding stations, and with increasing distance to the more populated main valley. Moose-induced browse damage was extensive at proximate distances (< 200 m) to feeding stations, decreased to a minimum at 1–2 km, and increased slightly again at 3–7 km distance from less intensely used feeding stations. Indices of moose activity distribution (i.e. piles of faecal pellets) resembled browsing activity.

We present new estimates on the national road kill for nine large and medium-sized mammals in Sweden. Our estimates are based on 705 drivers' reports on the number of animals accidentally hit during individually chosen reference periods. During 1960–2000, a total of 881 animal-vehicle collisions were reported based on 243.6 million driven kilometres, representing 0.37% of the overall mileage driven in Sweden during 1992, the mean reference year of all replies. The collision frequencies ranged from 0.07 incidents per million kilometres for medium-sized mustelids, over 0.42 for badgers Meles meles to 1.11 for hares Lepus spp. Our data suggest that during 1992, 7,000–13,500 moose Alces alces, 43,500–59,000 roe deer Capreolus capreolus, 63,500–81,500 hares, 22,000–33,000 badgers and 6,500–12,500 red foxes Vulpes vulpes may have been killed on Swedish roads. Among these game species, the extrapolated nation-wide road kill ranged between 7 and 97% of the average annual harvest, and between 1 and 12% of the assessed total populations in 1992. Our results are in agreement with other independent road kill estimates for Sweden. The data suggested an overall increase in the frequency of road kills over the past 40 years, which partly can be attributed to changes in traffic volume and wildlife population sizes (game bags). In most species, the estimated levels of nation-wide road mortality are not alarmingly high, although local impacts may be significant. In badgers and hares, the ratio of the estimated road kill to the annual harvest increased two fold, suggesting a steady increase in the relative importance of road mortality. We conclude that interviews with drivers can provide a cheap and useful index of wildlife traffic mortality.

In this study, we tested the efficiency of near infrared reflectance spectroscopy (NIRS) to assess nitrogen content in faeces of free-living ruminants. Faecal nitrogen (FN) content was analysed in 168 pellet groups from red deer Cervus elaphus and roe deer Capreolus capreolus in the growing season and in winter using both the standard Kjeldahl method and NIRS analysis. Estimates of nitrogen content obtained by the two methods did not differ (P > 0.1), and the correlation between FN values was significant (P < 0.001). FN content ranged within 1.10–4.58% of dry matter and, as anticipated, it was higher in the growing season than in winter in both species (P < 0.01). Faecal nitrogen values were also higher for roe deer than for red deer, although the difference was only significant in the growing season (P = 0.007). Our study confirmed that faecal nitrogen of free-living ruminants can be accurately determined with NIRS analysis. NIRS represents a low-cost analytical technique, which could replace conventional labourious methods and is highly promising for analyses of diet quality in free-living ruminants.