Practical techniques to estimate the sightability of mountain goats Oreamnos americanus during aerial surveys have not been developed or have been poorly tested. I evaluated sightability of 28 radio-collared goats in two study areas in southeastern British Columbia to assess whether sightability increased with increased helicopter survey effort, and to explore which factors might affect sightability. Three surveys at different survey efforts were conducted in each study area, during which attempts were made to locate collared goats 64 times. I detected no relationship between survey effort in the range tested (1.3-6.1 minutes/km²) and sightability (38-83%). Sightability averaged 63%. Only animal activity and larger group size influenced goat sightability. Sightability tended to decrease with increased vegetation cover. Survey efforts of > 2.0 minutes/km² do not appear to result in higher sightability. For surveys of large areas not well-known to surveyors, a 60-65% sightability correction may be realistic, with a target of approximately 1.5 minutes/km² effort.

The red grouse Lagopus lagopus scoticus differs from the willow grouse L. l. lagopus of mainland Europe in not developing a white winter plumage. Previous studies have suggested that plumage colouration in birds can have important consequences for heat transfer through the feather layer. We examined the thermal consequences of plumage colouration in both subspecies of grouse. There were no differences in feather density, plumage depth or thermal resistance of the plumage between dark rufous Scottish and white Scandinavian grouse. In still air, heat gained from simulated solar radiation was greater through dark than through white plumage. However, in wind there was no difference in heat load between dark and white plumages. Our study suggests that there may be a trade-off between thermal and camouflage benefits of plumage colour for grouse in the wild.

For some species, reliable quantitative estimates of population size can be difficult to obtain. Density estimates of red grouse Lagopus lagopus scoticus are usually obtained through counts using trained pointer dogs. In this paper, we examine two alternative, and potentially easier, methods for estimating red grouse breeding density: one direct, based on counts of males responding to playbacks of territorial calls, and one indirect, based on counts of droppings along transects. We counted grouse on 14 1-km² areas for 1-3 years in 2002-2004 using trained dogs and compared these density estimates (range: 23-220 grouse/km²) with density estimates derived from playback counts and dropping counts. For playback counts, we counted males responding to a playback of territorial calls at nine points spread over a given 1-km² area. For dropping counts, we counted the number of fibrous dropping roost piles along two 1-km transects across each 1-km² area. Generalised Linear Models indicated that male, female and total grouse density, measured by counts with dogs, could be predicted from playback counts of males, and that total grouse density could be predicted from dropping counts. However, playback counts provided better predictions than did dropping counts. Neither time of day nor wind affected responses to playback, but in clear weather fewer males responded than was expected. Playback counts could thus provide a useful alternative method for estimating grouse density, when or where counts with dogs are not feasible.

We investigated the potential for released captive-reared grey partridges Perdix perdix to restock regions from which the species has disappeared. Birds were released at two sites in Scotland (not concurrently) from 1997 to 2003 and monitored via spring and autumn counts, night-time surveys and radio-telemetry. Some wild female partridges were caught and radio-tagged each spring for comparison with reared females. The survival rate of 520 captive-reared birds released in autumn until the following spring was poor (around 10% overall) and was not significantly different for radio-tagged and visibly-marked birds. Carrying a radiotag did not alter the body condition of the birds. The breeding-season survival rate of released hens averaged 30% and was not significantly different to that of 44% for wild hens. However, the power to detect significant differences was low due to the small number of survivors. The major cause of mortality throughout was predation (82 and 55% of losses at the two sites), with red foxes Vulpes vulpes and raptors being the most significant predators. Reared partridges at the study site with legal predator control had higher survival rates than those at the other site, but this was not true for wild hens as raptor predation compensated for declining mammalian predation rates (19% of deaths were due to raptors at the site without predator control, 56% at the site with predator control). We suggest that the vulnerability to predation of reared birds was most likely due to inappropriate antipredator behaviour or an increased risk of predation near to release pens. Of the partridges that survived long enough to breed, three times more wild hens reached incubation than reared hens. No reared hens raised chicks in their first breeding season whilst the only hen that survived long enough to breed in her second year raised 14 young. Captive-reared grey partridges could not be used to increase the species' range unless 1) the number surviving their first year increased, 2) the higher breeding rate of two-year-old females suggested here was ubiquitous, and unless 3) appropriate management was in place first. Methods for improving the success of releases are discussed.

Small mammals make up an important link in the food chain as many predator species feed on them. There are indications that small mammal populations in Europe are declining due to the intensification of agriculture. According to national legislation, farmers in Switzerland have to cultivate at least 7% of their land as ecological compensation areas and, thus, some alternative habitats that are possibly beneficial for small mammals have been created. In this study, we estimated the diversity and density of small mammals on two types of conventional farmland field types (artificial grassland and autumn-sown wheat) and three types of ecological compensation areas (wild-flower strips, herbaceous strips and low-intensity meadows) by use of capture-recapture in March, May and July 2003. The common vole Microtus arvalis was the most abundant and predominant species in all habitat types except in herbaceous strips, which harboured the highest diversity with six species caught. In March the density of small mammals was generally very low, but significantly higher in wild-flower (mainly due to common vole) and herbaceous strips than in the other habitat types. In wild-flower and herbaceous strips, densities increased strongly from March to May and in July. On autumn-sown wheat fields, a strong increase occurred only from May to July and was caused by common vole. On artificial grassland and low-intensity meadows, densities of small mammals (mainly common vole) increased only marginally with low-intensity meadows supporting slightly higher densities. Thus, habitats that were not mown each year supported the highest densities of small mammals. This demonstrates that ecological compensation areas, such as wild-flower and herbaceous strips, make up an important refuge for small mammals. They probably also have positive effects on populations of many predator species that depend on small mammals, particularly if a mosaic with mown surfaces is created.

Invasive alien species rank among the world's greatest threats to biodiversity and cause huge economic losses. Eradication is a key management strategy for newly introduced pests, but it is frequently discarded due to the high costs. When populations become established and conflicts increase, policy-makers often resort to permanent population control. However, no cost-benefit analyses have been carried out so far to compare the two alternatives. We present the first cost-benefit analysis by comparing the permanent control campaign of coypu Myocastor coypus in Italy with the successful eradication carried out in UK in the 1980s. Data regarding the eradication came from literature, while costs and benefits of control were quantified through a national survey. In Italy, during 1995-2000, the damage amounted to € 11,631,721, control activities cost € 2,614,408, and 220,688 coypu were removed. Control campaigns did not stop the population expansion nor the increase in damage and economic losses at a national scale. However, the efficacy of local campaigns varied among different ecosystems. According to our predictions, the Italian coypu range may expand 2.5-3.3 times, and economic losses may reach € 9-12 millions/year. A comparison between the costs of the successful eradication carried out in East Anglia (€ five million over 11 years) and the permanent control campaign in Italy (€ 14 million over only six years) shows that even very costly eradications, if successful, may have a very positive cost-benefit ratio in the long term.

Many factors influence human attitudes towards large carnivores. In our study we explore different factors that affect attitudes towards four such species, i.e. wolverines Gulo gulo, lynx Lynx lynx, brown bears Ursus arctos and wolves Canis lupus. We examined attitudes through a representative sample of the Norwegian population. By using 12 independent variables chosen for this study, we were able to explain around 15-45% of the variance in attitudes towards the four species. In general, people displayed more negative attitudes towards wolves and bears than towards lynx and wolverines. However, they were more positive towards increasing the small populations of the first two species than the relatively large populations of the last two. The results showed that 34-44% of the respondents reacted negatively to the question ‘What do you think should be done about the size of the carnivore population?’. On the other hand, 73-87% reacted positively to the question ‘Do these species have a right to exist in Norway?’. To the question ‘How far do you want the carnivore species from your home?’, 41-66% answered > 10 km. The most important variables explaining negative attitudes towards all the large carnivore species regarded the concern of the respondents for their own and their family's safety. People became more negative with age; those who were afraid of the carnivores were in general more negative towards them, and those who experienced financial loss (i.e. farmers) by having large carnivores in their vicinity expressed negative attitudes. On the other hand, the excitement of seeing large carnivores in their natural environment had a positive influence on attitude. People from larger communities were in general more positive, whereas those who thought they had the species in their vicinity were more negative. Big-game hunters frequently showed negative attitudes, whereas those with higher levels of education tended to be more positive. Our results indicate that attitudes towards large carnivores are complex. However, people are in general more negative towards wolves and bears, which must be taken into account in conservation programmes.

The manner in which species partition space and time to minimize competition for shared, limited resources has been a major focus of theoretical and empirical ecology. Although numerous examples exist of intra-guild dietary separation among coexisting species, studies of spatio-temporal partitioning among species sharing a single food type are rare. We investigated spatio-temporal patterns of multi-species predation on individually-marked moose Alces alces calves in an Alaskan boreal forest community where moose are the only large herbivore, and constitute the primary prey of coexisting black bears Ursus americanus, brown bears U. arctos and gray wolves Canis lupus. The two most closely related predators, black bears and brown bears, overlapped temporally and spatially in their consumption of moose calves, as indicated by univariate analyses. Moreover, both bear species segregated spatially from wolves when killing moose calves. Hence, our study appears to support key predictions of predator coexistence on a shared resource: namely, that bears and wolves differentiate spatially or temporally in their use of a pulsed prey, presumably to minimize competition.

Owing to the Eurasian badger's Meles meles role as an agricultural pest, its potential role in the transmission of bovine tuberculosis and other management problems, accurate estimation of badger abundance is required. At present, no censusing method exists that is accurate, cost-effective and relatively non-invasive. In this article, we test the feasibility of estimating badger social group and population size by genotyping DNA extracted from remotely plucked hair, obtained using unbaited barbed-wire traps suspended above runs and main sett entrances. Social group size was independently estimated by direct observation. The study was performed on 11 social groups in a population in Luxembourg, and hair samples were collected on alternate days during a four-week period. A total of 332 hair samples was collected, from which 303 single-hair extracts gave rise to a complete genetic profile after a single round of amplification. Of 48 multiple-hair extracts, 23% gave rise to a mixed profile from multiple contributors. Of samples collected from different barbs of the same trap on the same collection day, 53% originated from different individuals. After applying two error-checking protocols, an extended singles filter and a mismatch filter, 55 unique profiles were obtained. Mark-recapture analysis estimated the population to contain 61 badgers, whereas direct observation suggested a population of 49 badgers. By comparison with direct observation, hair-trapping yielded a higher estimate for six social groups, an equal estimate for four groups and a lower estimate for one group. We conclude that hair-trapping by means of unbaited barbed-wire traps, placed at sett entrances and well-used runs, offers a method of censusing badgers that is relatively accurate and precise, comparatively non-invasive, potentially applicable in a variety of habitats and at different population densities, and not prohibitively expensive. We suggest that DNA should be extracted from single hairs, rather than from hairs pooled from a single barb or a single trap, in order to avoid mixed profiles.

Densities of otter Lutra lutra populations are difficult to measure. However, otters have to move between ice-free feeding areas in winter, and for this reason finding otter tracks is easy during the winter season. Snow tracking has been used for estimating the total population of otters in a 1,650 km² study area in central Finland since 1985 by the use of three methods. Using the home-range mapping method (HMM), all rivers, especially rapids and other possible feeding areas for otters, were studied carefully. Otter individuals were identified by size, age and course direction of the tracks, and the census was controlled by two revisits to possible feeding areas a few days after the first tracking. After the revisits, no further individuals were found in any of the 16 river systems. HMM gives exact estimates of the total population of otters, and in 2002/03, 52 otters (including 11 litters and 16 cubs altogether) lived in the study area. Litters are usually found while snow tracking, and the method therefore also supplies information on the productivity of the population. Using the segment method (SM), all shorelines of rivers and streamlets were divided into segments, and each segment was searched for otter tracks. The population estimate was mean number of animals determined from observed fresh signs in the sampled segments, and extrapolated across all segments in the study area. When the population was estimated by the positive segments found in SM, 59 otters were found; almost the same number as was estimated by using the HMM (52 otters). I also used a faster sampling method; the one-visit census (OVC). Only the most easily reachable otter sites of all possible home ranges were investigated within a few days. The number of permanent OVC sites was 111, and all sites were visited two to four days after the last snowfall. Using the OVC, about 50% of otters estimated by using the HMM were found in every sampling. The OVC method is cheap and reliable, and is therefore a useful tool for monitoring otter populations in large northern areas, such as for example in Finland, Sweden, Russia and Canada, given that infrastructures, i.e. roads, exist.

Non-invasive techniques for monitoring wildlife are increasingly used by researchers to identify the presence of carnivores in particular habitat types. For mid-sized carnivores the two primary methods used are camera trapping and track plates, both of which function by attracting an animal to a census apparatus which then records the visit by photograph or by track imprint. These techniques have rarely, however, been used to survey Asian mid-sized carnivores, and thus the value of the techniques in this region remains hypothetical. We used cameras and track plates to survey Indian foxes Vulpes bengalensis in and around Rollapadu Wildlife Sanctuary in the arid grasslands of central Andhra Pradesh and in Ranebennur Wildlife Sanctuary in western Karnataka. By surveying, we also address issues relating to fox activity and habitat use patterns. Cameras rapidly and efficiently detected the presence of foxes, and allowed us to show that foxes at both sites were strictly nocturnal during the periods of data collection. There was a significant relationship between grassland height and the latency to detection of foxes at Rollapadu. At both sites, foxes rarely visited the track plate stations that were run concurrently with cameras. We recommend that researchers attempting to survey foxes use cameras rather than enclosed track plates, and that efforts to survey other species non-invasively include an experimental design that allows for validation of the survey technique.