Twenty-five years ago, the snow leopard Uncia uncia, an endangered large cat, was eliminated from what is now Sagarmatha National Park (SNP). Heavy hunting pressure depleted that area of most medium–large mammals, before it became a park. After three decades of protection, the cessation of hunting and the recovery of wild ungulate populations, snow leopards have recently returned (four individuals). We have documented the effects of the return of the snow leopard on the population of its main wild prey, the Himalayan tahr Hemitragus jemlahicus, a ‘near-threatened’ caprin. Signs of snow leopard presence were recorded and scats were collected along a fixed trail (130 km) to assess the presence and food habits of the snow leopard in the Park, from 2004 to 2006. Himalayan tahr, the staple of the diet, had a relative occurrence of 48% in summer and 37% in autumn, compared with the next most frequent prey, musk deer Moschus chrysogaster (summer: 20%; autumn: 15%) and cattle (summer: 15%; autumn: 27%). In early summer, the birth rate of tahr (young-to-female ratio: 0.8–0.9) was high. The decrease of this ratio to 0.1–0.2 in autumn implied that summer predation concentrated on young tahr, eventually altering the population by removing the kid cohort. Small populations of wild Caprinae, for example the Himalayan tahr population in SNP, are sensitive to stochastic predation events and may be led to almost local extinction. If predation on livestock keeps growing, together with the decrease of Himalayan tahr, retaliatory killing of snow leopards by local people may be expected, and the snow leopard could again be at risk of local extinction. Restoration of biodiversity through the return of a large predator has to be monitored carefully, especially in areas affected by humans, where the lack of important environmental components, for example key prey species, may make the return of a predator a challenging event

Parasites, as organisms with a particular way of life, form an important part of biodiversity, not only regarding the number of known species, but also because of their relevant role within ecological processes. These two facts should justify conservation of parasites, at least within natural and protected areas. Little is known about such complex communities of parasites but they are often considered as pests, even out of the fields of public (human) health and animal production, that is, just in the natural environment or under natural conditions. It is increasingly assumed that wildlife diseases, including those produced by parasites, are one of the main bases for managing animal populations. Parasitic diseases may also be managed and, at this point, we can find multiple technical problems which, in certain occasions, lead into philosophical questions or true dilemmas. These considerations are illustrated by revising parasites of the Spanish ibex (Capra pyrenaica), an Iberian mountain ungulate the parasitofauna of which is relatively well known. As a big game species, its trophies become more and more appreciated. Therefore, human dimensions involved in management of its populations are considerably increased. Finally, reasons and opportunities for managing parasitic diseases affecting ibex are revised and discussed, under a global goal or perspective of conserving parasites within natural areas, particularly those that are protected. To be a parasite: what does it mean?Parasitism is a way of life. It is an ecological relationship (temporal or permanent) between two organisms, one designed as parasite, and the other one as host. According to Crofton (1971a, b) the main characteristics defining this kind of relation are: (i) the parasite has a physiological dependence on the host; (ii) heavy parasitations may result in host death; (iii) reproductive potential of parasites is higher than that of their hosts; and (iv) parasites are overdispersed within the host's populations. Some authors (see Gallego 1998) emphasize the concept of ecological dependence of parasites with respect to their hosts, which provide habitats for parasites. Therefore, parasites can provide information on

Between 1996 and 2005, 215 free-ranging Alpine chamois (Rupicapra rupicapra) were immobilised with xylazine hydrochloride. The 110 male and 105 female animals received a mean (sd) dose of 2.5 (0.6) mg/kg with a range from 1.4 to 4.8 mg/kg. The immobilisation was reversed in 201 of the animals with an intramuscular injection of 0.3 (0.1) mg/kg atipamezole (range 0.03 to 0.76 mg/kg), corresponding to a mean ratio of atipamezole:xylazine of 1:9.4 (4.3). All the chamois were immobilised, but shorter induction and recovery times, and deeper sedation with no reactions to handling were obtained in more than 80 per cent of the animals with doses of 2.6 to 3.6 mg/kg of xylazine, reversed with 0.26 to 0.36 mg/kg atipamezole (a ratio of 1:10), injected within 90 minutes.

In female mammals, reproduction requires high energy expenditure because of gestation and lactation, possibly leading to a fitness cost. Several studies, however, failed to find the expected negative correlation between current and future reproductive success, likely because of individual heterogeneity in reproductive potential. We compared reproductive performance and costs of reproduction for 40 female Alpine Ibex in one established population with 29 females translocated from the same population to a new colony. We investigate factors affecting pregnancy, fecundity and overwinter survival of juveniles, after accounting for individual heterogeneity. In both populations, prime-aged females experienced a strong reproductive cost. Senescent females, however, showed no evidence of reproductive costs. The colonizing population showed lower reproductive cost and better age-specific reproductive performance than the established population.We found a general pattern of low age-specific fecundity and reproductive success that was affected by environmental constraints. Age-specific reproductive success was unrelated to longevity.Although about 84% of adult females appeared to conceive, independently of environmental constraints, energy was allocated to reproduction in a highly conservative manner, leading to low age-specific fecundity (only 36 and 21% of prime-aged and senescent females were seen with a kid) but high kid survival (100% to weaning and 92% to 1 year). Our results suggest that females embarked in lactation only if they had a very high probability of raising their offspring. Our study highlights how reproductive performance and costs in this species vary with age and environment, and are the result of a highly conservative reproductive tactic.

Faecal pellet count is an indirect census method used to estimate the density of an animal population. Factors that affect the accuracy and precision of this method are the defecation rate, the decay time and the detectability of the droppings. In this study, we analysed the influence of some variables on the detectability of droppings: (i) environmental variables, EV (vegetation type, grass height, meteorological conditions); (ii) subjective variables, SV (operator, subjective visibility); (iii) faeces-species related variables, SRV (Capreolus capreolus Linnaeus, 1758; Cervus elaphus Linnaeus, 1758 and Lepus europaeus Pallas, 1778). The average values of dropping detectability, expressed as percentage of observations from the minimum detectability (0) to the maximum (1), were: 0.99 (SD = 0.07) for red deer faeces; 0.93 (SD = 0.16) for roe deer faeces; 0.89 (SD = 0.21) for European brown hare faeces. The red deer detectability value was statistically higher than the roe deer and European brown hare values (X 2 = 26.61, df = 2, p < 0.01). A generalised linear model (GLM) analysis shows that the variables which negatively affect the dropping detectability are different for the three species: (i) vegetation type, especially deciduous forest, for the red deer; (ii) grass height for the European brown hare; (iii) subjective visibility, especially the category "none", for the roe deer. These results suggest that the characteristics of both the study area and the species considered could affect the detectability of droppings, and therefore also the entire estimation density. So, faecal pellet count monitoring programmes should carefully take into account the environmental characteristics and should be performed when detectability is maximised (e.g. short grass, fewer leaves, less undergrowth).