Home About us Contact | |||
Lynx Population (lynx + population)
Selected AbstractsWhat shapes Eurasian lynx distribution in human dominated landscapes: selecting prey or avoiding people?ECOGRAPHY, Issue 4 2009Mathieu Basille In the multi-use landscape of southern Norway, the distribution of lynx is likely to be determined both by the abundance of their favoured prey , the roe deer , and the risk associated with the presence of humans because most lynx mortalities are caused by humans (recreational harvest, poaching, vehicle collisions). We described the distribution of the reproductive portion of the lynx population based on snow-track observations of females with dependent kittens collected over 10,yr (1997,2006) in southern Norway. We used the ecological-niche factor analysis to examine how lynx distribution was influenced by roe deer, human activity, habitat type, environmental productivity and elevation. Our first prediction that lynx should be found in areas of relatively high roe deer abundance was supported. However, our second prediction that lynx should avoid human activity was rejected, and lynx instead occupied areas more disturbed in average than those available (with the exception of the most densely occupied areas). Lynx, however, avoided the most disturbed areas and our third prediction of a trade-off between abundance of prey and avoidance of human activity was supported. On the one hand, roe deer in the most disturbed areas benefit to a large extent from current human land use practices, potentially allowing them to escape predation from lynx. On the other hand, the situation is not so favourable for the predators who are restricted in competition refuges with medium to low prey densities. The consequence is that lynx conservation will have to be achieved in a human modifed environment where the potential for a range of conflicts and high human-caused mortality will remain a constant threat. [source] Effects of food supplementation on home-range size, reproductive success, productivity and recruitment in a small population of Iberian lynxANIMAL CONSERVATION, Issue 1 2010J. V. López-Bao Abstract In a conservation context, food supplementation is a management tool used to reverse the decline of food-limited populations by means of positive changes in behaviour and fitness that may be reflected in population parameters. The critically endangered Iberian lynx Lynx pardinus has suffered a dramatic decline primarily because of the severe drop of its main prey, the European wild rabbit Oryctolagus cuniculus. To reverse this situation, a food supplementation programme has been implemented in Doņana, south-west Spain, since 2002. In this study, we assess the utility of providing artificial food to reduce home-range (HR) size, and to increase productivity, survival and recruitment in a scenario of low lynx density, as compared with reference data from the same population in the absence of extra food. Food supplementation produced a significant contraction of core areas, but not of complete lynx HRs. We did not detect any significant change in productivity or dispersal rates, but supplementation could have helped transient adult lynx to settle down. The positive effects of food supplementation may have been partly countered by factors such as inbreeding, Allee effects and disease outbreaks, whose effects may have been exacerbated in this small lynx population. Food supplementation, however, proved useful to retain individuals, to keep range sizes within their normal range of values, thus maintaining spatial organization, and to allow lynx reproduction and kitten survival in areas with very low prey density. Therefore, we recommend keeping an extensive and intensive supplementary feeding programme until the density of wild rabbits will enable the viability of this endangered lynx population. [source] Management measures to control a feline leukemia virus outbreak in the endangered Iberian lynxANIMAL CONSERVATION, Issue 3 2009G. López Abstract The feline leukemia virus (FeLV) is a retrovirus that affects domestic cats all over the world. Its pathogenic effects generally include anemia, immunosuppression or tumors. Dissemination over populations is linked to cat sociality, because the virus is transmitted by direct contact. Although the domestic cat is its common host, FeLV infection has also been described in some wild felids. In the Iberian lynx Lynx pardinus, some sporadic FeLV infection cases have been reported since 1994, but an outbreak with the involvement of several animals has never been described until now. During spring 2007, an FeLV outbreak hit the Doņana (SW Spain) population. The infection rapidly spread throughout the densest subpopulation throughout Doņana. Infected animals showed very acute anemic disease, most of them dying in <6 months. To avoid FeLV dissemination, a control program was carried out that included removal of viremic lynxes, vaccination of negative individuals and reduction of the feral cat population. The program was implemented both in Doņana and in Sierra Morena populations. In Doņana, around 80% of the total lynx population and 90% of the outbreak focus subpopulation were evaluated. Seven out of the 12 infected individuals found died and two reverted to latency; the remaining viremic animals have been kept in captivity. The outbreak appears to have been successfully confined to the subpopulation where the virus appeared and no more cases have been found since August 2007. In the larger Sierra Morena population, 8% of the lynx population was surveyed. Thirty-four uninfected Iberian lynxes were vaccinated at least once. The FeLV prevalence was found to be 27% in the Doņana population and 0% in the Sierra Morena population. [source] |