Looking for the Iberian lynx in central Spain: a needle in a haystack?

The Iberian lynx Lynx pardinus has suffered a dramatic reduction in its range throughout the Iberian Peninsula and at present is one of the most endangered mammals in the world. The latest studies report that, out of the 48 breeding areas that existed in 1990, only two populations are left in southern Spain. As a consequence, some of the formerly largest populations, such as Montes de Toledo (central Spain), are to all intents and purposes regarded as extinct. To determine the current distribution of Iberian lynx outside the two recognized populations, we surveyed five different areas where the species is considered extinct and collected 581 faeces for the genetic identification of the species. We identified 18 samples as belonging to Iberian lynx in four out of the five areas studied, providing clear evidence for the presence of lynx in central Spain. In some areas the species was detected repeatedly at different localities and on different dates, indicating a regular occurrence of an unknown number of individuals. The conservation implications of these results are discussed in terms of the genetic importance of the individuals found and future reintroductions of the species from an ongoing captive-breeding programme.     

Phylogenetic and phylogeographic analysis of Iberian lynx populations

The Iberian lynx (Lynx pardinus), one of the world's most endangered cat species, is vulnerable due to habitat loss, increased fragmentation of populations, and precipitous demographic reductions. An understanding of Iberian lynx evolutionary history is necessary to develop rational management plans for the species. Our objectives were to assess Iberian lynx genetic diversity at three evolutionary timescales. First we analyzed mitochondrial DNA (mtDNA) sequence variation to position the Iberian lynx relative to other species of the genus LYNX: We then assessed the pattern of mtDNA variation of isolated populations across the Iberian Peninsula. Finally we estimated levels of gene flow between two of the most important remaining lynx populations (Do?ana National Park and the Sierra Morena Mountains) and characterized the extent of microsatellite locus variation in these populations. Phylogenetic analyses of 1613 bp of mtDNA sequence variation supports the hypothesis that the Iberian lynx, Eurasian lynx, and Canadian lynx diverged within a short time period around 1.53-1.68 million years ago, and that the Iberian lynx and Eurasian lynx are sister taxa. Relative to most other felid species, genetic variation in mtDNA genes and nuclear microsatellites were reduced in Iberian lynx, suggesting that they experienced a fairly severe demographic bottleneck. In addition, the effects of more recent reductions in gene flow and population size are being manifested in local patterns of molecular genetic variation. These data, combined with recent studies modeling the viability of Iberian lynx populations, should provide greater urgency for the development and implementation of rational in situ and ex situ conservation plans.     

A comparison of scat counts and camera-trapping as means of assessing Iberian lynx abundance

Rigorous cost-effective census methods are an essential part of managing wild animal populations, particularly if the involved species require continuous monitoring. In recent years, the range and size of the Iberian lynx (Lynx pardinus) population have increased notably as a result of conservation programs. Given this expansive scenario, monitoring Iberian lynx using camera-traps may become logistically and financially unfeasible. Here, we test whether or not scat counts are as efficient as camera-trapping in predicting lynx densities and compare the cost of these two approaches to lynx monitoring. We found a significant positive linear relationship between these two methods of assessing Iberian lynx abundance. Lynx abundance assessment by scat counting was six times less expensive than camera-trapping; there was no significant effect of the two study areas on the observed patterns (GLM F_1,7?=?45.81, P?相似文献   

Effects of food supplementation on home-range size, reproductive success, productivity and recruitment in a small population of Iberian lynx

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 Doñana, 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.     

Human–felid conflict as a further handicap to the conservation of the critically endangered Iberian lynx

Most studies on felid depredation of livestock have focused on big cats, and little attention has been paid to this type of conflict in smaller species. The medium-sized Iberian lynx (Lynx pardinus) is not thought to be affected by conflict with humans. However, parallel to an increase in the range of the Iberian lynx in Andújar-Cardeña, an increased incidence of Iberian lynx attacks on livestock has been recorded. A 6-year overview of Iberian lynx predation on livestock in this population shows a total of 40 attacks involving 716 kills (31 attacks on poultry and nine on sheep). Although the majority of these attacks (78 %) were carried out against poultry, sheep depredation resulted in higher economic losses, mainly in extensive flocks (4.6 times more than semi-intensive flocks). An effective compensation program has been implemented in order to mitigate the consequences of the human–lynx conflict in this area. Given that this sort of conflict could become an acute impediment to future conservation of the most endangered felid, managers should anticipate and prevent the potential conflicts that could arise as Iberian lynx colonizes more developed areas.     

50,000 years of genetic uniformity in the critically endangered Iberian lynx

Low genetic diversity in the endangered Iberian lynx, including lack of mitochondrial control region variation, is thought to result from historical or Pleistocene/Holocene population bottlenecks, and to indicate poor long-term viability. We find no variability in control region sequences from 19 Iberian lynx remains from across the Iberian Peninsula and spanning the last 50,000 years. This is best explained by continuously small female effective population size through time. We conclude that low genetic variability in the Iberian lynx is not in itself a threat to long-term viability, and so should not preclude conservation efforts.     

Estimation of the Iberian lynx (Lynx pardinus) population in the Do?ana area, SW Spain, using capture�Crecapture analysis of camera-trapping data

The Iberian lynx (Lynx pardinus) has a highly restricted geographic distribution, limited even within the Iberian Peninsula. The last national survey reported less than 200 remaining individuals, distributed in two isolated areas??Andújar-Cardeña and Doñana??and in consequence, the Iberian lynx was listed by the International Union for Conservation of Nature as ??Critically Endangered??. In this study, we estimate the Iberian lynx population size in the Doñana area using capture?Crecapture analysis of camera-trapping data. A model with different capture probability for each individual (M_h) yielded an estimate of 26 Iberian lynxes (SE?=?5.26) more than 1 year old. It is considered that a small slant in the estimation of the number of individuals could exist due to the presence of dispersers inside the study area that were not detected. Our study shows: (1) a reduction in number since the 1980s (45 individuals), and falling below the theoretical threshold of genetic viability, (2) changes in the species?? spatial distribution in this area, and (3) as for other carnivore species, photographic capture?Crecapture methods are applicable for estimating the size of Iberian lynx populations     

Intraspecific interference influences the use of prey hotspots

Resource clumping (prey hotspots) and intraspecific competition may interact to influence predator foraging behaviour. Optimal foraging theory suggests that predators should concentrate most of their foraging activity on prey hotspots, but this prediction has received limited empirical support. On the other hand, if prey concentration at hotspots is high enough to allow its use by several individuals, increased competition may impose constraints on foraging decisions of conspecifics, resulting in a temporal segregation in the use of shared resources. We investigated how artificial prey hotspots influence foraging behaviour in the Iberian lynx Lynx pardinus, and examined variations in the use of prey hotspots by individuals with different competitive abilities. All lynx, irrespective of their position in the competitive hierarchy, focused their activity on prey hotspots. Supplemented lynx concentrated higher proportions of active time on 100 m circular areas around hotspots than non‐supplemented lynx did on any area of the same size. However, we found evidence for a dynamic temporal segregation, where inferior competitors may actively avoid the use of prey hotspots when dominants were present. Dynamic temporal segregation may operate in solitary and territorial predators as a mechanism to facilitate coexistence of conspecifics in the absence of opportunities for spatial segregation when they use extremely clumped resources.     

Competitive Asymmetries in the Use of Supplementary Food by the Endangered Iberian Lynx (Lynx pardinus)

Background

As a conservation tool, supplementary feeding programs may be directed to specific individuals or sectors of the target population whose productivity or survival is thought to be limited by food scarcity. However, the use of supplemental food by different sex and age classes has received little attention. We studied individual variation in the access of the endangered Iberian lynx (Lynx pardinus) to supplementary food.

Methodology/Principal Findings

From 5349 pictures taken with automatic cameras placed in 25 feeding stations, we identified 28 individuals whose sex and age were known. All individuals known to live in areas subjected to supplementation regularly visited feeding stations. Food consumption was not proportional to expected variations in energy demand within sex and age classes. Food consumption by males was higher than by females, and increased with age, in agreement with a despotic distribution. Food consumption also increased with lynx body mass, and this pattern held for individuals sharing the same breeding territories. The access of inferior competitors increased with the number of feeding stations available within lynx territories.

Conclusions/Significance

All lynx exposed to food supplementation made a regular use of extra food but individuals predicted to be competitively dominant visited stations more frequently than subordinates of the same breeding territory. Our results suggest that insufficient provision of supplementary food could restrict the access of juveniles, or even adult females, to feeding stations. Limited consumption by these target individuals may compromise the efficiency of the supplementary feeding programme at the population level, in endangered species that, as the Iberian lynx, exhibit marked sexual dimorphism in body size.     

Historical DNA reveals the phylogenetic position of the extinct Alpine lynx

During the last two centuries, lynx populations have undergone severe declines and extinctions in Europe. The Alpine lynx, once distributed across the whole Alpine arc, became extinct due to direct human prosecution and deprivation of its main prey in the 1930s. Similar to the Iberian lynx Lynx pardinus , its taxonomy has been subject to several controversies. Moreover, knowing the taxonomic status of the Alpine lynx will help to define conservation units of extant lynx populations in Europe. In this study, we investigated two mitochondrial DNA regions in museum specimens ( n =15) representing the autochthonous Alpine population and in samples from extant Eurasian lynx Lynx lynx populations in Europe and Asia ( n =17). Phylogenetic analysis (cytochrome b , 345 bp) placed the Alpine lynx within the Eurasian lynx lineage. Among all individuals examined, seven different haplotypes (control region, 300 bp) were observed but no unique Alpine haplotype was discovered. Haplotypes of the extinct Alpine population were identical to previously described haplotypes in Scandinavian lynx signifying a recent genetic ancestry with current European populations. Moreover, our genetic data suggest two distinct glacial refugia for the Carpathian and Balkan population. Overall this study demonstrates that historical DNA from extinct populations can help to disentangle the phylogenetic relationships and historical biogeography of taxa with only a limited number of extant populations remaining.     

Factors conditioning the camera-trapping efficiency for the Iberian lynx (Lynx pardinus)

Camera trapping is the most used method for surveying medium-sized carnivores in Spain. The main target for these surveys has been the Iberian lynx, the most endangered cat in the world. The Iberian lynx conservation program has received the largest EU LIFE projects grant. So, efficiency is a key goal for managing this grant. During 2003 and 2007, we have applied these funds to the survey of the Iberian lynx in Eastern Sierra Morena (Spain). Using two different techniques, we have studied both to see which is the most efficient. The survey developed in active latrines resulted more efficient than that of scent stations and live prey camera trapping throughout the years, although there has been a variation between years. Otherwise, the live prey method has been the one providing the greatest speed and number of pictures per entrance. We suggest that camera-trapping surveys can be improved in terms of efficiency for a wide range of species, or at least for the Iberian lynx. To improve the results, cameras might be placed in relation to breeding territories. With this determinant, camera-trapping surveys would be shorter than 120 days. Finally, we suggest how those surveys for medium carnivores should be designed.     

Experimental release of an Iberian lynx (Lynx pardinus)

Reintroduction to the wild of threatened species has become a modern additional justification for captive propagation. This conservation procedure is costly, and both economic resources and the absence of optimal conditions in the field limit the IUCN recommendations for reintroduction to a small proportion of potential candidate species. Furthermore reintroduction attempts often fail. In carnivores, reintroduction failure is attributed to unsuitable adaptation in the field by captive-reared animals, due to their lack of hunting skills, their tendency to leave the target area, their inadequate interaction with conspecifics or their excessive confidence in humans. This list of causes is based on very few studies of carnivore adaptation after reintroduction. In very rare and endangered species, monitoring individual case-histories is the only way to evaluate reintroduction success. We report a successful experimental release of an Iberian lynx (Lynx pardinus) which grew up in captivity. Careful feeding-training and avoidance of human contact during the captive phase, as well as good habitat quality and correct interaction with other wild lynx in the release site, seem to account for the observed success. Permanence of the lynx within the release area might be related to the availability of territory vacancies in the receiving population. Our results allow some optimism for future reintroductions of this endangered species in areas where it has become extinct recently.     

Genetic fingerprinting of germplasm accessions as an aid for species conservation: a case study with Borderea chouardii (Dioscoreaceae), one of the most critically endangered Iberian plants

BACKGROUND AND AIMS: Molecular markers have changed previous expectations about germplasm collections of endangered plants, as new perspectives aim at holding a significant representation of all the genetic diversity in the studied species to accomplish further conservation initiatives successfully. Borderea chouardii is a critically endangered allotetraploid dioecious member of Dioscoreaceae, known from a single population in the Iberian pre-Pyrenees. This population was reported to be highly structured into two genetically distinct groups of individuals corresponding to their spatial separation along the vertical cliff where it grows. In 1999, the Spanish Government of Aragón launched the first conservation programme for the ex situ preservation of this species, and since then a seed collection has been conserved at the Germplasm Bank of the Universidad Politécnica de Madrid. However, as some seed samples had not been labelled clearly at the time of collection, their origin was uncertain. METHODS: Genetic variation in germplasm accessions of B. chouardii was investigated using microsatellite (simple sequence repeat; SSR) markers. KEY RESULTS: The 17 primer pairs used detected 62 SSR alleles in the 46 samples analysed from five different germplasm stocks. Eight alleles scored from the wild population were not detected in the germplasm samples analysed. The relatedness of the germplasm samples to the wild subpopulations through neighbour-joining clustering, principal coordinates analysis (PCO) and assignment tests revealed a biased higher representation of the genetic diversity of the lower cliff (43 samples) subpopulation than that of the upper cliff (three samples). CONCLUSIONS: The collection of additional samples from the upper cliff is recommended to achieve a better representation of the genetic diversity of this subpopulation. It is also recommended that these stocks should be managed separately according to their distinct microspatial origin in order to preserve the genetic substructuring of the wild population.     

Conservation biogeography of ecologically interacting species: the case of the Iberian lynx and the European rabbit

Aim To relate the recent Iberian lynx decline to changes in the distribution of the European rabbit after the haemorrhagic disease outbreak of 1989. As Iberian rabbits evolved in two geographically separated lineages, being the recent lynx range practically restricted to the southwestern lineage, we also test if differential range dynamics exists for these lineages, with the consequent implications for lynx conservation and reintroduction planning. Location The Iberian Peninsula. Methods We modelled environmental favourability for the lynx based on its distribution before 1989, and for the rabbit using distribution data collected primarily after 1989, and validated them using independent abundance data. We compared both models and combined them in a lynx occurrence forecast. We correlated the prevalence of southwestern rabbit lineage with the environmental favourability for the rabbit. Results The environmental lynx model correlated with past lynx abundance data, but did not reflect its recent strong range contraction. The rabbit model correlated with recent rabbit abundance, but was negatively correlated with the environmental model for the lynx. The combination of both models forecasted lynx occurrence in a few separated nuclei, which encompass all recent lynx records. The prevalence of rabbit's southwestern lineage correlated negatively with favourability for the rabbit. Main conclusions The region to which the lynx became confined before 1989 is currently less favourable for rabbits, whereas more favourable areas remain outside lynx reach. This differential favourability correlates with rabbit phylogeographical structure, suggesting that the southwestern lineage is facing more unfavourable conditions or is less resilient to recent diseases. The loss of concordance between lynx distribution and the whole rabbit phylogeographical structure has prevented lynx persistence in northeastern rabbit lineage areas, which should be considered in lynx reintroduction planning. Similar conservation problems could affect other ecologically interacting species whose distributions’ overlapping has sharply diminished.     

Management measures to control a feline leukemia virus outbreak in the endangered Iberian lynx

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 Doñana (SW Spain) population. The infection rapidly spread throughout the densest subpopulation throughout Doñana. 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 Doñana and in Sierra Morena populations. In Doñana, 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 Doñana population and 0% in the Sierra Morena population.     

In situ feeding as a new management tool to conserve orphaned Eurasian lynx (lynx lynx)

High human‐caused mortality due to wildlife‐vehicle‐collisions and illegal killing leads to frequent cases of orphaned Eurasian lynx juveniles. Under natural conditions, this would result in starvation of the young. To avoid this, wildlife managers conventionally rear animals in captivity and release them later. However, this measure is an undesirable outcome for species conservation, managers, and animals alike. Increased awareness of Eurasian lynx orphaned by human‐caused mortality means managers must often intervene in endangered populations. In this study, we report for the first time a successful case of in situ feeding designed to avoid captivity of two orphaned Eurasian lynx. We exposed 13 roe deer and 7 red deer carcasses in the field to successfully support two orphans to the age of independence and confirm dispersal from the natal range. We present this management approach as a feasible and complimentary tool that can be considered in small or isolated large carnivore populations where every individual counts toward population viability.     

Evaluating mortality rates and causalities in a critically endangered felid across its whole distribution range

The conservation of endangered species requires accurate data, and knowledge of cause-specific mortality rates is one of the most important issues. In recent years, conservation programs for the critically endangered Iberian lynx Lynx pardinus have been developed on the basis of mortality data derived 30 years ago from the small Doñana population. Thus, there is an urgent need for an update of mortality rates and causes in both populations (Sierra Morena and Doñana). Here we use radio-tracking information from the whole range of the Iberian lynx to quantify mortality rates and identify their causes. Between 2006 and 2011, we radio-tagged 78 Iberian lynxes from its two remaining populations (39 from Sierra Morena and 39 from Doñana). Mortality events were evaluated to identify causes, and cause-specific annual mortality rates (AMR) were obtained using the nonparametric cumulative incidence function estimator. Overall, AMR was estimated at 0.16?±?0.05 (0.19?±?0.09 in Sierra Morena and 0.12?±?0.07 in Doñana). Disease was the main cause of mortality both for the whole population and the Doñana population. Poaching was the main cause of mortality in Sierra Morena. Our results suggest that the best strategy for conserving this species is to focus action on decreasing the fatal effect of disease and poaching. Given the possible existence of an underlying inbreeding-mediated immunosuppression, genetic management aimed at increasing the genetic diversity of this population is also recommended.     

Faecal genetic analysis to determine the presence and distribution of elusive carnivores: design and feasibility for the Iberian lynx

Noninvasive methods using genetic markers have been suggested as ways to overcome difficulties associated with documenting the presence of elusive species. We present and assess a novel, reliable and effective molecular genetic technique for the unequivocal genetic identification of faeces from the endangered Iberian lynx (Lynx pardinus). From mitochondrial DNA (mtDNA) cytochrome b and D-loop region sequences, we designed four species-specific primers (for products 130-161 bp long) that were considered to be likely to amplify degraded DNA. We compared two DNA extraction methods, various DNA amplification conditions and the robustness and specificity of the primer pairs with 87 lynx samples from 5 potentially different lynx populations and with 328 samples of other carnivore species. The utility of the identification technique was tested with faeces of different ages, with faeces from controlled field experiments, and with faeces collected from locales with possible lynx populations from throughout the state of Andalusia, Spain (8052 km2). Faecal mtDNA extraction was more efficient using PBS wash of the faeces instead of a faeces homogenate. Our assay increased from 92.6 to 99% efficiency with a second amplification and a reduction in template concentration to overcome polymerase chain reaction (PCR) inhibition. Our assay never produced false positives, and correctly identified all lynx faeces. Of 252 faeces samples of unknown species collected throughout Andalusia, 26.6% (from three different areas) were classified as Iberian lynx, 1.4% showed evidence of PCR inhibition and 1.2% were of uncertain origin. This method has proven to be a reliable technique that can be incorporated into large-scale surveys of Iberian lynx populations and exemplifies an approach that can easily be extended to other species.     

First breeding record of a one-year-old female Iberian lynx

According to literature, female Iberian lynx (Lynx pardinus) start reproducing at 3 years of age. In more recent years, females breeding at 2 years have been recorded in wild populations. Here, however, we describe the first breeding record for a one-year-old female Iberian lynx. This finding was obtained by camera-trapping data, provided by the yearly monitorization of the species that is carried out across its distribution area. A litter of two lynx kittens was found at the south-east limit of the Andujar-Cardeña population. Two camera-traps were set up near the den to identify the breeding female. Photographs obtained confirmed that the breeding female had already been identified the previous year at less than 3 months of age. The case reported here of a yearling female breeding is the first ever from historical distribution range of the species, and as such, is an exceptional event in the reproduction of the Iberian lynx.     

Long-distance Eurasian lynx dispersal – a prospect for connecting native and reintroduced populations in Central Europe

Dispersal is a key process for the maintenance of intraspecific genetic diversity by ensuring gene flow within and between populations. Despite the ongoing expansion of large carnivores in Europe, lynx populations remain fragmented, isolated, and threatened by inbreeding and loss of genetic diversity. In the course of large carnivore monitoring in the Czech Republic, several biological samples of Eurasian lynx were collected outside the permanent occurrence of this species. Using microsatellite genotyping we identified these as four dispersing lynx males and applied multiple methods (Bayesian clustering in STRUCTURE, Principal Component Analysis (PCA), frequency-based method in GENECLASS2, and machine-learning framework in assignPOP) to assign them to possible source populations. For this we used genotypes from five European lynx populations: the Bohemian-Bavarian-Austrian (N?=?36), Carpathian (N?=?43), Scandinavian (N?=?20), Baltic (N?=?15), and Harz (N?=?23) population. All four dispersers were successfully assigned to different source populations within Europe and each was recorded at a distance of more than 98 km from the edge of the distribution of the source population identified. Such movements are among the longest described for lynx in Central Europe to this point. The findings indicate the ability of lynx males to disperse in human-dominated landscape thus facilitation of these movements via creation and/or protection of potential migratory corridors together with protection of dispersing individuals should be of high importance in conservation of this iconic predator in Central Europe.