Rabbit (Oryctolagus cuniculus) abundance and protected areas in central-southern Spain: why they do not match?

European rabbits (Oryctolagus cuniculus), a keystone species in the Iberian Mediterranean ecosystem, are the staple prey of the Iberian lynx (Lynx pardinus) and the Spanish imperial eagle (Aquila adalberti). These predators require medium to high rabbit densities and a low degree of human disturbance. We compared rabbit abundances in areas of central-southern Spain under three levels of protection and management: protected areas, intensively managed (nonprotected) hunting estates, and other nonprotected areas. We used pellet abundance indices to estimate rabbit density in 118 surveys conducted during the summers of 2002 and 2003. We observed greater rabbit abundance in intensively managed hunting estates compared to protected areas and other nonprotected areas, perhaps because policy makers did not consider rabbit numbers when selecting priority areas. Alternatively, differences in game management practices (e.g., predator control or habitat management) may explain the higher rabbit densities observed in managed hunting estates. Our results suggest that the best feeding conditions for the Iberian lynx and the Spanish imperial eagle occur in intensively managed hunting areas, where such predators are frequently persecuted. The conservation of these endangered predators may require efforts to increase rabbit densities in protected areas.     

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   

Occupancy, colonization and extinction patterns of rabbit populations: implications for Iberian lynx conservation

In Mediterranean ecosystems, rabbits are a key prey species for many predators, such as the Iberian lynx, which is threatened with extinction and has gone extinct locally in several regions of its historical distribution range. One of these regions is Serra da Malcata Nature Reserve, Portugal, which is also currently proposed as a potential site for reintroduction. We intended to investigate annual variation, potential time trends and the effects of management practices on the rabbit population in Serra da Malcata as a model for future potential reintroduction areas. The rabbit population was monitored over 12?years (from 1997 to 2009) by counting latrines along linear transects. These data were used to estimate rabbit occupancy, colonization and extinction patterns using a likelihood-based method including habitat, population and topographic covariate effects. Our results suggest that initial occupancy, when management practices were absent, was driven by the presence of Erica spp. and Cistus ladanifer shrubs and by distance to summits. Site colonization was positively influenced by the presence of edges between shrubs and pastureland and by patterns of rabbit distribution in the previous sampling season. On the other hand, local extinction was negatively influenced by edges. We conclude that the increase in rabbit occupancy and local colonization patterns was clearly associated with management actions (particularly, the creation of pasturelands), although the recovery of the species was noticeably limited by previous patterns of spatial distribution.     

What shapes Eurasian lynx distribution in human dominated landscapes: selecting prey or avoiding people?

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.     

Evaluation of Camera Trapping for Estimating Red Fox Abundance

ABSTRACT The nature reserve Serra da Malcata, Portugal, was recently considered a site for Iberian lynx (Lynx pardinus) reintroduction. Because of potential disease risk posed by red foxes (Vulpes vulpes) in the area, a reliable estimate of fox abundance was critical for a dependable reintroduction program. We adapted camera-trapping techniques for estimating red fox abundance in the reserve. From July 2005 to August 2007, we conducted 7 camera-trapping sessions, allowing for individual identification of foxes by physical characteristics. We estimated abundance using the heterogeneity (M_h) model of the software program CAPTURE. Estimated density ranged from 0.91 ± 0.12 foxes/km²to 0.74 ± 0.02 foxes/km². By estimating red fox density, it is possible to define the number of foxes that must be sampled to assess the presence of potential fox-transmitted diseases that may affect lynx reintroduction.     

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.     

Phylogeography, genetic structure and diversity in the endangered bearded vulture (Gypaetus barbatus, L) as revealed by mitochondrial DNA

Bearded vulture populations in the Western Palearctic have experienced a severe decline during the last two centuries that has led to the near extinction of the species in Europe. In this study we analyse the sequence variation at the mitochondrial control region throughout the species range to infer its recent evolutionary history and to evaluate the current genetic status of the species. This study became possible through the extensive use of museum specimens to study populations now extinct. Phylogenetic analysis revealed the existence of two divergent mitochondrial lineages, lineage A occurring mainly in Western European populations and lineage B in African, Eastern European and Central Asian populations. The relative frequencies of haplotypes belonging to each lineage in the different populations show a steep East-West clinal distribution with maximal mixture of the two lineages in the Alps and Greece populations. A genealogical signature for population growth was found for lineage B, but not for lineage A; futhermore the Clade B haplotypes in western populations and clade A haplo-types in eastern populations are recently derived, as revealed by their peripheral location in median-joining haplotype networks. This phylogeographical pattern suggests allopatric differentiation of the two lineages in separate Mediterranean and African or Asian glacial refugia, followed by range expansion from the latter leading to two secondary contact suture zones in Central Europe and North Africa. High levels of among-population differentiation were observed, although these were not correlated with geographical distance. Due to the marked genetic structure, extinction of Central European populations in the last century re-sulted in the loss of a major portion of the genetic diversity of the species. We also found direct evidence for the effect of drift altering the genetic composition of the remnant Pyrenean population after the demographic bottleneck of the last century. Our results argue for the management of the species as a single population, given the apparent ecological exchangeability of extant stocks, and support the ongoing reintroduction of mixed ancestry birds in the Alps and planned reintroductions in Southern Spain.     

Biometrical analysis reveals major differences between the two subspecies of the European rabbit

The climatic oscillations that have occurred in the last few million years have strongly affected species distribution ranges. Highly divergent genetic lineages arose, some of which correspond to recognized subspecies that currently occupy small geographical areas. Understanding the implications of the genetic differences between these subspecies is crucial for proper conservation of Evolutionarily Significant Units. We use the two European rabbit subspecies, Oryctolagus cuniculus cuniculus and O. c. algirus, in the Iberian Peninsula as a model to investigate the repercussions at the biometric level of their largely recognized genetic differentiation. To accomplish this we analysed the ear and hind foot length, and the body mass of 999 adult rabbits from 27 locations across the distribution range of both subspecies in their native range, the Iberian Peninsula. Our results show biometric differences between the two subspecies, also explained by geographical location and sex, O. c. algirus being lighter and having shorter ear and hind foot lengths. We examine these findings under an evolutionary framework, and discuss their implications for current conservation efforts. Future research should focus on the ecological implications of these biometric differences, namely potential different habitat use and anti‐predatory strategies in the species' native range.     

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.     

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.     

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.     

Status survey of the critically endangered Iberian lynx <Emphasis Type="Italic">Lynx pardinus</Emphasis> in Portugal

A survey of the Iberian lynx was conducted in Portugal between January 2002 and November 2003 in order to define lynx status and distribution baselines. Intensive search for lynx scats, scat DNA analysis, and camera trapping were used in areas of potential lynx presence. Over 4,200 km were investigated during a global searching effort of 1,975 man-hours. DNA obtained from 168 scats was analyzed, producing no positive lynx amplifications. Camera trapping represented a total effort of 5,647 camera-days in three potential lynx areas, producing no positive detections. Although results cannot confirm the species’ extinction, the scenario is rather pessimistic and the Iberian lynx is probably no longer present in Portugal. Presently, considering the Portuguese lynx’s historical range, the only significantly suitable areas for the species are located in the southeastern part of the country bordering Andalusia where no recent evidence of lynx presence was recorded.     

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.     

Nuclear microsatellite and mitochondrial DNA analyses reveal the regional genetic structure and phylogeographical history of a sanguivorous land leech,Haemadipsa japonica,in Japan

Recent molecular studies have indicated that phylogeographical history of Japanese biota is likely shaped by geohistory along with biological events, such as distribution shifts, isolation, and divergence of populations. However, the genetic structure and phylogeographical history of terrestrial Annelida species, including leech species, are poorly understood. Therefore, we aimed to understand the genetic structure and phylogeographical history across the natural range of Haemadipsa japonica, a sanguivorous land leech species endemic to Japan, by using nine polymorphic nuclear microsatellites (nSSR) and cytochrome oxidase subunit one (COI) sequences of mitochondrial DNA (mtDNA). Analyses using nSSR revealed that H. japonica exhibited a stronger regional genetic differentiation among populations (G'_ST = 0.77) than other animal species, probably because of the low mobility of land leech. Analyses using mtDNA indicated that H. japonica exhibited two distinct lineages (A and B), which were estimated to have diverged in the middle Pleistocene and probably because of range fragmentation resulting from climatic change and glacial and interglacial cycles. Lineage A was widely distributed across Japan, and lineage B was found in southwestern Japan. Analyses using nSSR revealed that lineage A was roughly divided into two population groups (i.e., northeastern and southwestern Japan); these analyses also revealed a gradual decrease in genetic diversity with increasing latitude in lineage A and a strong genetic drift in populations of northeastern Japan. Combined with the largely unresolved shallow polytomies from the mtDNA phylogeny, these results implied that lineage A may have undergone a rapid northward migration, probably during the Holocene. Then, the regional genetic structure with local unique gene pools may have been formed within each lineage because of the low mobility of this leech species.     

Phylogeography of the common vole (Microtus arvalis) with particular emphasis on the colonization of the Orkney archipelago

To investigate the human introduction of the common vole Microtus arvalis onto the Orkney islands, the complete cytochrome b gene was sequenced in 41 specimens from both Orkney (four localities) and elsewhere in their range (26 localities). Orkney voles belonged to the same phylogenetic lineage, 'Western', as individuals from France and Spain indicating southwestern Europe as the most likely source area for the islands. This result is of interest with respect to the movement and trading links of the Neolithic people who likely transported the voles. As well as the Western lineage, our phylogenetic trees revealed three other purely European lineages: the 'Italian' (single specimen from N. Italy), the 'Central' (Germany, Netherlands, Denmark) and the 'Eastern' (Hungary, Slovakia, Poland, Ukraine, Finland, European Russia). Individuals from European Russia, W. Siberia, Georgia, Ukraine and Armenia formed a fifth distinct lineage coinciding with the distribution of the 'obscurus' chromosomal form of M. arvalis. These phylogeographical data suggest that M. arvalis occupied multiple refugia during the last glaciation.     

Allelic variation at the VHa locus in natural populations of rabbit (Oryctolagus cuniculus, L.)

The large interallelic distances between the three rabbit Ig V(H)a lineages, a1, a2 and a3, suggest that the persistence time of the V(H)a polymorphism could amount to 50 million years, which is much longer than that of MHC polymorphisms. Rabbit originated in the Iberian Peninsula where two subspecies coexist, one of which is confined to Southwestern Iberia (Oryctolagus cuniculus algirus). We studied the V(H) loci in the original species range to obtain a better understanding of the evolutionary history of this unusual polymorphism. Serological surveys revealed that sera from the subspecies algirus, when tested with V(H)a locus-specific alloantisera, showed either cross-reactivity ("a-positive" variants) or no reaction at all ("a-blank"). Using RT-PCR, we determined 120 sequences of rearranged V(H) genes expressed in seven algirus rabbits that were typed as either a-positive or a-blank. The data show that the V(H) genes transcribed in a-positive rabbits are closely related to the V(H)1 alleles of domestic rabbits. In contrast, a-blank rabbits were found to preferentially use V(H) genes that, although clearly related to the known V(H)a genes, define a new major allotypic lineage, designated a4. The a4 sequences have hallmark rabbit V(H)a residues together with a number of unprecedented amino acid changes in framework region 2 and 3. The net protein distances between the V(H)a4 and the V(H)a1, a2, and a3 lineages were 20, 29, and 21% respectively. We conclude that at least four distantly related lineages of the rabbit V(H)a locus exist, one of which seems to be endemic in the Iberian range.     

European rabbit population trends and associated factors: a review of the situation in the Iberian Peninsula

• 1 European rabbits are considered a keystone species in the Iberian Peninsula. Their populations have sharply declined over the past century, mainly due to habitat loss and the arrival of two viral diseases: myxomatosis in the 1950s and rabbit haemorrhagic disease (RHD) at the end of the 1980s. For the conservation of the Iberian Mediterranean ecosystem, it is important to determine whether rabbit populations are recovering two decades after the RHD outbreak, and to identify the factors associated with population recovery.
• 2 Here, we review the current knowledge on recent rabbit population trends in the Iberian Peninsula and the factors associated with these trends.
• 3 Although most rabbit populations are still declining in the Iberian Peninsula, a few seem to have recovered. In general, positive trends have been recorded in species‐friendly habitats characterized by non‐fragmented landscapes, interspersed patches of Mediterranean scrubland, good pastures and/or crops, soft soils that are suitable for warren construction and a Mediterranean climate with relatively high rainfall. Additionally, rabbits seem to be recovering better in areas where management practices (e.g. low hunting pressure, habitat management and predator control) are applied to increase their numbers.
• 4 From these findings, it is possible to identify five broad objectives for rabbit conservation in the Iberian Peninsula. First, it is clearly necessary to establish a long‐term programme for monitoring rabbit abundance and trends on a large scale. Second, the conservation and restoration of open Mediterranean scrubland should be a priority for stabilizing and maintaining existing healthy rabbit populations. Third, despite the lack of experimental evidence, management activities aimed at increasing the quantity and quality of both refuge and food should continue to be implemented. Fourth, legislation on the timing of the hunting season should be revisited following recommendations made by scientists. Finally, experimental approaches are required to investigate whether the control of generalist predators is a successful strategy to allow rabbit populations to recover.

     

Effect of wildfires and post-fire forest treatments on rabbit abundance

One of the main factors involved in the decline in the European wild rabbit in the Iberian Peninsula is the loss of suitable habitats caused by abandonment of agricultural and grazing activities. Nowadays, Mediterranean landscapes suffer from wildfires that affect extensive areas and produce considerable habitat changes. However, little is known about the influence of wildfires and post-fire treatments on rabbit abundance to address policies to recover their populations. To do so, we studied abundances of this species in four types of plots during three consecutive years after a wildfire in Catalonia (NE Spain): (A) unburnt forests, (B) burnt forests with removal of burnt trees but with branches left, (C) burnt forests with removal of burnt trees and branches, and (D) non-forested burnt plots. Rabbits progressively colonised burnt plots, where their abundance increased for at least 5 years after the fire, but decreased or even disappeared in unburnt ones, indicating that forest fires have a positive effect on rabbit populations. Although abundances did not differ between the three burnt plot types, plots with removal of burnt branches had the highest increase in abundance. In addition, soil covered by branches or by dense vegetation appeared negatively correlated with abundance, indicating that this could hinder rabbit movements, while some plant species could benefit rabbits by providing high quality food. Thus, post-fire treatments favourable to rabbit populations might therefore be a good way of increasing the conservation and economic value of areas affected by forest fires.     

Using historical accounts to set conservation baselines: the case of Lynx species in Spain

The knowledge of the historical range of organisms is necessary to understand distribution dynamics and their drivers as well as to set reference conditions and conservation goals. We reviewed written sources documenting the presence of lynxes in Spain between the sixteenth and nineteenth centuries, trying to infer whether Lynx records referred to the Iberian (Lynx pardinus) or the Eurasian (Lynx lynx) species. We compiled 151 spatially specific, non-redundant Lynx records, dating between 1572 and 1897. Records appeared split in two neatly separated areas, North and South. Arguably, all historical records from the South area correspond to Iberian lynx, since almost all of them fall within the estimated range of the species in the 1950s. This suggests that the core distribution area of the species remained relatively stable for centuries, until the second half of the twentieth century. The reported range in the 1950s is thus an appropriate scenario to set conservation goals for this critically endangered species. The North area extended from Galicia and northern Portugal to the Mediterranean, mainly occupying the Atlantic-climate area of northern Iberia. Reported direct measurements and the accumulation of indirect evidences suggest that most, if not all, northern Lynx records refer to the Eurasian lynx, which had been previously detected in archaeological sites of the area. This species was apparently present in the Iberian Peninsula until the early-nineteenth century. Our results provide an objective, baseline distribution of Lynx species in Spain useful to guide conservation efforts both at the Iberian and European levels.     

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.