Ectoparasites of the endangered Iberian lynx Lynx pardinus and sympatric wild and domestic carnivores in Spain

Abstract Ectoparasites can cause important skin disorders in animals and can also transmit pathogens. The Iberian lynx Lynx pardinus has been stated to be the most endangered felid in the world and such vector‐borne pathogens may threaten its survival. We surveyed 98 wild carnivores (26 Iberian lynxes, 34 red foxes Vulpes vulpes, 24 Egyptian mongooses Herpestes ichneumon, 11 common genets Genetta genetta, two Eurasian badgers Meles meles, one polecat Mustela putorius) and 75 domestic but free‐ranging carnivores (46 cats Felis catus, 29 dogs Canis familiaris) from June 2004 to June 2006 in the two areas where the last lynx metapopulations survive: Sierra Morena and Doñana (Andalusia, southern Spain). A total of 65% of lynxes were parasitized (50% by ticks, 19% by fleas, 4% by lice, 31% by hippoboscid flies), as were 75% of foxes (58%, 60%, 0%, 19%), 71% of mongooses (50%, 4%, 46%, 0%), 54% of genets (18%, 36%, 0%, 0%), 30% of cats (22%, 14%, 0%, 2%), and 7% of dogs (surveyed only for ticks). Both badgers presented ticks, fleas and lice. Five species of ixodid ticks (Rhipicephalus pusillus Gil Collado, Rhipicephalus turanicus Pomerantzev and Matikashvili, Ixodes ricinus (Linnaeus), Ixodes hexagonus Leach and Ixodes ventalloi Gil Collado; and Hyalomma sp.), four species of fleas (Ctenocephalides canis Curtis, Pulex irritans Linnaeus, Spilopsyllus cuniculi (Dale), Xenopsylla cunicularis Smit), three species of chewing lice (Felicola (Felicola) inequalis (Piaget), Trichodectes (Trichodectes) melis (Fabricius), and Felicola (Lorisicola) isidoroi Pérez and Palma), and one species of hippoboscid fly (Hippobosca longipennis (Fabricius)) were found. We did not detect any cases of mange. Hippobosca longipennis is a new record for Spanish wildlife, and all the flea species are new records for the Iberian lynx. Fleas were more frequent on lynxes and foxes in winter than in spring. Rhipicephalus spp. were more frequent on cats in spring than in any other season. These and other epidemiological findings are discussed with respect to the conservation of the Iberian lynx.     

Helminth parasites of the endangered Iberian lynx (Lynx pardinus) and sympatric carnivores

Five critically endangered Iberian lynxes (Lynx pardinus) and 35 other sympatric carnivores (19 feral cats Felis catus, 12 Egyptian mongooses Herpestes ichneumon, and 4 common genets Genetta genetta) were analysed for helminths in Sierra Morena and Do?ana area (southern Spain). Ancylostoma tubaeforme, which was believed to be harmful for lynx cubs according to a previous study, was present in the only lynx and in 53% of cats analysed in Do?ana (80% in adult cats). Other species shared in both areas were Toxocara cati (1 lynx, 31% of cats), Joyeuxiella pasqualei (1 lynx, 21% of cats) and Mesocestoides sp. (2 lynxes, 5% of cats). Only one mongoose was parasitized, harbouring larvae of two acantocephalan species not previously reported in the Iberian peninsula (Centrorhynchus (Sphaerirostris) lancea and Centrorhynchus (Longirostris) undulatus). Feral cats may be a reservoir for hookworms and other helminths affecting the Iberian lynx. In contrast, mongooses and genets may not play a role in the epidemiology of these species.     

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.     

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.     

First report of an intraerythrocytic small piroplasm in wild Iberian lynx (Lynx pardinus)

A wild injured Iberian lynx (Lynx pardinus) was taken from the Sierra Morena population. During the health check small intraerythrocytic piroplasms, morphologically indistinguishable from other feline piroplasms, were observed in Wright-Giemsa-stained blood films. Amplification by polymerase chain reaction of a portion of the 18S nuclear small subunit (NSS) rRNA gene and sequencing revealed similarity of the unknown organism with sequences obtained from Pallas's cat from Mongolia and from a domestic cat in Spain. In a retrospective (1993-2003) study of 50 Iberian lynx tissue samples, no amplifications of the 18S NSS rRNA gene of the organism were obtained. This is the first report of a naturally occurring erythroparasitemia in the Iberian lynx and the first documented case of naturally occurring piroplasm infection in a free-ranging felid from Europe.     

Proximate and ultimate causes of dispersal in the Iberian lynx Lynx pardinus

Most studies on the causes of animal dispersal focus on speciesof birds or small mammals, but there are few such studies onsolitary carnivores. A complete picture of the causes of animaldispersal is not possible without considering cases on a representativeset of animals. The Iberian lynx is a medium-size, solitarycarnivore that inhabits metapopulations, where dispersal playsa prominent role. Between 1983 and 1998 we studied the proximateand ultimate causes of dispersal in Iberian lynx in the Doñanametapopulation (southwestern Spain), based on radio-trackingof 49 individuals. Saturation of limited breeding areas in thissmall population leads to high dispersal rates in both sexes.Most lynxes dispersed from their natal area between 12 and 24months of age. Males younger than 1 year old tended to dispersein a higher proportion than females of the same age. However,high dispersal rates for both sexes by the age of 2 years andthe lack of differences in the dispersal distances do not supportinbreeding avoidance as an ultimate cause of dispersal. Dispersalmainly started between January and June (24/29 cases), whenmost social interactions occur, which supports the social subordinationhypothesis. Lynxes left the natal range at an earlier age fromthe local population with higher density, which supports intraspecificcompetition for resources as a cause for dispersal. However,prey seems not to be the limiting resource because dispersalmostly started during the season of increasing prey density,and individual probability of dispersal increases with preydensity in the natal area. Dispersers suffered higher mortalitythan nondispersing lynxes of the same age, due mostly to anthropogeniccauses. About half of the dispersers successfully settled ina territory at distances that differed between areas of origin,but not between sexes. Distances reached, shorter than thosereported for other similar-size solitary felids, are limitedby anthropogenic barriers that prevent connection with closermetapopulations.     

The use of camera trapping for estimating Iberian lynx (Lynx pardinus) home ranges

The use of non-invasive long-term monitoring data to estimate home ranges of the critically endangered Iberian lynx has been evaluated. This programme began in 2002 and consisting of both annual latrine and camera-trap surveys, with the aims of detecting and individually identifying the maximum number of individuals and delineating female home range boundaries. Radio-tracking data were used to evaluate the accuracy of home range estimates constructed with camera-trapping data. There was little overlap of camera-trapping home ranges (7.0%?±?1.47), which suggests the existence of real territories consistent with the land tenure system expected for the species. Camera trapping home range estimates were half the size of radio-tracking data (54.1%?±?6.0 of overlapping). When comparing core areas, only the radio-tracking data did not yield improved results (36.7?±?5.4 of overlapping). Estimation of territories, which escaped detection each year, ranged from 0.0% to 5.7%. The results produced by camera-trapping data in this non-intrusive monitoring programme could be considered precise, and are therefore well suited to provide the knowledge required for appropriate conservation of this endangered species.     

Cryobanking the genetic diversity in the critically endangered Iberian lynx (Lynx pardinus) from skin biopsies. Investigating the cryopreservation and culture ability of highly valuable explants and cells

Cryobanking skin samples permit preserving a maximum of genetic representation from the population biodiversity. This is a relevant aspect for threatened species, potentially menaced by an epizooty and from which it is difficult to obtain gametes. As a first step for properly cryobanking skin samples of a given species, the optimal conditions of culture and freezing have to be studied by covering a broad range of possibilities. This paper presents, for the first time, a systematic study of such conditions for the Iberian lynx (Lynx pardinus). To that end, we have analyzed twenty different culture conditions and fifteen different freezing solutions for skin explants, as well as three freezing solutions for isolated cells derived from them. The culture conditions included both two different culture strategies and several combinations of nutritional supplements and mitotic agents. For the freezing solutions, we have considered different concentrations of the permeating cryoprotectant dimethyl sulfoxide (Me₂SO) either alone (5%, 7.5%, 10%, 12.5% and 15% v/v for explants, 10% for isolated cells) or along with the non-permeating cryoprotectant sucrose (0.1 or 0.2 M). Our results have been analyzed through several quantitative parameters and show that only thawed explants cryopreserved in Me₂SO (10%) either alone or with sucrose (0.2 M) presented similar properties to those in optimal fresh cultures. In addition, for these freezing conditions, isolated thawed cells also presented high survival rates (90%) and percentages of cellular functionality (85%). These results, focussed on the most endangered felid in the world, could be also useful for other threatened/endangered species.     

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.     

The effect of attractant lures in camera trapping: a case study of population estimates for the Iberian lynx (Lynx pardinus)

Capture–recapture analysis of camera trap data is a conventional method to estimate the abundance of free-ranging wild felids. Due to notorious low detection rates of felids, it is important to increase the detection probability during sampling. In this study, we report the effectiveness of attractants as a tool for improving the efficiency of camera trap sampling in abundance estimation of Iberian lynx. We developed a grid system of camera stations in which stations with and without attractant lures were spatially alternated across known Iberian lynx habitat. Of the ten individuals identified, five were detected at stations with no attractant (blind sets), and nine, at the lured stations. Thirty-eight percent of blind set station’s independent captures and 10?% of lured station’s independent captures resulted in photographs unsuitable for correct individual identification. The total capture probability at lured stations was higher than that obtained at blind set stations. The estimates obtained with blind set cameras underestimated the number of lynxes compared to lured cameras. In our study, it appears that the use of lures increased the efficiency of trail camera captures and, therefore, the accuracy of capture–recapture analysis. The observed failure to detect known individuals at blind set camera stations may violate capture–recapture assumptions and bias abundance estimates.     

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.     

Investigations on reproductive physiology in the male Eurasian lynx (Lynx lynx)

This study characterized (in vivo) morphological and functional parameters of reproductive organs of adult male lynx (n = 3) prior to, during, and after the breeding season (n = 3). Size and morphology of the reproductive tract were monitored by transcutaneous (testes) and transrectal (accessory sex glands) ultrasonography. Semen was collected by electroejaculation. Ejaculate volume, sperm number, motility, and morphology of spermatozoa as well as testosterone concentrations in blood serum and feces were evaluated. The testes and prostate had seasonal changes in size and echotexture. The mean (+/- S.D.) maximum and minimum testicular volume were 2.8 +/- 0.8 cm3 and 1.5 +/- 0.3 cm3, respectively. Fecal testosterone concentrations were highest in February (1240 +/- 393 ng/g feces), with a second increase in May (971 +/- 202 ng/g feces), but concentrations were lowest in January (481 +/- 52.9 ng/g feces). Ejaculate volume, total sperm number and percentage of motile, and intact spermatozoa were maximal in March (the middle of the breeding season). In one of the eight litters, multiple paternity was proven; however, in the remaining seven litters, all 16 cubs were sired by the same male. This particular male had the most developed and active testes and best semen quality, which may be important for sperm competition.     

Characterization of reproductive activity in captive male Eurasian lynx (Lynx lynx)

This study characterizes the reproductive activity of male European lynx kept in Central Russia. Four captive adult males were subjected to an electroejaculation prior to (November), during (March) and after (June) the breeding season. Concentration, motility and morphological integrity of spermatozoa as well as testis diameter and testosterone levels in serum were evaluated. Additionally, fecal samples were collected for 2 years to determine the fecal testosterone secretion. Testis sizes and serum testosterone concentrations were characterized by little changes with highest levels in March (2.98 mm³; 1.96 ng/ml testosterone) and lowest in June (2.34 mm³; 0.75 ng/ml testosterone). In faeces, the highest testosterone concentrations were measured in February followed by a second increase in May. The volume of ejaculates and percentages of motile and intact spermatozoa reached the maxima in March. By performing two-male mating experiments, we could prove multiple paternity within three litters. Paternity analysis of litter also revealed that 26 of 31 cubs (84%) were sired from the same male, independently from being the first or second mating partner of the respective female. This particular male showed the most developed and activated reproductive tract and also had the best semen quality, which seems to be important for sperm competition.     

Social play in the development of sibling relations in Eurasian lynx (Lynx lynx)

Social play fulfills an important function in creating and maintaining relations between siblings. However, its relationship with the intralitter social processes is poorly understood. It was noticed that, in Eurasian lynx (Lynx lynx) litters, sex differences in social play are absent in the first 2–3 months of life. It was found that the most intense periods of play behavior (at an age of 9 and 12 weeks) coincide with periods of aggression. Gradual change in play interactions, which require close physical contact by play elements with increased motor activity, are described. This reflects the changes in the relevance of certain skills of lynx cubs as they grow older.