Genetics at the verge of extinction: insights from the Iberian lynx

Population viability might become compromised by the loss of genetic diversity and the accumulation of inbreeding resulting from population decline and fragmentation. The Iberian lynx (Lynx pardinus) provides a paradigmatic example of a species at the verge of extinction, and because of the well-documented and different demographic histories of the two remaining populations (Doñana and Andújar), it provides the opportunity to evaluate the performance of analytical methods commonly applied to recently declined populations. We used mitochondrial sequences and 36 microsatellite markers to evaluate the current genetic status of the species and to assess the genetic signatures of its past history. Mitochondrial diversity was extremely low with only two haplotypes, alternatively fixed in each population. Both remnant populations have low levels of genetic diversity at microsatellite markers, particularly the population from Doñana, and genetic differentiation between the two populations is high. Bayesian coalescent-based methods suggest an earlier decline starting hundreds of years ago, while heterozygosity excess and M-ratio tests did not provide conclusive and consistent evidence for recent bottlenecks. Also, a model of gene flow received overwhelming support over a model of pure drift. Results that are in conflict with the known recent demography of the species call for caution in the use of these methods, especially when no information on previous demographic history is available. Overall, our results suggest that current genetic patterns in the Iberian lynx are mainly the result of its recent decline and fragmentation and alerts on possible genetic risks for its persistence. Conservation strategies should explicitly consider this threat and incorporate an integrated genetic management of wild, captive and re-introduced populations, including genetic restoration through translocations.

Feline leukemia virus outbreak in the critically endangered Iberian lynx (Lynx pardinus): high-throughput sequencing of envelope variable region A and experimental transmission

The Iberian lynx is the most endangered felid species. During winter/spring 2006/7, a feline leukemia virus (FeLV) outbreak of unexpected virulence killed about 2/3 of the infected Iberian lynxes. All FeLV-positive animals were co-infected with feline hemoplasmas. To further characterize the Iberian lynx FeLV strain and evaluate its potential virulence, the FeLV envelope gene variable region A (VRA) mutant spectrum was analyzed using the Roche 454 sequencing technology, and an in vivo transmission study of lynx blood to specified-pathogen-free cats was performed. VRA mutations indicated weak apolipoprotein B mRNA editing enzyme and catalytic polypeptide-like cytidine deaminase (APOBEC) restriction of FeLV replication, and variants characteristic of aggressive FeLV strains, such as FeLV-C or FeLV-A/61C, were not detected. Cats exposed to FeLV/Candidatus Mycoplasma haemominutum-positive lynx blood did not show a particularly severe outcome of infection. The results underscore the special susceptibility of Iberian lynxes to infectious diseases.

Levels of heavy metals and metalloids in critically endangered Iberian lynx and other wild carnivores from Southern Spain

The Iberian lynx (Lynx pardinus) is the most endangered felid in the world with a wild population which probably stands at less than 200 individuals inhabiting two areas in Southern Spain (Doñana and Sierra Morena) that are known to have been contaminated by heavy metals and metalloids due to a long history of mining activities. This contamination may pose a threat to long term conservation efforts and hence, the concentrations of seven elements (As, Se, Cd, Zn, Cu, Pb, Hg) were determined in the liver, muscle and bone of 9 lynx, as well as 17 red foxes (Vulpes vulpes), 11 Egyptian mongooses (Herpestes ichneumon), 4 common genets (Genetta genetta) and 1 Eurasian badger (Meles meles). The mean concentrations found were below the threshold levels indicative of chronic intoxication in all the species studied. In general, genet and red fox were species with the highest concentrations of several elements in Doñana, whilst Iberian lynx had the lowest levels of most of them. Lynx from Sierra Morena had significantly higher concentrations of bone Pb (2.05 microg/g d.w.) than those from Doñana (0.13 microg/g d.w.), probably due to the mineralised underlying geology and/or the abandoned mine workings in Sierra Morena. Egyptian mongoose presented liver concentrations of Hg up to 9.7 microg/g d.w. A strong relationship between Hg and Se levels was found in liver and muscle samples of all the studied species, especially in mongoose. In conclusion, levels of the studied elements do not appear to represent a significant threat for the lynx or for the other carnivores studied. However, given the critical status of the Iberian lynx, a continuous monitoring scheme remains necessary.

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

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.