The role of the environment in the spatial dynamics of an extensive hybrid zone between two neotropical cats.

Identifying factors that create and maintain a hybrid zone is of great interest to ecology, evolution and, more recently, conservation biology. Here, we investigated the role of environmental features in shaping the spatial dynamics of a hybrid zone between the southern tigrina, Leopardus guttulus, and Geoffroy's cat, L. geoffroyi, testing for exogenous selection as the main force acting on its maintenance. These Neotropical felid species are mainly allopatric, with a restricted area of sympatry in the ecotone between the Atlantic Forest and Pampa biomes. As both biomes have experienced high rates of anthropogenic habitat alteration, we also analysed the influence of habitat conversion on the hybrid zone structure. To do this, we used 13 microsatellite loci to identify potential hybrids and generated ecological niche models for them and their parental species. We compared the influence of variables on parental species and hybrid occurrence and calculated the amount of niche overlap among them. Parental species showed different habitat requirements and predicted co-occurrence was restricted to the forest-grassland mosaic of the ecotone. However, hybrids were found beyond this area, mainly in the range of L. geoffroyi. Hybrids demonstrated higher tolerance to habitat alteration than parental types, with a probability of occurrence that was positively related with mosaics of cropland areas and remnants of natural vegetation. These results indicate that exogenous selection alone does not drive the dynamics of the hybrid zone, and that habitat conversion influences its structure, potentially favouring hybrids over parental species.

A Novel Genotype and First Record of Trypanosoma lainsoni in Argentina.

Trypanosomes are a group of parasitic flagellates with medical and veterinary importance. Despite many species having been described in this genus, little is known about many of them. Here, we report a genetic and morphological characterization of trypanosomatids isolated from wild mammals from the Argentine Chaco region. Parasites were morphologically and ultrastructurally characterized by light microscopy and transmission electron microscopy. Additionally, 18s rRNA and gGAPDH genes were sequenced and analyzed using maximum likelihood and Bayesian inference. Morphological characterization showed clear characteristics associated with the Trypanosoma genus. The genetic characterization demonstrates that the studied isolates have identical sequences and a pairwise identity of 99% with Trypanosoma lainsoni, which belongs to the clade of lizards and snakes/rodents and marsupials. To date, this species had only been found in the Amazon region. Our finding represents the second report of T. lainsoni and the first record for the Chaco region. Furthermore, we ultrastructurally described for the first time the species. Finally, the host range of T. lainsoni was expanded (Leopardus geoffroyi, Carenivora, Felidae; and Calomys sp., Rodentia, Cricetidae), showing a wide host range for this species.

Toxocariasis in Carnivora from Argentinean Patagonia: Species molecular identification, hosts, and geographical distribution.

Twenty four specimens of seven species belonging to the families Felidae, Mustelidae, and Canidae were obtained in Lanín and Nahuel Huapi National Parks from March 1996 to April 2016. Specimens were processed by necropsy in order to contribute to the knowledge of toxocariasis in wild carnivores of Argentinean Patagonia. The only Puma concolor and the seven Leopardus geoffroyi were positive for Toxocara cati. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the ITS-1 region from larval and adult DNA was carried out to confirm parasite species identification. This is the first molecular determination of T. cati from wild felids in Argentina and the study also fill gaps about the spatial distribution and hosts for Toxocara cati.

Daily rhythmicity of behavior of nine species of South American feral felids in captivity.

The authors analyzed the daily activity rhythms of the domestic cat and of eight of the ten feral felid species that are indigenous to South America. All species showed daily rhythmicity of activity in captivity under a natural light-dark cycle. The robustness of the rhythmicity varied from species to species, but the grand mean of 34% was within the range of robustness previously described for mammalian species ranging in size from mice to cattle. There was not a sharp division between diurnal and nocturnal felids. Instead, what was found was a gradient of diurnality going from the predominantly nocturnal margay (72% of activity counts during the night) to the predominantly diurnal jaguarundi (87% of activity counts during the day) with the remaining species lying in between these two extremes. The ecological implications of temporal niche variations are discussed.

Amblyomma aureolatum (Acari: Ixodidae): nuevos registros en las provincias de Buenos Aires y Santa Fe, Argentina

En los meses de julio de 2015 y enero de 2016 se colectaron garrapatas de un gato montés (Leopardus geoffroyi) localizado en la provincia de Buenos Aires y de un canino doméstico (Canis lupus familiaris) en la provincia de Santa Fe, respectivamente. El objetivo del presente trabajo es reportar el primer registro de Amblyomma aureolatum en la provincia de Buenos Aires y el primer hallazgo sobre caninos domésticos de la provincia de Santa Fe. Amblyomma aureolatum presenta importancia sanitaria ya que ha sido implicada como vector de Rickettsia rickettsii, uno de los agentes causales del grupo de las fiebres manchadas en humanos, y de Rangelia vitalii, agente causal de piroplasmosis en caninos domésticos, enfermedad vulgarmente conocida como "nambiuvú”. El presente reporte es un alerta para la comunidad sobre la presencia de A. aureolatum en nuevas localidades con el fin de implementar medidas profilácticas en caninos domésticos, para prevenir la infestación por este parásito y así evitar posibles patologías asociadas.

In July of 2015 and January of 2016, ticks were recovered from a Geoffroy’s cat (Leopardus geoffroyi) in Buenos Aires province and from a domestic dog (Canis lupus familiaris) in Santa Fe province, respectively. All ticks were identified as Amblyomma aureolatum. This report is the first record of A. aureolatum in Buenos Aires province and the first record in domestic dogs of Santa Fe province. Amblyomma aureolatum is a recognized vector of Rickettsia rickettsii, a spotted fever group agent in humans, and of Rangelia vitalii, a pathogenic piroplasmid of dogs, commonly referred to as "nambiuvú”. These findings allow local people to be aware of the presence of A. aureolatum to prevent infestations in dogs, and thus avoiding the occurrence of tick-borne diseases.

Mesocestoides sp. (Eucestoda, Mesocestoididae) parasitizing four species of wild felines in Southern Brazil / Mesocestoides sp. (Eucestoda, Mesocestoididae) parasitando quatro espécies de felinos silvestres no Sul do Brasil

Leopardus colocolo, Leopardus geoffroyi, Leopardus tigrinus and Puma yagouaroundi are wild feline species endangered mainly due to habitat destruction and vehicle run overs. Seventeen felines hit on the roads were collected in Southern Brazil and examined for parasites. Cestodes were identified as Mesocestoides sp. The parasites were found in the small intestine of the hosts with a prevalence of 66.7 percent (L. colocolo and L. tigrinus), 60 percent (P. yagouaroundi) and 50 percent (L. geoffroyi). Rodents and lizards were found in the stomach contents and they possibly were intermediate hosts of Mesocestoides sp. This is the first report of Mesocestoides sp. in wild felines in Brazil.

As espécies Leopardus colocolo, Leopardus geoffroyi, Leopardus tigrinus e Puma yagouaroundi, são felídeos silvestres ameaçados de extinção, principalmente pela destruição do hábitat e morte em rodovias. Dezessete felídeos foram coletados atropelados no sul do Brasil e, analisados na pesquisa de parasitos. Cestóides encontrados foram identificados como Mesocestoides sp. Os parasitos foram encontrados no intestino delgado dos hospedeiros com prevalência de 66,7 por cento (L. colocolo e L. tigrinus), 60 por cento (P. yagouaroundi) e 50 por cento (L. geoffroyi). Roedores e lagartos foram encontrados no conteúdo estomacal, podendo ser os hospedeiros intermediários para Mesocestoides sp. Este é o primeiro registro de Mesocestoides sp. em felídeos silvestres no Brasil.