Temporal activity and detection rates of chilla (Lycalopex griseus) in Tierra del Fuego, Argentina.

Designing mitigation strategies for invasive species requires a clear understanding of their ecology and behaviour. Chilla (or grey fox; Lycalopex griseus) were introduced to Isla Grande de Tierra del Fuego (Tierra del Fuego Island) in 1951 to control European rabbit (Oryctolagus cuniculus) populations. Although this management strategy was unsuccessful, the chilla spread across the island and are now considered invasive. Despite this, there is a lack of research concerning their ecology and behavioural patterns, particularly on the Argentinian side of the island. We assessed the detection rates and temporal activity patterns of chillas using camera traps in the Argentinian region of Tierra del Fuego Island. Chilla had average detection rates of 61.7 (SD ± 33.3, range = 13.5-105.7) per 100 trap nights. Although analysis by clock time suggested cathemeral activity patterns, when analysed by sun time the chillas exhibited distinct nocturnal activity patterns. These findings offer the first information on the detection rates of chilla on the Argentinian side of Tierra del Fuego Island and reveal new insights into their temporal activity patterns, providing an important basis for future research that may aid the development of more effective management and conservation strategies.

Epizootiology and Pathology of Sarcoptic Mange in Two Species of Fox (Lycalopex spp.) in Human-Dominated Landscapes of Central Chile.

Sarcoptic mange caused by Sarcoptes scabiei can have catastrophic consequences for wildlife. We inspected 122 Andean foxes (Lycalopex culpaeus), collected by active (n=66) or passive (n=56) surveillance, and 28 South American gray foxes (Lycalopex griseus; all from passive surveillance) for mange in Chile (2015-19). In Andean foxes, gross lesions of mange were diagnosed in 24% of passively and 9% of actively collected foxes, although observed prevalences might be underestimated. Seroprevalence was 37 and 18%, respectively, indicating that some individuals recovered from infection or were developing the disease. No differences were found between age and sex groups. Comparing data from passive surveillance, occurrence of gross lesions was lower in gray foxes (5%). Body condition was significantly better in Andean foxes without lesions than in diseased foxes, which had significantly lower albumin concentrations than healthy individuals. Among the 12 foxes with gross lesions, four, six and two individuals were categorized as having type I, type II, and type III lesions, respectively, based on clinical severity. Histologic severity correlated with gross lesions and included irregular epidermal hyperplasia with hyperkeratosis, which was marked in type II and III infections. Conventional PCR targeting of the cox1 gene fragment revealed four nucleotide sequence types, showing 99-100% identity among them and between 99% and 100% identity with previously published sequences of S. scabiei. A significant association between the occurrence of mange in foxes and distance to the nearest house was found. We speculate that diseased foxes tended to approach human settlements, perhaps in search of food. Visual inspection of 211 rural dogs from the study area did not reveal gross mange lesions in any animal. Sarcoptic mange is enzootic in the Andean fox in the study area and should be considered in the management of the species.

Widespread Infection with Hemotropic Mycoplasmas in Free-Ranging Dogs and Wild Foxes Across Six Bioclimatic Regions of Chile.

Blood samples of 626 rural dogs, 140 Andean foxes (Lycalopex culpaeus), and 83 South American grey foxes (L. griseus) from six bioregions of Chile spanning 3000 km were screened for Mycoplasma DNA by conventional PCR and sequencing. Risk factors of infection were inferred using Generalized Linear Mixed Models and genetic structure by network analyses. Overall, Mycoplasma haemocanis/Mycoplasma haemofelis (Mhc/Mhf) and Candidatus Mycoplasma haematoparvum (CMhp) observed prevalence was 23.8% and 12.8% in dogs, 20.1% and 7.2% in Andean foxes, and 26.5% and 8.4% in grey foxes, respectively. Both hemoplasmas were confirmed in all the bioregions, with higher prevalence in those where ticks from the Rhipicephalus sanguineus species group were absent. Candidatus M. haematominutum and a Mycoplasma sp. previously found in South American carnivores were detected in one fox each. Although the most prevalent Mhc/Mhf and CMhp sequence types were shared between dogs and foxes, network analysis revealed genetic structure of Mhc/Mhf between hosts in some regions. Male sex was associated with a higher risk of Mhc/Mhf and CMhp infection in dogs, and adult age with CMhp infection, suggesting that direct transmission is relevant. No risk factor was identified in foxes. Our study provides novel information about canine hemoplasmas with relevance in distribution, transmission routes, and cross-species transmission.

Endoparasitic fauna of two South American foxes in Chile: Lycalopex culpaeus and Lycalopex griseus / Fauna endoparasitária de duas raposas da América do Sul no Chile: Lycalopex culpaeus e Lycalopex griseus

Native foxes face serious threats related to anthropic activities and the uncontrolled pets. However, the transmission of several pathogens such as parasites by domestic dogs is an important conservation issue with limited attention in Chile. The lack of a proper identification of the helminths of wild canids in the country, based mostly in coprological studies, limited our knowledge in potential interspecific transmission. Thus, the aim of the present survey was to identify the parasitic fauna of two native canids, the Andean fox (Lycalopex culpaeus) (n=49) and Chilla (Lycalopex griseus) (n=17), from several localities in Chile through a complete parasitological survey. Sixteen different species were identified, 9 of which are new host records for Andean fox and two for Chilla fox in South America, and three are recorded for first time in Chile. Also, five of them are of zoonotic concern and six are known to use domestic dogs as their principal hosts. These findings have implications for public health and the conservation of canids whose interspecific transmission of parasites with domestic dogs is confirmed through these findings. The need for an exhaustive surveillance of wild carnivores is emphasized considering these hosts as important sources of micro- and macroparasites.(AU)

As raposas nativas enfrentam sérias ameaças devido às atividades antrópicas e contato com animais de estimação sem controle. Entretanto, a transmissão de patógenos, tais como parasitas de cães domésticos, é uma questão importante na conservação das raposas que têm sido pouco abordadas no Chile. A falta de uma identificação adequada dos helmintos de canídeos silvestres no país, que se baseia principalmente, em estudos coprológicos, limita o conhecimento sobre uma potencial transmissão interespecífica de parasitas. Assim, o objetivo do presente estudo foi identificar a fauna parasitária em dois canídeos nativos: a raposa andina (Lycalopex culpaeus) (n = 49) e a raposa chilla (Lycalopex griseus) (n = 17), provenientes de várias localidades do Chile, por meio de um levantamento parasitológico completo. Foram identificadas 16 espécies de parasitas, nove correspondem a novos registros de hospedeiros para a raposa andina e dois para a raposa chilla na América do Sul. Três espécies de parasitas são registrados pela primeira vez no Chile, cinco são motivo de preocupação zoonótica e seis são conhecidos por usar cães domésticos como seus principais hospedeiros. Esses achados têm implicações em saúde pública e na conservação de canídeos, pois confirmam a transmissão interespecífica de parasitas desde cães domésticos. A necessidade de vigilância exaustiva dos carnívoros selvagens é enfatizada considerando-se esses hospedeiros como importantes fontes de micro e macroparasitas.(AU)

Endoparasitic fauna of two South American foxes in Chile: Lycalopex culpaeus and Lycalopex griseus / Fauna endoparasitária de duas raposas da América do Sul no Chile: Lycalopex culpaeus e Lycalopex griseus

Abstract Native foxes face serious threats related to anthropic activities and the uncontrolled pets. However, the transmission of several pathogens such as parasites by domestic dogs is an important conservation issue with limited attention in Chile. The lack of a proper identification of the helminths of wild canids in the country, based mostly in coprological studies, limited our knowledge in potential interspecific transmission. Thus, the aim of the present survey was to identify the parasitic fauna of two native canids, the Andean fox (Lycalopex culpaeus) (n=49) and Chilla (Lycalopex griseus) (n=17), from several localities in Chile through a complete parasitological survey. Sixteen different species were identified, 9 of which are new host records for Andean fox and two for Chilla fox in South America, and three are recorded for first time in Chile. Also, five of them are of zoonotic concern and six are known to use domestic dogs as their principal hosts. These findings have implications for public health and the conservation of canids whose interspecific transmission of parasites with domestic dogs is confirmed through these findings. The need for an exhaustive surveillance of wild carnivores is emphasized considering these hosts as important sources of micro- and macroparasites.

Resumo As raposas nativas enfrentam sérias ameaças devido às atividades antrópicas e contato com animais de estimação sem controle. Entretanto, a transmissão de patógenos, tais como parasitas de cães domésticos, é uma questão importante na conservação das raposas que têm sido pouco abordadas no Chile. A falta de uma identificação adequada dos helmintos de canídeos silvestres no país, que se baseia principalmente, em estudos coprológicos, limita o conhecimento sobre uma potencial transmissão interespecífica de parasitas. Assim, o objetivo do presente estudo foi identificar a fauna parasitária em dois canídeos nativos: a raposa andina (Lycalopex culpaeus) (n = 49) e a raposa chilla (Lycalopex griseus) (n = 17), provenientes de várias localidades do Chile, por meio de um levantamento parasitológico completo. Foram identificadas 16 espécies de parasitas, nove correspondem a novos registros de hospedeiros para a raposa andina e dois para a raposa chilla na América do Sul. Três espécies de parasitas são registrados pela primeira vez no Chile, cinco são motivo de preocupação zoonótica e seis são conhecidos por usar cães domésticos como seus principais hospedeiros. Esses achados têm implicações em saúde pública e na conservação de canídeos, pois confirmam a transmissão interespecífica de parasitas desde cães domésticos. A necessidade de vigilância exaustiva dos carnívoros selvagens é enfatizada considerando-se esses hospedeiros como importantes fontes de micro e macroparasitas.