Diet, dietary selectivity and density of South American grey fox, Lycalopex griseus, in Central Chile.

The South American grey fox Lycalopex griseus is a canid widely distributed in southern South America; however, some aspects of its biology are still poorly known. We studied the diet and density of L. griseus in the Lago Peñuelas Biosphere Reserve, in Central Chile. The trophic niche breadth was B = 6.16 (Bsta = 0.47) and prey diversity was H' = 2.46 (Hmax ' = 3.17, J' = 0.78). The highest proportions of prey consumed in the diet were Oryctolagus cuniculus (52.21%) and other mammals (32.78%). We compared these results with a latitudinal gradient of diet results for this species in Chile. L. griseus eats mostly mammals (>90% of total prey), consuming the rodent Phyllotis darwini and reptiles in the northern zone; Oryctolagus cuniculus, Octodon degus and Abrocoma bennetti in the central zone; Abrothrix spp. and lagomorphs in the southern zone; and Lepus capensis and Ovis aries in the austral zone. The estimated density of L. griseus in Lago Peñuelas NR was 1.3 foxes/km2 .

Detection of Leishmania DNA in wild foxes and associated ticks in Patagonia, Argentina, 2000 km south of its known distribution area.

BACKGROUND: Zoonotic Visceral Leishmaniasis (ZVL) is a vector-borne disease affecting humans and other mammals and caused by the protozoan parasite Leishmania (Leishmania) infantum (syn. L. chagasi), belonging to the L. donovani complex. The regions in Northern Argentina (above 32 °S) are its southern distribution limit in South America. RESULTS: We detected Leishmania sp. DNA (most likely belonging to the L. donovani complex) in 37.5% of 32 grey foxes (Pseudalopex griseus) captured in Argentinean Patagonia (48°S and 50°S). Eleven monosexual pools of Amblyomma tigrinum ticks from eight different foxes (six grey foxes and two culpeo foxes P. culpaeus) were also positive. The southernmost known distribution limit for L. infantum, and the southernmost reported capture of a phlebotominae, had previously been 2000 and 750 km north of our study area, respectively. CONCLUSIONS: This finding is significant because it markedly extends the distribution area of leishmaniasis; supports the existence of a sylvatic cycle in the absence of dogs; and has implications in transmission, indicating that either sand fly distribution is broader than currently thought or non-sand fly Leishmania maintenance is possible. Additional molecular, parasitological, epidemiological and entomological studies are still needed.