The presence of the marsupial Dromiciops gliroides in Parque Nacional Los Alerces, Chubut, Southern Argentina, after the synchronous maturation and flowering of native bamboo and subsequent rodent irruption

Background: Dromiciops gliroides is a small nocturnal marsupial found in the temperate forests of Southern Chile and Argentina. It is the only living member of the order Microbiotheria. Here, we describe the discovery and first account of live trapping of D. gliroides in Parque Nacional Los Alerces (Los Alerces National Park) in the province of Chubut, Argentina. This account extends the distribution of this cryptic species south to Parque Nacional Los Alerces (PNLA). The study provides a description of the habitat they were captured in after a recent bamboo flowering and seeding event and subsequent rodent irruption, the first in 70 years in PNLA. Results: Four adult D. gliroides were captured during the study period, and both adult females captured had pouch young present, suggesting birth occurred in late October or early November. Habitat surveys revealed D. gliroides inhabited Nothofagus forest. A lack of fruiting plants in PNLA during the trapping period (spring) suggests their diet is likely restricted to insects at this time. No dreys were detected during habitat surveys, and hence, it is likely D. gliroides utilises tree hollows as refuges and nesting sites in PNLA. Significant threats to the population in PNLA were identified including introduced predators and human-related impacts due to farming and tourism. Conclusions: There is a breeding population of D. gliroides present in Parque Nacional Los Alerces. The newly discovered population now represents the most southern location for D. gliroides in Argentina.