Capture protocol, anesthesia, morphometric measurements and phenological observations of the Wolfssohn’s Viscacha ( Lagidium wolffsohni ) in Patagonia, Argentina

A capture and anesthesia protocol was developed and implemented for the Wolfssohn’s Viscacha (Lagidium wolffsohni), a poorly known hystricomorph rodent endemic to southern South America. The study was conducted in Parque Patagonia, Argentina, over a five-year period. It comprised 69 capture events and the handling of 59 individuals (16 juveniles and 43 adults). Capture techniques, anesthesia regimens, and the first comprehensive morphometric dataset for the species are described. Additionally, individuals were fitted with VHF collars that, combined with the use of camera traps, allowed the collection of phenological and life cycle data. Results revealed a significantly higher mean adult body weight (2.5 ± 0.1 kg) than previously reported, as well as crepuscular and nocturnal activity patterns that contrast with prior assumptions of diurnality. The mating season occurred during the winter months, from July to August. Births were documented from early November to mid-December, and juvenile males dispersed after reaching one year of age. The findings provide essential baseline data for the ecology and conservation of L. wolffsohni and highlight the importance of integrating ethical handling protocols with long-term monitoring strategies.