The activity of chinchilla males (Chinchilla lanigera) and their preferences regarding location in a polygamous housing system

The welfare of farmed chinchillas (Chinchilla lanigera) remains poorly understood due to their short domestication history. An unresolved question concerns whether males in polygamous housing systems require a personal cage. This study evaluated daily activity patterns and location preferences of males kept under farm conditions, comparing newly formed family groups with long-established ones. Twelve family groups, each comprising one male and four females connected by a male-only corridor, were studied. Six groups had been established for 2–3 months (young families) and six for more than one year (old families). Each male was tested in two housing conditions: with and without access to a personal cage. Continuous infrared video recordings were analyzed with a standardized ethogram to document both the males’ locations (corridor, personal cage, female cages) and their behaviors (resting, locomotion, feeding, grooming, interactions). Males exhibited a clear nocturnal rhythm, with peak activity between 19:00 and 06:00, and resting dominated during daytime. Regardless of housing condition, males strongly preferred the corridor (12–20 h/day) and used personal cages for only ~135 min/day. Family type influenced behavior: males from young families showed more locomotion and exploratory sniffing, whereas those from old families more often entered female cages and developed preferences for specific partners. Restricting access to personal cages increased time spent with a preferred female, particularly in old families. These findings demonstrate that the corridor is the central element of male activity and welfare in polygamous systems, while personal cages are of limited importance. Family stability and social bonds should be considered in welfare assessments and housing recommendations for farmed chinchillas.