Is the desert marsupial Thylamys pallidior another semelparous species?

ALBANESE, M. SOLEDAD; ASTIÉ, ANDREA; OJEDA, RICARDO A.

Belfast

Congreso; 11th International Mammalogical Congress 2013; 2013

Queen´s University, Belfast; International Federation of Mammalogist; The Mammal Society

Studies on marsupials have shown that species inhabiting seasonal environments synchronize their breeding season with the most favorable time of the year. An extreme expression of this seasonal strategy is semelparity. Although is rare among mammals, it has been described in some dasyurid and didelphid marsupials. The aim of this study was to characterize the reproductive strategy of the desert opossum by analyzing its population structure and response to environmental seasonality. We analyzed data from live-trapping during 3 periods in Ñacuñán Reserve (Mendoza, Argentina): 1984-1988; 2005-2007 and 2011-2013. In all cases captures showed seasonality in population structure. We found evidence of generation replacement with young animals occurring in summer (high resource availability). Reproductive females were trapped in spring and early summer. Almost no recapture exceeded 1 year. If we consider iteroparity - semelparity as a gradient, we suggest that this species is much nearer to a semelparous strategy.