Reproduction and population dynamics of Didelphis aurita Wied-Neuwied (Mammalia: Didelphimorphia) in the periurban environment of Santa Catarina Island, in southern Brazil

The various aspects of reproduction and population dynamics of Didelphis aurita were studied through capture-recapture on Santa Catarina Island, in southern Brazil. Surveys were carried out from April 1996 to March 1997. The study area was located near the stream of a swamp in a disturbed Atlantic Forest area. On 880 trap-nights, 31 opossums were captured on 108 occasions during one year. The results of this paper indicate a seasonal polyestrous reproduction pattern. Autumn-winter population levels grew on account of juvenile recruitment. The sex ratio favored females in first captures and total captures. Emigration was discussed as being the main reason for the female bias. The effects of sampling procedures over deviation in the pouch young sex ratio of resident females were also discussed