Shrew Opossums: Paucituberculata

Little is known about the particulars of breeding among shrew opossum species. Field researchers have found lactating (producing milk for young) females of the Chilean shrew opossum in February, March, May, October, November, and December, suggesting a breeding season from December through May, and no breeding from June through September, the coldest months in the Southern Hemisphere. Breeding season for the silky shrew opossum, which lives in a less stressful climate, is thought to begin in July.

Since shrew opossums are marsupials, the unborn young remain in the females' uterus (YOO-ter-us; womb) only a few days, then are born in an incomplete state, to be suckled by the mother until they complete development. Suckling shrew opossums cling to their mother as she moves about. Litters probably number up to four individuals.

If alarmed, a shrew opossum will hop forward repeatedly on all fours, a mode of locomotion unique to the Caenolestidae. Shrew opossums have also been observed climbing trees, though not foraging in trees. The animals rest during the day in hollow logs and burrows. Despite their fattened tails, Chilean shrew opossums have been observed running across packed snow in midwinter.