Reserva Ecológica Costanera Sur

Sitio realizado por aficionados a la observación de aves desde 10 de enero 2006

Thick-tailed Opossum - Lutreolina crassicaudata

Family Didelphidae Vulgar names may cause great confusion as in this case. The Spanish word "comadreja" was assigned to our opossum due to the similarity of these two species and so it stayed. They only share the name and their external similarity. In fact, they belong to two different groups inside mammalia. The weasel of Europe is a placental (the offspring is nourished through a placenta in the uterus till full develoment) and our opossum is a marsupial (the placenta is poor and full development must be completed outside), though in this case it is not known for certain if the abdominal bag functions like that.
Comadreja colorada/Thick-tailed Opposum© J. Simón Tagtachian
Elongated body. Hair is short and plain in colour varying from orange, rufous, yellowish, dark brown. The snout is short and the ears are small and rounded. The legs are short. The tail is almost as long as the body and gets thinner to the tip.
Comadreja colorada/Thick-tailed Opossum© J. Simón Tagtachian
Solitary and terrestrial, though climbs and swims easily
Comadreja colorada/Thick-tailed Opossum© Sergio Cusano

Feeds on small mammals, birds, reptiles, fish, insects and mollusks and less frequently on fruits and plants.
Comadreja colorada/Thick-tailed Opossum© Alberto Gurni
Comadreja colorada/Thick-tailed Opposum© Claudia Furman
On a tour at the Visitors' Center

© J. Simón Tagtachian

© Roberto Ares
Something white moved through the vegetation of the Viamonte Canal. Only when I saw its head did I associate it to an opossum. The Thick-tailed Opossum is not uncommon since it is a resident, but an albino individual in fact it is since they are not frequent in the wild. We could not see it in great detail so I might be confusing it with the white ferret, which is not at the reserve but it is presently being sold as a pet. So I consulted Marcelo Canevari, a specialist in mammals and author of several books, and Lucas Damer, a naturalist working at the reserve, to clear up the doubt. Both were of the opinion that it seemed an albino thick-tailed opossum.