Encounter With A Water Opossum

A few years ago I was traveling with a family from Florida with 2 teenage boys. We were staying at the Selva Verde Lodge, on the Sarapiqui River near Puerto Viejo. The boys were eager to take a night walk along the river, as night walks can be very productive, and this one was no exception.WATER OPOSSUM
ZORRO DE AGUA
Chironectes minimus

We shined our light on what we thought was a frog and were making a move to grab it but to our surprise it turned out to be a Water Opossum (Chironectes minimus). Having heard of this rare marsupial for a long time, I was very excited to see one for the first time.

We had approached it in a very agressive manner and it swam away from us very quickly, but we were able to follow it with out flashlights. It did not swim in a straight line but had an evasive pattern of very tight circles, more like that of a moth caught on the water surface.

The water Opossum or "Zorro de Agua" is only one of nine different opossums found in Costa Rica. It is found almost everywhere in the country from sea level to about 1800 meters. It is almost always found near rivers, streams, or lakes. It is most common around fast moving water in the hills and mountains and is rare or absent in the slow moving waters of the lowlands.

It is common in many areas althoa few people have seen them as they are exclusively nocturnal and spend their days deep in their dens dug into the banks of a river or stream. They buid their nests of leaves and grasses.

These Water Opossums are marsupials and have a very interesting pouch with the opening towards the rear. They usually bear two to three young which are carried in the mother's pouch. The pouch has a sphincter muscle which keeps the young dry while the mother swims. The male also has a pouch.

The Water Opossum is a strong swimmer and have large hind feet which are completely webbed. At night they move over the rocks along the shore searching for any small creature they might eat. The palms of their front paws have very rough skin which helps hold onto their prey.