LA SELVA-BRAULIO CARRILLO MAMMALS 15 



or have occurred in the past within the province, but whose presence there lacks 

 adequate documentation. 



Species of Verified Occurrence 



ORDER MARSUPIALIA 



Family Didelphidae 



Caluromys derbianus 

 Woolly Opossum, Zorro de Balsa 



Woolly opossums are found from southern Mexico south through western 

 Colombia and extreme northwestern Ecuador (Fig. 4). Two subspecies of Caluromys 

 derbianus are recognized in Costa Rica; C. derbianus centralis from the eastern 

 slopes and lowlands and C. derbianus pallidus from the western slopes and lowlands. 

 They are found from sea level to about 1 ,600 m. The biology of woolly opossums 

 was reviewed by Bucher and Hoffmann (1980). 



Woolly opossums have been observed at La Selva on at least 12 occasions. 

 One was seen eating the fruits of Piper near the field station in July 1984. We 

 examined an adult male woolly opossum (testes measured 11x9 mm) found dead 

 on the Southwest Trail at La Selva on 25 March 1986. Another adult male was 

 electrocuted on the wires behind the laboratory building on 20 January 1987. 



Specimen examined (1)— Finca La Selva, 3 km S of Puerto Viejo, 70 m 

 [1 male, FMNH]. 



Fig. 4. Woolly opossum, Caluromys derbianus. Photo by R. K. LaVal. 



