12 NORTH AMERICAN FAUNA 75 



heavier moss growth than we found at the lower elevations. We set traps and mist 

 nets along the main trail at the l,0(X)-m and 1,500-m sites. 



The fifth study site (10°01'N, 84°07'W), at 2,050 m, was situated in an aban- 

 doned pasture 5 km east of Vara Blanca. Traps and mist nets were placed in the 

 nearby primary forest along the main trail and along a small stream. Landslides 

 seemed common at this elevation, probably caused by unstable soils, steep slopes, 

 and high rainfall. Key tree species at this elevation again included Ocotea austinii 

 and Quercus corrugata. 



We used a guard station located 2 km north and 0.5 km east of Sacramento 

 for camp at 2,600 m. It is on the Pacific side of Volcan Barva, and the nearby 

 habitats are mostly pasture and several successional stages of forest. This site is 

 within the montane rain forest life zone. Key tree species included Drymys winterii 

 and Quercus costaricensis. Traps and mist nets were set along the road and in 

 pastures found between forest patches. 



The La Selva Biological Station is the field station of the Organization for 

 Tropical Studies located 3 km south of Puerto Viejo de Sarapiqui (10°27'N, 

 84°00'W); elevation ranges from 35 to 135 m. Mean annual rainfall is 3,990 mm, 

 with the wettest months being November, December, and February; mean monthly 

 temperatures range from 24.5° C (December) to 26.1° C (April). La Selva lies 

 within the tropical wet forest zone and grades into tropical premontane wet forest, 

 with lowland evergreen forest the dominant forest type. Vegetation and habitat types 

 of La Selva have been described by Slud (1960), Holdridge et al. (1971), Sawyer 

 and Lindsey (1971), Hartshorn (1983), D. Lieberman et al. (1985), and M. Lieber- 

 man et al. (1985). One unusual feature of the subcanopy of the La Selva forest 

 is the diversity and abundance of dwarf palms (Hartshorn 1983), especially the 

 broad-leaved species, Geonoma congesta and Asterogyne martiana. The fruits and 

 seeds of these palms serve as food for small mammals and the leaves are used by 

 Dermanura watsoni for tent construction. The forest at La Selva is complex with 

 perhaps as many as 400 species of trees; however, Pentaclethra macroloba 

 (Mimosaceae) is the dominant tree species. Because of possible errors in identifica- 

 tion by untrained observers, logbook notations from La Selva were screened by 

 us. We have included only those reports that we believe to be reliable, unless other- 

 wise discussed in the species accounts. 



The habitat types along the La Selva- Volcan Barva altitudinal transect were 

 described in greater detail by Hartshorn and Peralta (1988). 



