LA SELVA-BRAULIO CARRILLO MAMMALS 



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Sciurus deppei 

 Deppe's Squirrel, Ardilla de Miravalles or Chiza Negra 



Deppe's squirrel is found from Tamaulipas and Veracruz of eastern Mexico 

 to northern Costa Rica. A single subspecies, Sciurus deppei miravallensis , has been 

 described from Costa Rica; the type locality is Volcan de Miravalles in the Cor- 

 dillera de Guanacaste at 1,500 ft (Harris 1931, 1943). The distribution of this squir- 

 rel in Costa Rica is poorly understood. We have observed it throughout much of 

 the Guanacaste lowlands of northwestern Costa Rica and at Monte verde, where 

 it is quite abundant. 



Although the only published records of this squirrel are from extreme north- 

 western Costa Rica (McPherson 1985), squirrels identified as S. deppei have been 

 recorded at La Selva on several occasions. We cannot confirm that S. deppei occurs 

 as far east and south in Costa Rica as La Selva; however, we suspect that this species 

 is more widely distributed in the country than believed previously. 



Oryzomys couesi 

 Coues' Marsh Rice Rat, Raton 



Coues' marsh rice rat is found from southern Texas and eastern Mexico to 

 the Caribbean lowlands of extreme northern Colombia (Hershkovitz 1987). The 

 systematic position of Oryzomys couesi has long been in a state of flux. It was 

 originally proposed as a full species based on specimens taken in Guatemala; 

 however. Hall (1960) suggested that the populations known as couesi from Cen- 

 tral America intergraded with O. palustris to the north and were best considered 

 a subspecies of O. palustris. Recent karyologic studies have demonstrated that 

 O. couesi has a large submetacentric X chromosome, whereas O. palustris has 

 a large acrocentric X; both have a diploid number of 56 (Benson and Gehlbach 

 1979). Both karyotypes are known from Texas and Mexico which suggests that 

 two species are involved, although they have not been obtained from the same 

 locality. 



Although no specimens of this species have been observed at La Selva or in 

 Braulio Carrillo, it seems likely that O. couesi does occur there because it is widely 

 distributed throughout the Caribbean lowlands of Central America and has been 

 collected at several localities in the Caribbean lowlands of Costa Rica. Rice rats 

 are often abundant in cultivated fields and in weedy gardens. 



Urocyon cinereoargenteus 

 Gray Fox, Tigrillo or Zorra Gris 



Gray foxes are among the most widely distributed of the New World carnivores, 

 being found from southern Canada across most of the United States (except for 

 the northwestern States) through Mexico and Central America to northern Colom- 

 bia and Venezuela. Little has been published on the distribution or ecology of gray 

 foxes in the tropics. They may be found throughout the middle and higher eleva- 

 tions of Costa Rica. They appear to be most common in altered habitats. Although 



