ABSTRACT
The rice rats (genus Oryzomys, family Cricetidae) are a diverse group of small rats which occur from southern North America to southern South America. Species range from arboreal to terrestrial or riparian and occur in habitats as different as tropical rainforest and temperate grassland. Breeding may be seasonal or aseasonal. Average litter size ranges between three and five and may change significantly in a population from year to year. The sex ratio of captured animals is biased towards males, and males usually move greater distances between captures than females. Population ecology has been studied for species in North, Central, and South America, as well as in the Caribbean and Galapagos Islands. 1–4
