Nesting and digging behavior in three species of Calomys (Rodentia; Cricetidae)

Two sets of behaviors relevant for the construction of shelters, nest building and digging, were studied in three con-generic species of South American cricetid rodents. Significant differences were observed among the three species in both sets of behaviors, but not between sexes within the same species. Calomys musculinus built the largest nests, C. laucha showed the highest number of digging bouts and the shortest digging latency, and C. venustus scored low in both nesting and digging behaviors. In general, these observations are consistent with the few, anecdotal records of the shelters used by these species in the field. The low nesting and digging scores of C. venustus are correlated with that species' low thermal conductance, but the marked differences in the nesting and digging scores of C. musculinus and C. laucha cannot be accounted for by differences in their basal metabolic rates or thermal conductances.