Ecological Importance of Nest Construction in the Hispid Cotton Rat (Sigmodon hispidus)

Abstract

Nest construction by the hispid cotton rat (Sigmodon hispidus) was examined in two different climatic regions. Field and laboratory studies were designed to determine factors which might affect nest construction. Field investigations were conducted during the winter of 1973-74 to learn if nests differed between localities having strikingly contrasting climates. Field-constructed nests of the hispid cotton rat from northeastern Kansas and southern Florida differed significantly. Laboratory investigations used wild-captured and laboratory-born (Fa) cotton rats from both areas. These animals constructed nests in environmental chambers adjusted to simulate winter conditions characteristic of each locality. Each rodent was allowed to construct four nests, two with vegetation brought from their home locality and two with vegetation from the other locality. Nests were constructed similarly under the stimulus of a particular climate regardless of the animals' origin, sex, type of vegetation used or experience. However, nests differed in several parameters between the simulated climates. These experiments indicate that hispid cotton rats from Kansas and Florida are capable of modifying their nest construction to cope with different climatic conditions.