Social System

Photo by Roger W. Barbour

N. macrotis is a solitary species (Linsdale and Tevis, 1951), but lives in stable social groups (Hamm et all, 2002; Wallen, 1982). Colonies are made up of 3-15 houses (English, 1923). The majority of woodrats present in a colony are permanent residents (Wallen, 1982). While N. macrotis does have a home range, it also exhibits territorial behavior in its core area and will actively defend its nest against conspecifics (Sakair and Noon, 1997). Each permanent resident occupies one house but may utilize common houses (Wallen, 1982).  Not all houses are used with equal frequency.  Wallen (1982) classified houses as occupied houses, common houses, and low use houses.  Most visits between woodrats occur in common houses. A common house is a house that is not permanently occupied and can be frequented by any individual (Wallen, 1982). A male's home range is larger than a female's home range regardless of age (Sakai and Noon, 1997; Cranford, 1977). The literature about the length of time spent living in a house varies. Reported stays are as short as 26 days (Cranford, 1977) to months (Wallen, 1982). The density of houses in an area also varies in the literature and ranges from 14 individuals/ha (Cranford, 1977) to 45 individuals/ha (Matocq, 2004). Contrary to Kelly (1989), both Linsdale and Tevis (1951) and Matocq (2004) did not observe philoparty among female N. macrotis. Also in conflict is whether females remain in their natal area (Sakai and Noon, 1997) or disperse (Matocq, 2004). The motivation behind the woodrat social system appears to be selfish as there is no evidence for kin altruism or reciprocal altruism in this species.

This website was completed in partial fulfillment of the requirements for Biology 323, Animal Behavior, at Davidson College in the spring semester 2008

Please direct questions, comments, or suggestions regarding this site to Carolyn Kiss or Dr. Verna Case