Commonly found on the inside of old, abandoned buildings are broken floorboards, peeling wallpaper, and thick nests of sticks protruding from crevices in the walls and ceilings. Similar gnarls of sticks can be found between rock ledges and in the corners of the occasional cave. These are most likely evidence of a long-time resident of western North America: Neotoma cinerea. Common names include the Bushy-tailed woodrat, packrat, and trade rat. While its nests are certainly noticeable, the Bushy-tailed woodrat is rarely seen due to its nocturnal nature. Below are some facts about this illusive rodent.
The Bushy-tailed woodrat can weigh from 300-600 grams for males and 250-350 grams for females. This wide range of weight reflects its large geographical distribution, with the larger woodrats living in the far north. Males and females are sexually dimorphic; meaning that they differ strongly in appearance. In the case of Bushy-tailed woodrats, the males are 8-10% larger than females (pestcontrolcanada.com).
Bushy-tailed woodrats have large black eyes, round furless ears, grey and brown fur on the back and sides and white or buff fur on the undersides and feet. The male woodrat’s body length can reach over 8 inches, not including the tail. The tail is slightly shorter than the body and is covered in bushy long fur.
The Bushy-tailed woodrat is nocturnal and active year-round. It is solitary, with male and female territories overlapping. While the actual rodent is rarely seen, its presence is usually noticed by the large nests the woodrat builds out of sticks, foliage, bones, and any number of human items. It is sometimes called a trade rat because of its habit of dropping whatever it is carrying in exchange for a new, perceivably better item. These nests can be found in rock ledges, boulder fields, and very noticeably in the interiors of abandoned buildings.
Bushy-tailed woodrats are considered herbivores, with a flexible diet that includes leaves, seeds, and shrubs. They will dry their food on a rock before storing it in middens found within the nest. The same woodrat homes are used by succeeding generations, and over time much of the forage stored in the middens has been preserved by the crystalized urine from the woodrats. Scientists have been able to analyze some of these middens and found that the contents can be thousands of years old; this provides a strong picture into the past conditions and vegetation.
The breeding season for Bushy-tailed woodrats runs from January to August, with the peak occurring somewhere between March and June. Gestation lasts 27 to 32 days, and litter sizes range from 1 to 6. Young are weaned between 26 to 30 days and dispersal occurs at 2 months. Sexual maturity occurs around 11 months. While female young may stay closer to where they were born, males tend to disperse further in search of their own territory to defend.
Bushy-tailed woodrats are rarely a problem with humans unless they build unwanted nests in manmade structures. While they have been known to carry parasites responsible for disease (such as fleas and ticks responsible for bubonic plague or spotted fever), these are rarely transferred to humans because of the low frequency of contact between people and Bushy-tailed woodrats. Some of the bushy-tailed woodrat’s predators include weasels, bobcats, coyotes, great horned owls, and red tailed hawks.