Big-Eared Woodrat

Neotoma macrotis

Neotoma macrotis in Greek means “new cutter with big ears.”

Physical Characteristics

Woodrats usually rest in their houses during the day and venture out only after dusk. If you are fortunate to spot one during the day, look for big eyes, large mobile ears, a soft brown pelt covering an 8 inch body, and an 8 inch long lightly furred tail. They have extremely sharp, delicate claws that can penetrate bark easily, giving them good traction on trunks and branches. If you shine a powerful flashlight into trees at night you might see their red “eyeshine.”

Habitat

Dense foliage with 90% canopy coverage, including mature oaks of at least one species; earth that is neither bare nor covered with dense mat-forming shrub cover; large stumps, rocks, logs, or sizable living branches for anchoring houses; vegetation for building; California bay laurel leaves (or eucalyptus leaves) for parasite control; oaks or trees with cavities for nesting if possible; thistledown, shreddable bark, and other soft materials for lining nests.

Diet

Acorns, oak leaves (especially of coast live oak), elderberry, coffeeberry, poison oak (leaves, berries, and seeds), toyon (leaves and berries), California bay laurel (blossoms, fruit and seeds), chamise, willows (bark, leaves and flowers), manzanitas (leaves, berries), wavy-leafed soap plant, grasses, gooseberry, blackberry, sticky monkey flower, popcorn flower, honeysuckle, sages, and parts of more than 60 other kinds of plants; also insects, mushrooms and truffles.

Behavior

Mostly nocturnal. May reduce activity on moonlit or rainy nights. Woodrats like to avoid moonlight, but when they have to be out under a full moon, they try to stay under cover. In order to move quietly, they regularly clear leaves from trails by grabbing them with their teeth or flipping them aside with their paws. They are active year-round.

At night you may hear the woodrats thumping the tips of their tails against wood, earth, or leaves, a unique form of communication that can sound like drumming, whirring, rustling or rattling. The thump to indicate sexual availability, warn other woodrats of the approach of predators, or intimidate intruders.

Formerly thought to be solitary animals, woodrats are actually quite social. Each animal usually lives alone in his or her lodge, but the lodge may be surrounded by 10, 30, or well over a 100 other houses. Many of these structures are unoccupied except during the peak of the breeding season, a situation that seems to suit woodrats well. Females visit each other in unoccupied “common houses” adjacent to their residences, and “lovers” also meet in these houses. In addition to facilitating visits and romantic rendezvous, unoccupied houses are probably used for food storage, quick refuge in times of danger, temporary sleeping quarters and real estate that can be passed on to children.

Houses

Most houses are constructed around concealed logs, stumps, branches or rocks. Most are raggedy domes or inverted cones about 3 feet high and 3 or 4 feet wide, though some rise to a height of 8 feet. The house has multilevel complex of rooms, corridors and terraces that might easily fill a space one thousand times the size of its single owner/occupant.  Such a house can remain in use for over 60 years as generation after generation keeps adding foliage to the outside and remodeling the inside by chewing out new passageways and rooms.

Large woodrat dwellings have 3 or 4 waterproof sleeping rooms that double as birthing nests and nurseries. Sleeping nests, which are often under logs or rocks in the safest part of the house, have been found to be dry after 4 days of drenching rain. Lodges also have pantries, leaching rooms, latrine areas and openings that admit light and air to every level. The occupants line their sleeping nests with soft plant material such as thistledown or finely shredded bark and clever fumigators that they are, scatter leaves of California bay laurel around the edges when available. They nibble the outside edges of these leaves to release powerful volatile oils that kill 73% of flea larvae and other nest parasites. They also replace used leaves with fresh ones every 2 to 3 days.

Woodrats often sort the food in their pantries into types: acorns in one room, fungi in another, leaves in the third. This separate stashing may have to do with the temperature and drying needs of the food source. The animals also place toxic leaves (sage, toyon, coffeeberry, etc) in special leaching rooms where they are left to outgas before being eaten.

Latrines are just outside the back door, but when danger or bad weather threatens, a house occupant will poop in the doorway. When too much dung accumulates in the doorway, the hygiene-conscious housekeeper will wall off that part of the house or have a housecleaning day and carry the dung away.

Composed of a dense mass of interlocking vegetation, a well-built woodrat house is nearly impregnable. Badgers, wild pigs and black bears may be the only animals that have the strength and anatomical equipment to breach a woodrat stronghold.

The interiors of woodrat lodges are cool and moist, providing relief from summer heat and dryness for the many creatures that take up residence in them. Mice find woodrat houses to be admirably suited to their needs, as do brush rabbits, salamanders, centipedes and dozens of other animals.

Breeding

Breeds from December to September, with a peak in mid-spring, or all year when acorns are especially plentiful. They have 1 to 4 pups, usually 2 to 3, with up to 5 litters per year. Mothers nurse for 3 weeks and care for their young for 8 weeks. Woodrats are polygamous, polyandrous, or monogamous, depending on the availability of members of the opposite sex. They do not migrate.

Nests are located in the house, and are constructed of shredded grass, leaves, and other miscellaneous materials (e.g., bird feathers).  The nest is defended against competitors.

Predators

Bobcats, eagles, hawks, badgers, black bears, mountain lions, coyotes, foxes, skunks, long-tailed weasels, rattlesnakes, gopher snakes, feral & domestic dogs & cats, more.

References

California Wildlife Habitat Relationships System, California Department of Fish and Game, California Interagency Wildlife Task Group; www.dfg.ca.gov/biogeodata/cwhr/cawildlife.aspx

Secrets of the Oak Woodlands – Plants & Animals Among California’s Oaks by Kate Marianchild