Neotoma floridanaeastern woodrat

Geographic Range

Neotoma floridana can be found from southern South Dakota, south to eastern Texas, east through central Florida, north to the western and Piedmont areas of Maryland, and west following the Appalachian Mountains toward southwestern Nebraska. Some individuals have been found as far east as coastal North Carolina and as far west as Colorado. (Palmer, 1957; Webster, et al., 1985; Wiley, 1980)

Habitat

Neotoma floridana is an eastern woodland species but has also been observed in the grasslands of the Midwest and coastal areas of the Southeast. Eastern woodrats inhabit deciduous forests in mountainous areas, swamps and marshes in coastal areas, and sometimes inhabit abandoned buildings. (Webster, et al., 1985; Wiley, 1980)

  • Range elevation
    1740 (high) m
    5708.66 (high) ft

Physical Description

Neotoma floridana is known for its short, stocky body and exceptionally long tail. The tail can be between 15 to 20 cm long. Eastern woodrats have long, soft fur which tends to be a brownish-gray on the back. The fur is darker dorsally and the underside and feet are white. The tail is bicolored; dark brown on the top and white on the bottom. There is a noted seasonal change in pelage color. In winter the dorsal pelage is dark brown to grayish and the sides tend to have a yellowish color. This fades around March to become a more uniform brown color during the rest of the year. The eyes are large, black and tend to appear bulging.

Newborn woodrats have folded pinnae and closed eyes. Birth weight is about 11 to 14 g and length is 87 to 96 mm. The ears unfold at around 9 days and the eyes open in 15 to 21 days. The first molt occurs at 5 to 6 weeks and the second molt follows immediately after the first.

Adults have an average weight of 275 g and average length of 38 cm. (Palmer, 1957; Webster, et al., 1985; Wiley, 1980)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    217 to 333 g
    7.65 to 11.74 oz
  • Range length
    34 to 43 cm
    13.39 to 16.93 in
  • Average length
    38 cm
    14.96 in

Reproduction

Mating relationships are first determined by establishing dominance. If the male establishes dominance then most likely the pairing will result in offspring. If the female becomes dominant then the male is often killed during fighting. When a successful mating pair is established, the male will follow the female around drumming his hind feet and sniffing the perineal area of the female. If the female is receptive, she will assume a position ideal for copulation. If copulation does not happen immediately, the female will start to pursue the male. She follows him around until copulation occurs. Once breeding is complete, the pair does not associate further and males are likely to try and make other attempts at breeding. (Asdell, 1964; Wiley, 1980)

Breeding season is typically from February to August, although there are some instances of year-round breeding. The gestation period is 31 to 36 days. When young are born they are cleaned then immediately attach to a teat. Young remain attached to one of their mother's teats until they are 3 to 4 weeks old. The litter size ranges from 1 to 6, with 2 and 4 being most common. Females born early in the year may breed as early as their first summer, males begin to breed in the year after their birth. (Asdell, 1964; Golley, et al., 1975; Asdell, 1964; Golley, et al., 1975; Wiley, 1980)

  • Breeding interval
    Females generally give birth once a year.
  • Breeding season
    Neotoma floridana breeds from February to August and sometimes into late September.
  • Range number of offspring
    1 to 6
  • Average number of offspring
    3
  • Average number of offspring
    3.5
    AnAge
  • Range gestation period
    31 to 36 days
  • Range weaning age
    3 to 4 weeks
  • Range time to independence
    70 to 90 days
  • Range age at sexual or reproductive maturity (female)
    5 to 6 months
  • Average age at sexual or reproductive maturity (male)
    1 years

Females are responsible for all parental care. Young are born in an altricial state, with their eyes and ears closed. After young are born, females defend the nest and nurse the young for 3 to 4 weeks. They remain attached to her teats until they are weaned and then disperse at from 70 to 90 days old. The caching behavior of the mother has also been shown to influence future caching behavior in offspring. (Wiley, 1980; Post, et al., 1998; Wiley, 1980)

  • Parental Investment
  • altricial
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female

Lifespan/Longevity

Eastern woodrats have been reported living up to 8.6 years. Most eastern woodrat mortality, however, occurs in the first year of life. (Wiley, 1980)

Behavior

Eastern woodrats, like other woodrats are best known for building large dens, or "middens," out of sticks. These dens can be found in a variety of locations including rock outcrops, brush piles, bases of large trees, briar patches, or in abandoned human structures. These dens are used for shelter from the elements, nesting, food storage, and defense. Eastern woodrats will use any available resource to construct a midden. Middens can contain bones, rocks, and dung as building materials. An eastern woodrat will stay in such their midden temporarily or for life. Only one eastern woodrat will inhabit a midden at any time, with the exception of females and their young, but middens will be used by many woodrats over generations and each new woodrat continues to build on the midden. In this way woodrat middens can grow to heights of 5 feet. Teeth marks within the bones found in houses suggest that the woodrats use them to sharpen their teeth.

Eastern woodrats are aggressive towards other woodrats. Battles are usually accomplished through jabs with the head and front feet. Fighting is rarely limited to a particular sex, but when a female is involved she is most often the aggressor. They are primarily nocturnal, although some activity may occur during late afternoon. Eastern woodrats spend most of the day sleeping. They are capable of running rapidly and are decent climbers. (Palmer, 1957; Webster, et al., 1985; Wiley, 1980)

  • Average territory size
    662 m^2

Home Range

Eastern woodrats stay fairly close to their constructed middens and limit foraging to about 21 m from them. Home ranges are altered as a result of increased sexual activity, voluntary wandering, and preference to a type of food not located immediately within the occupied home range. The home range of adult males tends to be larger than adult females. The average home range for an adult male is estimated at 0.26 ha, with 0.17 ha being average for an adult female. Some overlap in home ranges has been observed along with intolerance to other individuals. Thus, there typically tends to be a buffer area between home ranges. (McMurry, et al., 1993; Wiley, 1980)

Communication and Perception

Eastern woodrats only squeal during fights or if injured. Typically, noises are made by grinding teeth or thumping the hind feet. The thumping usually occurs as a result of anger or fear. They have a highly developed sense of smell and their hearing is also extremely good. The vibrissae located at the front of the face are used for tactile sensing and help rats navigate in the dark. (Wiley, 1980)

Food Habits

Eastern woodrats are known for their foraging and caching habits. They store fruits, seeds, and leaves in their large middens to eat during the winter. They also include many non-food items in midden collections, such as jewelry, paper wads, bottle caps, and other shiny objects, which they seem to be curious about. In one study, Martin et al. (1951) reported that 5 to 10% of their diet was made up of oak (Quercus) acorns. Two to five percent of the diet is made up of greenbrier (Smilax species), goldenrod (Solidago), and prickly pear (Opuntia). Sumac (Rhus), mesquite (Prosopis), and walnut (Juglans), each constituted 0.5% of the diet. Insects are reported as making up a very small portion of the diet as well. (Martin, et al., 1951; Martin, et al., 1951; Palmer, 1957)

  • Animal Foods
  • insects
  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit

Predation

The most common predators of eastern woodrats are great horned owls (Bubo virginianus), spotted skunks (Spilogale putorius), long-tailed weasels (Mustela frenata), black snakes (Elaphe species), and timber rattlesnakes (Crotalus horridus). Eastern woodrats avoid predation by being mostly active at night, taking refuge in their large dens, and being vigilant for predator activity. They are also cryptically colored. (Webster, et al., 1985; Wiley, 1980)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Eastern woodrats are known for their large middens, which may become valuable habitat to other animals. They are prey for raptors, large snakes, and mammalian predators, and they influence plant communities through their seed predation and caching. Common parasites of this species include: warble flies (Cuterebra species), ticks (Ixodes species), mites (Eutrombicula species), fleas (Orchopeas species), chiggers (Trombicula species), and nematodes (Longistriata species). (Wiley, 1980)

Commensal/Parasitic Species
  • warble flies (Cuterebra species)
  • ticks (Ixodes species)
  • mites (Eutrombicula species)
  • fleas (Orchopeas species)
  • chiggers (Trombicula species)
  • nematodes (Longistriata species)

Economic Importance for Humans: Positive

Eastern woodrats have no known economic value.

Economic Importance for Humans: Negative

When eastern woodrats live near farms they are often considered pests. These woodrats, however, do very little economic harm to crops. (Nowak, 1999)

Conservation Status

While Neotoma floridana is considered secure globally, there are a few subspecies in certain regions that are of concern. Neotoma floridana illinoensis has been considered a species of special concern and is monitored by the Tennessee Department of Environment and Conservation. Neotoma floridana floridana is considered threatened by the North Carolina Natural Heritage Program. Neotoma floridana smalli (Key Largo woodrats) is listed as endangered by the United States Fish and Wildlife Service. According to McCleery et al. (2006), the decline in the population is due to habitat fragmentation and degradation, parasites, and predation by feral cats. Key Largo woodrats are isolated on the island of Key Largo, Florida. Almost half of the species' original home range has been lost since the early 1970s. There are approximately 850 ha of suitable land left on the island, most of which is found within two protected areas: Dagny Johnson Key Largo Hammock Botanical State Park and Crocodile Lake National Wildlife Refuge. (McCleery, et al., 2006; Mengak and Laerm, 2007; Nowak, 1999)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Brandi Guilliams (author), Radford University, Karen Powers (editor, instructor), Radford University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynous

having more than one female as a mate at one time

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

suburban

living in residential areas on the outskirts of large cities or towns.

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Asdell, S. 1964. Patterns of Mammalian Reproduction (2nd ed.). Ithaca, NY: Cornell University Associates.

Golley, F., K. Petrusewicz, L. Ryszkowski. 1975. Small mammals: their productivity and population dynamics. New York: Cambridge University Press.

Martin, A., H. Zim, A. Nelson. 1951. American Wildlife and Plants: A Guide to Wildlife Food Habits. New York: Dover Publications Inc..

McCleery, R., R. Lopez, N. Silvy, P. Frank, S. Klett. 2006. Population Status and Habitat Selection of the Endangered Key Largo Woodrat. The American Midland Naturalist, Vol. 155, No. 1: 197-209.

McMurry, S., R. Lochmiller, J. Boggs, D. Leslie, D. Engle. 1993. Woodrat Population Dynamics Following Modication of Resource Availability. American Midland Naturalist, Vol. 129, No. 2: 248-256.

Mengak, M., J. Laerm. 2007. Neotoma floridana. Pp. 546 in M Griep, W Ford, B Chapman, eds. Land Manager's Guide to Mammals of the South. Durham, NC: USDA Forest Service and The Nature Conservancy.

Nowak, R. 1999. Walker's Mammals of the World Vol. 2, Sixth Ed.. Baltimore: The Johns Hopkins University Press.

Palmer, E. 1957. Fieldbook of Mammals. New York: E.P. Dutton and Company, Inc..

Post, D., M. McDonald, O. Reichman. 1998. Influence of Maternal Diet and Perishability on Caching and Consumption Behavior of Juvenile Eastern Woodrats. Journal of Mammalogy, Vol. 79, No. 1: 156-162.

Webster, W., J. Parnell, W. Biggs. 1985. Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill: The University of North Carolina Press.

Wiley, R. 1980. Neotoma floridana. Mammalian Species, Vol. 139: 1-7.