|Scientific Name:||Neotoma floridana|
|Species Authority:||(Ord, 1818)|
Neotoma magister previously was included in this species. Evidence from analyses of variation in mtDNA, allozymes, and morphology indicates that N. magister is a highly distinct lineage (Hayes and Harrison 1992, Hayes and Richmond 1993).
This species may hybridize with N. micropus, but introgression along the narrow contact zone has been judged as insubstantial (see Musser and Carleton, in Wilson and Reeder 1993, 2005).
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Linzey, A.V. & NatureServe (Jordan, R.A. & Hammerson, G.)|
|Reviewer(s):||Amori, G. (Small Nonvolant Mammal Red List Authority) & Chanson, J. (Global Mammal Assessment Team)|
Listed as Least Concern because it is very widespread, although generally not common, it occurs in many protected areas and its population is not declining fast enough to qualify in a more threatened category.
|Range Description:||This species is distributed over much of the south-central and southeastern United States, from Nebraska and eastern Colorado east to North Carolina, south to Texas, Gulf coast, and central Florida. Florida subspecies smalli of Key Largo is separated from populations in peninsular Florida by about 240 km. Schwartz and Odum (1957) suggested that Neotoma invaded the eastern United States from the Southwest, where the subfamily is well-represented, with one segment of the taxon moving north along the Appalachian Plateau and the other spreading out along the Coastal Plain.|
Native:United States (Alabama, Arkansas, Colorado, Florida, Georgia, Illinois, Kansas, Louisiana, Mississippi, Missouri, Nebraska, North Carolina, Oklahoma, South Carolina, Texas)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is generally uncommon (Schwartz and Schwartz 1981), but total population size certainly is in excess of 10,000 individuals. The eastern woodrat appears never to have been abundant over much of the range, but few data are available on population trends. Characterized by low densities, with a Kansas study reporting 0.20/ha in one year and 0.82/ha in another. Density was estimated at 7.6/ha over 851 ha at Key Largo, Florida (Humphrey 1988). Population density in Pennsylvania was 1-4/ha. Densities of 5-8 adults per hectare are probably high for the species (Burt and Grossenheider 1976).|
|Habitat and Ecology:||
Eastern woodrats occur in wooded areas, ravines, floodplain forest; swamps and osage orange and other hedges in some areas in southern United States. The coastal subspecies has been found in a wide variety of habitats, including lowland deciduous forests from Florida northward to southeastern North Carolina, generally inside or near edges of forests, primarily deciduous forest. Other habitats include low, wet areas, ranging from marshes to swamps and swamp hammocks. In Georgia and Florida, habitat is wet areas in hammocks and densely vegetated swamps, where nests are built in hollow trees or along stream banks in dense tangles of cabbage palmetto (Hamilton and Whittaker 1979).
David Webster (UNC-Wilmington) suggested that the species is habitat-specific and confined to particular soil types. Preferred habitat in North Carolina consists of low-lying deciduous forests with a dense cover of palmetto (Sabal minor). The Rocky Point, Pender County, population is restricted to an unusual woodland dominated by dense shrub layer of Sabal major established on a unique soil (Pender Series) with a very shallow, acidic A-horizon and a slightly alkaline B-horizon (Webster et al. 1985). The habitat there appears to be similar to the palmetto forests of Florida where woodrats are relatively abundant.
Young are born in a nest in a rocky crevice, in or under a tree, in a brush pile, in an abandoned building (Schwartz and Odum 1957), or in a similar site; rarely in the lower branches of a tree. In the Midwest nests generally are sheltered by a stick house (Hayes and Harrison 1992). Nest commonly is used in successive years, may become quite large. Harper (1927) described a nest of sticks and other debris that filled a hollow cypress stump and rose to a height of three feet. Working in Gulf Coast Florida, Pearson (1952) described nests in barns, hollow logs, and subterranean chambers under stumps, tree bases, and root masses. Nest sites were not excavated to any extent by the rats themselves. The majority of nests described by Pearson were found in dense tangles of low shrubs with only small midden heaps scattered around them. Schwartz and Schwartz (1981) described typical woodrat nests as being large, 1.5 to 4 ft in diameter and >3 ft in height. The internal nest cavity was typically 5-8 inches in diameter and carefully lined with finely shredded bark, leaves or grass. The exterior was a jumbled mass of sticks, dried grass, leaves, and assorted rubbish (old bones, pieces of metal, small rocks, etc.) collected by the rat. Nests were left open at the top in sheltered areas, but were roofed over in exposed situations such as in low trees and shrubs. Nests were used all year and, in some cases, for an entire lifetime. Woodrats continually added to their nests and established nests might have several levels and nest cavities.
It breeds from March to October in Oklahoma, mainly February to October in Kansas, apparently all year in Florida and coastal Georgia, all year except reduced in winter in Oklahoma. Females are polyestrous with a cycle of 4-6 days. Gestation probably lasts about 33-39 days (Hamilton 1953). Litter size is usually 2-4 (average three) (Hamilton and Whitaker 1979), with up to 2-3 litters per year. The young are altricial with eyes opening in 15-21 days (Schwartz and Schwartz 1981). Sexual maturity is reached in less than one year and some females, though not males, may breed in their first season (Wiley 1980). Adults appear to live at least three years in the wild (Merritt 1987). Neotoma may have a reproductive potential that is "considerably lower" than other cricetid rodents, based on life span (Schwartz and Schwartz 1981).
The nests of N. magister and presumably N. floridana provide shelter for a large array of other animals, including rabbits, white-footed mouse, snakes, toads, salamanders, as well as spiders and many other invertebrates (Merritt 1987). Woodrats use communal latrine sites and urination sites (Schwartz and Schwartz 1981, Merritt 1987). Latrine areas appear to be used over extended periods of time and by more than one individual.
Pearson (1952) inferred from the distribution of nest sites that woodrats may be at least partly colonial. Other authors have described the woodrat as largely solitary and aggressive, sharing their houses only during the breeding season and when rearing young, and with most captured animals carrying scars apparently from fighting with conspecifics (Nowak and Paradiso 1983). Merritt (1987) described the closely related N. magister as territorial, engaging in aggressive displays of foot thumping and teeth chattering to challenge conspecifics at nest sites.
Schwartz and Schwartz (1981) described home ranges in Missouri as 0.3 ha for males and 0.2 ha for females. Goertz (1970) calculated home ranges of 0.26 ha for males and 0.17 ha for females in Oklahoma.
Wiley (1980) suggested that the black rat snake and the long-tailed weasel are potential predators because their size allows them to enter woodrat houses. Eastern woodrats feed opportunistically on seeds, nuts, fruits, fungi, buds, stems, roots, and foliage. Fall and winter diet may be dominated by stored nuts and seeds (Schwartz and Schwartz 1981). Woodrats are active all year and do not hibernate, but may remain in their nests for extended periods during inclement weather (Schwartz and Schwartz 1981). They are largely nocturnal (Wiley 1980); most active during first few hours of darkness.
There are no major threats to this species overall. The primary threat in the southeastern United States is probably habitat loss. Human modification of Coastal Plain habitats, including forestry practices that favour pine monocultures, fire suppression, and development (golf courses, residential, etc.), probably are putting increasing pressure on remaining populations. The requirement for mature lowland hardwoods in the rapidly developing Southeast puts the species at particular risk. Removal of abandoned buildings and barns might also be harmful by removing potential nesting places.
While the species is probably secure over most of its range, several subspecies of eastern woodrat have undergone declines in recent years. The main threat in North Carolina appears to be habitat loss. The population on Bald Head Island, Brunswick County, was extirpated in 1966, and the Scotts Hill population was destroyed by 1987 when the area was converted to a pine plantation. While the woodrat persists at Rocky Point, much of the lowland forest habitat there was destroyed by the construction of Interstate 40. Predation is a threat for all herbivore species. Feral cats can be a serious threat in developed areas. Woodrats have been shown to suffer from many ecto- and endoparasites and, while the effects of these parasites on Neotoma populations remains unknown, Alan (1987) suggested that at least one population in Florida may have been extirpated by an outbreak of ticks. Neal (1967; cited in Alan 1987) suggested that fluctuations in woodrat populations in the Mississippi River Basin may be linked to abundances in acorn crops, and other authors have linked fluctuations to extreme weather conditions (Nawrot and Klimstra 1976). Hall (1988) pointed out a correlation between gypsy moth spread and woodrat declines in Pennsylvania, suggesting that depressed acorn production may impact woodrat over-winter survival (see Norris 1992).
|Conservation Actions:||There are probably many protected occurrences of this species.|
|Citation:||Linzey, A.V. & NatureServe (Jordan, R.A. & Hammerson, G.) 2008. Neotoma floridana. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 30 January 2015.|