Allegheny woodrat

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Allegheny woodrat
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Cricetidae
Genus: Neotoma
Subgenus: Neotoma
Species: N. magister
Binomial name
Neotoma magister
Baird, 1857
Neotoma magister range.jpg
Allegheny Woodrat range
Synonyms

Neotoma floridana magister

The Allegheny woodrat (Neotoma magister), is a species of "pack rat" in the genus Neotoma. Once believed to be a subspecies of the eastern woodrat (Neotoma floridana), extensive DNA analysis has proven it to be a distinct species.[2]

Description[edit]

The Allegheny woodrat is a medium-sized rodent almost indistinguishable from the closely related eastern woodrat, although slightly larger on average, and often with longer whiskers. Adults typically range from 31 to 45 cm (12 to 18 in) in total length, including a tail measuring 15 to 21 cm (5.9 to 8.3 in). Males weigh 357 g (12.6 oz) on average, while females are slightly smaller, weighing an average of 337 g (11.9 oz).[3]

It is the second-largest member of the native North American rats, and can weigh up to a pound, roughly the size of an eastern gray squirrel.[citation needed]

The fur is long, soft, and brownish-gray or cinnamon in color, while the undersides and feet are white. They have large eyes, and naked ears. Their most distinguishing feature is their tails: while the tails of European rats are naked with only slightly visible hairs, the tails of woodrats are completely furred with hairs about one-third of an inch long, and predominantly black above and white beneath.

The whiskers are unusually long, typically over 5 cm (2 in) in length. About 50 whiskers are found on each side, consisting of a mixture of stiff black hairs and softer white ones.[3]

Habitat and ecology[edit]

Allegheny woodrats prefer rocky outcrops associated with mountain ridges such as cliffs, caves, talus slopes, and even mines. This is mostly true for Pennsylvania and Maryland. In Virginia and West Virginia, woodrats are found on ridges, but also on side slopes in caves and talus (boulders and breakdown) fields. The surrounding forest is usually deciduous.[4] Throughout their range, they are found in mixed pine-oak forest,[5] but they are also found in a range of other forest types, most commonly with a mix of hardwood trees.[3]

Their diets primarily consist of plant materials including buds, leaves, stems, fruits, seeds, acorns, and other nuts. They store their food in caches and eat about 5% of their body weight a day.[6] Predators include owls, skunks, weasels, foxes, raccoons, bobcats, large snakes, and humans. At one point, the Allegheny rat was hunted for food and sometimes killed due to false identification based on its resemblance to more problematic European rats.[7]

Behavior[edit]

Nocturnal, Allegheny woodrats spend their nights foraging, collecting food and nesting materials. They are most active during the earlier part of the night, from about a half hour after sunset, and again shortly before dawn. During the summer, males have home ranges of about 6.5 ha (16 acres), and females of about 2.5 ha (6.2 acres).[3] However, these contract dramatically in the late fall and winter, when little fresh food is available, and they rely instead on their caches to survive. At such times, home ranges may shrink to as little as 0.65 ha (1.6 acres).[8]

Individuals are generally aggressive towards each other, especially when competing for nest sites, and, while home ranges may overlap, each actively defends its own den.[9] They are generally quiet animals, but have been reported to make "squeaking" and "whimpering" noises in captivity.[10]

They very rarely travel more than 150 feet from their home ranges.[citation needed]

They also collect and store various nonfood items such as bottle caps, snail shells, coins, gun cartridges, feathers, and bones. This trait is responsible for the nickname "trade rat" or "pack rat".[6] These rats form small colonies in which their nesting areas consist of a network of underground runways and many conspicuous latrines. Latrines are large fecal piles the rats deposit on protected flat rocks.[4] In some cases, researchers have found dried leaves placed around the nesting area which appear to act as alarms to warn the rats of approaching danger.[7]

In addition to the latrines, Alleghany woodrats of both sexes also scent mark various objects around their home ranges, using a scent gland on their undersides.[11] The gland becomes particularly prominent around the breeding season, and is said to produce a strong odor.[12]

Reproduction[edit]

Unlike most other rodents, Allegheny woodrats are not a prolific breeders. The breeding season is variable across their range, but is broadly between March and October, and they average two or three litters per year. Gestation lasts 30 to 36 days, and results in the birth of a litter of one to four young (typically two)[12][13]

The young are born hairless and blind, weighing 15 to 17 g (0.53 to 0.60 oz). They become fully furred at two weeks, and open their eyes at three weeks. They live with their mothers in nests composed of grass, bark, and similar materials, often located in relatively inaccessible crevices or ledges.[3][12]

Allegheny woodrats become sexually mature at three to four months of age,[3] and, in the wild, have been known to live up to 58 months.[14]

Distribution and status[edit]

Allegheny woodrats are mainly distributed along the Appalachian Mountains. They have historically been found as far north as Connecticut and possibly Massachusetts, where they are now extirpated (extinct), southeastern New York (extirpated), northern New Jersey, and northern Pennsylvania southwestward through western Maryland, Tennessee, Kentucky, West Virginia, northern and western Virginia to northeastern Alabama and northwestern North Carolina with isolated populations north of the Ohio River in southern Ohio (extirpated) and southern Indiana (reintroduced). The Tennessee River is generally accepted as the southern range limit.[15] There are no recognised subspecies. Fossils belonging to the species are known from mid Pleistocene deposits in Maryland and West Virginia.[3]

Although the Allegheny woodrat is not federally listed, it is in major decline and is state listed:[15][16]

State Status
AL Threatened
CT Extirpated
IN Endangered
KY Apparently Secure
MA Extirpated
MD Endangered
NC Endangered
NJ Endangered
NY Extirpated/possibly Endangered
OH Extirpated
PA Threatened
TN Threatened
VA Species of Concern
WV Threatened

Causes and management of decline[edit]

Gypsy moth defoliation of hardwoods along the Allegheny Front near Snow Shoe, Pennsylvania, in July 2007, may be a cause of woodrat population declines.

>

In parts of their range (New York, New Jersey, and Pennsylvania), the Allegheny woodrat population has been in decline over the past 30 years. They have been extirpated from Connecticut, Massachusetts, New York, and parts of Pennsylvania, New Jersey, and Maryland.

The reasons for the decline are not yet entirely understood, but are believed to involve a combination of factors. The first reason is a parasite, the raccoon roundworm, Baylisascaris procyonis, which is almost always fatal to woodrats.[17] Raccoons easily adapt to environmental change, and have thrived in the traditional woodrat habitat, increasing infection by the parasite, which enters woodrats because they eat the plant and seed material in raccoon feces. Another frequently cited cause is near total loss of American chestnuts caused by chestnut blight and of defoliation of oaks by an invasion of gypsy moths (lowering available supplies of acorns for woodrats). Increased competition for acorns with overabundant white-tailed deer, and increasing populations of black bear and turkey may also have a negative impact on woodrat survival. Predation by great horned owls has also been cited. Finally, increased human encroachment causes fragmentation and destruction of the woodrats' habitat.[18]

Indiana's Nongame and Endangered Wildlife Program currently monitors status, distribution, and population. They are also conducting[when?] field searches for new localities and research to identify the factors for decline.[6]

New Jersey's Division of Fish and Wildlife's Endangered and Nongame Species Program supported research by Kathleen LoGiudice. She developed a drug to be distributed through bait that the raccoons would eat, disrupting the growth and shedding of the roundworm parasite for about three weeks, effectively reducing the deposition of roundworm eggs near woodrat nesting sites, therefore reducing the threat of the parasite in woodrats.[19]

Pennsylvania is conducting a three-year study[when?] partially funded by a Game Commission State Wildlife Grant and being led by Indiana University of Pennsylvania in an attempt to shed light on the daily and seasonal movements of woodrats, identify high-quality woodrat habitat, and learn whether providing food caches can boost a population. Their work will include radiotelemetry, DNA profiling and mark-recapture trapping.[20]

Maryland's Department of Natural Resources conducts[when?] trappings and surveys to study the woodrat's habitat.[21]

Researchers at the University of Georgia have studied Allegheny woodrats in Virginia since 1990. Currently, they are investigating DNA relationships of Allegheny woodrats under a grant from the Virginia Department of Game and Inland Fisheries. They are comparing modern DNA to historic DNA from museum specimens as a way to characterize remnant genetic diversity in the species.[citation needed]

References[edit]

  1. ^ Linzey, A.V. & NatureServe (Hammerson, G., Whittaker, J.C. & Norris, S.J.) (2008). Neotoma magister. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 3 August 2009. Database entry includes a brief justification of why this species is of near threatened.
  2. ^ Edwards, C.W. & Bradley, R.D. (2001). "Molecular phylogenetics of the Neotoma floridana species group". Journal of Mammalogy 82 (3): 791–798. doi:10.1644/1545-1542(2001)082<0791:MPOTNF>2.0.CO;2. 
  3. ^ a b c d e f g Castleberry, C.B., et al. (2006). "Neotoma magister". Mammalian Species: Number 789: pp. 1–5. doi:10.1644/789.1. 
  4. ^ a b "Pennsylvania Game Commission"
  5. ^ Castleberry, N.L., et al. (2002). "Allegheny woodrat (Neotoma magister) food habits in the central Appalachians". American Midland Naturalist 47 (1): 80–92. doi:10.1674/0003-0031(2002)147[0080:AWNMFH]2.0.CO;2. 
  6. ^ a b c "Indiana Division of Fish and Wildlife"
  7. ^ a b " NYS Dept. of Environmental Conservation"
  8. ^ Hornsby, B.S., et al. (2005). "Fall movements of Allegheny woodrats in harvested and intact stands in West Virginia". Northern Journal of Applied Forestry 22 (4): 281–284. 
  9. ^ Kinsey, K.P. (1977). "Agonistic behavior and social organization in a reproductive population of Allegheny woodrats, Neotoma floridana magister". Journal of Mammalogy 58 (3): 417–419. doi:10.2307/1379342. 
  10. ^ Mengak, M.T. & Zadnik, A.K. (2005). "Behavior of captive Allegheny woodrats (Neotoma magister) in Virginia". Banisteria 26: 11–14. 
  11. ^ Kinsey, K.P. (1976). "Social behaviour in confined populations of the Allegheny woodrat, Neotoma floridana magister". Animal Behaviour 24 (1): 181–187. doi:10.1016/S0003-3472(76)80112-1. 
  12. ^ a b c Poole, E.L. (1940). "A life history sketch of the Allegheny woodrat". Journal of Mammalogy 21 (3): 249–270. doi:10.2307/1374753. 
  13. ^ Mengak, M.T. (2002). "Reproduction, juvenile growth and recapture rates of Allegheny woodrats (Neotoma magister) in Virginia". American Midland Naturalist 148 (1): 155–162. doi:10.1674/0003-0031(2002)148[0155:RJGARR]2.0.CO;2. 
  14. ^ Mengak, M.T., et al. (2002). "Longevity record for a wild Allegheny woodrat (Neotoma magister) in West Virginia". Virginia Journal of Science 53 (3): 167–170. 
  15. ^ a b "natureserv"
  16. ^ "Team Woodrat status"
  17. ^ "Allegheny Woodrat in Alabama"
  18. ^ Balcom, Betsie J.; Richard H. Yahner (April 1996). "Microhabitat and Landscape Characteristics Associated with the Threatened Allegheny Woodrat". Conservation Biology 10 (2): 515–25. doi:10.1046/j.1523-1739.1996.10020515.x. JSTOR 2386866. 
  19. ^ "Allegheny Woodrat - New Jersey"
  20. ^ "A Rocky Existence: The Woodrat In Pennsylvania". The Outdoor Wire. 17 July 2007. Retrieved 10 February 2010. 
  21. ^ "In Pursuit of the Allegheny Woodrat"

External links[edit]