Beach vole
The beach vole (Microtus breweri) is a species of rodent in the family Cricetidae. It is found only in the United States, and its natural habitat is temperate grassland.
Beach vole | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Cricetidae |
Subfamily: | Arvicolinae |
Genus: | Microtus |
Subgenus: | Mynomes |
Species: | M. breweri |
Binomial name | |
Microtus breweri (Baird, 1858) | |
Muskeget Island, between Tuckernuck Island and Marthas Vineyard, is the only known home of the beach vole, also known as the Muskeget vole. There is a question whether the Muskeget vole is a unique species or a subspecies of the meadow vole (M. pennsylvanicus).
Distribution
M. breweri can only be found on Muskeget Island, off the west coast of Nantucket, Massachusetts, United States. However, throughout the history of Muskeget Island, it might also have appeared on nearby South Point and Adams Islands, which are considered as a part of Muskeget Island in a rather broad point of view. Moreover, the island has moved about 1,000 feet eastwardly over the last about 200 years, along with its changing process of shape, size and position due erosion and tidal buildup.[2]
Habitat and diet
These voles are mainly dominating a wide habitat of poison ivy (Rhus radicans) and the beach grass (Ammophilia breviligulata). Areas of bare sand, saltwater marsh and some fresh water also are found on the island. They not only burrow in coarse, loose sand, but also on loose soil under or near any of their shelters.[2] M. breweri feeds on beach grass stalks, leaves and seeds, and insect adults and larvae. Their predators include cats, short-eared owls, northern harriers and the common garter snakes. Their home range is usually less than one acre.[2][3]
Reproduction and behavior
The young beach voles are born in the burrow nests or underneath fragments of wreckage or at the base of goldenrod (Solidago). They are larger voles compared to the meadow voles (Microtus pennsilvanicus). They show many of the attributes of a K-selected organism, such as large size, later age at maturation, sex ratio weighted towards the males, and low reproductive output.[4] The adults can breed from the spring to the fall, and the gestation can last for about one month. Every year, an individual female beach vole can produce up to several litters of three to five young offspring, but most will live for less than one year.[2] The beach voles have a habit of building their runways above or underground through the beach grass. The runways may contain some cut grass. During winter, tunnels become more common due to the cold weather.[4]
References
- Linzey, A.V. & Hammerson, G. (NatureServe) (2008). "Microtus breweri". IUCN Red List of Threatened Species. 2008. Retrieved 11 June 2009.CS1 maint: ref=harv (link) Database entry includes a brief justification of why this species is of vulnerable.
- David Kenneth Wetherbee; Raymond Parke Coppinger; Richard E. Walsh (1972). Time Lapse Ecology, Muskeget Island, Nantucket, Massachusetts. MSS Educational Pub. Retrieved 28 December 2012.
- Tamarin, Robert H. (1977). "demography of the Beach Vole (Microtus breweri) and the Meadow Vole (Microtus pennsylvanicus) in Southeastern Massachusetts". Ecology. 58 (6): 1310–1321. doi:10.2307/1935083. JSTOR 1935083.
- Tamarin, Robert H. (1977). "Reproduction in the Island Beach Vole, Microtus breweri, and the Mainland Meadow Vole, Microtus pennsylvanicus, in Southeastern Massachusetts". Journal of Mammalogy. 58 (American Society of Mammalogists): 536–548. doi:10.2307/1380002. JSTOR 1380002.
- Musser, G. G. and M. D. Carleton. 2005. Superfamily Muroidea. pp. 894–1531 in Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore.