Geographic Range
Peromyscus polionotus
occurs in the southeastern United States. Populations in the continental United
States have been found scattered throughout parts of Mississippi, Tennessee, North
Carolina, South Carolina, and south to Florida (Whitaker and Hamilton, 1998; Wilson
and Ruff, 1999). This species of deer mouse also inhabits coastal islands off the
southeastern sea board (Nowak 1999).
Habitat
Oldfield mice inhabit diverse environments. These mice typically occupy early successional
habitats such as abandoned fields, beach dunes, and scrub habitats (Wilson and Ruff,
1999). They dig underground nest cavities which lie 0.3 to 0.9 meters below the surface.
There is a leading and an escaping tunnel. A mound of soil or sand marks the entrance
of the leading tunnel.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- desert or dune
- savanna or grassland
- scrub forest
- Other Habitat Features
- suburban
- agricultural
Physical Description
Adult females are slightly larger than adult males (Wilson and Ruff 1999). Total length
ranges from 110 to 150 millimeters with the average tail length ranging from 40 to
60 millimeters. Weight varies between 10 and 15 grams (Wilson and Ruff 1999).
Peromyscus polionotus
has several distinguishing characteristics. This species is smaller in size and has
a smaller skull compared to other species in th genus
Peromyscus
. The white and brown colored tail, with a white underside, are two identifiable characteristics
(Whitaker and Hamilton, 1998).
Distinct local color variation is found among the subspecies. For example, individuals
inhabiting the beach tend to have less pigmented hair than individuals of an inland
population (Wilson and Ruff 1999). This pale coloration may help beach populations
blend into the sandy environment, thus avoiding predation.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
Reproduction
These mice are monogamous, with the breeding pair remaining together for a period
of time.
- Mating System
- monogamous
Breeding of
Peromyscus polionotus
occurs throughout the year. There is a decline in breeding activity during the summer
(Wilson and Ruff 1999).
Gestation is 24 days in length but may be a few days longer if a previous litter is
still nursing (Whitaker and Hamilton, 1998). Litter size ranges between three and
four individuals. The average age for the first estrus cycle in a female is 29.6 days
(Nowak, 1999).
- Key Reproductive Features
- iteroparous
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
At birth, the young are helpless, weighing only 6 to 7 grams. They are pink in color
and hairless with the exception of vibrissae around the nose. The eyes do not open
until the thirteenth or fourteenth day of life. The litter is weaned around 20-25
days after birth. Above-ground activity occurs after weaning.
- Parental Investment
- altricial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- male
- female
-
provisioning
Lifespan/Longevity
Oldfield mice probably live for no longer than about 18 months in the wild.
Behavior
Oldfield mice are primarily nocturnal. Highest levels of activity have been recorded
on moonless or cloudy evenings. These mice are also hoarders and excellent diggers.
Stashes of seeds have been found underground in their burrowed nests. Oldfield mice
construct and use extensive burrows. They are most likely restricted to sandy and
loamy soils throughout their range because of their reliance on tunneling.
Home Range
Oldfield mice probably occupy the same general area throughout their lives and may
defend small territories.
Communication and Perception
Like other Peromyscus species, oldfield mice have keen vision, hearing, and tactile sensation. They use chemical cues extensively in communication.
Food Habits
Oldfield mice are granivorous, feeding on the seeds of grasses and herbs. They store
food in underground caches (Wilson and Ruff, 1999). They will also consume arthropods,
insect parts have been found in nests (Gentry and Smith, 1968).
- Animal Foods
- insects
- Plant Foods
- seeds, grains, and nuts
- Foraging Behavior
- stores or caches food
Predation
Oldfield mice are preyed upon by many small predators, such as raptors, owls, snakes,
weasels, foxes, and cats (Whitaker and Hamilton, 1998). They escape predation by
seeking refuge in their burrows and by being active primarily at night.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Oldfield mice are an important prey base for small predators in the areas in which
they live. They may also play an important role in influencing seed survivorship
of the plant communities in which they occur. The following parasites have been found
in individuals living in Florida: nematodes- six species, trematodes- one species,
acanthocephalans- one species, and fleas- two species (Whitaker and Hamilton 1998).
- fleas ( Siphonaptera )
- nematodes ( Nematoda )
- trematodes or flukes ( Trematoda )
- acanthocephalans ( Acanthocephala )
Economic Importance for Humans: Positive
Oldfield mice are excellent models for genetic research and have been used extensively to study variation in pigment controlling genes.
- Positive Impacts
- research and education
Economic Importance for Humans: Negative
It has been reported that
Peromyscus polionotus
can be a pest when it digs up the seeds of local gardeners for consumption (Whitaker
and Hamilton 1998).
- Negative Impacts
- household pest
Conservation Status
Several subspecies of
P. polionotus
are on conservation lists. The status varies by subspecies. For example, on the
IUCN list, some subspecies are listed as extinct while others are listed as endangered,
critically endangered, or lower risk. Beach development and water recreation are
just two causes for this mouse being in danger of extinction (Wilson and Ruff, 1999).
A third probable danger to
P. polionotus
is climatic. For example, the coast along the Gulf of Mexico has been subject to
hurricanes and other violent weather in the past. Swilling et. al (1998) have recorded
populations of
Peromyscus polionotus
to be severely reduced several months after Hurricane Opal hit the Alabama coast.
Subspecies of oldfield mice considered endangered are: Peromyscus polionotus allophrys , Peromyscus polionotus ammobates , Peromyscus polionotus peninsularis , Peromyscus polionotus phasma , and Peromyscus polionotus trissyllepsis , all of which occur in Florida and Alabama. Peromyscus polionotus niveiventris are considered threatened, they occur in Florida. Additional subspecies recognized by the IUCN are Peromyscus polionotus leucocephalus , near threatened in Florida, and Peromyscus polionotus decoloratus , extinct from Florida.
Other Comments
Fossil evidence in the geological record dates this mouse back to the late Pleistocene
epoch (Wilson and Ruff 1999).
Additional Links
Contributors
Desirae Foust (author), University of Northern Iowa, Jim Demastes (editor), University of Northern Iowa.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- desert or dunes
-
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
- 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.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- suburban
-
living in residential areas on the outskirts of large cities or towns.
- agricultural
-
living in landscapes dominated by human agriculture.
- 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.
- 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.
- monogamous
-
Having one mate at a time.
- 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).
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- 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.
- fossorial
-
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- 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
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- stores or caches food
-
places a food item in a special place to be eaten later. Also called "hoarding"
- 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.
- threatened
-
The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).
- herbivore
-
An animal that eats mainly plants or parts of plants.
- granivore
-
an animal that mainly eats seeds
References
Gentry, J., M. Smith. 1968. Food habits and burrow associates of *Peromyscus polionotus*. Journal of Mammalogy , 49: 562-565.
Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition VII . Baltimore and London: The Johns Hopkins University Press.
Swilling Jr, W., M. Wooten, N. Holler. 1998. Population dynamics of Alabama beach mice (*Peromyscus polionotus ammobates*) following Hurrican Opal. American Midland Naturalist , 140, no 2: 287-298.
Whitaker Jr., J., W. Hamilton Jr.. 1998. Mammals of the Eastern United States . Ithaca and London: Cornell University Press.
Wilson, D., S. Ruff. 1999. The Smithsonian Book of North American Mammals . Washington and London: Smithsonian Institution Press.