Mexican Fox Squirrel
Encyclopedia
The Mexican Fox Squirrel (Sciurus nayaritensis) is a species of tree squirrel
found throughout the Sierra Madre Occidental
as far south as Jalisco
, Mexico, northward into the United States only in the Chiricahua Mountains
of southeastern Arizona
. This species, or its subspecies, is sometimes called the Apache, Nayarit, or Chiricahua fox squirrel .
and occasionally epigeous fungi, and insects Koprowski, J.L., Corse, M.C. (2001) Food habits of the Chiricahua fox squirrel (Sciurus nayaritensis chiricahuae). Southwest. Nat. 46, 62-65.. Mexican fox squirrels occasionally cache large seeds by scatterhoarding them in leaf litter and topsoil .
The ecology of Mexican fox squirrels has not been studied thoroughly, particularly outside the United States. Densities are often very low . Mexican fox squirrels typically produce a single small litter of 1 or 2 young in late spring or summer . Mexican fox squirrels nest in ball-shaped dreys composed of sticks and leaves in trees; cavities within large trees are occasionally used, especially by nursing females. They are known to communally nest at times. Large raptors, canids, felids, procyonids
and snakes are likely the major predators. Mexican fox squirrels are notably silent and appear to prefer to seek cover and remain motionless. If startled, they may bark and chuck from safe locations in trees.
forests with a mixture of pine and oak to higher elevation mixed conifer forests < 2700 metres (8,858.3 ft) . Riparian areas with large cottonwoods and sycamores often harbor the highest densities. In the United States, the squirrel lives only in the Chiricahua Mountains of southeastern Arizona . The Mexican fox squirrel inhabits forests that were historically maintained by frequent, low-severity fire, and uses areas with open understory and large trees that are typical of such forests .
Tree squirrel
Tree squirrels include over a hundred species that are found on all continents except Antarctica, and are the members of the squirrel family most commonly referred to as "squirrels"...
found throughout the Sierra Madre Occidental
Sierra Madre Occidental
The Sierra Madre Occidental is a mountain range in western Mexico.-Setting:The range runs north to south, from just south of the Sonora–Arizona border southeast through eastern Sonora, western Chihuahua, Sinaloa, Durango, Zacatecas, Nayarit, Jalisco, Aguascalientes to Guanajuato, where it joins...
as far south as Jalisco
Jalisco
Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...
, Mexico, northward into the United States only in the Chiricahua Mountains
Chiricahua Mountains
The Chiricahua Mountains are a mountain range in southeastern Arizona which are part of the Basin and Range province of the southwest, and part of the Coronado National Forest...
of southeastern Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
. This species, or its subspecies, is sometimes called the Apache, Nayarit, or Chiricahua fox squirrel .
Physical
Mexican fox squirrels have a grizzled brown back with a yellow to rufous underside, and a charcoal tail frosted with white. Two molts occur each year; the winter pelage is more rufous and the scrotum is often ringed with white. Mass is approximately 700 grams (24.7 oz) .Behavior
Mexican fox squirrels are diurnal, non-territorial, and do not hibernate during the winter months. The Mexican fox squirrel forages extensively on the ground and in the forest canopy for tree seeds, flowers, and fungi. Seeds from the cones from pine, Douglas-fir, and true firs are extracted by removing individual cone scales. Acorns and walnuts are also eaten when available, along with a variety of other tree seeds, hypogeousEpigeal
Epigeal, epigean, epigeic and epigeous are biological terms describing an organism's activity above the soil surface.In botany, a seed is described as epigeal when the cotyledons of the germinating seed expand, throw off the seed shell and become photosynthetic above the ground...
and occasionally epigeous fungi, and insects Koprowski, J.L., Corse, M.C. (2001) Food habits of the Chiricahua fox squirrel (Sciurus nayaritensis chiricahuae). Southwest. Nat. 46, 62-65.. Mexican fox squirrels occasionally cache large seeds by scatterhoarding them in leaf litter and topsoil .
The ecology of Mexican fox squirrels has not been studied thoroughly, particularly outside the United States. Densities are often very low . Mexican fox squirrels typically produce a single small litter of 1 or 2 young in late spring or summer . Mexican fox squirrels nest in ball-shaped dreys composed of sticks and leaves in trees; cavities within large trees are occasionally used, especially by nursing females. They are known to communally nest at times. Large raptors, canids, felids, procyonids
Procyonidae
Procyonidae is a New World family of the order Carnivora. It includes the raccoons, coatis, kinkajous, olingos, ringtails and cacomistles. Procyonids inhabit a wide range of environments, and are generally omnivorous.-Characteristics:...
and snakes are likely the major predators. Mexican fox squirrels are notably silent and appear to prefer to seek cover and remain motionless. If startled, they may bark and chuck from safe locations in trees.
Habitat
Mexican fox squirrels are found in forest ranging from low elevation (~1500 metres (4,921.3 ft)) MadreanMadrean Region
The Madrean Region is a floristic region within the Holarctic Kingdom in North America, as delineated by Armen Takhtajan and Robert F. Thorne...
forests with a mixture of pine and oak to higher elevation mixed conifer forests < 2700 metres (8,858.3 ft) . Riparian areas with large cottonwoods and sycamores often harbor the highest densities. In the United States, the squirrel lives only in the Chiricahua Mountains of southeastern Arizona . The Mexican fox squirrel inhabits forests that were historically maintained by frequent, low-severity fire, and uses areas with open understory and large trees that are typical of such forests .
Geographic variation
There are three subspecies .- S. n. nayaritensis: southern portion of the range. This is a smaller and more yellow subspecies.
- S. n. chiricahuae: Chiricahua Mountains of southeastern Arizona (USA). An endemic form, it is characterized by more reddish throughout.
- S. n. apache: northern and middle portion of the range. This is a form intermediate in size and coloration.
External links
- Smithsonian National Museum of Natural History, North American Mammals, Sciurus nayaritensishttp://www.mnh.si.edu/mna/image_info.cfm?species_id=302