Mearns's squirrel | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Sciuridae |
Genus: | Tamiasciurus |
Species: | |
Subspecies: | T. d. mearnsi |
Trinomial name | |
Tamiasciurus douglasii mearnsi (Townsend, 1897) | |
Synonyms | |
Tamiasciurus mearnsi |
Mearns's squirrel (Tamiasciurus douglasii mearnsi) is a subspecies of the Douglas squirrel endemic to Mexico. [2] It is endangered and occurs in low densities, and is threatened by habitat loss. [1] [3] It is possibly also threatened by competition from the eastern gray squirrel, which was introduced to the range of Mearns's squirrel in 1946, but may not be present anymore. [3] It is closely related to other subspecies of the Douglas squirrel, but far less is known about its behavior, which was first studied in detail in 2004. [3] It is named for the 19th-century American naturalist Edgar Mearns. [4]
Although formerly considered a distinct species due to its isolated habitat, phylogenetic evidence indicates that it has little genetic differentiation from the Douglas squirrel, and that the clades comprising the Douglas squirrel are paraphyletic with respect to it, and due to this it was reclassified as a subspecies of the Douglas squirrel. [5] Despite this, it is very different from any other member of Tamiasciurus in habitat and behavior, and thus it is thought to be of major conservation value. [6]
Mearns's squirrel is a relatively small tree squirrel, with an average head-body length of 20 cm (7.9 in), and weighing about 270 g (9.5 oz). They have soft, dense, fur, which is grey-brown on the upper body and white with yellow patches on the underparts. There is a stripe of solid black fur on each flank, and a narrow band of reddish-yellow fur runs down the middle of the back. The tail is bushy, with darker fur than the body, but fringed with white and yellow. The fur on the head is mostly grey, becoming yellowish towards the snout, and with dark ears and clear rings of white fur around the eyes. [4]
Mearns's squirrel is known from only three sites in the Sierra de San Pedro Mártir in Baja California, Mexico. [4] The region is surrounded by areas of chaparral and desert, isolating the tree squirrel from its closest relatives elsewhere, and indicating that it is likely a relict population isolated by forest fragmentation during the Pleistocene. [7] The three sites all consist of pine and fir forests at altitudes of 2,100–2,400 m (6,900–7,900 ft), [1] and cover an area of no more than 40,655 ha (157 sq mi). [4]
Mearns's squirrel is diurnal and herbivorous, feeding mainly on the seeds of fir and pine trees. Unlike its closest relatives, such as the Douglas squirrel, it does not hoard food for future use, [3] and it rests in cavities in trees, rather than constructing nests from leaves. [8] The squirrels do not appear to be territorial, and two individuals may sometimes share the same resting cavity. [9] Vocalizations are known to include a high-pitched "rattle", a chirp, and a barking sound. [10]
The mating season lasts from around February to August, with one or two litters of two to five young being born each year. [4]
The southern flying squirrel or the assapan is one of three species of flying squirrel found in North America. It is found in deciduous and mixed woods in the eastern half of North America, from southeastern Canada to Florida. Disjunct populations of this species have been recorded in the highlands of Mexico, Guatemala, and Honduras.
The northern flying squirrel is one of three species of the genus Glaucomys, the only flying squirrels found in North America. They are found in coniferous and mixed coniferous forests across much of Canada, from Alaska to Nova Scotia, and south to the mountains of North Carolina and west to Utah in the United States. They are light brown with pale underparts and grow to a length of 25 to 37 cm. They are proficient gliders but uncoordinated walkers on the ground. They feed on a variety of plant material as well as tree sap, fungi, insects, carrion, bird eggs and nestlings. They mostly breed once a year in a cavity lined with lichen or other soft material. Except when they have young, they change nests frequently, and in winter a number of individuals may huddle together in a shared nest. Unlike most members of their family, flying squirrels are strictly nocturnal.
Pine squirrels are squirrels of the genus Tamiasciurus, in the Sciurini tribe, of the large family Sciuridae.
The Douglas squirrel is a pine squirrel found in western North America, from the Pacific Northwest to central California, with an isolated subspecies in northern Baja California, Mexico. It is sometimes known as the chickaree or pine squirrel, although these names are also used for the American red squirrel. Variant spellings of the common name are Douglas' squirrel and Douglas's squirrel. The Native Americans of Kings River called it the "Pillillooeet", in imitation of its characteristic alarm call.
The American red squirrel is one of three species of tree squirrels currently classified in the genus Tamiasciurus, known as the pine squirrels. The American red squirrel is variously known as the pine squirrel or piney squirrel, North American red squirrel, chickaree, boomer, or simply red squirrel. The squirrel is a small, 200–250 g (7.1–8.8 oz), diurnal mammal that defends a year-round exclusive territory. It feeds primarily on the seeds of conifer cones, and is widely distributed across much of the United States and Canada wherever conifers are common, except in the southwestern United States, where it is replaced by the formerly conspecific southwestern red squirrel, and along the Pacific coast of the United States, where its cousin the Douglas squirrel is found instead.
Abert's squirrel or the tassel-eared squirrel is a tree squirrel in the genus Sciurus native to the southern Rocky Mountains from the United States to the northern Sierra Madre Occidental of Mexico, with concentrations found in Arizona, New Mexico, and southwestern Colorado. It is closely associated with, and largely confined to, mature ponderosa pine forests. It is named in honor of the American naturalist John James Abert; nine subspecies are recognised. It is recognizable by its tufted ears, gray color, pale underparts and rufous patch on the lower back. The squirrel feeds on the seeds and cones of the Mexican pinyon and the ponderosa pine when they are available, but will also take fungi, buds, bark, and carrion. Breeding normally occurs in summer, with a spherical nest being built high in the canopy.
The Bolivian squirrel is a tree squirrel that is endemic to South America. Little is known of the species, which may represent a species complex.
The Amazon dwarf squirrel is a chipmunk-sized tree squirrel native to South America.
Bangs's mountain squirrel is a poorly known species of tree squirrel, that only lives in Costa Rica and Panama. It can be found in mountain rain forests at an altitude between 1,900 and 2,600 metres, and lives mainly in the tree tops, but sometimes on the forest floor as well. One of its habitats is at the summit of the Poás Volcano in Costa Rica, in a Clusia forest that is almost inaccessible to humans.
The Mexican gray squirrel is a tree squirrel in the genus Sciurus native to Guatemala and eastern and southern Mexico. It has been introduced to the Florida Keys.
The Santander dwarf squirrel is a small tree squirrel endemic to Colombia.
The Bhutan giant flying squirrel, also known as the Gray's giant flying squirrel or noble giant flying squirrel, is a species of rodent in the family Sciuridae. This species lives in Himalayan forests and it is one of the largest flying squirrels. Like other flying squirrels, it is mainly nocturnal and able to glide long distances between trees by spreading out its patagium, skin between its limbs.
The forest giant squirrel or Stanger's squirrel is a species of rodent in the family Sciuridae found in Angola, Benin, Burundi, Cameroon, the Central African Republic, the Republic of the Congo, the Democratic Republic of the Congo, Ivory Coast, Equatorial Guinea, Gabon, Ghana, Kenya, Liberia, Nigeria, Rwanda, Sierra Leone, Tanzania, Togo, and Uganda. Its natural habitats are subtropical or tropical moist lowland forests and plantations.
The Caucasian squirrel or Persian squirrel, is a tree squirrel in the genus Sciurus found in temperate broadleaf and mixed forests in south-western Asia.
The Arizona gray squirrel is a tree squirrel, in the genus Sciurus, endemic to the canyons and valleys surrounded by deciduous and mixed forests in eastern Arizona and northern Mexico.
The Mexican fox squirrel is a species of tree squirrel found throughout the Sierra Madre Occidental of Mexico as far south as Jalisco — and northward into the Chiricahua Mountains of southeastern Arizona, U.S.
The Uinta chipmunk or hidden forest chipmunk, is a species of chipmunk in the family Sciuridae. It is endemic to the United States. Formerly known as Tamias umbrinus, phylogenetic studies have shown it to be sufficiently distinct from the eastern chipmunk as to be placed in a separate genus, Neotamias. The same studies have also suggested that Palmer's chipmunk may actually be a subspecies of Uinta chipmunk, although the two are still generally regarded as separate species.
John L. Koprowski, Dean and Professor, Haub School of Environment & Natural Resources, University of Wyoming, mammalogist, conservation biologist, and leading expert on the ecology and conservation of wildlife, especially squirrels, was born in 1961 in Lakewood, Ohio.
Sherman's fox squirrel is a subspecies of the fox squirrel. It lives in the U.S. states of Florida and Georgia in fire-prone areas of longleaf pine and wiregrass, especially around sandhills. A tree squirrel, Sherman's fox squirrel has lost much of its habitat to farming and development. This type of squirrel nests in oak trees using leaves and Spanish moss.
Pallas's squirrel, also known as the red-bellied tree squirrel, is a species of squirrel native to Greater China, India, and Southeast Asia.