Southwestern red squirrel
| Southwestern red squirrel | ||||||||||||
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Southwestern red squirrel |
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| Tamiasciurus Fremdonti | ||||||||||||
| Audubon & Bachman , 1853 |
The Southwest American Red Squirrel ( Tamiasciurus fremonti ; synonym : Tamiasciurus hudsonicus fremonti ) is a type of red squirrel ( Tamiasciurus ) within the croissant (Sciuridae). It lives in the central United States east of the Rocky Mountains . The species has long been considered a subspecies of the common red squirrel ( Tamiasciurus hudsonicus ), but is now considered a separate species.
features
The south-western red squirrel reaches a head-body length of 19.4 to about 21.9 centimeters and a tail length of 10.4 to 14.6 centimeters with an average weight of 220 to 240 grams. The fur is reddish-brown to olive-gray with a light to pale reddish band, which is particularly noticeable in the olive-gray individuals. The belly side is white to creamy white and is separated from the back side by a coal black stripe on the sides of the body. The eyes are usually surrounded by a white to sand-colored eye ring and the muzzle and chin are also white to sand-colored. In winter the ears can have black tufts of ears, and light spots are often also formed behind the ears. The tail corresponds in color to the back with individual white to creamy white hairs; the underside of the tail is usually red.
The karyotype consists of a chromosome set of 2n = 46 chromosomes.
distribution
The southwestern red squirrel occurs in four subspecies in the central United States east of the Rocky Mountains . The distribution area extends from the east of Colorado and the southeast of Utah over Arizona to New Mexico and Texas .
Way of life
The species lives in coniferous and mixed forests, which are dominated by pines , spruces and firs and have a closed canopy. In some areas, the animals are also found in open parklands, secondary forests, and in urban and suburban areas with tall trees.
The southwestern red squirrel is diurnal with an activity maximum around noon. It is also active all year round and only takes short periods of rest in winter in extreme weather conditions . Like most tree squirrels, it feeds primarily on different seeds ( granivores ). As an opportunistic omnivorous animal, however, it also eats other parts of the plant such as buds, flowers and fruits, as well as animal food such as insects, bird eggs and nestlings as well as carrion. In addition, above-ground and underground mushrooms are often eaten, especially in late summer. The animals collect cones and seeds and set up camps in the area of large trees, under branches, in litter and in the ground, which serve as winter supplies. They are not very social and defend their territories as territories against conspecifics. The districts usually have an area of less than one hectare , but can also be significantly smaller or larger depending on the resources and population density. In most habitats, the population density is 0.8 to 1.3 individuals per hectare. The defense usually consists of aggressive noises, posing and stamping the feet; very seldom there are fights between the animals. In winter it happens that individual adult animals, mostly females, share a nest. His alarm calls, for example in the event of threats from potential predators, consist of a series of loud and high-pitched calls.
The animals build nests in the branches of the trees, in tree hollows and, more rarely, in abandoned animal burrows in which they raise their young. The females have a very short mating period after ovulation , during which they mate with several males. They usually have one litter, more rarely two, per year and usually give birth to 2 to 4 young animals. The young animals leave the nest for the first time after about 7 to 8 weeks and are suckled by the mother for about 14 weeks. A few weeks after weaning, they leave the mother and spread out.
Systematics
The southwestern red squirrel is classified as an independent species within the genus of the red squirrel ( Tamasciurus ), which consists of about three species. The first scientific description of the species comes from the American naturalists John James Audubon and John Bachman from the Rocky Mountains in 1853 without a specific location. The species is partially regarded as a subspecies of the common red squirrel ( Tamiasciurus hudsonicus ) and thus as Tamiasciurus hudsonicus Fremdonti , but is now considered an independent species.
Within the species, four subspecies are distinguished with the nominate form :
- Tamasciurus Fremdonti Fremdonti Audubon & Bachman, 1853 : nominate form; occurs in eastern Colorado and southeastern Utah.
- Tamasciurus Fremonti grahamensis J.A. Allen, 1894 : occurs at Mount Graham in southeast Arizona.
- Tamasciurus Fremdonti lychnuchus Stone & Rehn, 1903 : occurs in central and southeastern New Mexico and in northern Texas.
- Tamasciurus Fremdonti mogollonensis Mearns, 1890 : occurs in central, northern and western Arizona.
Status, threat and protection
The Southwest Red Squirrel is not listed as an independent species by the International Union for Conservation of Nature and Natural Resources (IUCN) (as of April 2020). The animals are comparatively common, especially in the northern part of their range, less common in the southern part and usually isolated and isolated due to the fragmented habitats. They usually respond to fragmentation caused by roads and deforestation with a retreat, and forest fires pose a threat to populations in dry forests .
The subspecies Tamasciurus Fremdonti grahamensis occurs only at Mount Graham in southeastern Arizona, and it is assumed that there are fewer than 300 individuals.
supporting documents
- ↑ a b c d e f g h i j k l J.L. Koprowski, EA Goldstein, KR Bennett, C. Pereira Mendes: Fremont's Squirrel Tamiasciurus Fremonti. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 740 , ISBN 978-84-941892-3-4 .
- ↑ a b c Tamiasciurus hudsonicus Fremdonti . In: Don E. Wilson , DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
- ^ Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 80-83. ISBN 978-1-4214-0469-1
literature
- JL Koprowski, EA Goldstein, KR Bennett, C. Pereira Mendes: Fremont's Squirrel Tamiasciurus Fremonti. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 740 , ISBN 978-84-941892-3-4 .