Stain paver
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Spotted burrower ( Xerospermophilus spilosoma ) |
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| Xerospermophilus spilosoma | ||||||||||||
| ( Bennett , 1833) |
The spotted squirrel ( Xerospermophilus spilosoma , syn .: Spermophilus spilosoma ) is a species of squirrel from the genus Xerospermophilus . It occurs from the southwestern United States to the north and central Mexico .
features
The fleckenziesel reaches a head-trunk length of about 18.5 to 25.3 centimeters, the tail is about 55 to 92 millimeters long and is thus significantly shorter than the rest of the body. The weight is 100 to 200 grams. The animals have a gray, cinnamon-colored to brown or reddish color on their backs, which is interspersed with a distinct mottling with white to light sand-colored spots. The animals show a great variability in coloration and spotting. The ventral side is whitish, light cinnamon or pink-sand colored. The color of the tail corresponds to the color of the back, but becomes darker red-brown to black towards the tip of the tail, the underside is cinnamon-brown in the middle.
distribution
The spotted squirrel occurs in the United States from southeastern Wyoming and southwestern South Dakota through Texas , Arizona and New Mexico to the north and central Mexico . In Mexico, the species is native to northern Sonora , Chihuahua and Coahuila south to northern Jalisco , northern Guanajuato and Tamaulipas .
Way of life
The spotted squirrel is diurnal and lives in dry, sandy habitats with sparse vegetation such as desert grasslands, bushland, heavily grazed areas, sand dunes, sandy coastal areas and grassy ruderal areas, cemeteries and school areas in residential areas. It is omnivorous and, like other ground squirrels, its food consists primarily of different parts of plants such as buds, sprouts, flowers and leaves as well as seeds, insects and small vertebrates. Like other ground squirrels, the animals live on the ground and in simple underground burrows up to a meter deep. Depending on the region, the animals usually overwinter for several, usually seven to eight months. This not very deep hibernation begins in the adult animals in July to August, in the young animals in late September and lasts until early spring. The young of the previous year wake up before the adult males, these leave their burrows about two to three weeks before the females. The activity range is relatively large for both sexes, it is about 1.0 to 4.9 hectares for the males and 0.5 to 1.6 hectares for the females. The density of the buildings and thus the population density is relatively small.
The mating season begins after the females have awakened in March. During the mating season, the males behave very territorially and aggressively towards other conspecifics. The gestation period lasts about 28 days, after which the females throw five to eight young animals in the burrow. The young animals leave the den for the first time after three to four weeks, and weaning takes place after another three weeks.
The most important predators for the fleckenziesel are martens, dogs, birds of prey and snakes.
Systematics
The fleckenziesel is classified as an independent species within the genus Xerospermophilus , which consists of four species. The species has long been classified as part of the ground squirrel and, like the Perote ground squirrel, within the subgenus Ictidomys . After a comprehensive molecular biological investigation, however, both species were assigned to the now independent genus Xerospermophilus . The first scientific description comes from the British zoologist Edward Turner Bennett from 1833. He described the species as Spermophilus spilosoma on the basis of individuals from the region around the city of Victoria de Durango , today in the Mexican state of Durango in Mexico. In 1863 Robert Kennicott described a new species of the genus with Spermophilus obsoletus from Nebraska , which today as well as the two species Spermophilus canescens and Spermophilus cryptospilosus described by Clinton Hart Merriam in 1890 are considered as taxonomic synonyms and subspecies.
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Phylogenetic system of the genus Xerospermophilus according to Fernández 2012
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In a phylogenetic study with a focus on the relationship of the Perote ground squirrel, the spot ground squirrel was identified as a sister species of the Perote ground squirrel and compared to the other two species of the genus, the Mojave ground squirrel and the round-tailed ground squirrel. Within the species, together with the nominate form, thirteen subspecies are distinguished:
- Xerospermophilus spilosoma spilosoma : nominate form; in the Mexican state of Durango.
- Xerospermophilus spilosoma altiplanensis : high altitude in the western and central state of Chihuahua. The back color is dark and yellowish.
- Xerospermophilus spilosoma ammophilus : in the extreme north of the state of Chihuahua. It is a very light, pale shape found in the sand dunes around Ciudad Juárez .
- Xerospermophilus spilosoma annectens : in southern Texas and on the Rio Grande in the USA. The color corresponds to the nominate shape, but the skull is longer, has a narrower skull base and is wider in the area of the eyes.
- Xerospermophilus spilosoma bavicorensis : endemic to the basin of the Laguna de Babícora in Chihuahua. The subspecies is large and has an unusually black coat for the species.
- Xerospermophilus spilosoma cabrerai : in San Luis Potosí and the surrounding area in central Mexico. The shape is large and dark. The first description was in 1951 as Citellus spilosoma cabrerai by the American zoologist Walter Woelber Dalquest , who caught the animals near Nuñez in San Luis Potosí.
- Xerospermophilus spilosoma canescens : from south-central New Mexico via Texas to Coahuila in Mexico. The shape has a reddish tinge with distinct speckles on the back, with the back spots being larger and more numerous. The subspecies was introduced in 1890 by Clinton Hart Merriam as a separate species Spermophilus cryptospilosus .
- Xerospermophilus spilosoma cryptospilotus : In the quadrangle of Arizona, Utah, Colorado and New Mexico. The shape is pale and rather reddish with noticeable spots on the back. The subspecies was introduced in 1890 by Clinton Hart Merriam as a separate species Spermophilus canescens .
- Xerospermophilus spilosoma marginatus : in southeastern Colorado and southwestern Kansas, New Mexico, western Texas and bordering Oklahoma. The speckles on the back are reduced, the back color is pale and gray with a reddish tinge.
- Xerospermophilus spilosoma obsoletus : in southeastern Wyoming, northeastern Oklahoma, western Nebraska, and northwestern Kansas. The rather gray-brown form has less distinct to indistinct spots. In 1863 Robert Kennicott described this subspecies as a separate species Spermophilus obsoletus from Nebraska .
- Xerospermophilus spilosoma oricolus : in the coastal area of Tamaulipas in Mexico. The shape is clearly spotted, the hind legs are cinnamon brown-sand colored.
- Xerospermophilus spilosoma pallescens : in central Mexico. The shape is darker in the back area and has very small spots.
- Xerospermophilus spilosoma pratensis : in northern Arizona. The shape is small with a short tail, the back and the tip of the tail are dark. The subspecies was also introduced by Clinton Hart Merriam in 1890.
Status, threat and protection
The European Union for Conservation of Nature and Natural Resources (IUCN) classifies the spotted peas as not endangered (least concern). This is justified by the relatively large distribution area, the assumed large populations and the ability to colonize a wide range of habitats. The species is relatively common in the region; potential causes of danger are not known.
supporting documents
- ↑ a b c d e f g h i j Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 368-369. ISBN 978-1-4214-0469-1
- ↑ a b c Xerospermophilus spilosoma in the IUCN Red List of Threatened Species 2015.4. Posted by: AV Linzey, R. Timm, ST Álvarez-Castañeda, I. Castro-Arellano, T. Lacher, 2008. Retrieved May 18, 2016.
- ↑ Matthew D. Herron, Todd A. Castoe, Christopher L. Parkinson: Sciurid phylogeny and the paraphyly of holarctic ground squirrels (Spermophilus). Molecular Phylogenetics and Evolution 31, 2004; Pp. 1015-1030. ( Full text , PMID 15120398 )
- ↑ Kristofer M. Helgen, F. Russell Cole, Lauren E. Helgen, Don E. Wilson: Generic Revision in the holarctic ground squirrels genus Spermophilus. Journal of Mammalogy 90 (2), 2009; Pp. 270-305. doi : 10.1644 / 07-MAMM-A-309.1
- ↑ a b Spermophilus (Ictidomys) spilosoma In: Don E. Wilson , DeeAnn M. Reeder (Ed.): 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 .
- ↑ a b c d e f Donald P. Streubel, James P. Fitzgerald: Spermophilus spilosoma. Mammalian Species 101, 1978; Pp. 1-4. ( Full text )
- ^ A b Jesús A. Fernández: Phylogenetics and biogeography of the microendemic rodent Xerospermophilus perotensis (Perote ground squirrel) in the Oriental Basin of Mexico. Journal of Mammalogy 93 (6), 2012; Pp. 1431-1439. doi : 10.1644 / 11-MAMM-A-409.1
- ↑ Walter Wölber Dalquest : Two new mammals from central Mexico. Proceedings of the Biological Society of Washington 64, 1951; Pp. 105-107. ( Full text ).
- ^ Robert Kennicott: Descriptions of four new species of Spermophilus, in the collections of the Smithsonian Institution. Academy of Natural Sciences of Philadelphia Proceedings, 1863; Pp. 157-158. ( Digitized version )
literature
- Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 368-369. ISBN 978-1-4214-0469-1
- Donald P. Streubel, James P. Fitzgerald: Spermophilus spilosoma. Mammalian Species 101, 1978; Pp. 1-4. ( Full text )
Web links
- Xerospermophilus spilosoma inthe IUCN Red List of Threatened Species 2015.4. Posted by: AV Linzey, R. Timm, ST Álvarez-Castañeda, I. Castro-Arellano, T. Lacher, 2008. Retrieved May 18, 2016.