Baja California ground squirrel
| Baja California ground squirrel | ||||||||||||
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| Otospermophilus atricapillus | ||||||||||||
| Bryant , 1889 |
The Baja California ground squirrel ( Otospermophilus atricapillus , syn .: Spermophilus atricapillus ) is a species of squirrel from the genus Otospermophilus . He lives exclusively on the Baja California peninsula, which belongs to Mexico .
features
The Baja California ground squirrel reaches a head-torso length of about 23.0 to 30.0 centimeters and weighs 230 to 500 grams. The tail becomes about 20 centimeters long and is thus shorter than the rest of the body, but very long and pronounced compared to other ground squirrels. The species of the genus have a brown speckled to blotchy back, which results from the brown-sand-colored banding of the back hair. A noticeable feature of the Baja California ground squirrel is a dark, triangular spot that extends from the back of the head over the neck and front back. The hair on the back and tail is black at the base and whitish-pink-sand-colored at the top. The animals have a light eye ring around their eyes. The species differs from the rock ground squirrel ( Otospermophilus variegatus ) by the back spot, compared to the California ground squirrel ( Otospermophilus beecheyi ) both have a significantly longer tail.
distribution
The Baja California Ground Squirrel is endemic to the peninsula Baja California in the Mexican state of Baja California Sur (South Baja California). According to alternative sources, it is also found in the extreme south of Baja California .
Way of life
The Baja California ground squirrel lives mainly in mountainous regions of volcanic origin with dry bush vegetation. The typical vegetation of the habitat include various cactus as Pachycereus pringlei , Cylindropuntia cholla , the Organ Pipe Cactus ( Stenocereus thurberi ) and Stenocereus gummosus and other desert plants such as Prosopis juliflora , lysiloma candida , Bursera cerasiflora and Jatropha cinerea . As a habitat specialist, the ground squirrel is very fragmented within its range, although the animals can mainly be found near waterholes in the Gigantas Sierra and Sierra de San Francisco .
Little information is available about the way of life and few observations have been made on the behavior and ecology of the Baja California ground squirrel. As with other species of ground squirrel, the diet probably consists mainly of vegetation and available seeds and insects. Since the animals were also caught in winter, they are likely to be active year round or only have a short winter break. Predators are probably coyotes ( Canis latrans ), and Enderleinellus orboni is a known species of animal lice that parasitizes the Baja California ground squirrel.
Systematics
The Baja California ground squirrel is classified as an independent species within the genus Otospermophilus . The species has long been classified as part of the ground squirrel and within the subgenus Otospermophilus , but after a comprehensive molecular biological investigation this was considered as an independent genus together with several other genera. The first scientific description comes from the American zoologist Walter E. Bryant from the year 1889. He described the species as a subspecies of the rocky ground squirrel under the name Spermophilus grammurus atricapillus based on individuals from the Comondú region on the Baja California peninsula. In 1959 it was first viewed as a separate species Spermophilus atricapillus by Hall and Kelson .
The rock squirrel is considered a sister species of Baja California Ziesels, but in molecular biological investigations on could mitochondrial DNA lying cytochrome b sequences no significant differences are identified; the sequence differences of the Baja California ground squirrel were within the genetic variance of the rock ground squirrel.
Apart from the nominate form, no subspecies are distinguished within the species .
Status, threat and protection
The Baja California ground squirrel is endangered by the International Union for Conservation of Nature and Natural Resources (IUCN), which lists the Baja California ground squirrel as a subspecies of the California ground squirrel ( Otospermophilus beecheyi ). However, there are no concrete numbers available. This is justified by the limited distribution area with an area of less than 5000 km 2 and the strong fragmentation of the habitats. In addition, a decrease is assumed due to the hunting of the animals, in some areas the species is considered a pest on pumpkin and Datil plantings.
supporting documents
- ^ A b 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 c d e f g Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 292-293. ISBN 978-1-4214-0469-1
- ↑ a b c d Otospermophilus beecheyi ssp. atricapillus in the IUCN Red List of Threatened Species 2015.1. Posted by: ST Álvarez-Castañeda, I. Castro-Arellano, T. Lacher, 2008. Accessed June 25, 2015.
- ↑ 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 )
- ↑ a b Spermophilus atricapillus 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 .
- ↑ Sergio Ticul Alvarez-Castañeda, Gustavo Arnaud, Eric Yensen: Spermophilus atricapillus. Mammalian Species 521, 1996; Pp. 1-4. ( Full text ( memento from June 26, 2015 in the Internet Archive ))
- ↑ Sergio Ticul Alvarez-Castañeda, Patricia Cortés-Calva: Genetic evaluation of the Baja California rock squirrel Otospermophilus atricapillus (Rodentia: Sciuridae). Zootaxa 3138, 2011; Pp. 35-51. ( Full text ( memento from June 26, 2015 in the Internet Archive ))
literature
- Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 292-293. ISBN 978-1-4214-0469-1
