Mexican barbed pocket mouse
| Mexican barbed pocket mouse | ||||||||||||
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| Heteromys irroratus | ||||||||||||
| Gray , 1868 |
The Mexican pocket mouse ( Heteromys irroratus , synonym : Liomys irroratus ), also Mexico pocket mouse , is a type of pocket mouse . It is the species with the northernmost distribution area of the genus and occurs in several subspecies from the extreme south of the American state of Texas to the south of Mexico .
features
The Mexican barbed pocket mouse reaches a head-torso length of about 12.5 centimeters in males and 11.9 centimeters in females. The tail becomes about 9.6 to 16.9 inches long and the average weight is about 34 to 50 grams. The ear length is 12 to 15 millimeters and the rear foot length 23 to 37 millimeters. Within the species there are sometimes clear regional differences between the individuals of the various subspecies from the comparatively large Heteromys irroratus guerrerensis to several medium-sized subspecies to the smaller Heteromys irroratus jaliscensis , Heteromys irroratus texensis and Heteromys irroratus torridus . The males are on average significantly larger than the females in all subspecies. The fur of the adult animals is coarse and contains individual stiffened, spiky hairs on the back and on the sides of the body. The back fur is grayish-brown in color and is usually separated from the white side of the abdomen by a sand or pink area. The hair of the back fur is not curly and hardly covers the spiky hair.
The front areas of the soles of the hind feet are sparsely hairy and they have five tubercles. The claw of the second toe of the hind feet is shaped like a spoon, which is probably an adaptation to digging activities. The tail is slightly hairy and darker on the top than on the underside.
The molars have medium-height crowns and the premolars are lower. The tympanic cavities are only slightly flattened. The karyotype consists of 2n = 60 chromosomes (FN = 62).
distribution
The Mexican barbed pocket mouse is the northernmost species of barbed pocket mouse and occurs in several subspecies from the extreme south of the American state of Texas to the south of Mexico . The altitude distribution ranges from sea level to altitudes of 3500 meters.
Way of life
The Mexican barbed pocket mouse lives in different habitats from the steppes and bush regions in northern Mexico through thickets and forests to the cloud forest regions of the Mexican mountain ranges up to heights of 3500 meters. The species is mostly limited to relatively dry habitats, but the subspecies Heteromys irroratus guerrerensis in particular occurs in moist cloud forest regions. In regions in which the Mexican barbed pocket mouse occurs sympathetically with the colored barbed pocket mouse ( Heteromys pictus ), it lives in the drier heights, while the colored barbed pocket mouse can be found in the moister lowland regions . Despite the drought adaptation, the Mexican quill vole does not occur in arid areas with rainfall below 500 mm per year.
The animals are nocturnal and live on the ground. They build nests, the entrances of which are often covered with leaves or other plant material. They are active all year round and feed primarily on seeds, but also on green parts of plants and insects. They transported the food in their fur-lined cheek pouches and store them in their burrows. The animals also need access to water.
The animals are probably primarily solitary and the males mate with several females. The litter of the animals consists of two to eight, on average four to five, young animals, with the breeding season taking place throughout the year with a peak in the number of litters in August.
Systematics
The Mexican pocket mouse is classified as an independent species within the genus of the pocket mouse ( Heteromys ), which consists of 16 species. The first scientific description comes from John Edward Gray from 1868, who introduced the species on the basis of individuals from Oaxaca in Mexico. Gray already assigned the species to the genus Heteromys in the first description , later it was assigned to the genus Liomys together with other species , which is now considered paraphyletic and has been dissolved. Within the genus, the Mexican barbed pocket mouse forms a group of species with the colorful barbed pocket mouse ( Heteromys pictus ) and the Jalisco barbed pocket mouse ( Heteromys spectabilis ).
Within the species, seven subspecies are distinguished together with the nominate form :
- Heteromys irroratus irroratus Gray, 1868 : nominate form; occurs in southern Mexico in central and southern Oaxaca.
- Heteromys irroratus alleni Coues , 1881 : occurs in north-central to northeastern Mexico in the north of the Trans -Mexican volcanic belt (Sierra Volcánica Transversal), from the south of Chihuahua to the north of Michoacán and Tlaxcala and the north of the Sierra Madre Oriental in Nuevo León and the southwest of Tamaulipas .
- Heteromys irroratus bulleri Thomas , 1893 : lives in western and central Jalisco .
- Heteromys irroratus guerrerensis Goldman , 1911 : lives in southwest Mexico in the west of Guerrero in the cloud forest of the Pacific foothills of the Sierra Madre del Sur
- Heteromys irroratus jaliscensis J.A. Allen , 1906 : occurs in Jalisco, south of Zacatecas and southern Nayarit .
- Heteromys irroratus texensis Merriam , 1902 : occurs as the northernmost subspecies from the south of the American state of Texas to northeastern Mexico in the states of Puebla and Veracruz .
- Heteromys irroratus torridus Merriam, 1902 : lives in southern Mexico south of the transmexican volcanic belt in southern Puebla, in Morelos , in Guerrero and in the north of Oaxaca.
Investigations on molecular biological data of the mtDNA suggest that there are three related clusters within the species and thus possibly two not yet described cryptic species . It is assumed that especially Heteromys irroratus guerrerensis as well as the currently not recognized Heteromys irroratus acutus listed under Heteromys irroratus alleni could represent independent species.
Status, threat and protection
The Mexican quill mouse is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as “not endangered” (least concern). The habitats in the forest areas are decreasing and it is assumed that the population sizes of the species are also declining, but there are no known threats that could endanger the population.
supporting documents
- ↑ a b c d e f g h i j k l Mexican Spiny Pocket Mouse. In: David J. Hafner: Subfamily Heteromyoninae, Genus Heteromys. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (editors): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 196. ISBN 978-84-941892-3-4 .
- ↑ a b c Heteromys irroratus in the Red List of Threatened Species of the IUCN 2018. Posted by: I. Castro-Arellano, R. Timm, ST Álvarez-Castañeda, 2016. Retrieved January 6, 2019.
- ↑ a b c d Liomys irroratus . 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 .
- ^ Duke S. Rogers, Victoria L. Vance: Phylogenetics of Spiny Pocket Mice (Genus Liomys): Analysis of Cytochrome b Based on Multiple Heuristic Approaches. Journal of Mammalogy 86 (6), December 14, 2005; Pp. 1085-1094. doi : 10.1644 / 04-MAMM-A-185R3.1
- ↑ John C. Hafner, Jessica E. Light, David J. Hafner, Mark S. Hafner, Emily Reddington, Duke S. Rogers, Brett R. Riddle: Basal Clades and Molecular Systematics of Heteromyid Rodents. Journal of Mammalogy 88 (5) October 18, 2007; Pp. 1129-1145. doi : 10.1644 / 06-MAMM-A-413R1.1
literature
- Mexican Spiny Pocket Mouse. In: David J. Hafner: Subfamily Heteromyoninae, Genus Heteromys. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (editors): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 196. ISBN 978-84-941892-3-4 .
Web links
- Heteromys irroratus in the endangered Red List species the IUCN 2018 Posted by: I. Castro-Arellano, R. Timm, ST-Álvarez Castañeda, 2016. Retrieved on January 6 of 2019.