Scarturus elater (Lichtenstein, 1825)
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publication ID |
https://doi.org/ 10.5281/zenodo.6591722 |
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DOI |
https://doi.org/10.5281/zenodo.6591634 |
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persistent identifier |
https://treatment.plazi.org/id/482287C8-ED56-7D75-B180-FD85CAEE7607 |
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treatment provided by |
Felipe |
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scientific name |
Scarturus elater |
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Small Five-toed Jerboa
French: Gerboise meneuse / German: Kleiner Pferdespringer / Spanish: Jerbo pentadactilo pequeno
Other common names: Five-toed Jerboa
Taxonomy. Dipus elater Lichtenstein, 1825 ,
“ Von den Kisten des Aral-Sees [= north coast of Aral Sea],” Kyzylorda Region, Kazakhstan .
Previously included in the genus Allactaga and later Paralactaga, which has recently been found to be a junior synonym of Scarturus . Morphologically and genetically, S. elateris in the subgenus Microallactaga, the sister group of subgenus Paralactaga. Molecular reconstructions retrieved at least three deeply divergent partially sympatric lineages in Iran and Kazakhstan that are definitely separate cryptic species, but current knowledge does not allow delineation of these forms and estimation of level of genetic heterogeneity within each of them. Forms aralychensis and indicus are probably separate species. Six subspecies recognized.
Subspecies and Distribution.
S.e.aralychensisSatunin,1901—Armenia,Azerbaijan(Nakhichevan),extremeETurkey(Aralik),andNW&CIran.
S.e.caucasicusNehring,1900—SEGeorgiaandAzerbaijan.
S.e.indicusGray,1842—SETurkmenistan,Afghanistan,EIran,andWPakistan.
S. e. zausanicus Shenbrot, 1991 — E Kazakhstan (Lake Zaysan Basin), NW China (N Dzungarian Basin in Xinjiang), and SW Mongolia. View Figure
Descriptive notes. Head—body 90-120 mm, tail 140-190 mm, ear 28-41 mm, hindfoot 43-58 mm; weight 32-77 g. There is no significant secondary sexual dimorphism. Condylo-basal lengths of skulls are 24-27-7 mm, zygomatic breadths are 18-4-21-7 mm, and maxillary tooth row lengths are 4-4-5-5 mm. Head and dorsum vary from clayish gray to sandy gray, with different mixtures of sandy yellow, pinkish, or ocherous; sides and ventral pelage are pure white; and tail banner is wide and well flattened, with short (5—15 mm) white, whitish, or ocherous basal ring sometimes with narrow longitudinal dorsal dark strip, relatively long (20-35 mm) black subterminal field, and mediumlength (15-20 mm) white terminal tuft. Toes of hindfeet are naked from below; conic calluses at bases of toes are large and high, with medium-width bases and rounded apexes. Auditory bullae are distinctly but not strongly inflated. Mastoid cavity is medium-sized and not subdivided into sections; tympanic cavity is extremely small. Front surfaces of incisors are white; incisors are weakly deflected forward. P' is 1-4—1-8 times smaller in diameter than M®. Molars are medium-crowned, with terraced masticatory surfaces; crown heights of unworn molars are 80-100% of their lengths. Glans penis is heart-shaped, 2-8-4 mm long and 1-2-2-5 mm wide, markedly compressed in dorsoventral direction, subdivided by deep longitudinal dorsal fold into two lateral lobes; surfaces of lobes are covered by single-vertex, backward-directed aciculae increasing in size in backward direction; and aciculae cover all surfaces of lobes and are arranged in 3-4 concentric rows with 6-8 aciculae in each row (elatertype) or aciculae cover only distal part of lobes and are arranged in two concentric rows with 5-7 aciculae in each row (indicus-type). Os penis (baculum) is absent. Chromosomal complement has 2n = 48 and FN = 96.
Habitat. Desert and semi-desert zones, avoiding only large open spaces completely lacking shrubs and areas with very dense vegetation. The Small Five-toed Jerboa does not live in sand but is able to cross sandy areas and occupy small patches of hard soil in large sand massifs.
Food and Feeding. Diets of Small Five-toed Jerboas vary geographically and seasonally. In northern parts of the distribution, they feed mainly (c.80% by volume) on seeds, but in southern parts, seeds and green plant parts are eaten in equal proportions. Insects and underground plant parts are consistent but minor parts of the diet. Small Five-toed Jerboas mainly eat green plant parts in early spring and late summer and seeds in late spring, early summer, and autumn. Local lists of forage plants include 21-58 species of shrubs, grasses, and forbs.
Breeding. Breeding patterns of Small Five-toed Jerboas vary geographically. In western and northern parts of the distribution, breeding usually peaks in spring and late summer/early autumn, with a mid-summer interruption. In southern parts of the distribution, breeding also peaks in early summer. Litters have 1-9 young (average range 3-8-5-6). Overwintering females produce 2-3 litters/year. Yearlings born in spring become sexually matured in the next autumn at 2-5-3-5 months old; those born in autumn mature at the end of the next spring at c.9 months old. Gestation was estimated by different authors at 20-21 days. Young nurse for 35-40 days.
Activity patterns. The Small Five-toed Jerboa is crepuscular and nocturnal. Most individuals become active at dusk, 15-25 minutes after sunset. In spring and summer, individuals are active all night, but in autumn, their activity is usually limited to the first one-half of the night. Hibernation in Kazakhstan and Central Asia lasts 2-5—4-5 months from mid-October to early December to mid-February/March, with interruptions during thaws. In Azerbaijan, hibernation was not recorded, but aboveground activity decreased in winter.
Movements, Home range and Social organization. When moving slowly, Small Fivetoed Jerboas use bipedal pacing with alternating support by left and right hindfeet. At medium speeds and when running fast, they use asynchronous ricochet jumps. Maximum hop is 202 cm, and maximum speed is 8:3 m/s. Escape behavior is characterized by running fast, with frequently changes in direction, vertical jumps, jumps into shrub canopy, and finally hiding under a shrub. Use of burrows as night shelters is relatively rare. At high density, mean home range is 1-1 ha for males and 0-81 ha for females, and home ranges widely overlap regardless of sex. At low density, home ranges can be 4-6-40 ha; home ranges of females marginally overlap, and home range of an adult male usually overlaps home ranges of 1-3 females. Summer burrows are simple and usually have one main tunnel starting at the ground’s surface, typically with a plugged entrance and ending in a nest chamber 10-13 cm in diameter and 10-115 cm deep (usually 40-70 cm); lengths of tunnels are 45-300 cm. In most cases, burrows have 1-2 additional tunnels ending with emergency exits and several (up to seven) additional chambers. Winter burrows are similar in construction to summer burrows, but they are deeper (110-160 cm) and have special hibernation chambers. Small Five-toed Jerboas usually do not build special night shelter burrows but use burrows of other rodents as night shelters. In the wild, they are mainly solitary but relatively frequently can be seen in groups of 2-3 individuals. Interactions in the wild are aggressive c.35% of the time; mutual avoidance is typical. In lab conditions, interactions between individuals of the opposite sex include naso-nasal and naso-anal contact and mutual cleaning.
Status and Conservation. Classified as Least Concern on The IUCN Red List (as Allactaga elater ).
Bibliography. Colak &Yigit (1998b), Dianat et al. (2013), Krystufek & Vohralik (2005), Lay (1967), Moshtaghi et al. (2016), Shenbrot et al. (2008).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
