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Spalax ehrenbergi
Middle East blind mole rat
(Also: Palestine mole rat)


By Nicole Santarosa and Phill Moll

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Rodentia
Family: Spalacidae
Genus: Spalax
Species: Spalax ehrenbergi

Geographic Range

Spalax ehrenbergi is widely distributed in the eastern Mediterranean region, from northeastern Libya through Egypt, Jordan, Syria, and southern Turkey. Within this region, these mole rats are found in fragmented areas with appropriate soils for burrowing. (Hutchins, 2004; Schlitter, et al., 2008)

Biogeographic Regions
palearctic (Native )

Habitat

Range elevation
0 to 2000 m
(0.00 to 6561.68 ft)

Though Middle East blind mole rats are not found in desert areas, they seem to prefer habitats with sandy and loamy soils. They are strictly fossorial and inhabit dry steppes, semi-desert, and agricultural areas, especially cultivated fields. They spend the vast majority of their lives in their underground burrows and tunnel systems. These are complex, with nesting chambers, storage areas, tunnels used for foraging, and aboveground mounds with sleeping chambers. Burrows are dug deeper in the hot months of the year. (Dewey, 2003; Hutchins, 2004; Schlitter, et al., 2008)

Habitat Regions
temperate ; terrestrial

Terrestrial Biomes
savanna or grassland ; chaparral

Other Habitat Features
agricultural ; riparian

Physical Description

Range mass
250 to 400 g
(8.81 to 14.10 oz)

Range length
150 to 270 mm
(5.91 to 10.63 in)

Range basal metabolic rate
0.62 to 1.03 cm^3 oxygen/hour

Middle East blind mole rat body length ranges from 150 to 270 mm and the pelage is bluish, dark gray. They are characterized by their lack of an external tail, pinnae reduced to small ridges, and subcutaneous eyes. Other fossorial morphological adaptations include robustly built and streamlined bodies with large heads, powerful limbs, and small claws. Males are larger than females. (Dewey, 2003; Hutchins, 2004; Schlitter, et al., 2008)

The dental formula for Spalax ehrenbergi is 1/1, 0/0, 0/0, 3/3 = 16. The two large incisors are orthodont and are oriented in front of the lips so that the incisors can be used to dig even when the mouth is closed. The cheek teeth are rooted and display enamel patterns that resemble the letters "z" and "s." (Hutchins, 2004; Musser and Carleton, 2005)

Spalax ehrenbergi has a highly polymorphic karyotype with over 30 chromosomal forms. It has been posited that some of these forms are likely to be distinct species. It has been suggested that at least four distinct cryptic species (Spalax carmeli, Spalax galili, Spalax golani, and Spalax judae) exist. (Musser and Carleton, 2005; Nevo and Shkolnik, 1974)

Other Physical Features
endothermic ; homoiothermic; bilateral symmetry ; polymorphic

Sexual Dimorphism
male larger

Reproduction

Females only mate with one male for each breeding season, but may mate with different males throughout their lifetime, making them serially monogamous. Spalax ehrenbergi mating behavior is categorized into three stages: agonistic, courtship, and copulation. Courtship takes place during the winter season, which is the only time males and females will be found in overlapping territory. This species is highly aggressive, with severe aggressive displays occurring within and between the sexes. Due to their aggressive nature, courtship is a very long process involving the male and female engaging in repeated mating displays until their aggressive behavior is attenuated. Seismic signaling is used to initiate the first contact between the male and female's respective burrows. This involves both males and females drumming their heads against the ceilings of their burrows to create vibrations. The mating pair begins with face-to-face touching of their incisors which proceeds to nibbling and courtship calls, which contributes to reducing the intensity of the aggressive displays between the pair. After the courtship ritual the male will dig a “copulation hollow” which is where the actual mating will take place. After the pair becomes habituated to the hollow the female will initiate copulation by turning her back towards the male. Immediately after copulation the male will fill in the “copulation hollow” and the pair will separate and return to solitary lifestyles. (Dewey, 2003; Gazit and Terkel, 2000; Heth, et al., 1987; Nevo, 1969; Zuri and Terkel, 1998)

Mating System
monogamous

Breeding interval
Females seem to breed once yearly.

Breeding season
Middle East blind mole rats breed in the winter, from November to March.

Range number of offspring
1 (low)

Average number of offspring
3 to 4

Average gestation period
34 days

Range time to independence
4 to 6 weeks

Middle East blind mole rats breed in the winter, from November to March. Females construct elaborate breeding mounds and nesting chambers in preparation for breeding. Gestation lasts 34 days and the average litter size is 3 to 4 (range 1 to 5) pups. Young are born from January to April. As the offspring develop, aggressive interactions between the pups increase to the point where they are forced to disperse from each other. Once the pups begin dispersing, the mother reciprocates aggressive displays to aid in kin dispersal and ensure her young do not attempt to settle in her territory. Young are independent at 4 to 6 weeks old. Time to first reproduction is not reported, but is likely to be within their first year of life. (Dewey, 2003; Gazit and Terkel, 2000; Heth, et al., 1987; Nevo, 1969; Zuri and Terkel, 1998)

Key Reproductive Features
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous

Females provide sole parental care. In a study done by Gazit and Terkel (2000), males exhibited limited parental care and intermittently brought food to the female’s territory if the males had acquired a large food surplus during the wet season. The young are born naked and helpless but develop quickly, leaving the nest and becoming independent at 4 to 6 weeks old. (Dewey, 2003; Gazit and Terkel, 2000; Zuri and Terkel, 1998)

Parental Investment
altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)

Lifespan/Longevity

Range lifespan
Status: wild

4.5 (high) years

Average lifespan
Status: wild

3 years

Range lifespan
Status: captivity

15 (high) years

Middle East blind mole rats lives around 3 years in the wild, but can live up to 15 years in captivity. Maximum lifespan in the wild is given as 4.5 years. (Dewey, 2003; Heth, et al., 1988)

Behavior

Middle East blind mole rats are fossorial and highly aggressive. Generally single individuals occupy burrow systems and they are quite territorial. Middle East blind mole rats are active during the day. Middle East blind mole rats dig complex underground burrows and establish complex networks of tunnels in pursuit of food. (Heth, et al., 1988; Nevo, et al., 1975; Zuri and Terkel, 1998)

Key Behaviors
fossorial ; diurnal ; sedentary ; solitary ; territorial

Home Range

Home range size (burrow extent) is not reported in the literature.

Communication and Perception

Middle East blind mole rats are completely blind, their eyes being beneath a layer of skin. They rely heavily on vocalizations, olfaction, and touch. Six distinct vocalizations are used: attack, crying, invitation, courting, release, and threat calls. Courtship calls consist of a low murmur that reduces aggression between potential mates. All Spalax ehrenbergi calls are at a low frequency and are specialized for low frequency hearing. Head thumping against tunnel ceilings is also used in vibrational communication, which has shown to be advantageous in long distance communication and is used to signal territoriality and initiate mating rituals. Although the eyes of Spalax ehrenbergi are not used for visual purposes, they are still photoreceptive. In a study done by Sanyal et al. (1990), it was shown that the eyes are used for detecting photoperiodicity, which allows them to distinguish the various stages of the day. (Gazit and Terkel, 2000; Heth, et al., 1987; Heth, et al., 1988; Nevo, 1969; Nevo, et al., 1975; Sanyal, et al., 1990)

Communication Channels
tactile ; acoustic ; chemical

Other Communication Modes
pheromones ; vibrations

Perception Channels
visual ; acoustic ; vibrations

Food Habits

Middle East blind mole rats are strict herbivores and primarily feed on the underground roots, stems, tubers, and seeds of plants. They dig extensive underground tunnels in search of food and use underground chambers to store excess, harvested food. (Dewey, 2003; Hutchins, 2004; Schlitter, et al., 2008)

Primary Diet
herbivore (Granivore , Lignivore)

Plant Foods
leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts

Foraging Behavior
stores or caches food

Predation

Spalax ehrenbergi has adapted to a strict fossorial lifestyle, which provides good protection from most predators. No natural predators are reported in the literature, although they are sometimes persecuted by humans. (Hutchins, 2004; Schlitter, et al., 2008)

Anti-predator Adaptations
cryptic

Ecosystem Roles

Spalax ehrenbergi is a primary consumer and through its diet of underground plant roots, tubers, and seeds; it shapes and defines that plant biodiversity and availability in an ecosystem. The extensive burrowing and tunneling activitie of this species also affects the water, nutrient, and air composition of soils. (Hutchins, 2004; Schlitter, et al., 2008)

Ecosystem Impact
soil aeration

Economic Importance for Humans: Positive

Although Middle East blind mole rats are often regarded as agricultural pests, they are useful in research. They have been instrumental in locating significant and important archeological sites by bringing buried artifacts and bones to the surface. They have also acted as an important species in the medical research field. Their hypoxic fossorial environment has resulted in some unique adaptations that are of interest to medical communities concerned with treating ischemia and cancer. Lastly, populations seem to be undergoing rapid speciation and there is great chromosomal and allozyme diversity within the species. It is currently being utilized as an important model species to study and elucidate the patterns and mechanisms behind speciation. (Avivi, et al., 1999; Hutchins, 2004; Nevo, 1969; Nevo, et al., 1975; Schlitter, et al., 2008)

Positive Impacts
source of medicine or drug ; research and education

Economic Importance for Humans: Negative

Middle East blind mole rats eat roots and tubers and are considered an agricultural pest in some areas because they eat crop and disturb them with their digging. Libyans believe that touching Spalax ehrenbergi results in blindness, although to this date they have not been shown to be a vector for any human diseases. (Hutchins, 2004; Schlitter, et al., 2008)

Negative Impacts
crop pest

Conservation Status

IUCN Red List of Threatened Species [Link]
Data Deficient
More Information

US Federal List [Link]
No special status

CITES [Link]
No special status

According to the IUCN Red List, Spalax ehrenbergi is considered “data deficient,” which means there is not enough known about their population numbers to make an accurate assessment. Populations are thought to be decreasing, perhaps as a result of intensified agriculture in some areas. Middle East blind mole rats are considered common in appropriate habitat and are considered agricultural pests in some areas, where they may be persecuted. (Dewey, 2003; Schlitter, et al., 2008)

For More Information

Find Spalax ehrenbergi information at

Contributors

Nicole Santarosa (author), University of Michigan, Phill Moll (author), University of Michigan, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan, Tanya Dewey (editor), Animal Diversity Web, University of Michigan Museum of Zoology.

References

Avivi, A., M. Resnick, E. Nevo, A. Joel, A. Levy. 1999. Adaptive hypoxic tolerance in the subterranean mole rat Spalax ehrenbergi: the role of vascular endothelial growth factor. Federation of European Biochemical Societies., 452: 133-140.

Dewey, T. 2003. Rats, Mice, and Relatives V: All other rats, mice, and relatives. Pp. 281-298 in M Hutchins, A Evans, J Jackson, D Kleiman, J Murphy, D Thoney, eds. Grzimek's Animal Life Encyclopedia, Vol. 16, 2nd ed Edition. Detroit: Gale.

Gazit, I., J. Terkel. 2000. Reproductive behavior of the blind mole-rat (Spalax ehrenbergi) in a seminatural burrow system. Canadian Journal of Zoology, Volume 78, Issue 4: 570-578. Accessed March 28, 2009 at http://proquest.umi.com/pqdlink?Ver=1&Exp=03-27-2014&FMT=7&DID=54325918&RQT=309&clientId=17822&cfc=1.

Heth, G., E. Frankenberg, E. Nevo. 1988. "Courtship" Call of Subterranean Mole Rats (Spalax ehrenbergi): Physical Analysis. Journal of Mammology, Volume 69, Issue 1: 121-125. Accessed March 28, 2009 at http://www.jstor.org/sici?sici=0022-2372(1988)69:1%3C121:%27COSMR%3E2.0.CO;2-&cookieSet=1#&origin=sfx%3Asfx.

Heth, G., E. Frankenberg, A. Raz, E. Nevo. 1987. Vibrational communication in subterranean mole rats (Spalax ehrenbergi). Behavioral Ecology and Sociobiology, Volume 21, Number 1: 31-33. Accessed March 28, 2009 at http://www.springerlink.com/content/g66568ht846377wk/.

Hutchins, M. 2004. Rats, mice, and relatives V. Pp. 281-295 in D Kleiman, V Geist, M Mcdade, eds. Grizimek's Animal Life Encyclopedia, Vol. 16, 2nd Edition. New York: Thomson and Gale.

Musser, G., M. Carleton. 2005. Mammal Species of the World. Washington, D.C.: Smithsonian Institution Press.

Nevo, E., A. Shkolnik. 1974. Adaptive metabolic variation of chromosome forms in mole rats, Spalax. Cellular and Molecular Life Sciences, 30/7: 724-726.

Nevo, E. 1969. Mole Rat Spalax ehrenbergi: Mating Behavior and Its Evolutionary Significance. Science, Volume 163, Issue 3866: 484-486. Accessed March 28, 2009 at http://www.jstor.org/sici?sici=0036-8075(1969)163:3866%3C484:MRSEMB%3E2.0.CO;2-#&origin=sfx%3Asfx.

Nevo, E., G. Naftali, R. Guttman. 1975. Aggression Patterns and Speciation. Proceedings of the National Academy of Sciences of the United States of America, Volume 72, Issue 8: 3250-3254. Accessed March 28, 2009 at http://www.jstor.org/stable/info/64545?seq=1.

Sanyal, S., H. Jansen, W. de Grip, E. Nevo, W. Jong. 1990. The Eye of the Blind Mole Rat, Spalax ehrenbergi Rudiment With Hidden Funtion?. Investigative Ophthalmology & Visual Science, Vol. 31, No. 7: 1398-1404. Accessed April 09, 2009 at http://www.iovs.org/cgi/reprint/31/7/1398.

Schlitter, D., G. Shenbrot, B. Kryštufek, M. Sozen. 2008. "Spalax ehrenbergi. In: IUCN 2008. 2008 IUCN Red List of Threatened Species" (On-line). Accessed March 30, 2009 at http://www.iucnredlist.org/details/14326.

Zuri, I., J. Terkel. 1998. Ontogeny of agonistic behaviour in dispersing blind mole rats (Spalax ehrenbergi). Aggressive behavior, Volume 24, Issue 6: 455-470. Accessed March 28, 2009 at http://cat.inist.fr/?aModele=afficheN&cpsidt=2424378.

To cite this page: Santarosa, N. and P. Moll 2009. "Spalax ehrenbergi" (On-line), Animal Diversity Web. Accessed June 01, 2012 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Spalax_ehrenbergi.html

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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