Eospalax baileyi
Creators: name: Don E. Wilson
name: Russell A. Mittermeier
name: Thomas E. Lacher, Jr
Publisher: name: Lynx Edicions
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Spalacidae
Eospalax
Eospalax baileyi

description: 9.
Plateau Zokor
Eospalax baileyi
French: Zokor des plateaux / German: Qinghai-Blindmull / Spanish: Zocor de altiplano
Taxonomy. Myospalax baileyi Thomas, 1911,
between Nagchuka (or Hokow) and Tatsienlu, Ramasong, W Szechwan, China.
Although O. Thomas in 1911 treated E. baileyi as separate species, G. M. Allen in 1940 included it as a subspecies offontanieru. S. Y. Song in 1986 regarded baileyi as a subspecies of rufescens. Many references to E. fontanierii and E. rufescens pertain instead to the betterstudied E. baileyi. In recent years, various studies support treating E. bailey: as a distinct species from E. fontanierii, E. rufescens, and E. cansus based on mtDNA, cranial morphology, molar shape, hair morphology, and features of internal organs. Molecular data weakly suggest a close relationship to E. smithii or E. rufescens. Four to six deeply divergent, geographically discrete, mitochondrial clades have been identified within E. baileyi, and these may show some overlap with the three morphological groups suggested by Tang Lizhou and colleagues in 2009. Additional research is required to determine if E. baileyi warrants further division into multiple species or subspecies. Monotypic.
Distribution. Qinghai, Gansu, and W Sichuan (China).
Descriptive notes. Head-body 160-235 mm,tail 33-61 mm; weight 173-490 g. Male Plateau Zokorsare larger than females. They are pale rufous-brown with pinkish buff. Tail is short and densely furred with whitish hairs. Feet are also hairy. Young are gray. Incisive foramina is restricted to premaxilla.
Habitat. Alpine meadows, steppe meadows, shrubs, and farmland. at elevations of 2800-4500 m on the Qinghai-Tibet Plateau. The Plateau Zokor prefers moist soil and degraded grassland and avoids desert, irrigated land, and boulder fields. Microclimate of its burrows allows for less extreme temperature swings and milder temperatures overall. While aboveground January temperatures may be —4 to —=38°C, burrows maintain a temperature of 0-5°C. Humidity is high (79-87-3%) in these burrows compared to dry external climate (31-7-53-3%). Nevertheless, microclimate in burrows presents challenges. Oxygen levels are low (17-18:4% in burrow compared to 20-4% externally), and carbon dioxide levels are extremely high (0-22-1-5% in burrow compared to 0-03% outside). The Plateau Zokoris a subterranean and a high-elevation species, and it has substantially elevated red blood cell counts and hemoglobin concentration; it is extremely efficient at delivering oxygen to tissue. Oxygen pressure in arterial blood of the Plateau Zokoris 1-5 times higher than laboratory rats, and oxygen pressure in venous blood is 0-26 times that of lab rats.
Food and Feeding. Plateau Zokors feed on roots and shoots of forbs, grasses, and some shrubs. They prefer taproots and storage organs of plants such as Notopterygium forbesii (Apiaceae), Potentilla anserina (Rosaceae), Morina chinensis (Caprifoliaceae), and dandelions (Taraxacum, Asteraceae). Plants are accessed from feeding tunnels belowground. The Plateau Zokor will grab roots and pull the entire plant down into the tunnel system where it is consumed. All zokors have an adaptation in the thumb claw where it is shortened and wears away leaving a central gap. Under laboratory conditions, the Plateau Zokor uses this thumb claw to clean off taproots such as dandelions. The root is then held in both hands, resting in these thumb gaps,as it is consumed.
Breeding. Male and female Plateau Zokors never share a burrow. Mating occursat the intersection of burrows of neighboring males and females. During the mating period, males will dig multiple long tunnels, presumably in hopes of entering female territories. Males and females mate with multiple partners during a single mating period. Females give birth once a year, usually in April-May. Litter sizes are about three young (1-5), and lactation lasts c.50 days.
Activity patterns. Plateau Zokors live mostly belowground. They are active year-round but have higher activity levels in spring and autumn and lowest in winter. The Plateau Zokorsleeps very deeply and can be handled or subjected to loud noises without waking up.
Movements, Home range and Social organization. Burrows of Plateau Zokors are complex, with tunnel systems reaching ¢.100 m in length and depths of 0-8-1-5 m for males and 2-2-5 m for females. Burrow systems contain transportation and foraging tunnels, 1-2 nest chambers, food stores, and dead end tunnels. Soil is brought to the surface when digging, and their presence is evident by presence of mounds that can take up 15-20% of the surface above the burrow system. Dispersal is probably aboveground and male-biased, but this has not been observed directly. They are solitary and intolerant of one another, becoming aggressive when encountering others. Densities are 5-70 ind/ha and average 15 ind/ha. Predators include the Tibetan Fox (Vulpesferrilata), the Steppe Polecat (Mustela eversmannii), the Chinese Mountain Cat (Felis bietr), Pallas’s Cat (Otocolobus manul), the Eurasian Lynx (Lynx lynx), the upland buzzard (Buteo hemilasius), and the saker falcon (Falco cherrug). The Gray Wolf (Canis lupus) and the Brown Bear (Ursus arctos) occasionally eat Plateau Zokors.
Status and Conservation. Not assessed on The IUCN Red List. Classified as least concern on the 2016 China Red List whereit is treated as a distinct species. The Plateau Zokor has a wide distribution and large population. An annual eradication program was implemented in the 1990s, which reduced population size to less than one-third of its formersize. Livestock grazing appears to increase prevalence of Plateau Zokors because it leads to an increase in the types of plants with taproots they prefer. This increase in zokors may in turn further accelerate landscape deterioration, but the system is complex, and researchers debate positive and negative impacts. The Plateau Zokor is considered an ecosystem engineer. A single individual transfers more than 1000 kg of soil to the surface annually. Its burrowing activities mix and aerate soil, increase environmental heterogeneity, enhance infiltration of water into the soil, and thereby curtail erosion. These activities also lessen uptake of greenhouse gases and appear to facilitate spread of invasive plant species. Abandoned burrows are used as shelters by a variety of small mammals (such as the Root Vole, Microtus oeconomus, and Gansu Pika, Ochotona cansus), birds (such as the ground tit, Pseudopodoces humilis, the black-winged snowfinch, Montifringilla adamsi, and several species of ground-sparrows such as Pyrgilauda blanfordi, P. davidiana, P. ruficollis, and P. taczanowski), amphibians and reptiles. Dried bone of Plateau Zokor, known as “Sailonggu,” is used in traditional Tibetan medicine as a treatment for inflammation. It is used as a medicinal replacement for Tiger (Panthera tigris) bone, which serves a similar function.
Bibliography. Allen (1940), Ellerman & Morrison-Scott (1951), Fan Naichang & Shi Yinzhu (1982), He Ya et al. (2012), Jiang Zhigang et al. (2016), Lawrence (1991), Li Baoguo & Chen Fuguan (1989), Li Wenjing et al. (2009), Lin Gonghua, Li Wenjing et al. (2011), Lin Gonghua, Zhao Fang et al. (2014), Musser & Carleton (2005), Smith & Johnston (2008a), Song (1986), Su Junhu et al. (2014), Tang Lizhou, Wang Liuyang et al. (2010), Tang Lizhou, Zhang Tongzuo, Lin Gonhua & Su Jianping (2010), Tang Lizhou, Zhang Tongzuo & Su Jianping (2009), Thomas (1911a, 1911b), Wang Yingxiang (2003), Wei Dengbang et al. (2006), Wu Panwen et al. (2007), Yang Chuanhua et al. (2012), Zhang Weiet al. (2014), Zhang Yanming (2007a, 2007b), Zeng Jinxiang et al. (1984), Zhou Caiquan & Zhou Kaiya (2008), Zhou Caiquan et al. (2004).
description: Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Spalacidae, pp. 108-142 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on pages 133-134, DOI: 10.5281/zenodo.6609100