Tenrec ecaudatus (Schreber, 1778)

Russell A. Mittermeier & Don E. Wilson, 2018, Tenrecidae, Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona: Lynx Edicions, pp. 134-172 : 164

3.

Tailless Tenrec

Tenrec ecaudatus

French: Tenrec commun / German: GroRer Tenrek / Spanish: Tenrec sin cola

Other common names: Common Tenrec

Taxonomy. Erinaceus ecaudatus Schreber, 1778 ,

“Madagascar.”

Synonym Centetes ecaudatus , named by]J. K. W. Illiger in 1811, was frequently used well beyond the mid-20" century. Despite large differences in size and general appearance, similarities between 7 Tenrec and Hemicentetes have been recognized based on some morphological and behavioral characteristics. Morphological and molecular studies have confirmed that the two genera form a clade and are sisters to the other two genera of Tenrecinae, Echinops and Setifer . Monotypic.

Distribution. N, Northern Highlands, W, Central Highlands, E & S Madagascar. Introduced on Réunion, Mauritius, and the Seychelles, and possibly Comoro Is.

Descriptive notes. Head-body 182-350 mm, ear 19-36 mm, hindfoot 31-48 mm; weight 148-430 g. Captive Tailless Tenrecs can weigh more than 2 kg. Adults are sexually dimorphic: males being larger than females, with broader heads and longer canines. They have no external tail; dorsal surface of head and dorsal and lateral surfaces of body are covered with mix of hairs and bristly spines, varying from grayish brown to reddish brown or dark brown; spines are pale for most of their lengths, with dark band and light-colored tips. Mane of longerstiff erectile hairs occurs on crest and mid-dorsal region of body. Ventral surface is sparsely covered with buffy soft bristly hair; head and limbs are covered with short bristly hair. Infants andjuveniles have buff or light brown venter and distinct dorsal spinous pelage of dark brown contrasting with five longitudinal bands of light-colored spines; broad mid-dorsal band of multiple spines forms stridulating organ; white-tipped spines on nape of neck form low crest. Distinctive juvenile pattern and color are lost during molt to subadult pelage. Dental formulais 12/3, C1/1,P 3/3, M 3-4/3 (x2) = 38-40; M* erupts very late in life and is rarely present.

Habitat. Humid, sub-humid, dry, and dry spiny forests; open woodland; transitional habitats; and degraded, agricultural, and urban areas from sea level to elevations of c.1680 m. Tailless Tenrecs occur in all phytogeographic zones of Madagascar.

Food and Feeding. The Tailless Tenrec is insectivorous and omnivorous. Diets mainly contain soil-dwelling larvae, including a high proportion of Coleoptera larvae, also termites, ants, Lepidoptera larvae, centipedes, and some fruit. Occasionally, small vertebrates such as frogs and snakes and small snails are eaten. Seasonal and reproductive changes in diet are noted; e.g. on the Seychelles, more fruit is consumed especially prior to entering seasonal torpor. The Tailless Tenrec forages with its nose close to the ground; probes into cracks, crevices, and soil surface with its nose; and digs to find prey.

Breeding. Breeding activity occurs from mid-October to early November in Périnet (Analazamaotra Special Reserve), and young are born in December—January after gestation of 56-64 days. At Périnet, one female was found with 25 embryos, and three others each had 18 embryos; the record number is 32 embryos. Litter size is geographically and seasonally variable: c.25 young where there is marked seasonal variation in dry western Madagascar, c.20 young in humid eastern forests that are less seasonally variable, and 15-16 young on the Seychelles where seasonal climate is least variable. Large litters place heavy demands on females during lactation, and females are probably dependent on stored fat remaining from the previous period of torpor for successful reproduction. Young are altricial, born with eyes and auditory meatus closed, but longitudinal dorsal hair tracts are visible. Spines are visible at ¢.7 days old, and eyes open at 9-14 days. By c.3 weeks old, young begin to accompany their mothers on foraging trips, and by 35-60 days old, young start to forage in smaller groups or alone, and contact with their mothers is gradually reduced. Young stridulate by standing high on their legs, with their crests and central spines erect, and produce pulses of sound by rubbing mid-dorsal spines of their stridulating organs together. Sound ranges from just audible to humans to ultrasound and is believed to function as communication within family groups.

Activity patterns. Tailless Tenrecs are mainly nocturnal, but females and juveniles can be partly diurnal. During wet austral summer, they spend the day in burrows underground or in hollow logs, emerging at night to forage. Burrows of males are relatively shallow, and those of females are long, deep, and complicated, leading to leaflined nest chamber. In an investigation of a burrow system near Périnet containing an adult female and four young, over a 24hour period, ambient temperatures were 22-5-25-5°C in the burrow but were 18-29°C in the shade outside the burrow. Daily activity is bimodal: captive female with four infants had peaks of activity at 20:00 h and again between 01:00 h and 02:00 h. During field observations, Tailless Tenrecs were sighted in late afternoon to dusk, with other sightings between 18:00 h and 21:00 h and 01:00 h and 05:00 h. Females in late pregnancy and lactating are active day and night. Young follow the same pattern when they accompany their mothers to forage, up until the age at which they molt from juvenile to adult pelage. On the Seychelles, breeding season is followed by a period of fattening by the end of which individuals can double their body mass prior to entering torpor. Tailless Tenrecs are torpid from austral autumn to austral spring; they excavate a burrow, sealing it from the inside, and remain torpid for 5-6 months. Males emerge c.1 month before females. Tailless Tenrecs are terrestrial, but some forelimb characteristics are suggestive of digging behavior. They have been observed climbing on steep rock faces, but not usually in trees, and swimming in rice paddies. They will swim to escapeif startled.

Movements, Home range and Social organization. Tailless Tenrecs are solitary while foraging and occupy individual burrows; however, their individual home ranges overlap. Home ranges are 1-3 ha or more, depending on availability of food and other resources. Marking behavior includes deposition of feces near burrow entrances and at specific places where an individual digs a small hole, defecates, urinates, wipesits perineum, and then kicks back to cover deposits. They also mark by perineal dragging across the ground. If startled or threatened,initial reaction is to freeze and then run. In captivity, Tailless Tenrecs respond to predator odor or disturbance by piloerection, especially crest and mid-dorsal hairs; stamping forefeet, hissing, and puffing; opening mouth in a wide gape; and attempting to bite. Females with young, if unable to flee, will act as a group in the same defensive manner and ultimately rush toward the threat.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Tailless Tenrec is widespread, has a stable overall population, and occurs in primary and disturbed habitats. It is locally threatened by overhunting, but it does not face any major conservation threats.

Bibliography. Ade (1996), Asher & Hofreiter (2006), Butler (1937), Eisenberg & Gould (1970), Everson et al. (2016), Goodman & Jenkins (1998, 2000), Goodman et al. (1999), Gould (1965), Gould & Eisenberg (1966), llliger (1811), Nicoll (1985a, 1986, 2003, 2009), Olson & Goodman (2003), Poux, Madsen, Glos et al. (2008), Poux, Madsen, Marquard et al. (2005), Rand (1935), Salton & Sargis (2008a, 2008b, 2009), Soarimalala & Goodman (2011), Stephenson et al. (2016c¢).

Figures

1. Lesser Hedgehog Tenrec (Echinops telfairi), 2. Greater Hedgehog Tenrec (Setifer setosus), 3. Tailless Tenrec (Tenrec ecaudatus), 4. Lowland Streaked Tenrec (Hemacenteles semispinosus), 5. Highland Streaked Tenrec (Hemicentetes nigriceps), 6. Large-eared Tenrec (Geogale aurita), 7. Mole-like Rice Tenrec (Oryzorictes hova), 8. Four-toed Rice Tenrec (Oryzorictes tetradactylus), 9. Dobson’s Shrew Tenrec (Nesogale dobsoni), 10. Talazac’s Shrew Tenrec (Nesogale talazact), 11. Montane Shrew Tenrec (Macrogale monticola), 12. Dryad Shrew Tenrec (Microgale dryas), 13. Short-tailed Shrew Tenrec (Microgale brevicaudata), 14. Pygmy Shrew Tenrec (Microgale parvula), 15. Lesser Long-tailed Shrew Tenrec (Mucrogale longicaudata), 16. Drouhard’s Shrew Tenrec (Microgale drouhardi), 17. Taiva Shrew Tenrec (Microgale taiva), 18. Pale Shrew (Tenrec Mucrogalefotsifotsy), 19. Greater Long-tailed Shrew Tenrec (Microgale principula), 20. Cowan's Shrew Tenrec (Microgale cowant), 21. Naked-nosed Shrew Tenrec (Microgale gymnorhyncha), 22. Shrew-toothed Shrew Tenrec (Microgale soricoides), 23. Major's Shrew Tenrec (Microgale major), 24. Gracile Shrew Tenrec (Microgale gracilis), 25. Thomas’s Shrew Tenrec (Microgale thomasi), 26. Grandidier’s Shrew Tenrec (Muicrogale grandidieri), 27. Web-footed Tenrec (Microgale mergulus), 28. Least Shrew Tenrec (Muicrogale pusilla), 29. Dark Shrew (Tenrec Microgalejobihely), 30. Nasolo’s Shrew Tenrec (Microgale nasoloi), 31. Jenkins’s Shrew (Tenrec Microgalejenkinsae)

Distribution. N, Northern Highlands, W, Central Highlands, E & S Madagascar. Introduced on Réunion, Mauritius, and the Seychelles, and possibly Comoro Is.