Bioacoustics of Tenrec ecaudatus

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.

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.