Females will also erect their quills toward a male if they are not reproductively receptive and will stick spines in the male’s genitals; males have been known to fight among one another if females are present. During courtship the male approaches the female hissing with his snout in the air. If accepted, the male will then nose the female around the neck area followed by nosing her in the cloaca while the female then grabs his snout with her jaws.
Copulation occurs during Madagascar’s rainy season between November and May for both Hemicentetes species and ovulation only occurs after copulation. If winter conditions are absent, breeding can potentially occur year-round. However, females are only fertile up to a year after they are born. Average gestation takes 55 to 58 days. The average litter size is 6.3 for lowland streaked tenrecs (H. semispinosus) and 1.3 for highland streaked tenrecs (H. nigriceps). Litter size increases in captivity for both species. Lowland streaked tenrecs have as many as 11 offspring in captivity and highland streaked tenrecs have given birth to a maximum of 4. Young streaked tenrecs weigh about 11 g and are 55 to 67 mm in length. By day 25, both species are weaned; adulthood is reached by day 40 (maturity in other spiny tenrec species [Setifer setsosus and Echinops telfairi] doesn’t occur for 6 months). Females can be reproductively active by day 25 in lowland streaked tenrecs; they may be the only tenrec that can breed in the same season in which they were born. They have an elevated resting metabolic rate during reproduction.
Breeding interval: Lowland streaked tenrecs usually breed once a year, but can sometimes breed twice within the same season.
Breeding season: Breeding occurs between November and May.
Range number of offspring: 1 to 11.
Average number of offspring: 6.3.
Range gestation period: 55 to 58 days.
Average weaning age: 25 days.
Average time to independence: 40 days.
Average age at sexual or reproductive maturity (female): 25 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; viviparous
Average birth mass: 11.5 g.
Average number of offspring: 4.
Average age at sexual or reproductive maturity (female)
Sex: female: 35 days.
Most information on parental care in streaked tenrecs is based on captive animals. In preparation for birth, a pregnant female will use her snout as a spade to clear away a depression in the ground within the burrow. When the young are born, the female will help clear away tissue from the snout area so that they are able to breathe. The male will help protect the young by allowing them to huddle around him. The female takes care of both cleaning and replacing the lining in the nest. If the offspring wander too far from the nest, females will carry them back to the nest. Mothers maintain contact with their offspring while foraging by using both smell and the stridulation organ after the stridulation organ starts working in the young. Offspring are born without spines, but begin to develop them within the first 24 hours of life.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female)
- Gould, E., J. Eisenberg. 1966. Notes on the biology of the Tenrecidae. Journal of Mammalogy, 47: 660-686.
- Marshall, C., J. Eisenberg. 1996. Hemicentetes semispinosus. The American Society of Mammalogists, 541: 1-4.
- Stephenson, P. 2003. Hemicentetes, Streaked Tenrecs. Pp. 1281-1283 in S Goodman, J Benstead, eds. The Natural History of Madagascar. Chicago and London: University of Chicago Press.
- Stephenson, P. 2007. Species profile: streaked tenrecs, Hemicentetes. Afrotherian Conservation Newsletter, 5: 1-3.
- Symonds, M. 2005. Phylogeny and life histories of the ‘Insectivora’: controversies and consequences. Biological Reviews, 80: 93-128.
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Tenrecinae, known as the spiny tenrecs, is a subfamily of Afrotherian mammals within the Tenrecidae family. Tenrecinae contains five hedgehog-like species in four genera (Hemicentetes, Tenrec, Setifer, and Echinops), all indigenous to Madagascar. The common tenrec (Tenrec ecaudatus) also flourishes on Réunion, Mauritius, the Comoros, and the Seychelles, Indian Ocean islands where it has been introduced (Olsen 2013; Smith 2012).
Spiny tenrecs range from 80 grams to 2 kilograms (2.8 oz to 4.4 lbs) in size, generally larger than species in the three other tenrec subfamilies, and are mostly solitary and nocturnal (Garbutt 2007). Omnivores, they feed primarily on insects and soft invertebrates such as earthworms, though some species also eat baby rodents and frogs (Olsen 2013, Garbutt 2007). Barbed, quill-like spines are a distinguishing feature found throughout the Tenrecidae family. These spines are especially prominent on the coat of all five spiny tenrec species and are arranged much like the spines on a hedgehog (however hedgehog spines are derived from multiple hairs while tenrec spines are formed from a single modified hair; Olsen 2013, Garbutt 2007). When threatened, a spiny tenrec will curl into a ball, exposing its spines in self-defense. This similarity to a hedgehog-like life strategy is just one example of the considerable convergent evolution to other insectivore species for which the Tenrecidae family is well known (Olsen 2013, Garbutt 2007).
The genus of streaked tenrecs, Hemicentetes, is unusual in that its members produce sound with specialized row of quills that they stridulate, or rub together (Garbutt 2007; Davies 2011). Stridulation is thought to be a way for mothers and offspring to communicate. In contrast to other tenrecs, which are solitary, streaked tenrecs share burrows with related individuals (Garbutt 2007). The lowland streaked tenrec (Hemicentetes semispinosus) is also unusual in that it is partially diurnal (active during the daytime; Olsen 2013, Garbutt 2007). In addition, the barbed spines of this genus can detach and become lodged in an unlucky predator’s skin (Garbutt 2007).
The larger spiny tenerecs are hunted as a food and hide source and E. telfairi is successfully farmed on Réunion Island for meat, a practice that may spread (Olsen 2013; Harduin 1994; Tatayah and Driver 2000). Hunting does not appear to reduce population sizes of these species. The IUCN rates all five spiny tenrec species as “of least concern” on the red list of threatened species, since these animals are common within their limited distribution and readily adaptable to disturbed habitats, often among human habitation, and they breed readily (Jenkins and Goodman, 2013a,b; Olson and Goodman 2013; Vololomboahangy and Goodman 2013a,b). The common tenrac, Tenrec ecaudatus, is the most fecund mammal known. It can have a litter of 32 babies up to twice a year, and females may have up to 29 nipples (Garog 1999; Olsen 2013). The lowland streaked tenrec holds the mammalian record for shortest generation time: 25 days (Olsen 2013).
Spiny tenrecs are becoming more integrated into the Western world: several species, including the lesser hedgehog tenrac (Echinops telfairi) and the greater hedgehog tenrec (Setifer setosus) have become popular in the pet trade (Wikipedia 2013; Crittery Exotics 2012). Interestingly, however, due to the fact that spiny tenrecs are difficult to distinguish from hedgehogs, the US Department of Agriculture has banned their entrance into the US, because hedgehogs carry Foot and Mouth disease (even though tenrecs do not; Olsen 2013). The nuclear genome of one Tenrecinae species, the lesser hedgehog tenrec (Echinops telfairi), has been sequenced as part of the 29 Mammals Genome Project (Broad Institute 2013; Lindblad-Toh et al. 2011). The complete mitochondrial genome of this species had previously been sequenced (Nikaido 2003). This tenrec may become a model organism in science as its genome is explored, providing wider evolutionary diversity to the more conventional set of model organisms.