The Quills That Sing

Every tenrec on Madagascar, whatever it looks like, descends from a single ancestor that reached the island and then radiated into an extraordinary range of forms: mole-like burrowers, an otter-like species that hunts aquatic insect larvae in rice-paddy canals, hedgehog-like spiny grazers, and shrew-like foragers that make up most of the family’s roughly twenty species. Their only meaningful living relatives anywhere else on Earth are the giant otter shrew of West Africa and the solenodon of Cuba and Haiti, an isolation so complete that tenrecs are considered among the most primitive living placental mammals.

A hedgehog, a mole, an otter, a shrew, all one family.

One species holds an outright mammalian record: 47 tail vertebrae, more than any other mammal alive. The largest of the family, the tailless tenrec, can grow to the size of a rabbit, while others fit easily in a closed hand. It is the same evolutionary story told of Madagascar’s lemurs, played out instead in an animal most visitors never think to look for.

The tailless tenrec holds a second record, this one for reproduction: a maximum litter size of 32 young in a single birth, more than any other mammal on Earth, though wild litters usually run smaller depending on the mother’s age and habitat. Births cluster around the rainy season’s peak in January, timed to the moment insect prey is most abundant.

Hibernation is just as extreme. Through the dry austral winter, from May to October, the tailless tenrec seals itself into a narrow burrow a meter or two deep and lets its body temperature fall to as low as 11 degrees Celsius, suspending its own breathing for up to 45 minutes at a stretch, sleeping straight through without the periodic waking most hibernating mammals need.

The striped tenrecs of the genus Hemicentetes carry a specialized patch of quills on their backs called a stridulating organ, which they vibrate against each other to produce sound across a striking range, from tones a human ear can hear up to ultrasonic frequencies near 200 kilohertz. Family groups use it to keep track of each other in the dark; a mother uses it to call her young back through leaf litter they cannot see across.

An instrument built entirely out of its own spines.

It is a communication method found almost nowhere else among mammals, quills doing the work more typically left to a voice. The same tenrecs also carry barbed, detachable quills for defense, driven into the snout of any predator that pushes too close, while several species more broadly use tongue-clicking for a form of echolocation, another sense pressed into unusual service in a nocturnal animal with famously weak eyesight.

Striped tenrecs live in family groups that can number more than twenty individuals across three generations, sharing a burrow dug near a stream, complete with a dedicated nesting chamber. It is a genuinely complex social structure, unusual among small insectivorous mammals, most of which live solitary lives and meet only to breed.

For an animal so easy to overlook, hiding by instinct and avoiding almost every predator on the island through sheer secrecy rather than speed or size, that scale of family life is the detail most likely to surprise anyone who finally gets a close look: not a lone forager passing quietly through the leaf litter, but one member of a large, ongoing household, still there tonight, still there most nights, entirely unnoticed by everyone walking past.