Ellen Daugherty reports on the lowland streaked tenrec that elegantly demonstrates the ability of Madagascan species to fill unusual ecological niches
Since Madagascar’s split from India 88 million years ago, the island has been geographically isolated and its species have been left to evolve on their own, without any major apex predators. This isolation has led to around 75% of species on the island being endemic, and are generally not found in the wild anywhere else in the world. This unique ecosystem has led to all sorts of species filling up the ecological niches of animals that we would usually find around the globe. For instance, Madagascar’s main predator, the fossa, is actually closely related to the mongoose family, but fills the niche of a big cat, such as a lion or leopard. This is where we come to this week’s creature feature, the lowland streaked tenrec, that fills the ecological niche of a hedgehog, only it is much more extraordinary looking.
There are around 30 species of tenrec on the island, but the lowland streaked tenrec is by far the most unusual, and is found only in eastern parts of Madagascar. It does its foraging on the ground of tropical rainforests, hunting for insects, worms, and sometimes even fruit. Their most distinguishable feature is their black and yellow quills, that are used for protection against predators – which is most likely to be the fossa.
However, unlike the European hedgehog, the tenrecs quills are used for something much more specialised than just protection. They live within family groups in underground burrows and use a variety of methods to communicate. Scientists only recently discovered that the lowland streaked tenrecs actually communicate with their quills, in which they rub together the non-barbed quills in the middle of their back to create a high-pitched ultrasonic call. This means they can communicate information about the environment, food sources, or impending danger. This type of echolocation, where body parts are vibrate to communicate, is rarely seen in mammals and is usually observed in insects, such as crickets.
Only the unique history of Madagascar had led to species evolving characteristics that transcend the usual barriers of their class. The lowland streaked tenrec is just one example of how convergent evolution, in an environment that has been geographically isolated for 88 million years, can allow different species to fill a variety of unusual ecological niches.