Friday, May 3, 2013
I is for INDRI
The Indri is a large species of Lemur found only on the secluded island of Madagascar. The Indri evolved in the same way as every other Lemur, from smaller individuals that came to the island from Africa around 50 million years ago. Due to the fact that there were no other primates to complete with, Lemurs soon adapted to live in a variety of habitats, producing a diverse range of different species. Locally, the Indri is known as the 'babakoto' which means little father or ancestor of man. As the native people believe that the Indri (with its lack of visible tail) resembles their ancestors, their is a certain taboo over consuming it, meaning that the Indri does receive some protection in parts of their native environments.
The Indri is the largest of all living Lemur species today, with some individuals reaching nearly a metre in height. The average Indri however, tends to be between 60 and 80 cm tall with a tail of just 5cm (all other Lemurs have tails that are around the same length as their bodies). The Indri has a dense coat of black silky fur with a varying number of white patches depending on the geographic region. Their toes and fingers are very dexterous and are good for grasping and their long hind legs aid them in leaping up to 10 metres between vertical branches in the forst. The yellow eyes of the Indri face forwards to help them to judge the distance before making a jump.
Like all Lemurs, the Indri is found only on the island of Madagascar in lowland jungle and tropical forests. Lemurs are arboreal animals and they spend the majority of their lives, eating, sleeping and mating high up in the trees. Today, the Indri is only found in small pockets of protected forest in Eastern Madagascar, due to increased levels of logging and the clearing of land for agriculture across the island. Although actual figures are unknown there are thought to be less than 10,000 Indri left in Madagascar as the species is under severe threat in its natural environment.
The Indri is a sociable animal, living in small family units of between 2 - 6 individuals, that consist of a male and female pair with their young. Lemurs are unique among primates as it is the females who are the dominant ones, and they get to feed first while the males defend their territory. Indris communicate through a series of eerie wailing calls, both to unite families and also to mark their territory, that can be heard up to 2km away. They also urinate along borders to mark out their patch. One of the most noticeable differences between Lemurs and Monkeys is their dog-like snout which gives Lemurs an excellent sense of smell so that are able to sniff out these markings with ease and avoid confusion.
Female Indris reach sexual maturity at about 8 or 9 years of age, when they are able to have one infant every 2 or 3 years. The babies are usually born in May or June after a gestation period of between 4 and 5 months. The infant clings onto the belly of its mother for the first few months of life, and it then moves round onto her back. The babies are independent at 8 months but generally remain with their mother until the age of 2 or 3. Sadly, half of all Indri babies are thought to die before the age of 2, usually due to sickness or injury. Although adult Indris have been known to live well into their twenties, their average life span is between 15 and 18 years.
The Indri is herbivorous, unlike many other primates that will munch on almost anything in sight. Indris are diurnal animals and are most active in the day when they hunt for food, both in the trees and on the ground. Females get first pickings and are often found foraging for new leaves. Young leaves make up the majority of the Indri's diet along with fruits, seeds and flowers, which are easily picked up with their nimble fingers. Indris are known to eat a wide variety of plant matter although it is thought they predominantly eat vegetation that comes from the trees.
Living high up in the trees means the Indri is safe from many ground-dwelling predators, however, there are a number of animals that have no problem getting up to the Indri's height. The native cat-like Fossa (see previous post re this animal) is the main predator and is an incredibly agile and primarily tree-dwelling mammal that has evolved to catch one thing, Lemurs. Other predators of the Indri include large birds of prey such as hawks, and reptiles including snakes, all of which the Indri are thought to have different danger signals for. One of the largest threats to Madagascar's Indri populations however is habitat loss, as hundreds of acres of natural jungle are being cleared every day.
The Indri is most closely related to more primitive primates including Bushbabies, Pottos and Lorises. There are nearly 100 species of lemur but the Indri is the only remaining species in its genus. Before the island was ravaged by deforestation, it is thought that a different population of Indri occupied nearly every ridge in the eastern forests. The colour of the Indri differs between popularion, with individuals further south thought to have more patches of white, while those in the more northern areas tend to be darker.
Indri populations are now thought to be drastically low, as it can only be found in protected forest regions (where logging and land devastation still occurs). Although it is thought there are up to 10,000 individuals left in the wild other estimates are more concerning claiming that there may be as few as 1,000 Indri remaining, but they are now protected with the listing as an ENDANGERED species. One of the biggest worries to science is that the Indri does not do well in captivity so that captive breeding programmes to try and rehabilitate the dying populations are likely to be unsuccessful.
Kingdom = Animalia; Phylum = Chordata; Class = Mammalia; Order = Primates; Family = Indriidae
Genus = Indri; Scientific Name = Indri indri; Common Name = Indri; Other Name = Babakoto