August 29, 2012

Wildlife Wednesday: Lemurs

Frisky, bright-eyed lemurs rule the treetops of the tropical rainforest. Wild lemurs live only on Madagascar, a large island off the east coast of Africa, and on the nearby Comoros Islands. Lemurs vary greatly in size and appearance. The pygmy mouse lemur, for example, looks like a mouse and weighs about as much as a slice of bread, 30 g. It is the smallest species of lemur. The largest lemur, the indri, is about the size and weight of a large house cat, 7 kg. It looks like a skinny black-and-white giant panda bear.

Indris are one of the largest living lemurs. Their diet includes seeds, fruit, young leaves, and flowers and they can weight up to 13kg (29lbs).
But lemurs are not related to mice or pandas. They are primates. Lemurs are the most primitive type of primate, prosimians. Compared to other primates, lemurs have smaller brains and rely more on their sense of smell than their sense of sight. Also, their hands and feet are not as well adapted for grasping as those of other primates.
Madagascar is home to 60 different kinds of lemurs ranging from the world’s largest lemur to the smallest primate. The forests have provided shelter and food for lemurs since they have lived there which may have been more than 60 million years ago.
Scientists believe that millions of years ago the ancestors of today’s lemurs did a strange and unexpected thing. Those that lived in Africa hopped on logs and seaweed “rafts” and drifted across the Indian Ocean to Madagascar. During an evolution that lasted millions of years, different species developed. Lemurs’ behaviors and adaptations evolved differently from the primates in other parts of the world.
About 2,000 years ago, another species of primate settled on Madagascar: Homo sapiens, or human beings. Their arrival spelled trouble for the lemurs. Humans hunted lemurs for food and took over parts of their habitat. By the 1600s, humans had driven about 16 lemur species to extinction.
Scientists are not sure of the number of lemur species living today. But some of the best known include the brown lemurs, ring-tailed lemurs, sifakas, indris, and ruffed lemurs. These species are diurnal, or active during the day. Dwarf lemurs, mouse lemurs, and aye-ayes are some species that are nocturnal. New species are still being discovered. In 2005, scientists discovered two new mouse lemur species. One is about the size of a squirrel. The other is about the size of a hamster.   

Hop, skip, jump! That’s how sifaka lemurs travel across the ground. Their legs and arms are long compared to their bodies – so bounding across open areas, which they don’t like to do, is the quickest way to get from one safe tree to the next!

Lemurs are forest creatures. Many species live in Madagascar’s tropical rainforests, but some live in dry deciduous forests. The lemurs’ strong hands and fingers help them to climb trees easily. Their muscular legs are adapted for jumping. When they need a change of scenery, they hop to another branch.
Brown lemurs and ring-tailed lemurs scamper along the forest floor on all fours. But other lemur species find traveling on the ground to be a challenge. Their bodies just aren’t built for walking. Sifakas solve the problem by hopping sideways on their back legs, as if they were on a pogo stick.
Many lemurs are herbivores. They will eat almost everything the forest’s trees and plants have to offer. Ring-tailed lemurs, for example, eat fruits, flowers, buds, bark, sap, seeds, and leaves. Some species, such as the mouse lemurs, are omnivores. They eat insects, eggs, frogs, and lizards as well as plants.
This aye-aye has successfully found a grub and is enjoying its meal. Their third or middle finger is very helpful for finding and grabbing insects. The middle finger can be up to three times longer than its other fingers!

The aye-aye eats insect larvae. It has several adaptations that help it find larvae. Like bats and dolphins, it uses echolocation to find food. The aye-aye moves along a branch, tapping it with its middle finger. Its huge ears listen carefully for an echo that signals that larvae are inside the branch. Then the aye-aye rips away the bark with its teeth. It scoops out the larvae with its hook-like third finger.
Some lemur species, such as the dwarf and mouse lemurs, have litters of two or more young. Others, such as the sifakas and ring-tailed lemurs, give birth to one baby at a time.
After a few months, young lemurs are ready to find their own food. This lemur is ready to explore its surrounding environment and forage for food.
After a baby lemur is born, it latches on to its mother’s belly, where it stays hidden and safe from predators. Like all mammals, it feeds on its mother’s milk. When it is a few weeks old, the baby starts riding piggyback. After about three months, mom lets the baby know it’s time to get off her back. She sends it off to find its own food! Lemurs reach adulthood at about age three. They may live to be 20 to 25 years old.
Lemurs are social creatures and most of them live in troops. They benefit from living in groups by getting protection, food and mating opportunities.

Lemurs stick together. Ring-tailed lemurs form groups called troops with as many as 25 members. Sifakas and brown lemurs live in smaller groups of 3 to 12. Why do they do it? There’s safety in numbers. Hawks and other predators are less likely to attack a group than a lone lemur. It’s also easier for lemurs to defend territory as a group.
One way lemurs communicate with each other is with smells. Lemurs have scent glands at their wrists, chests, and the base of their tails. Lemurs rub these glands against twigs or branches to mark the borders of their group’s territory and feeding areas. When rival groups of lemurs get a whiff of these markings they either stay away or get ready for a fight.
Usually, older female lemurs are in charge of a group or a troop. When conflicts between groups happen, it’s the females who fight. First, they try to scare the other group away with loud battle cries. If that doesn’t work, they start biting and swiping at the rival females. Lead females also get the best food and the comfiest places to sleep. If a male attempts to challenge one of these ferocious females, she just might smack him!
Male ring-tailed lemurs have an unusual way of fighting with each other. The fight starts when one male grabs his tail and slathers it with stinky stuff from his scent glands. Then he waves his tail at a rival male. The rival may back off to get away from the bad smell. Or he may get his own tail in on the action and try to stink out the other male. Stink fights sometimes last as long as an hour! 
When danger is near, lemurs make a ruckus. After one lemur gives a piercing warning call, others may join in. The sound of a dozen or so lemurs crying out all at once—a behavior called mobbing—can be frightening. When European explorers first heard mobbing lemurs, they thought they were hearing the sounds of restless ghosts. In fact, the name “lemur” comes from the Latin word for ghost.

Each species has its own set of calls that may include groans, snorts, yaps, squawks, and screams. Certain calls warn others in the group of predators. Other calls help lemurs stay in touch with members of their groups. For example, if a sifaka is unsure of where the others have gone, it makes a call that sounds like “sheef-auk.” This is how the sifakas got their name.
Madagascar has one of the highest levels of biodiversity in the world, with plants and animals that are found nowhere else on Earth. But many of these plants and animals are endangered species. Today, all species of lemur are in some danger of becoming extinct. In fact, scientists rank lemurs as among the most endangered of all primates.
The local people of Madagascar sell materials from the forests such as charcoal and plants. Humans cut down the forests of Madagascar for farming, shelter, materials and industry. Habitat destruction threatens the survival of lemurs.
One reason lemurs are endangered is that people are burning and cutting down Madagascar’s tropical rainforests to clear the land for farming and to get wood for fuel. The loss of forests leaves lemurs with fewer places to live and find food.
Hunting is another major threat to lemurs. Lemurs are a traditional food for some peoples of Madagascar. Although it is against the law to hunt Madagascar’s lemurs, some people do it anyway. Aye-ayes face a special danger. A traditional belief, or fady, of the Betsimasaraka people calls for them to kill any aye-ayes they see. Aye-ayes are thought to be bad luck. There are other fadys, however, against killing other species of lemurs. These fadys may give some protection to sifakas and indris but they are bad news for aye-ayes.
Scientists have singled out Madagascar as one of the world’s top priorities for conservation. The government of Madagascar has set up dozens of reserves to protect lemurs and their habitat. Scientists have also started captive-breeding programs that give the most endangered species a better chance of surviving.
Ecotourism in Madagascar gives people a chance to see lemurs in their natural habitat and learn about the creatures. Some lemurs are as curious as tourists so people are able to get a close-up experience with them.
International groups have teamed up with the Madagascar government to work on conservation. They are looking for ways for people to make a living that do not add to habitat loss. Ecotourism may be part of the answer. Ecotourism can provide jobs that offer a sustainable way of making a living and protect species and their habitat. Ecotourism also gives visitors from around the globe the chance to see lemurs in their natural habitat and understand the importance of saving them from extinction.

No comments:

Post a Comment

Let me know what's up??