Eastern Avahi

Woolly lemurs are small and secretive, protecting them from some predators. Their primary wild predators are Henst's goshawks, which find them while resting on exposed branches during the day.

(Flannery, 2000; Harcourt & Thornback, 1990; Wolfheim, 1983)

Known Predators:

• humans (Homo sapiens)
• owls (Strigiformes)
• Henst's goshawks (Accipiter henstii)

Avahi laniger typically weighs between 600 and 1,300 g. Head and body length varies between 300 and 450 mm.

Woolly lemurs are typically grey-brown or reddish-brown in color, but color varies within the species. Th forearms, hands, legs, and feet are white and the tail is reddish-orange. The fur is thick and woolly (hence the common name), unlike other members of the family Indriidae, which have silky fur. Woolly lemurs have a spherical face which is covered in short hairs, their small ears are concealed within the woolly fur. Avahi laniger has large eyes and a short snout, and a characteristic white stripe that goes up the thigh. Sexes are similar, and it is nearly impossible to distinguish between males and females from a distance, though males have slightly larger molars and skulls. The lower incisors of woolly lemurs are modified into comb-like structure.

(Nowak, 1991; Parker, 1990)

Range mass: 600 to 1300 g.

Range length: 300 to 450 mm.

Sexual Dimorphism: male larger

Other Physical Features: endothermic ; bilateral symmetry

Little is known about the lifespan of A. laniger. They are reportedly unsuccessful in zoos, living no longer than three months in captivity outside of Madagascar. However, other members of the family Indriidae are reported to live over 23 years in captivity. It is reasonable to assume that A.laniger has a similar potential lifespan.

(Parker, 1990; Tattersol and Sussman, 1975; Nowak, 1991)

Typical lifespan
Status: captivity: few (low) months.

Avahi laniger is found in tropical regions. The population found in western Madagascar (A. laniger occidentalis) occupy dry seasonal forest where the elevation varies. In east Madagascar, A. laniger laniger occurs in a humid coastal forest at lower elevations.

(Flannery, 2000; Nowak, 1991; Parker, 1990)

Range elevation: 800 to 2000 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: rainforest ; scrub forest

There are two subspecies of A. laniger: Avahi laniger laniger is found in eastern Madagascar, and A. laniger occidentalis is found in northwestern Madagascar. The two subspecies are so similar that some researchers do not consider them to be distinct, though some behavioral differences have been noted.

(Flannery, 2000; Tattersall & Sussman, 1975)

As in other primates, it is likely that these animals use a variety of modalities of communication. Vocal communication has been reported. In addition, tactile communication, especially within the family unit, is expected. Visual communication, in the form of body postures and gestures probably also occurs.

Communication Channels: visual ; tactile ; acoustic

Perception Channels: visual ; tactile ; acoustic ; chemical

Woolly lemurs are a species of great concern in conservation efforts, as are many other species in the Lemuridae and Indriidae families. This concern is mainly due to the considerable amount of habitat loss in Madagascar's tropical rainforests. Although this island known for extraordinary levels of endemic biodiversity and conservationists are working hard to protect lemur species, habitat loss and the hunting of lemurs for food continues at a rapid pace.

(Harcourt & Thornback, 1990; Nowak, 1991)

US Federal List: endangered

CITES: appendix i

IUCN Red List of Threatened Species: least concern

None known

Although A. laniger is an endangered species, it is still hunted for food by Malagasy people.

(Harcourt & Thornback, 1990)

Positive Impacts: food

Woolly lemurs act as a prey species for several predators, including humans. Through its folivory, A. laniger may influence plant composition in the forests where they live.

(Flannery, 2000)

The diet of A. laniger is very similar to that of the closely related species Indri indri. The two species are able to live in the same area and share the same diet because they have different activity periods. Avahi laniger is active at night, whereas I. indri is a diurnal species. Although woolly lemurs have been known to eat flowers and fruits, their diet consists mainly of young leaves. They eat only the leaf blade, leaving the midrib and petiole behind.

One male A. laniger studied by Harcourt (1991) made some interesting feeding actions. The male often went to the end of a branch to pick leaves, then returned to the main trunk to eat them. He was also seen eating bits off leaves that remained attached to the tree.

(Cowlishaw & Dunbar, 2000; Harcourt, 1991)

Avahi laniger eats the leaves, buds, and twigs of: Harongana, Hafotra malady, Bararata, Hafidahy, Varongy, Voara, Herodrano, Fatsikahitra, Tavolarano petite feuille, Tavolomalady, Malambovany, Rotra madinika, Rahiaka, Mahanoram, Sary, Karambitoma, Rotra and Fohaninasity.

Plant Foods: leaves; fruit; flowers

Primary Diet: herbivore (Folivore )

Woolly lemurs are found only on the northwest and eastern sides of the island of Madagascar, off the southern coast of Africa.

(Harcourt and Thornback, 1990; Wolfheim, 1983)

Biogeographic Regions: ethiopian (Native )

Other Geographic Terms: island endemic

Like many mammals on Madagascar, male and female A. laniger seem to mate for life. Couples stay together, raise their young, and live as a family.

(Parker, 1990)

Mating System: monogamous

Breeding occurs from March to May, followed by a gestation of approximately 135 days. Infant woolly lemurs are born during August and September and develop slowly. The baby stays with its mother and is weaned the following wet season. The time to weaning averages 6 months. Other members of the family Indriidae become independent after about 2 years of age.

(Nowak, 1991; Jolly, 1984)

Breeding interval: These interbirth interval of these animals is not known.

Breeding season: Breeding occurs from March to May.

Range number of offspring: 2 (high) .

Average number of offspring: 1.

Range gestation period: 120 to 150 days.

Range weaning age: 8 to 12 months.

Average weaning age: 6 months.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous

Although it is the mother that does most of the care for infant woolly lemurs, the father stays close by. Males have never been seen with a clinging infant.

Infants are dependent upon the mother until they are fully capable of feeding and traveling on their own. From birth to about 2 months, the infant is carried crosswise on the mothers' front side, and nurses 3 to 4 times a day in lengthy sessions. The mother situates herself in a comfortable position to settle down for an afternoon nap and feed her young. As the infant gets older, it moves from being carried on the front to the back and then begins to slowly venture away from the mother.

Feeding behavior begins incidental to play. Young begin playing with the food that the mother is eating, and casually gnaw on the twig or fruit. Thus they gradually learn which foods are safe and good to eat.

At this age, infants become more aware of the surrounding environment by grasping onto nearby branches. By 6 months, the now-weaned infant learns to leap from branch to branch following its mother. Infants do occasionally fall, sometimes up to 30 feet. In a few more months, they learn how to judge distances and make difficult leaps. At one year of age infant woolly lemurs become independent, although the mother is still close by. Even at 2 years of age, the relationship between mother and child is relatively close.

(Harcourt, 1991; Jolly, 1984; Nowak, 1991)

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning, Protecting: Female); post-independence association with parents; extended period of juvenile learning

The eastern woolly lemur typically lives in monogamous pairs, but small groups of up to five related individuals have also been reported (4) (6). As a nocturnal and arboreal species, pairs or groups usually pass the day sleeping huddled together in thick foliage, several metres off the ground (2) (4) (6). Just after dusk, the pairs normally spend some time grooming, before going off to forage alone in the tree canopy, all the while maintaining contact through regular high-pitched whistles. Most foraging activity occurs in the first and last two hours of darkness, with the time in between normally spent resting and grooming (2) (4). When resting, it assumes a characteristic vertical posture by clinging to upright tree limbs and trunks (2) (4) (6). Leaves comprise the vast bulk of this species' diet, but very occasionally it will also take fruits and flowers (2) (4). Mature females are thought to be capable of producing a single infant each year, around August and September (4). Initially the young cling to the female's belly, but when older are transported on the back (2) (4).

In addition to being listed on Appendix I of CITES, which prohibits trade in the species except under exceptional circumstances, the eastern woolly lemur is present within several protected areas, including at least five national parks and two special reserves (1) (2) (3) (4). One of the main priorities for the conservation of this species is to resolve the uncertainty surrounding the taxonomic status of Avahi populations in Ankarana and the Kalambatritra Special Reserve (1).

While the common name of the woolly lemurs refers to their thick, tightly-curled fur, the generic name is an interpretation of their high-pitched defensive call, ava hee. Like all species in the genus, the eastern woolly lemur possesses a long, thin tail and elongated, powerful hind limbs that enable it to leap spectacular distances from one vertical perch to another (2) (4) (5). The upperparts of its body are grey-brown to reddish, becoming paler towards the rump, with the tail being noticeably rufous. The chest and abdomen are a much paler grey, while the backs of the thighs have conspicuous and highly distinctive white patches (2) (4). A small rounded head, large eyes and mostly hidden ears gives its face an almost owl-like appearance (4). Originally, Avahi laniger was split into two subspecies, but in 1990, the slightly smaller and paler, western woolly lemur was elevated to full species status as Avahi occidentalis (2) (4).

Found in tropical moist lowland and montane forest, and in secondary forest (1) (2) (4).

In the wake of recent genetic studies, and the description of several new species of Avahi, the exact distribution of the eastern woolly lemur has become unclear (1). In the past, the species' range was thought to extend the entire length of Madagascar's eastern rainforests, from the extreme south, possibly right up to the island's northern tip (1) (2) (4). However, the most recent distribution given for the species shows it as occurring only in the northern half of the island (1).

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix I of CITES (3).

Although the eastern woolly lemur population is probably declining in response to habitat loss caused by logging and slash-and-burn agriculture, it is still relatively widespread and common. Furthermore, its nocturnal habit makes it less vulnerable to hunting, compared with many of the diurnal lemur species in the Indriidae family (1) (2) (4).

The eastern woolly lemur (Avahi laniger), also known as the eastern avahi or Gmelin's woolly lemur, is a species of woolly lemur native to eastern Madagascar, where it lives in the wet tropical rainforest at low elevations along the eastern coast of the island or they can also inhabit the northern tip of the island with other species. The woolly lemur name refers to their thick, tightly curled hair, whereas their generic name avahi refers to their high-pitched defensive call. The eastern woolly lemur almost has an owl-look with its large eyes, small rounded head, and ears that are mostly hidden. This nocturnal animal weighs 1.0–1.3 kg (2.2–2.9 lb) and reaches a length of 27–29 cm (11–11 in) with a tail of 33–37 cm (13–15 in). Its diet consists mainly of leaves and buds with fruits, flowers, and bark.

Eastern woolly lemurs live in monogamous pairs together with their offspring. The eastern woolly lemur's breeding season ranges from March to May with the baby lemurs being born around August to September.

Other lemur species that live in the same rainforests as eastern woolly lemur are the diademed sifaka (Propithecus diadema) and the red-bellied lemur (Eulemur rubriventer). In southeastern rainforests, sympatric lemur species of A. meridionalis are the brown mouse lemur (Microcebus rufus), the greater dwarf lemur (Cheirogaleus major), the fat-tailed dwarf lemur (Cheirogaleus medius) and the collared brown lemur (Eulemur collaris) in Sainte Luce Forest, and the southern lesser bamboo lemur (Hapalemur meridionalis) in Mandena Forest.

According to one study, a male lemur rarely interacts with more than one other individual when sleeping, traveling or grooming. At night, he would spend about 40% of the time with his partner either grooming or resting.

As of 2020, the eastern woolly Llemur continues to exist; however, based on a 2000 study, the entire lemur population might be endangered if the forests continues to "disappear at a disastrous rate". This could be due to many reasons, for example deforestation and forest degradation.