Indriidae

(vertebrate zoology) A family of Madagascan prosimians containing wholly arboreal vertical clingers and leapers.

(Indriidae)

Class: Mammalia

Order: Primates

Family: Indriidae

Thumbnail description
Medium- to large-sized primates with powerful hind limbs and short snouts

Size
Weight: 2.2–16.1 lb (1.0–7.3 kg); head and body length: 10.4–20.5 in (264–520 mm)

Number of genera, species
Extinct: 6 genera, 10 species; Extant: 3 genera, 8–10 species

Habitat
Subtropical spiny desert and its gallery forest, humid moist tropical forest, tropical dry forest

Conservation status
Extinct: 10 species; Critically Endangered: 3 species; Endangered: 5–7 species

Distribution
Throughout remaining forests in Madagascar

Evolution and systematics

There are five families of primates on the island of Madagascar, all lemurs. The family Indriidae has lost three-fifths of its species in the past 1,000 years. The extinct indriids consisted of the subfamilies: the Paleopropithecinae, the sloth lemurs, and the Archaeolemurinae, the baboon lemurs. The extinct lemurs were all larger than the extant lemurs, with body weights ranging from 27–441 lb (12–200 kg). The sloth lemurs (4 genera, 7 species) and baboon lemurs (2 genera, 3 species) were found throughout the north, west, and south of Madagascar. With long forelimbs and curved finger bones, the sloth lemurs climbed slowly and hung from tree branches to feed on leaves and tough vegetation. Body weight ranges are estimated at 22–441 lb (10–200 kg). The baboon lemurs were arboreal and terrestrial quadrupeds, feeding on leaves, tough seeds, and husked fruits. Body weights are estimated at 38–62 lb (17–28 kg).

The living Indriidae is comprised of three genera, including 8–10 species (depending on the authority). The medium-sized (15.4–17.6 lb [7–8 kg]), tailless indri consists of one species Indri indri. Woolly lemurs have been divided into a widespread eastern rainforest species (Avahi laniger) and a western species A. occidentalis. Originally divided into two species, Propithecus verreauxi (a smaller-bodied species in spiny desert and dry tropical forests in western Madagascar) and P. diadema (larger-bodied, eastern rainforest), a third species P. tattersalli, the golden crowned sifaka, was described in 1988. Recent molecular and morphometric evidence suggests that the diademed sifaka group, previously allopatric subspecies, consists of four species (P. perrieri, P. candidus, P. diadema, P. edwardsi). P. tattersalli is found in both wet and dry tropical forest in a limited area near Daraina, in northeastern Madagascar. Based on molecular evidence, it has come under recent controversy as to whether it should remain a distinct species. Paleaopropithecus has been found in limestone caves of the Manamby Plateau, north of Tulear. Forest destruction and human hunting may be partially responsible for the contraction of the range of the extant species and the extinction of Paleopropithecus, Archeolemur, Archaoindris, Babakotia, Hadropithecus, and Mesopropithecus.

Physical characteristics

Indriids are medium- to large-sized prosimians. The extinct species Archeoindris fontoynonti weighed up to 400 lb (181 kg), while the smallest species in the family, the eastern woolly lemur Avahi laniger, weighs about 2.3 lb (1 kg). Most indriids have tails shorter than their bodies, with the tail of the indri reduced to a few inches (about 5 cm). The extant indriids are magnificent leapers, with hind limbs longer than their forelimbs. Ears are small, bare or tufted, and rounded. The skin of the face is bare, and the snout is foreshortened. The eye color is often brown in woolly lemurs, orange or amber in sifakas, and yellow-green in indris. The fur is short, dense, and of various colors including brown, beige, white, orange, and black; often with head crowns, head ruffs, saddle backs, and eyebrows contrasting colors from the rest of the body. Indriids have five fingers on each of its two forefeet and five toes on each of its two hind feet; all with bare nails, except for the grooming claw on the second digit of their feet. Males have central chest scent glands, and females have anal scent glands.

Indriids have a dental tooth comb and small upper incisors with a reduced dental formula of only two premolars and four, rather than six, teeth in their tooth comb. Indriids retain the primitive primate features of a simple postorbital bar, relatively small brain case, and a well-developed rhinarium. All species of indriid, whether nocturnal or diurnal, have reflective eyes (tapetum lucidum) to increase perception in low light levels. Indriids are uniform in their cranial morphology and have a tympanic ring that lies free in the bulla and a large stapedial artery. The digestive tract has an enlarged caecum and a large intestine for digesting vegetation.

Distribution

The family is a widespread successful group confined to Madagascar.

Habitat

Indriids are primarily arboreal, and are found in a wide range of ecotypes including primary forests, disturbed forest fragments, spiny desert, and gallery forests.

Behavior

Indriids have various social systems, with woolly lemurs and indris living in monogamous pairs, and sifakas living in various social configurations including multi-male and multi-female. Predator attacks have been observed on woolly lemurs, indris, and sifakas. Periodic killing of both adult and infant sifakas by the carnivore fossa (Cryptoprocta ferox) has been observed with respect to rainforest sifakas. Hensti's goshawk, a large raptor, has stalked and pursued woolly lemurs during the day, and remains have been found in the goshawk nest.

Indriids are primarily arboreal, although the Verraux's sifakas from the spiny desert occasionally travel on their hind legs in a bouncy gait for several meters. Woolly lemur families sleep together on low, shaded branches. Sifakas and indris sometimes sleep in pairs high in the trees. Indriids communicate with a variety of vocalizations from long distance piercing whistles (woolly lemurs) to loud clarinet-like duets (indris) to dog-like barking, honking, and sneezing (sifakas). All species communicate through scent marking. Chemicals from chest (males) and anal (females) glands may constitute individual signatures and indicate reproductive condition, sex, or dominance rank in sifakas. Avahis and indris do not have chest glands, but do use perianal glands in scent marking. Sexual dimorphism does not occur in body size or canine length in any indrid, and females are dominant over males in sifakas and indris. Dominance interactions have not been studied in woolly lemurs.

Feeding ecology and diet

Indriids are vegetarians, feeding on young and mature leaves of trees. In addition, rainforest sifakas feed on lianas, parasites, hemiparasites, herbs, and ferns. Sifakas eat three times as many different plant species as sympatric indris. Seeds are an important diet item for sifakas and fat intake is five times higher for sifakas than indris. Woolly lemurs eat leaves that are high in tannins, and are often found at higher densities in disturbed or edge forests. Flowers are a diet item of sifakas. Both sifakas and indris eat soil, often red clay on a weekly basis. It is unknown if woolly lemurs eat soil. Indris occasionally eat bark.

Reproductive biology

Sexual maturity is generally achieved between 3–5 years of age in indris and sifakas. Data concerning sexual maturity of woolly lemurs does not exist. Both males and females emigrate from natal groups after sexual maturity in indris, woolly lemurs, and sifakas. Male and female sifakas may change groups more than once, or occasionally remain in their natal group for a lifetime. Sifakas are seasonal breeders, mating in December or January. Male testicles begin to increase in size three months before the mating season (when the females come into estrus). Female sifakas have a 10–36 hour interval when they are in estrus, and they may come into estrus 1–3 times each year. In the wild they usually are pregnant after one breeding season. Females have swollen, bright pink vulvas when in estrus. Sifaka mating occurs when a male clasps a female around the waist and thrusts 10–50 times. Indris mate face-to-face, while hanging from a branch. Indris gestate for about six months. The smaller verraux's sifaka has a gestation of five months, while the larger diademed sifaka gestate for six months. A single infant is born fully furred and able to cling. Weights at birth are small, less than 0.2% of the mother's weight. Weaning occurs at about six months of age.

Conservation status

IUCN conservation status is Endangered for all living indriid species except for the Critically Endangered forms of Propithecus perrieri, Propithecus diadema, and Propithecus candidus.

Significance to humans

Sifakas and indris are often protected from traditional hunting by "fadys" (taboos). Malagasies recognize the human qualities of their hands and faces and therefore do not kill them as they are considered spirits of the ancestors.

Species accounts

Resources

Fleagle, John G. Primate Adaptation and Evolution, 2nd ed. San Diego, CA: Academic Press, 1999.

Garbutt, Nick. Mammals of Madagascar. New Haven, CT: Yale University Press, 1999.

Godfrey, L. R., W. L. Jungers, K. E. Reed, E. L. Simons, and P. S. Chatrath. "Subfossil Lemurs Inferences about Past and Present Primate Communities in Madagascar." In Natural Change and Human Impact in Madagascar, edited by S. M. Goodman and B. D. Patterson. Washington, DC: Smithsonian Institution Press, 1997.

Mittermeier, Russell A., Ian Tattersall, William R. Konstant, David M. Meyers, and Roderic B. Mast. Lemurs of Madagascar. Chicago, IL: University of Chicago Press, 1994.

Rowe, Noel. The Pictorial Guide to the Primates. New York: Pogonias Press, 1996.

Simons, E. L. "Lemurs: Old and New." In Natural Change and Human Impact in Madagascar, edited by S. M. Goodman and B. D. Patterson. Washington, DC: Smithsonian Institution Press, 1997.

Pochron, S. T., and P. C. Wright. "Flexibility in Mating Systems in a Prosimian Primate." Behavioral Ecology and Sociobiology (2003): 31–42.

Pollock, J. I. "The Song of the Indris (Indri indri: Primates: Lemuroidea): Natural History, Form, and Function." International Journal of Primatology 7 (1986): 225–264.

Simons, E. L., D. A. Burney, P. S. Chatrath, L. R. Godfrey, W. L. Jungers, and B. Rakotosaminmanana. "AMS14 Dates on Extinct Lemurs from Caves in the Ankarana Massif of Northern Madagscar." Quartenary Research 42 (1995): 249–254.

Wright, P. C. "Lemur Traits and Madagascar Ecology: Coping with an Island Environment." Yearbook of Physical Anthropology 42 (1999): 31–42.

Organizations

Duke University Primate Center, Division of Fossil Primates. 1013 Broad Street, Durham, NC 27705 United States. Phone: (919) 416-8420. Fax: (919) 416-8584. Web site: .

Institute for the Conservation of Tropical Environments. N-543 SBS Bldg., SUNY at Stony Brook, Stony Brook, NY 11794-4364 United States. Phone: (631) 632-9440. Fax: (631) 632-7692. E-mail: icte@notes.cc.sunysb.edu Web site: .

[Article by: Patricia Wright, PhD]

A family of non-human primates that includes indrises.

The noun has one meaning:

Meaning #1: a family of Lemuroidea
  Synonym: family Indriidae

Indridae[1] Fossil range: Pleistocene to Recent
Indri (Indri indri)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Strepsirrhini
Infraorder:	Lemuriformes
Family:	Indriidae Burnett, 1828
Genera
Indri Avahi Propithecus

The Indridae (also spelled Indriidae) are a family of strepsirrhine primates. They are medium to large sized lemurs with only four teeth in the toothcomb instead of the usual six. Indriids, like all lemurs, live exclusively on the island of Madagascar.

The group was once much larger, and, in addition to the thirteen species living today, also contains eleven extinct species in six genera. Most if not all were larger animals, called 'sloth lemurs'. These included the chimpanzee-sized Palaeopropithecus and the gorilla-sized Archaeoindris. Most went extinct within the last 1500 to 2000 years, after humans colonized Madagascar.

Contents 1 Characteristics 2 Classification 3 See also 4 References

Characteristics

The ten extant indrid species vary considerably in size. Not counting the length of their tails, the avahis are only 30cm in length, while the Indri is the largest extant strepsirrhine. The tail of the Indri is only a stub, while avahi and the sifaka tails are as long as their bodies. Their fur is long and mostly from whitish over reddish up to grey. Their black faces, however, are always bald. The hind legs are longer than their fore limbs, their hands are long and thin, and their thumb cannot be opposed to the other fingers correctly.

All species are arboreal, though they do come to the ground occasionally. When on the ground, they stand upright and move with short hops forward, with their arms held high. In the trees, though, they can make extraordinary leaps and are extremely agile, able to change direction from tree to tree. Like most leaf eaters they adjust for the low nutrient content of their food by long rests. Often it can be seen lying stretched on trees sunning themselves. Indrids live together in family federations from two to 15 animals, communicating with roars and also with facial expressions.

Indrids are strict vegetarians, eating mostly leaves, fruits and flowers. Like some other herbivores, they have a large cecum, containing bacteria that ferment cellulose, allowing for more efficient digestion of plant matter.^[2] They have fewer premolar teeth than other lemurs, with the dental formula of:

Dentition
2.1.2.3
2.1.2.3

Females and males usually mate monogamously for many years. Mostly at the end of the dry season, their four to five-month gestation ends with the birth of a single offspring, which lives in the family for a while after its weaning (at the age of five to six months).

Classification

There are 19 living species in the family, divided into 3 genera.^[1][3]

• Order Primates
  • Suborder Strepsirrhini: non-tarsier prosimians
    • Infraorder Lemuriformes
      • Family Indriidae: woolly lemurs and allies
        • Subfamily Indriinae
          • Genus Indri
            • Species Indri, Indri indri
          • Genus Avahi
            • Species Eastern Woolly Lemur, Avahi laniger
            • Species Western Woolly Lemur, Avahi occidentalis
            • Species Sambirano Woolly Lemur, Avahi unicolor
            • Species Bemaraha Woolly Lemur, Avahi cleesei
            • Species Peyrieras' Woolly Lemur, Avahi peyrierasi
            • Species Southern Woolly Lemur, Avahi meridionalis
            • Species Ramanantsoavana's Woolly Lemur, Avahi ramanantsoavana
            • Species Betsileo Woolly Lemur, Avahi betsileo
            • Species Moore's Woolly Lemur, Avahi mooreorum
          • Genus Propithecus
            • Species Diademed Sifaka, Propithecus diadema
            • Species Silky Sifaka, Propithecus candidus
            • Species Milne-Edwards' Sifaka, Propithecus edwardsi
            • Species Perrier's Sifaka, Propithecus perrieri
            • Species Golden-crowned Sifaka, Propithecus tattersalli
            • Species Verreaux's Sifaka, Propithecus verreauxi
            • Species Coquerel's Sifaka, Propithecus coquereli
            • Species Van der Decken's Sifaka, Propithecus deckenii
            • Species Crowned Sifaka, Propithecus coronatus
        • Family †Archaeolemuridae
        • Family Daubentoniidae: Aye-aye
        • Family Cheirogaleidae: dwarf and mouse lemurs
        • Family Lemuridae: lemurs
        • Family Lepilemuridae: sportive lemurs
        • Family †Megaladapidae
        • Family †Palaeopropithecidae
    • Infraorder Lorisiformes: lorises, pottos, galagos and allies
  • Suborder Haplorrhini: tarsiers, monkeys and apes

See also

• Holocene extinction event

References

Wikispecies has information related to: Indridae

1. ^ ^{a b} Groves, C. (2005). Wilson, D. E., & Reeder, D. M.. ed. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 119-121. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3/browse.asp?id=12100075. 
2. ^ Pollock, J.I. (1984). Macdonald, D.. ed. The Encyclopedia of Mammals. New York: Facts on File. pp. 327–329. ISBN 0-87196-871-1. 
3. ^ Mittermeier, R. A. et al. (2008). "Lemur Diversity in Madagascar". International Journal of Primatology 29: 1607–1656. doi:10.1007/s10764-008-9317-y. 

v • d • e Extant primate families by suborder Kingdom Animalia · Phylum Chordata · Class Mammalia · Infraclass Eutheria · Superorder Euarchontoglires Strepsirrhini Cheirogaleidae · Lemuridae · Lepilemuridae · Indriidae · Daubentoniidae · Lorisidae · Galagidae Haplorrhini Tarsiidae · Cebidae · Aotidae · Pitheciidae · Atelidae · Cercopithecidae · Hylobatidae · Hominidae

v • d • e Extant species of family Indriidae Kingdom: Animalia · Phylum: Chordata · Class: Mammalia · Order: Primates · Suborder: Strepsirhini Indri Indri (I. indri) Avahi (Woolly lemurs) Bemaraha Woolly Lemur (A. cleesei) · Eastern Woolly Lemur (A. laniger) · Moore's Woolly Lemur (A. mooreorum) · Western Woolly Lemur (A. occidentalis) · Sambirano Woolly Lemur (A. unicolor) · Peyrieras' Woolly Lemur (A. peyrierasi) · Southern Woolly Lemur (A. meridionalis) · Ramanantsoavana's Woolly Lemur (A. ramanantsoavani) · Betsileo Woolly Lemur (A. betsileo)]] Propithecus (Sifakas) P. diadema group: Diademed Sifaka (P. diadema) · Silky Sifaka (P. candidus) · Milne-Edwards' Sifaka (P. edwardsi) · Perrier's Sifaka (P. perrieri) · Golden-crowned Sifaka (P. tattersalli) P. verreauxi group: Verreaux's Sifaka (P. verreauxi) · Coquerel's Sifaka (P. coquereli) · Decken's Sifaka (P. deckenii) · Crowned Sifaka (P. coronatus) Category

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