Propithecus edwardsiMilne-Edward's sifaka

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Geographic Range

Propithecus edwardsi is found only on the island of Madagascar which lies off the southwest coast of Africa. They are only found in a small area of southeastern Madagascar from the Mangoro and Onvine rivers in the north to the Rienana River in the south, within the Andringitra National Park. Formerly they probably occurred as far south as the Manampatrana River. A clinal gradient seems to be expressed between Propithecus edwardsi and Propithecus diadema due to a change in environments. They are both found in the same area but P. diadema is found on more inland mountain ranges. ("IUCN Redlist", 2008; Konstant, et al., 2006; Tattersall and Sussman, 1975; Tattersall, 1982)

Habitat

Milne-Edward's sifakas live on the eastern coast of Madagascar in the coastal mountain range in primary and secondary forest habitats from 600 to 1600 m elevatiion. Forested habitats in these mountains have been reduced by human exploitation, although areas are now protected in refuges. ("IUCN Redlist", 2008; Konstant, et al., 2006; Tattersall and Sussman, 1975; Tattersall, 1982)

  • Range elevation
    600 to 1600 m
    1968.50 to 5249.34 ft

Physical Description

Milne-Edward's sifakas are black or chocolate brown sifakas with white patches on the hind legs and back. These white patches are not always present and sometimes are replaced by silver-tipped hairs. They have a short, naked black face with forward facing eyes for increased depth perception. The ears are also naked but generally covered by the fur on the head. Males have a dark black or brown gular gland. Their eyes are orange-red. Head and body length is from 42 to 52 cm, tail length is from 41 to 48 cm, and weight is from 5 to 6.5 kg. (Konstant, et al., 2006; Tattersall and Sussman, 1975)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    5 to 6.5 kg
    11.01 to 14.32 lb
  • Range length
    42 to 52 cm
    16.54 to 20.47 in

Reproduction

Milne-Edward's sifakas are generally not monogamous for life. Family groups normally have one adult pair which reproduces. The rest of the family group is usually the offspring of this pair. During the mating season, towards the end of May, males sometimes move through groups, which helps to maintain diversity in the gene pool. Milne-Edward's sifakas currently tend to live in somewhat larger groups because of the restriction of their home ranges due to habiat loss. Males use their gular glands to stimulate estrus in females. They mark trees and branches and even mark the fur on the head and back of the members of the opposite sex. Males follow females smelling their genitalia to determine mating readiness. (Tattersall, 1982)

Milne-Edward's sifakas reproduce slowly. Females reproduce every other year, with birth in June and July. Family groups tend to have one pair of breeding adults, the rest of the group are their offspring from past seasons. Groups typically only grow by one or two new members every breeding season. ("IUCN Redlist", 2008; Tattersall and Sussman, 1975; Tattersall, 1982)

  • Breeding interval
    Females breed every other year.
  • Breeding season
    End of May
  • Range number of offspring
    1 to 2
  • Range gestation period
    17 to 22 weeks
  • Average weaning age
    2 months
  • Average time to independence
    8 months

Milne-Edward's sifaka young are carried on their mother's stomach until they are ready to latch onto their backs at about 3 to 4 weeks old. Once an infant sifaka starts to try climbing and leaping on its own, it is not unusual to see them fall. Sifakas learn by watching adults. When a mother sifaka sees that her young as fallen, she goes to take care of it. Females are usually in charge of taking care of the infants. However, it is not uncommon to see male sifakas providing food to females to give to their young and sometimes the young of others. (Tattersall, 1982)

  • Parental Investment
  • precocial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • male
      • female
    • protecting
      • female
  • post-independence association with parents
  • extended period of juvenile learning

Lifespan/Longevity

Milne-Edward's sifakas can live a long time and reproduce slowly. Almost half of all young Milne-Edward's sifakas do not survive beyond 1 year because of predation and stress associated with habitat loss. Some mortalities of young are the result of infanticide by males from outside of family groups. (Konstant, et al., 2006; Tattersall and Sussman, 1975; Tattersall, 1982)

Behavior

Milne-Edward's sifakas are found in small family groups of 3 to 9 individuals. They use vertical clinging and leaping to move through their complex, forested habitats. Their excellent depth perception is used to carefully pick their landing spot. They use their powerful hind legs to launch themselves from a tree, then swing their body around in mid-leap to land hind legs first on the target tree. They do not move around on ground well because they have short legs and longer arms. Their feet are semi-digitigrade and they have an opposable hallux for clinging to branches. While foraging they move more slowly on thinner branches. They use larger trees and branches for travelling. They have a tooth comb formed by their bottom incisors that is used for personal and social grooming. Play behaviors seem to occur more during the wet season and grooming occurs during periods of rest. Occasionally members of the family group greet each other with a brief nose-touch. (Konstant, et al., 2006; Tattersall and Sussman, 1975; Tattersall, 1982)

Home Range

Groups of Milne-Edward's sifakas typically range over 100 to 250 hectares. Population densities are estimated at about 8 individuals per square kilometer. (Konstant, et al., 2006; Tattersall, 1982)

Communication and Perception

Milne-Edward's sifakas use different sounds to communicate. “Moos” are used to inform others of group’s location. Warning calls include a sudden “zusss” sound to warn of enemies on the ground and barking, which warns of aerial threats. When they are lost, individuals whistle to let their group know where to find them. Allogroooming is a form of tactile communication and it is likely that other forms of touch and body language are used among individuals. Scent marking by males is a form of sexual communication. (jrank.org, 2009)

Food Habits

Milne-Edward's sifakas are mainly frugivores, but they also eat leaves, seeds, and flowers. They eat a wide variety of plants on a daily basis and throughout the year, with their diet varying with seasonal availability of foods. (Gould and Sauther, 2006; jrank.org, 2009; Konstant, et al., 2006)

  • Plant Foods
  • leaves
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit
  • flowers

Predation

Milne-Edward's sifakas are preyed on by fossas (Cryptoprocta ferox). In order to avoid these predators they use their jumping speed which surpasses the speed of a fossa in the trees. Young may also be preyed on by large raptors, although this has not been documented. (Tattersall and Sussman, 1975; Tattersall, 1982; Tattersall and Sussman, 1975; Tattersall, 1982; Tattersall and Sussman, 1975; Tattersall, 1982; Tattersall and Sussman, 1975; Tattersall, 1982)

Ecosystem Roles

Milne-Edward's sifakas eat fruit which helps to disperse the seeds of the trees they forage in. They also help to create awareness of endangered endemic species and generate support for forest conservation in Madagascar. (Gould and Sauther, 2006)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Milne-Edward's sifakas are sometimes hunted for food, but hunting is restricted due to difficulty acquiring guns. They also create a need for selective logging so that the remaining forest has the characteristics necessary to support populations of Milne-Edward's sifakas. They are an important and charismatic member of native Malagasy forests. (Tattersall, 1982)

Economic Importance for Humans: Negative

Milne-Edward's sifakas have no recorded negative impacts on humans. (Tattersall, 1982)

Conservation Status

Milne-Edward's sifakas are endangered primarily because of habitat loss. Over the past thirty years the total wild population has decreased by more than 50%. It is predicted that the population will experience another 50% decrease over the next three years. Loss of habitat is due to logging, gold mining, and illegal rum production. Other human impacts include hunting, mostly in the northern part of their habitat. Hunting and deforestation are considered the most serious threats to Propithecus edwardsi populations. In an effort to help conserve the species there are a few national parks set aside in their range. There are reports of them living in some forests outside of these parks. There are no known captive populations. ("IUCN Redlist", 2008)

Contributors

Lorraine Negron (author), University of Michigan-Ann Arbor, Robin Weber (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor, Tanya Dewey (editor), Animal Diversity Web.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

young precocial

young are relatively well-developed when born

References

2008. "IUCN Redlist" (On-line). Accessed April 08, 2009 at http://www.iucnredlist.org/details/18359.

Gould, L., M. Sauther. 2006. Lemurs: Ecology and Adaptations. New York: Springer.

Konstant, W., F. Hawkins, E. Louis, O. Langrand, J. Ratsimbazafy, R. Rasoloarison, J. Ganzhorn, S. Rajaobelina, I. Tattersall, D. Meyers. 2006. Lemurs of Madagascar. Colombia: Conservational International.

Tattersall, I. 1982. The Primates of Madagascar. New York: Columbia University Press.

Tattersall, I., R. Sussman. 1975. Lemur Biology. New York and London: Plenum Press.

jrank.org, 2009. "Sifakas, Avahis, and Indris: Indriidae" (On-line). Animal Life Encyclopedia. Accessed July 27, 2009 at http://animals.jrank.org/pages/2952/Avahis-Sifakas-Indris-Indriidae.html.