Geographic Distribution and Habitat
The white-collared lemur (Eulemur cinereiceps), also called the white-collared brown lemur or the gray-headed lemur, is endemic to a thin strip of tropical lowland and montane forest in southeastern Madagascar, from the Manampatrana River south to the Mananara River. They have one of the most restricted ranges of all the true lemurs, and only about 270 square mi (700 square km) of habitat remains. Madagascar’s forest is sadly dwindling and, coupled with human-caused climate change, the amount of habitat suitable for white-collared lemurs is expected to be dramatically reduced even further in the coming decades.
Prior to 2008, white-collared lemurs were known by the scientific name Eulemur albocollaris. A 2008 study found that the populations known as E. albocollaris were actually synonymous with gray-headed lemurs (E. cinereiceps), a species that had already been described. The older scientific name, E. cinereiceps, was kept, and both common names are now used to describe the same species.
Size, Weight, and Lifespan
White-collared lemurs have an average body weight of 4.4–5.5 lbs (2–2.5 kg), with no significant weight difference between males and females. Their bodies measure about 16–18 inches (40–45 cm) long, and their tail adds another 20–22 inches (50–55 cm) of length. They are believed to live to an age of about 20–25 years.
Male white-collared lemurs have an overall gray body, transitioning to a warm buff color on their undersides. Females are reddish brown over most of their bodies. As one of their common names implies, the hair on their heads is gray. Their other common name comes from the males’ fluffy white “collar” under their chin and down their neck towards their chests. Females have a less distinct reddish-brown beard. Males may also have a dark brown stripe down the center of the back and tail. They have small ears and a rather pointy snout. Their large eyes are a beautiful orange color, and stand out brilliantly against the black of their faces. They have a long, fluffy tail that helps them to balance, and powerful hind legs—an essential for their leaping lifestyle.
Ex situ conservation:
Conservation actions that occur outside of the species’ natural habitat, such as captive breeding programs in zoos.
A society in which the members of a social group break off into smaller groups and then rejoin as a larger group.
The act or process of mating organisms of different varieties or species to create a hybrid.
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The diet of white-collared lemurs is dominated by fruit. In fact, those living along the coast, where fruit is abundant, are some of the most frugivorous (fruit-eating) lemurs in all of Madagascar. They also supplement their diet with leaves, flowers, nectar, mushrooms, and insects. Nectar is a particularly important food source in the dry season when other foods are less abundant.
Behavior and Lifestyle
White-collared lemurs are arboreal (tree-dwelling) and move about quadrupedally (on all four limbs), leaping frequently with their powerful hind legs. They tend to stay in a vertical posture as they grip onto tree trunks and branches. They most often stick to the upper layers of the forest and favor forest edges. White-collared lemurs are thought to be cathemeral, meaning that they have irregular periods of rest and activity, awake both at night and during the day. This may be a response to resource scarcity, as members of a group can take advantage of the full 24 hours of the day to forage, rather than only foraging during the day or at night.
White-collared lemurs have one of the most restricted ranges of all lemurs. Not only are they endemic to Madagascar, they are isolated to a small strip of habitat of which only about 270 square miles (700 square km) remains!
An apple (or tamarind) a day keeps the doctor away, and white-collar lemurs certainly believe that. They are some of the most fruit-dependent lemurs in Madagascar!
White-collared lemurs have fission-fusion social groups, with typical group sizes ranging from four to seventeen individuals. Fission-fusion groups are relatively rare in the mammal world, and it is thought that this group structure may be an adaptation to poor habitat quality. When populations are high and food availability is low, groups can reform to better ensure food access to all individuals. Unlike many other lemur species, neither the males nor the females have any sort of social hierarchy system that we know of.
White-collared lemurs communicate primarily through vocalizations and scent. Their snout holds an astounding amount of olfactory receptors that gives them an impressive sense of smell. They can detect danger and find their offspring using only their nose. They also have scent glands on their wrists and genital areas that can be used to mark habitat, alert other group members to threats, and play a role in mating.
Because of their shy nature, little is known about the reproductive habits of white-collared lemurs. It is not even known whether they are monogamous or polygynous. Based on closely related species, it is likely that white-collared lemurs mate between June and July and give birth between September and November. Gestation is likely about 120 days. Other closely related species give birth to one offspring typically, although twins may be born occasionally. The parenting style of white-collared lemurs is not well understood. However, if they are like many other lemur species, the baby likely stays with its mother during the first few weeks of life, clinging onto her chest then riding on her back. The father may also regularly carry his baby. Many lemur babies are weaned at about five to six months of age.
As fruit eaters, white-collared lemurs likely play an important role as seed dispersers. While predation data is lacking, they are likely a food source to animals such as fossas and hawks.
The International Union for Conservation of Nature lists white-collared lemurs as Critically Endangered (IUCN, 2019), appearing on the IUCN Red List of Threatened Species.
Over the last 24 years, or approximately three generation lengths, their population is believed to have dropped by more than 80%, a substantial loss. The main threats against white-collared lemurs are a decline in habitat area and quality, unsustainable levels of hunting, loss of genetic diversity, and climate change.
Since humans arrived on the island of Madagascar almost 2,000 years ago, it’s lost 80–90% of its natural forest cover and suffered mass extinctions of its native wildlife as a result. Between 1973 to 2017, the island lost an astounding 37% of its forest cover. Almost half of the remaining forest is located less than 330 feet (100 m) from the forest edge, an indication of significant habitat fragmentation. With the extremely limited range of the white-collared lemur, they are heavily threatened by loss of habitat. Sadly, white-collared lemurs are also an easy target of trappers, especially during the fruiting season of the strawberry guava. They are also hunted with firearms, particularly when they enter coffee plantations.
In 1997, a cyclone reduced white-collared lemur populations near the coast by about 50%. While populations have recovered from that storm, it is believed that it caused a significant reduction in genetic diversity within the species, which may be a threat as the overall population continues to decline. Additionally, about half of the remaining white-collared lemurs have undergone significant hybridization with red–fronted lemurs (E. rufifrons), further reducing genetic diversity. This is a major threat, as a species is much less likely to survive long-term with limited genetic diversity.
The last and arguably most overwhelming threat is climate change. Madagascar is considered to be one of the top five countries most impacted by climate change, despite contributing very little to its cause. In addition to causing immense hardship for the Malagasy people in the form of droughts and food shortages, climate change has and will continue to heavily impact the animal life of the island. It is predicted that climate change alone will result in a 99% reduction in white-collared lemur range between 2000 and 2080. Additionally, food shortages may drive people to hunt sensitive species, potentially to extinction. The changing climate will also affect the availability of resources for the lemurs. Their food sources may die out, migrate to new areas, or change their flowering and fruiting times, leaving the lemurs with times of the year without food. Drought has also been shown to cause some older lemurs to be unable to produce milk for their infants. Climate change is an overwhelming threat to a species that is already facing significant pressure from habitat loss, hunting, and loss of genetic diversity.
White-collared lemurs are listed in Appendix I of the Convention on International Trade in Endangered Species (CITES), an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival. The only protected areas they live in are the Manombo Special Reserve, the Agnalazaha Forest, which is managed by the Missouri Botanical Garden, and the Vondrozo Forest Corridor. Even in protected areas, there is significant pressure from humans. For example, 75% of the vegetation plots at the Manombo Special Reserve show signs of human disturbance. These protected areas cover less than 5% of the total remaining habitat available to white-collared lemurs in their range. A high priority for conservation is to protect the forest adjacent to the Manombo Special Reserve. As for ex situ conservation, there is only one zoo in the world that keeps a breeding group of white-collared lemurs, Linton Zoo in the UK.
- Johnson, S. E., et al. 2011. Gray-headed Lemur (Eulemur cinereiceps) Abundance and Forest Structure Dynamics at Manombo, Madagascar. Biotropica, 43(3), 371–379. http://www.jstor.org/stable/41241894
Written by K. Clare Quinlan, May 2022