NOSY BE SPORTIVE LEMUR
Geographic Distribution and Habitat
The Nosy Be sportive lemur (Lepilemur tymerlachsoni), also known as Hawks’ sportive lemur, lives on the island of Nosy Be in the Lokobe region of northwestern Madagascar. The species inhabits primary and secondary forests where foliage is lush and dense and where hollowed tree trunks offer them obscure places to nest peacefully. Their need to remain hidden and out of harm’s way makes sportive lemurs especially vulnerable to any degree of forest degradation.
Formerly considered a subspecies of Gray’s sportive lemur, Lepilemur dorsalis, recent genetic analysis has established the Nosy Be sportive lemur as a distinct species, L. tymerlachsoni.
Size, Weight, and Lifespan
Nosy Be sportive lemurs are medium-sized primates. Fully grown, they are approximately 19–27 inches (50–68 cm) in length. Based on data for other sportive lemur species, the Nosy Be variety weighs somewhere between 1 and 2 pounds (450–900 grams).
It is not currently known how many years the Nosy Be or other sportive lemurs can survive in the wild.
In ecology, the ability of an animal to avoid observation or detection by other animals through methods such as camouflage, nocturnality, subterranean lifestyle, and mimicry.
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Sportive lemur species all look extremely similar to one another, with most of their differences observable only at the genetic level. While they do (in countenance) resemble a weasel, their large eyes are strikingly “primate” in fashion. These are specially adapted for nighttime use and bear semblance to the eyes of fellow nocturnal (active at night) Strepsirrhine (moist-nosed) primate species like tarsiers, pottos, and lorises.
Their status as primates is also given away by their large hind legs. These act as powerful mechanisms for making daring leaps between trees as they traverse the canopy during their nightly forages. The long and flexible digits on their hands—complete with special pads—give them the grip and cushioning to achieve such leaps with confidence and grace.
The colors of sportive lemurs’ fur conveniently matches those of the tree trunks and branches to which they so regularly cling. The pelage of the Nosy Be sportive lemur is primarily a light brownish gray. A circle of darker gray fur covers his face. Out of this mask-like feature gaze his two bulbous red ochre eyes. The fur on his back has a redder hue with a black stripe running down the contours of his spine. His fur diffuses to a reddish gray complexion around his rear and extremities. This coloration continues down the length of his tail.
A Nosy Be sportive lemur eats a variety of leaves, fruit, and bark. Leaves make up the bulk of her diet, however. The abundant cellulose natural to such a diet makes digestion a lengthy ordeal. While special bacteria living in her gut aids digestion, she still spends most of her awake time resting while her fibrous meal is processed.
Behavior and Lifestyle
Sportive lemurs employ a number of cryptic strategies to defend themselves against predators. As primarily preventative measures, these behaviors define many of the species’ customs and habits.
As arboreal creatures, sportive lemurs rarely leave the comforts of the trees. Hollow trunks provide obscure places for individuals to nest. A nest provides him with a safe place to retreat during the day. At night he climbs out of his nest in search of food.
This solitary and clandestine lifestyle is not conducive to socializing. Beyond mating, child-rearing, and defending their territories from members of the same sex, there is little evidence to suggest that sportive lemurs are particularly social in nature. More research needs to be done to determine if other forms of social interactions take place between sportive lemurs, and to what extent.
Leaping between trees is a sportive lemur’s primary method of getting around. When traversing branches, she crawls on all fours. On the rare occasion that she ventures to the ground, she hops in a manner similar to kangaroos or her sifaka cousins.
Due to their cryptic defensive behaviors, the Nosy Be and other sportive lemur species are difficult for humans to study. Performing more thorough research is necessary to better understand the nuances of their behaviors and lifestyles.
The basal metabolic rate of sportive lemurs is one of the lowest for any primate, an adaptation that allows them to conserve energy efficiently and that aids the digestion of toxic chemicals found in their fibrous diets.
Sportive lemurs have been reported to occasionally re-ingest their own feces, possibly because it can still retain nutritive value post-digestion.
Sportive lemurs may be the smallest prosimians who rely on a strictly vegetarian and highly fibrous diet.
When the sun is up, a Nosy Be sportive lemur is likely curled up in his nest, safe and hidden from predators. He awakes at night to forage alone.
A female Nosy Be sportive lemur follows a very similar routine to a male, except when she is caring for an infant. Then, mother and offspring forage together.
Male or female, the cryptic routines of sportive lemurs make it difficult for humans to study them thoroughly. While their general preference for solitude suggests a mostly solitary existence, sportive lemurs may be more social than humans currently have evidence to suggest. More research remains to be done concerning the daily life and group dynamics of the Nosy Be sportive lemur.
Sportive lemurs make loud calls at night that sound similar to those made by crows. Researchers have not yet worked out the purpose of such calls. Other methods of communication have not been reported but are certainly possible. Only more research can reveal the degrees to which sportive lemurs, like the Nosy Be, communicate with one another.
Some sportive lemur species are known to “eavesdrop” on the alarm calls of other nearby animals, like birds and other lemurs. Such behavior allows the lemur to remain silent and not draw attention to themselves but still know when a predator is about. It is not yet known if the Nosy Be sportive lemur exhibits similar behavior, but its evidence in other sportive lemur species certainly makes the idea possible.
The reproduction and family bonds of sportive lemurs, like the Nosy Be, are not well researched. Sportive lemurs are possibly monogamous creatures, meaning that a male and female form a mating couple. However, there is no research suggesting that mating couples ever form permanent bonds. More likely, sportive lemurs form couples in order to mate—but males and females do not forage, travel, or spend time exclusively with one another beyond intercouse.
While other sportive lemurs are known to mate seasonally, the Nosy Be’s mating season is undetermined. Generally, Nosy Be births have been observed to take place between August and November.
Females give birth to a single offspring. The role she plays in her baby’s upbringing is currently unclear. But it can be assumed that she cares for him until he is ready to break out on his own. This process, from gestation to the time he is weaned, is one that more research is needed to clarify.
There is no evidence to suggest that male sportive lemurs play any role in their offspring’s upbringing.
The roles that sportive lemurs, like the Nosy Be, play in their ecosystems is unclear and remains to be researched.
The Nosy Be lemur is preyed upon by the Madagascar harrier hawk and the Madagascar buzzard.
The Nosy Be sportive lemur is classified as Critically Endangered by the International Union for Conservation of Nature (IUCN, 2018), appearing on the IUCN Red List of Threatened Species.
The species is affected most drastically by habitat loss and forest degradation. The conversion of forests into farms severely limits the number of sites where sportive lemurs can make their nests. Without viable nesting sites, individuals lack safe places to retreat during the day when they are meant to be asleep, leaving them vulnerable to predation.
Humans local to the island of Nosy Be are known for catching Nosy Be sportive lemurs for illegal sale to tourists as pets. The needs of primates are complex and signature to each species. Keeping any species of a primate as a pet essentially guarantees them a slow and painful death—the Nosy Be sportive lemur is no exception.
As the Nosy Be sportive lemur only lives on this one island off the coast of Madagascar, these practices have caused their numbers in the wild to decline rapidly.
Efforts to conserve sportive lemur species currently consist of erecting nesting boxes in areas where logging has destroyed their habitats.
The Nosy Be sportive lemur only lives in one protected area. This is the Lokobe Strict Reserve on the southeastern part of Nosy Be island.
Much research still needs to be done concerning the Nosy Be sportive lemur’s taxonomy, population size, distribution, and ecological roles, and the ways in which the species is threatened. Fortunately, since 2011, the environmental non-governmental organization Frontier has been looking into some of these concerns in order to gain a better understanding of the species and determine the best methods for its conservation.
Written by Zachary Lussier, December 2019