Sahamalaza Sportive Lemur

11th June 2010

The Sahamalaza sportive lemur was only discovered in 2004 and less than 3,000 individuals are estimated to remain in the wild. There are hardly any roads or vehicles in NW Madagascar where these lemurs live and there are no sportive lemurs in captivity anywhere in the world either… so unless you make a very special effort, you will never get to see one!

Physical Description: Sportive lemurs are nocturnal, so one of the main features about them are the large orange eyes, which are especially adapted for seeing in the dark. They also have a great sense of smell and the tips of their pointed little noses are wet like a dog’s and very sensitive. They weigh between around 700-900g each, but females are up to 200g heavier than males. Head and body length is approximately 26cm, and the tail is equally long. The colour of their fur has elements of grey and red-brown, but this is variable depending on light conditions and possibly age of individuals. They all have lighter belly fur, which ranges from grey to creamy coloured.
Habitat: The Sahamalaza sportive lemurs only live on the Sahamalaza Peninsula, which they were named after. It is situated in the NW of the island of Madagascar. Both the vegetation and climate of this area are transitional between the dry west coast and the humid rainforest region in the northwest. This forest region contains semi-deciduous and evergreen trees, and much of the peninsula is lined with mangrove forests and coral reefs.
Diet: The majority of the sportive lemurs’ diet consists of leaves, although they sometimes also eat fruit, flowers, latex, bark, and perhaps small insects and grubs. It is very rare for leaf-eating primates to be nocturnal, presumably because leaves are relatively low in sugars at night, since photosynthesis occors at a lower rate or not at all. The metabolic rates of Lepilemur are amongst the lowerst recorded in mammalian folivores, and they are amazingly adapted for surviving mainly on leaves despite their small size. Extreme laziness appears to be an important factor. Sportive lemurs have been found to be inactive for around 50% of their waking time, to sit around essentially doing nothing for up to 2hrs at a time and to travel on average only 343m per night. Prolonged rates of inactivity presumably allow the digestion and detoxification necessary due to low quality food and to reduce overall energy expenditure. A famous primatologist therefore suggested in the 1980s that Lepilemur can only fulfil their dietary requirements with the aid of caecophagy, i.e. eating their own poo. However, this behaviour was not observed in other long-term studies.
Life History: After a surprisingly long gestation period of 5 months, single offspring are born around November. This coincides with the beginning of the rainy season in Sahamalaza, when there is the most food available in the forest. Infants are carried in the mouth of the mother and, like in other sportive lemur species, they are presumably parked in dense vegetation whilst the mother is foraging for food. However, no studies of Lepilemur sahamalazensis infants or mothering behaviour have ever been carried out, and all information is based on anecdotal evidence. In other Lepilemur species, infancts were weaned at the after around two months, and the females provided all of their care. Older offspring may stay near their mothers and share the sleeping site for up to around two years. However, the different Lepilemur have varied social organisations, and this has not been studied in detail for Sahamalaza sportive lemurs. In the little observation time that has been spent with this subspecies, individuals were mainly found to occupy sleeping sites alone.
Associations: Sahamalaza sportive lemurs share their habitat with greater mouse lemurs (Mirza zaza), which are also nocturnal. They have been observed feeding in nearby trees, but no interactions have been witnessed. Another beautiful species of lemur that lives in the same region is the blue-eyed black lemur (Eulemur flavifrons). These larger lemurs are active both during the day and at night, which is an activity pattern referred to as “cathemeral”.  They have often been seen disturbing the sportive lemurs’ rest time by crashing around near their sleeping sites, and at night they have been observed to scare Lepilemur away from certain feeding trees.
Communication: Lepilemur defend their home ranges by territorial advertisement calls and aggressive displays. Along with the use of at least 9 distinctive calls, sportive lemurs were found to use loud call exchanges as a vocal display for signalling territory ownership, thereby limiting the amoung of direct fighting. There are also calls which sportive lemurs use specifically to inform their mate of food resources or to warn them about dangerous predators in the area.

The vocalisations of various species of Lepilemur have been described as extremely different, which scientists have found useful to tell the different species apart, since it’s a lot easier to listen to them than to do DNA analysis!  The Sahamalaza sportive lemurs’ calls have not yet been studied, but there are described as loud, strange calls that can be heard quite far away. Lemurs get their name from the fact that their calls often sound strange and spooky – the word “lemur” comes from the Latin word for “ghost”.

Although scent-marking is common in other prosimians, possible scent-marking behaviour was only rarely observed or not observed at all in Lepilemur studies. However, scent distribution may occur naturally and unnoticed by the observer due to their posture, which brings their genitalia into constant contact with tree-trunks. In order to move around their habitat,
Mating: Mating has been observed in the months of May and June in Sahamalaza sportive lemurs, and this appears to be the mating season for most sportive lemur species. During the mating season, males and females spend a lot more time together than during the rest of the year. In fact, males have been found to carefully guard females they have mated with. In some species of sportive lemurs, a male-female pair is formed once the animals have reached sexual maturity, and they spend their days huddled together in their sleeping site. It appears from short-term research that Sahamalaza sportive lemurs prefer to sleep alone, and spend most of the night searching for food on their own. However, couples have been seen to travel together for several hours at a time.
Other Behaviour: Lepilemur are described as “vertical clingers and leapers”, which means they rest in a vertical position and can bounce from one vertical stem to another thanks to an elongated femur. Very few of the jumps done by Sahamalaza sportive lemurs have been measured… but they definitely jump further than five metres easily. If you calculate the weight to distance ratio, you will find that a normal adult human would have to jump at least half a kilometre in one go to be as sporty as the sportive lemurs!
Conservation status of sportive lemurs in general: Although sportive lemurs appear to be widely distributed along the periphery of Madagascar in relatively high densities, many species and subspecies have received little scientific attention. This problem has been multiplied due to recent advances in genetic analyses, which have allowed the standard listing of only seven species of Lepilemur to be seriously questioned and many new sportive lemurs to be described. At least 22 distinct species are now thought to exist and a variety of additional subspecies have also been suggested. Several sportive lemur species are now in grave danger of extinction since they occupy shrinking, increasingly fragmented forest habitats Some species may become extinct even before they are discovered, or before sufficient data have been collected to implement effective conservation strategies.
Conservation of Lepilemur sahamalazensis: The Sahamalaza sportive lemur has been classified by the IUCN as “Critically Endangered”, which means they are one of the most threatened species in the world. This status was awarded due to an estimated population size reduction of 80% over a 10 year period due to habitat loss and hunting. The Sahamalaza sportive lemur is the first Lepilemur species, and indeed the first nocturnal lemur, to be included on Conservation International’s List of the World's Top 25 Most Endangered Primates in the world. Their forest habitat is constantly being burnt down for agricultural purposes and the wood is also logged. Nowadays, their habitat is restricted to a small, fragmented forest landscape on and immediately surrounding the Sahamalaza Peninsula. All over their range, they are being hunted by an increasingly large and hungry population of humans, and whether the recent creation of the Sahamalaza National Park will help to conserve them is unclear. Both researchers and tourists are encouraged to visit and study this fascinating creature and to help with its conservation.
Did you know?  Sahamalaza sportive lemurs like to sleep in tree holes or tangled vegetation during the day. This is a dangerous business since they could be spotted by birds of prey, boas or other possible predators. Therefore, they spend most of the daytime in looking out for predators and only take short naps in between staring into the distance in a sleepy state.