BEMARAHA WOOLLY LEMUR
Geographic Distribution and Habitat
Bemaraha woolly lemurs, also known as John Cleese’s avahis, appear only in the Tsingy de Bemaraha region of West Madagascar, north of the Manambolo River. Surveys of the wider area did not reveal any woolly lemurs, which suggests that the species inhabit an extremely limited range. They have been recorded primarily in subhumid, dry deciduous forests as well as forests near seasonal rivulets and swamps close to the Bemaraha massif.
Size, Weight, and Lifespan
Average sizes, weights, and lifespans for Bemaraha woolly lemurs are difficult to assess given their limited range and population size. Only one individual has ever been captured: an adult male, who weighed 1.82 pounds (830 g). Other woolly lemur species weigh an average of 1.32–2.65 pounds (600–1200 g) and measure between 12–20 inches (30–50 cm). Life expectancy for both Bemaraha woolly lemurs and other woolly lemurs is unknown.
The Bemaraha lemur’s facial fur is slightly paler than that of the upper forehead and crown. A thin chevron of black traces the border between face and forehead, after which their fur shifts from beige to light-brown. Paired with black-lidded and starkly maroon eyes, the Bemaraha lemur wears a panoply of dusky contrasts. Their body is mostly the same color as their forehead and crown. However, their chests, their bellies, and the insides of their arms are light gray. The backs of their legs are white. Their tale is beige or brown-gray, with a slight reddishness tone at the root.
Few primatologists have conducted detailed observations of the Bemaraha lemur’s diet and feeding behaviors. A 1991 field study found that they feed on buds, sprouting buds, and young leaves; a later survey suggests that the lemur may exhibit behaviors similar to western woolly lemurs, Avahi occidentalis, which rely on relatively rare but large tree species for food.
Behavior and Lifestyle
Bemaraha woolly lemurs are only active at night. The aforementioned 1991 field study recorded three distinct peaks of nocturnal activity. Other woolly lemur species, like western woolly lemurs, Avahi occidentalis, travel in male-female pairs—this is potentially true of Avahi cleesei, though it has not been directly recorded. Bemaraha woolly lemurs use multiple sleeping sites (5 over a 10-day period, in the 1991 field study).
John Cleese, the comedian and former Monty Python member, is the best-known advocate of lemur conservation—Avahi cleesei was named in his honor. He has starred in several films, documentaries, and shorts about lemurs, including Fierce Creatures and In the Wild: Operation Lemur with John Cleese. The latter film tracked an effort, partially funded by Cleese, to reintroduce black-and-white ruffed lemurs into Madagascar’s Betampona Reserve.
Very little is known about the daily life and group dynamics of Bemaraha woolly lemurs other than the facts mentioned in the previous section. However, we can cautiously draw information from related species. Since Bemaraha woolly lemurs live in male-female pairs, like western woolly lemurs, it is plausible that the group dynamics of the latter apply to the former. For instance, in western woolly lemur pairs, conflicts are initiated and resolved by the female, and females tend not to submit to their male partners. Non-pair copulation has never been recorded in Avahi species.
Three classes of vocalizations have been recorded in Bemaraha woolly lemurs: “vou-hy” calls, whistles, and growls. Vou-hy calls do not appear to be uttered at regular times, though they coincide with activity peaks. Along with whistles, vou-hy calls are often answered by a corresponding sound from another individual. Whistles and growls are much less loud and conspicuous than vou-hy calls.
No information (save that already mentioned) about reproduction and family has been directly recorded for Bemaraha woolly lemurs, and little has been recorded about comparable species. In western woolly lemurs, male-female pairs travel with their offspring, but it is unknown whether this is also true of Bemaraha woolly lemurs. Other woolly lemurs gestate for 4–5 months, after which offspring ride on their mother’s back for a few months before being weaned at 6 months. After roughly a year, woolly lemur offspring can live independently.
The ecological role of Bemaraha woolly lemurs is unclear. Their (probable) specialized relationship to a few rare tree species may imply that they help, perhaps through seed dispersal, to perpetuate those trees in their geographical range, and their small size makes it likely that larger animals prey upon them.
The International Union for Conservation of Nature lists Bemaraha woolly lemurs as Critically Endangered (IUCN, 2018), appearing on the IUCN Red List of Threatened Species.
Their range is less than 200 square miles (500 square kilometers), and as of 2005, their population, extent of occurrence, area of occupancy, habitat quality, and number of mature individuals were all declining. The subhumid forests in which they reside are under continuous pressure from bushfires and human activity. It is overwhelmingly likely that the species would vanish if these forests disappear since the Tsingy de Bemaraha is their only recorded habitat.
Bemaraha woolly 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.
Lemurs are the most threatened group of mammals in the world. Consequently, dozens of organizations are working to help lemurs in Madagascar and elsewhere. In 2015, the IUCN created the Lemur Conservation Network to connect conservation organizations, research groups, and zoos focused on preserving lemur populations; in 2021, the LCN became an independent non-profit. Their member organizations focus on (among other issues), community support, reforestation, pet education, and rehabilitation. For Bemaraha woolly lemurs, reforestation (and prevention of future habitat loss) is the most crucial effort, since they depend so heavily on the particular subhumid deciduous forests in which they reside.
Further research on Bemaraha woolly lemurs is absolutely crucial. Very little information is available on the species—unsurprisingly, given its relatively recent discovery, nocturnal habits, limited range, and low population size. Nonetheless, a concerted effort to learn more about the extent and lifestyles of Bemaraha woolly lemurs (and other woolly lemurs) will be necessary to guide conservation efforts. In 2012, the IUCN recommended surveys to identify additional populations and individuals; these have yet to be carried out.
Written by Eli Elster, June 2023