MOUNTAIN DWARF GALAGO
Geographic Distribution and Habitat
Mountain dwarf galagos are also known as Amani dwarf galagos and Uluguru bushbabies. They are endemic to Kenya and Tanzania, specifically in the rare and rich habitat of the biologically significant Eastern Arc Mountains.
Of the five recently re-classified Paragalago species, mountain dwarf galagos live at some of the highest elevations of all (at 1,200-2,000 m, or 3,937-6,561 ft, above sea level). They prefer the mid-to-high canopy of submontane and montane tropical forest habitats.
Africa’s Eastern Arc Mountains rank as one of the most at-risk biodiverse ecosystems in the world, supporting a large number of endemic and nearly endemic species of animals and plants, including the mountain dwarf galago. The region is in dire need of conservation, as it is under continual threats of deforestation, a factor that contributes to the mountain dwarf galago’s severe vulnerability. Surveys conducted in the Eastern Arc Mountains suggest that the mountain dwarf galago can be found on only seven of the 11 mountains in the range.
Until 2017, the mountain dwarf galago was classified as one of the seven species of “dwarf bushbabies” in the Galagoides genus found disparately across Africa. Now, based on a closer examination of these bushbabies’ communication calls, skull shapes, teeth arrangements, and molecular genetic data, researchers believe there’s a distinction to be made within the genus. The proposed new Paragalago genus comprises the mountain dwarf galago and four other dwarf galago species, all of which are found in mountain and coastal forest habitats along the southeastern coast of Africa. They others are: the Kenya Coast galago, P. cocos, the Tanzania Coast dwarf galago, P. zanzibaricus, the Mozambique dwarf galago, P. granti, and the Rondo dwarf galago, P. rondoensis. The two remaining dwarf bushbabies in the original Galagoides genus are found in westerly regions of Africa.
Size, Weight, and Lifespan
Generally speaking, bushbabies are small, diminutive primates and the mountain dwarf galago is no exception. One of the smallest of galago species, the mountain dwarf galago only grows to about 5 in (12.7 cm) tall, with a tail that is longer than the body at 7 in (18 cm). They weigh an average of 3 oz (85.1 g). Scientists have not observed sexual dimorphism in this species.
In captivity, bushbabies live into their mid-teens, but little is known about the specific lifespan of the mountain dwarf galago species.
One of the biggest challenges in distinguishing between various species of bushbabies—and a contributing reason why so little is known about the mountain dwarf galago—is that they are not readily identifiable by appearance alone. In short, they’re hard to study. Some species are indistinguishable from each other; in other instances, there is significant variation in body size and fur color within the same species.
Primatologists note that this lack of physical diversity between species is likely due to their auditory adeptness: equipped with oversized ears, bushbabies tend to rely less on physical features and more on sounds to pick out members of their own species. Broadly speaking, bushbabies’ pale, bald ears can move independently of one another. Relative to body size, the bushbabies’ ears are the largest among all primates.
Scientists describe the mountain dwarf galago as having reddish-toned fur with a long and slender nose stripe of creamy yellow. Dark brown rings circle their saucer-like eyes and their bushy tail ends in a dark tip. Like other bushbabies, they have a toilet claw for grooming. The toilet claw is a specialized grooming claw common to prosimians.
Much is not known about the mountain dwarf galago’s diet, but researchers believe that their diet is similar to that of other bushbabies. That is, they are omnivorous, with a menu consisting of insects, fruit, and gum, proportions of which depend on the time of year, food availability, and whether or not the individual is pregnant or lactating.
Behavior and Lifestyle
The arboreal mountain dwarf galago is considered to be somewhat of a loner. During the day, he sleeps alone or with two to three other individuals (both male and female). At night, he navigates the canopy quadrupedally, likely climbing, running, and leaping on all fours. He tends to have a broader home range than his female counterpart.
As a nocturnal primate, the mountain dwarf galago will leave his nest around sunset, perhaps starting off with a small group but soon parting ways to forage alone. He spends a great deal of the night on the move, foraging for food close to the ground, at midstory, and higher in the canopy. He returns to the nest prior to dawn. Several factors can affect nighttime rituals; colder temperatures may send him back to the nest earlier and bright moonlit nights may keep him wandering longer.
Nest building and preference varies by bushbaby species. Some researchers note that the mountain dwarf galago appears to be quite particular about his sleeping arrangements, preferring to sleep in a nest of his own construction. Other researchers, however, have found that he may make use of tree holes and squirrel dreys made of twigs, dry leaves, and grass.
The calls of the mountain dwarf galago and other bushbabies have provided researchers with important clues on how to identify between galago species. The mountain dwarf galago’s unique rolling, double unit repetitive call helped researchers first classify its species.
Researchers also relied on communication calls to help confirm that the mountain dwarf galago and four other species belong in the new Paragalago genus (distinct from the Galagoides genus) in 2017. Specifically, the researchers found that the sounds the mountain dwarf galago makes during mating and when in danger (such as buzzy alarms, mobbing yaps, and advertisement calls) are like the calls made by the other species now identified in the new Paragalago genus.
The mountain dwarf galago gives birth to one or two young per year, with each gestation period lasting three to four months.
To the extent that mountain dwarf galagos include fruit in their diet, they may be considered seed dispersers and play a role in repropagating rapidly disappearing forests. They also serve as prey to other primates, including gray-cheeked mangabeys (Lophocebus albigena), blue monkeys (Cercopithecus mitis), and chimpanzees (Pan troglodytes).
The Internation Union for Conservation of Nature has assessed the mountain dwarf galago is Vulnerable (IUCN, 2019), noting that the species is at high risk due to habitat loss and forest degradation, both of which are the result of agricultural expansion and illegal logging.
In 2017, the International Union for Conservation of Nature (IUCN) and the International Primatological Society placed the mountain dwarf galago on its list of the 25 most endangered primates due to the fragility of its habitat.
The mountain dwarf galago’s habitat is under severe threat by continuing loss and degradation of its habitat from agriculture and timber harvesting. This places the entire species at risk. Its geographic range is severely fragmented. There is continuing decline in the extent of the galagos occurrence, the areas of its occupancy, the size and quality of its habitat, the number of locations where the mountain dwarf galago occurs, and the number of mature individuals.
In addition to the severe loss of its Eastern Arc Mountain habitat, the mountain dwarf galago may be hunted by natural predators including other primates and nocturnal predators, such as owls, genets, and snakes.
The mountain dwarf galago is listed as an Appendix II species by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which means that although there’s no immediate threat of extinction, close monitoring is warranted.
National parks and forest reserves in both Tanzania (the Udzungwa Mountains National Park and the Udzungwa Scarp Forest Reserve) and Kenya (the Taiti Hills Forest Reserve) help provide some protection for mountain dwarf galagos, but more research is needed to understand the full scope of work necessary to protect this species.
Written by Christine Regan Davi, March 2018