MOUNTAIN DWARF GALAGO
Geographic Distribution and Habitat
The mountain dwarf galago is also known as the Amani dwarf galago and the Uluguru bushbaby. The mountain dwarf galago is endemic to Eastern Arc Mountains of Tanzania, which is rich in biodiversity, but also one of the most at-risk ecosystems on the planet. They are found at altitudes of 3,937–6,522 feet (1,200–2,000 meters) and prefer the mid-to-high canopy of tropical forest habitats found within the Eastern Arc Mountains. As of 2020, a potential subspecies of the mountain dwarf galago has been documented (on film) in the Taita Hills of Kenya. This subspecies lives in the relatively cool montane forests at an altitude of 4,593–6,400 feet (1,400–1,950 meters).
The mountain dwarf galago was, until 1995, classified as a subspecies of the Demidoff’s dwarf galago (Galagoides demidoff). The separation occurred based on their unique calls.
Until 2017, the mountain dwarf galago was classified as one of the seven species of “dwarf galagos” in the Galagoides genus found disparately across Africa. Based on a closer examination of these galagos’ communication calls, skull shapes, teeth arrangements, and molecular genetic data, researchers named an eastern dwarf galago genus, Paragalago, comprising 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. The 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 galagos in the original Galagoides genus are found in westerly regions of Africa.
Size, Weight, and Lifespan
Mountain dwarf galagos have a head-body length of 5–5.5 inches (125–138 millimeters), and weigh between 2.6 and 3.7 ounces (74–98 grams). The tail is longer than the body, measuring between 6.7 and 7.8 inches (169–199 millimeters). The mountain dwarf galago is one of the smallest galago species. Sexual dimorphism has not been observed by scientists. Captive galagos live into their mid-teens, but little is known regarding the specific lifespan of the mountain dwarf galago.
The mountain dwarf galago has dark reddish fur, with a yellow-white stripe trailing down its nose, and dark brown rings around its eyes. Similar to the Demidoff’s dwarf galago, their muzzle appears “turned up,” and their bushy tail is reddish at the base and darker at the tip.
Like other galagos, which are nocturnal (active at night) and rely heavily on their sense of hearing, the mountain dwarf galago has large independently moving bat-like ears and big saucer-like eyes to navigate within the environment and find food. In addition, like other galagos, they have a specialized grooming claw known as a “toilet claw,” and long hind limbs relative to their forelimbs, which they use to leap from tree to tree.
Not much is known about the mountain dwarf galago’s diet, but scientists believe that it is similar to that of other galagos. That is, the species is omnivorous, with a diet consisting of fruits, insects, and gum. Diet proportions depend on the time of year, food availability, and whether or not an individual [female] is pregnant or lactating.
Behavior and Lifestyle
Mountain dwarf galagos are nocturnal, arboreal (spend most of their time in the trees), and primarily solitary. Mountain dwarf galagos sleep during the day either alone or in groups ranging from two to ten individuals, leave their nest at around sunset, and forage for food at night close to the ground, at mid-story, and higher in the canopy. If living in a group, members typically split up to forage, and navigate the canopy by climbing, running, and leaping on all fours. Individuals return to the sleeping nest before dawn. Several factors can affect nighttime rituals; individuals may head back to the nest early when out in colder temperatures, while bright moonlit nights may encourage prolonged activity.
Nest building and preference varies between the various species of galago. Some studies note that the mountain dwarf galago appears to be quite particular about its sleeping arrangements, preferring to sleep in a self-built nest. However, other studies have found that the species may make use of tree holes, as well as tangles of vegetation.
Predators of the mountain dwarf galago include raptors, genets, snakes, and blue monkeys (Cercopithecus mitis).
A bushbaby? Yes! Galagos are also called bushbabies, which get their name from their calls, which can resemble that of a human baby.
When sleeping during the day, mountain dwarf galagos fold their ears to cover their earholes. This prevents the sounds in their forest habitat from waking them up.
Though primarily solitary, individuals may sleep together in family groups. Studies have not shown any sort of hierarchy among individuals. When it comes to galagos in general, males tend to have a broader home range than females, which may overlap those of females; females maintain a territory that is shared with their female offspring, while males leave their mothers’ territory after puberty to establish a territory of their own.
The calls of the mountain dwarf galago and other galagos have provided researchers with important clues on how to differentiate species from one another. The mountain dwarf galago’s unique rolling, double unit repetitive call helped researchers first classify their species.
Communication calls were also key to confirming that the mountain dwarf galago and four other species belong in the genus Paragalago in 2017. Specifically, it was 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 identified in Paragalago.
The mountain dwarf galago is most often heard at dusk, but the alarm call has been heard throughout the night.
Like other galagos, the mountain dwarf galago scent-marks using urine and secretions from special scent glands to communicate with other individuals.
Much about the reproduction and family life of the mountain dwarf galago is unknown and requires further research. Female galagos vary in the number of offspring they birth each year. The mountain dwarf galago typically gives birth to one or two young per year, and gestation typically lasts three to four months. Mothers are the sole caregiver of their young, and bonds are maintained by grooming. Most galago mothers transport their infants in their mouths, and when foraging away from the sleeping nest, they settle their young in tree holes or vegetation to hide them from predators while they forage alone.
Sexual maturity is reached across galago species between eight and eighteen months of age.
The mountain dwarf galago serves as a prey species for a variety of animals, including genets, raptors, snakes, and blue monkeys. Also, to the extent that they include fruit in their diet, they may be considered seed dispersers, thus playing a role in repropagating rapidly disappearing forests in their habitat. They can also be considered pest controllers, due to their diet consisting of insects.
The International Union for Conservation of Nature lists the mountain dwarf galago as Vulnerable (IUCN, 2019), appearing on the IUCN Red List of Threatened Species.
The mountain dwarf galago has been named one of the world’s most at-risk primates. Their numbers continue to decline due to a number of factors. While their home in the Eastern Arc Mountains is rich in biodiversity, it is also one of the most at-risk ecosystems in the world. The main threats to the mountain dwarf galago and their forest habitat are logging and wood harvesting, as well as land conversion for agricultural use. Fire and fire suppression are other, albeit lesser causes for the decline in mountain dwarf galagos and their habitat. All of these factors:
• Severely fragment their habitat
• Continually decline the occurrence of the mountain dwarf galago’s extent within their geographic range
• Lower habitat quality and size
• Lower the number of individuals who reach maturity
The lack of thorough research on the mountain dwarf galago, coupled with the physical resemblance to other nearby galago species, has also led to misconceptions of the geographic range. As with all galagos, their species-unique calls are key to differentiating one from another, and getting a better idea of their range.
The mountain dwarf galago is listed in Appendix II 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.
Mountain dwarf galagos can be found in two protected areas of Tanzania: the Udzungwa Mountains National Park and the Udzungwa Scarp Forest Reserve. Their numbers fare better in these locations compared to unprotected areas.
The Taita Hills in Kenya, which also makes up part of the Eastern Arc Mountains, is another homestead of the mountain dwarf galago. As more galago species were discovered and named as unique taxon over time (largely due to research into their genetics, reproductive anatomy, and most unique between species, their vocalizations), mountain dwarf galagos, along with two other species (the Rondo dwarf galago, Paragalago rondoensis, and the Tanzania Coast dwarf galago, Paragalago zanzibaricus) have made their presence known in the Taita Hills! However, it’s possible these observations may be of a new subspecies of the mountain dwarf galago, tentatively called the Taita mountain dwarf galago. While this subspecies has not been formally identified, it was captured on film as part of a 2020 study. What an amazing achievement!
In-place education regarding mountain dwarf galagos and their conservation needs are included in international legislation, and subject to any international management and trade controls. Ultimately, along with further action(s) to control the reduction and degradation of the habitat, more research on the species’ taxonomy, range in numbers and population, and threats are needed to protect and ultimately save them from extinction.
Written by Sienna Weinstein, December 2023