Members of both sexes frequently use vocal communication. Vocalizations can even be used to distinguish between the individuals of this species. Their most notable call may be heard from 400 feet away and lasts for 4 to 5 seconds, longer than the calls of O. crassicaudatus (Rowe, 1996). Researchers have been able to group different calls based on their function and have observed alarm calls, sex calls, distress calls in response to fear, and infant click calls that elicit contact from the mother. Foot-rubbing may even be used for communication. Individuals rub their feet against another material and vary the intensity of the sound they produce. This behavior produces a sound that is not different from background noise, so foot-rubbing may allow small-eared galagos to communicate with conspecifics without alerting predators (Hagar, 2001). Small-eared galago males have been observed using foot-rubbing during aggressive encounters with other males.
Other forms of communication include the use olfactory signals. Otolemur garnettii has been observed to engage in urine washing, which it accomplishes by urinating on its hands and then rubbing the urine on the bottom of its feet. This behavior allows galagos to leave their scent on everything they touch. Males seem to engage in urine washing more often than females (Tandy, 1976). In addition to marking their scent on objects, individuals can communicate by sniffing one another.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: pheromones ; scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
Small-eared galagos are labeled as “lower risk” on the IUCN redlist and on Appendix II of CITES to limit international trade of this species.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: least concern
Small-eared galagos have no negative economic impact on humans.
Otolemur garnettii individuals are important members of the ecosystems in which they live and they may help in ecotourism ventures.
Positive Impacts: ecotourism
Small-eared galagos may have an important ecological role in the forests of East Africa because they eat fruit and insects. They may serve as seed dispersers for a variety of plant species, thus influencing the plant composition of the ecosystem.
Ecosystem Impact: disperses seeds
Small-eared galagos primarily feed on fruit and insects. About half of their diet is composed of fruit and half is composed of insects (Nash and Harcourt, 1986).
Animal Foods: insects
Plant Foods: fruit
Primary Diet: omnivore
Otolemur garnettii is also known as the small-eared galago or Garnett’s greater galago. This species is found in East Africa, ranging from the southern half of Somalia to Tanzania (Bearder et al., 2003) and on the island of Zanzibar (Groves, 2001).
Biogeographic Regions: ethiopian (Native )
Middle to high canopies in coastal, riverine, and highland forests form the natural habitat for small-eared galagos. They are also found in farmland plantations.
Average elevation: 5 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; scrub forest
Other Habitat Features: agricultural
Small-eared galagos can live for up to 15 years (Bearder, 1987).
Range lifespan
Status: captivity: 15 (high) years.
Average lifespan
Status: captivity: 14.0 years.
Average lifespan
Sex: female
Status: captivity: 15.0 years.
Average lifespan
Sex: male
Status: captivity: 15.7 years.
Otolemur garnettii are relatively small members of the genus Otolemur, with short ears. They were once considered subspecies of Otolemur crassicaudatus. Average ear length is 45 mm compared to the larger ear length of 62 mm in O. crassicaudatus (Rowe, 1996).
Small-eared galago males are only slightly larger than females. Adult males weigh an average of 794 grams, females weigh 734 grams (Fleagle, 1999). Otolemur garnettii has a thick and bushy tail that is longer than its entire body. Total body length averages 266 mm and tail length averages 364 mm (Rowe, 1996).
Small-eared galagos can be recognized by the red to gray-brown color of their pelage and by the presence of a brown, white, or black tip on their tail (Rowe, 1996). Their faces are uniformly colored (Groves, 2001). There are four subspecies of small-eared galagos that can be distinguished by the coloration of their fur (Groves, 2001). Otolemur garnettii garnettii has slightly greenish tones in its red-brown fur, the yellow color of its underside, and the presence of black tip on the last half of its tail. Otolemur garnettii panganiensis lacks green tones in its pelage and only possesses a black tip on the last quarter of its tail. Otolemur garnettii lasiotis is more gray than O. g. garnettii and tends to have a white-tipped tail. Otolemur garnettii kikuyuensis is characterized by its yellow-white underside, an iron gray pelage, and a black tip on the last quarter of its tail (Groves, 2001).
Range mass: 721 to 822 g.
Range length: 230 to 338 mm.
Average length: 266 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic
Sexual Dimorphism: male larger
Average basal metabolic rate: 3.927 W.
The most likely predators of small-eared galagos are genets (Genetta tigrina) and puff adders (Vipera lotievi) (Nash, 1983).
Known Predators:
The O. garnettii mating system is usually described as promiscuous, as both males and females have multiple mates. The act of mating in this species can take up to 120 minutes. It has been suggested that the extremely long duration of mating in this species is one way that males guard females from other males (Rowe, 1996).
Mating System: polygynandrous (promiscuous)
In the wild, O. garnettii has been observed breeding seasonally once each year between August and October (Nash and Harcourt, 1986). Captive populations can give birth throughout the year, which indicates that females have a continuous estrus cycle (Masters et al., 1988). Females usually give birth to one infant and members of both sexes reach sexual maturity when they are about 20 months old (Nash and Harcourt, 1986). Weaning occurs after approximately 140 days (Rowe, 1996).
Breeding interval: In the wild, breeding occurs once every year, usually between August and October.
Breeding season: Mating can occur throughout the year.
Average number of offspring: 1.
Range gestation period: 130 to 135 days.
Average gestation period: 130 days.
Average weaning age: 140 days.
Average time to independence: 4-5 weeks.
Range age at sexual or reproductive maturity (female): 12 (low) months.
Average age at sexual or reproductive maturity (female): 20 months.
Range age at sexual or reproductive maturity (male): 12 (low) months.
Average age at sexual or reproductive maturity (male): 20 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 46 g.
Average number of offspring: 1.
Parental investment seems to be provided only by mothers. They carry infants in their mouths but leave them while foraging (Rowe, 1996). Before weaning, mothers provide offspring with high-energy milk and protect them from predators and other dangers.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female)
The northern greater galago (Otolemur garnettii), also known as Garnett's greater galago, Garnett's galago, or the small-eared greater galago, is a nocturnal, arboreal primate endemic to Africa.
Four subspecies of Otolemur garnettii are recognized:
This species has a large body size relative to other galagos. The ears are small relative to the round head with short, wide snout. The eyes are large and binocular.[3] The dentition formula is 2:1:3:3.[4]
The coloration depends upon subspecies: O. g. garnetti exhibits green-tinged reddish brown dorsal pelage. The ventral side is yellow and the terminal half of the tail is black. O. g. lasiotis has lighter and more gray toned fur than O. g. garnetti. The ventral side is white and the tail's terminal end of the tail is only slightly darker than the rest with a white tip. O. g. kikuyuensis exhibits iron gray fur tinged with green on its back, flanks and limbs. The ventral side is yellow-white. The tail is usually light brown with the terminal quarter being black. O. g. panganiensis is reddish brown to gray lacking the greenish hints in other species, while the ventral surface varies from white to yellow. The terminal quarter of the tail is dark brown or black.[4]
The northern greater galago has a head-and-body length of 23–34 cm (26 cm average), a tail length of 31–44 cm (average 36 cm) and body weight of 0.5–1 kg (mean 0.75 kg).[3] This species exhibits significant degree of sexual size dimorphism with males larger than the females. This is due to bimaturism, where males have a longer period of growth and have an average 19% greater body mass than females.[5] The average male is 794 g and the average adult female is 734 g.[4]
The species is found in coastal regions of East Africa ranging from the Juba River in Somalia to the Ruvuma River in Tanzania. It also can be found inland throughout the Kenyan highlands and on the islands of Zanzibar and Pemba.[3] The species is restricted to coastal and riverine forests or Kenyan highland forest. It does not inhabit woodland savannah.[3] The actual geographic range of each subspecies is as follows: O. g. garnetti is restricted to Zanzibar and the Pemba Islands. O. g. lasiotis is found along the Kenyan coast as far north as the Juba River and south to Tanga Region, Tanzania. Its range extends inland to the Taita Hills and Kibwezi. O. g. kikuyuensis is found in the Kenyan Highlands. O. g. panganiensis is found throughout Tanzania from the border of Mozambique north to Tanga.[4]
The northern greater galago is a nocturnal predominantly arboreal primate. During the day, they sleep alone in trees and emerge at night. They tend to focus on a particular portion of their home range for several nights while foraging, then move on to concentrate on a new section after a short time.[4] They are quadrupedal and are capable of hopping short distances from tree to tree. Unlike their larger relatives the brown greater galagos, northern greater galagos can land hind feet first when leaping.[3] Their diet consists primarily of fruit and insects, approximately a 50/50 mix.[6] They are capable of learned behaviors to fish and consume mollusks when available.[4]
Greater northern galagos are solitary and live and forage in their home range marked by urine and scent gland on chest. Males and females disperse from their birth territory, with males doing so earlier and moving farther away.[4] Males and females do not have ranges that overlap with same sex and same-aged individuals. Males have territories that overlap with several females. However, females tend to be dominant over males. Males tend to follow females around and females show more aggression to transient individuals passing through their home territory than do males.[4] These species are less social compared to Otolemur crassicaudatus likely due to the fact they are frugivorous. It is more profitable to exclude non related individuals from areas where fruit is available.[4] They still exhibit some social play. Social grooming is not present instead reciprocal licking performs function of grooming while minimizing social interaction.[4]
Male galago species possess very distinctive penile morphology that can be used to classify species.[7] The northern greater galago penis is on average 18 mm in length and width of shaft is even from body to bottom of tip. The baculum is clearly visible at the tip. The glans terminates with a characteristic set of curves which does not occur in any other species. The surface is spined with doubled headed or even tridentate penile spines pointing towards the body. They are less densely packed than in Otolemur crassicaudatus.[8][9][10]
Northern greater galagos are promiscuous in their sexual behavior. The female comes into estrus once a year in the spring. The male is drawn to a female in heat and emits a sex call. If the female is receptive, she will allow copulation with the male licking her head following intercourse. This process may be repeated.[4] The gestation period for this species is 130 days with females usually only having one offspring at any time. Twins are rare.[3][6] Mothers carry their infants with their mouths to nests and leave them while they forage, returning to nurse their young. Infants are weaned by the 5th week and reach sexual maturity by 20 months of age.[4]
A low-coverage genomic sequence of the northern greater galago, was completed in 2006.[11] As a 'primitive' primate, the sequence is particularly useful in bridging the sequences of higher primates (macaque, chimp, human) to close non-primates such as rodents. The current 2x coverage is not sufficient to create a full genome assembly, but will provide comparative data across most of the human assembly.
The northern greater galago (Otolemur garnettii), also known as Garnett's greater galago, Garnett's galago, or the small-eared greater galago, is a nocturnal, arboreal primate endemic to Africa.
