Hapalemur griseus (Link, 1795)
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publication ID |
https://doi.org/ 10.5281/zenodo.6638668 |
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DOI |
https://doi.org/10.5281/zenodo.6646132 |
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persistent identifier |
https://treatment.plazi.org/id/A70287F4-C258-FFA5-FFED-FE547964F9D3 |
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treatment provided by |
Carolina |
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scientific name |
Hapalemur griseus |
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Gray Bamboo Lemur
French: Lémur gris / German: Grauer Bambuslemur / Spanish: Lémur del bambu gris
Other common names: Eastern Gray Bamboo Lemur, Eastern Lesser Bamboo Lemur, Gray Gentle Lemur; Beanamalao Bamboo Lemur (gilbert), Ranomafana Bamboo Lemur (ranomafanensis)
Taxonomy. Lemur griseus Link, 1795 ,
Madagascar.
In 2001, C. P. Groves elevated three former H. griseus subspecies to full species as H. griseus , H. alaotrensis , and H. occidentalis . He did not, however, recognize the southern bamboo lemur, H. (griseus) meridionalis, which, in 2002, J. Fausser and coworkers considered to be a valid species. This left H. griseus as monotypic. In 2007, however, J. Rabarivola and coworkers described two new subspecies (ranomafanensis and gilbert). They were characterized by their own karyotypes, but described as subspecies rather than as distinct species because available molecular data did not distinguish them. Despite there being no good type localities for any of the Hapalemur taxa, Rabarivola retained Mantadia as the type locality for the nominate subspecies griseus . Three subspecies are recognized.
Subspecies and Distribution.
H. g. ranomafanensis Rabarivola et al., 2007 — CW & CE Madagascar, occurs in two, widely separated population pockets, one in the W in the forests of Tsingy de Bemaraha, probably as far as the Betsiboka River, and the other in the E in forests to the S of the Mangoro and Onive rivers (except Beanamalao, the type locality of gilberti). View Figure
Descriptive notes. Head—body 28-30 cm, tail 35-37 cm; weight 813 g ( griseus ) to 967 g (gilbertr). The nominate subspecies griseus and the “Ranomafana Bamboo Lemur” (H. g. ranomafanensis) are the smallest of the bamboo lemurs. Male and female Gray Bamboo Lemurs are similar in size. Coat color ranges from gray to olivaceous to rustbrown above, and lighter colored on the face and underparts (in “Beanamalao Bamboo Lemur,” H. g. gilberti, the underside is gray in its anterior part and reddish in the posterior). There are usually darker and more reddish patches on the head and shoulders. The muzzle is short, and ears are relatively large (smaller in Beanamalao and Ranomafana bamboo lemurs) but nearly hidden in the fur. The tail is gray to dark gray and relatively long, being ¢.120% of the head—body length.
Habitat. Primary and secondary, tropical moist lowland, and montane forest, generally in stands of dense bamboo and areas of bamboo vines. The subspecies ranomafanensis has been found on guava plantations during the fruiting season.
Food and Feeding. Bamboo constitutes at least three-quarters of the diet of the Gray Bamboo Lemur, primarily in the form of new shoots and leaf bases. Individuals gain access to these by pulling new leaves from the end of a branch, biting the soft base, and then discarding the tough leaf blade. Other food items include fig leaves, grass steins, young leaves, small fruits, flowers, sugar cane, and fungi. At Ranomafana National Park, the majority of the diet (89-1%) consists of two species of bamboo lianas and Cephalostachyum perrieri ( Poaceae ). Individuals also feed on fruits (1-2%), fungi (0-5%), mushrooms (1:4%), leaf petioles (0-6%), flowers (0-4%), and new leaves (0-3%). Fruit-eating tends to be opportunistic, occurring during summer when fruits are most abundant, while consumption of new leaves and flowers occurs only in October—-November. C. perrieri tends to be consumed more in the first wet season than the second wet season, and bamboo lianas are exploited more than C. perrieri during both dry seasons. Groups of Gray Bamboo Lemurs spend more time feeding during cooler, drier months compared with the warmer, wetter months. Dietary diversity increased toward the end of the dry season, corresponding to gestation. In another study at Ranomafana, groups of Gray Bamboo Lemurs consumed more than 40 plant species but 72% of their diet consisted of giant bamboo ( Cathariostachys madagascariensis, Poaceae ). The rest of the diet was other types of bamboo and grasses ( Cephalostachyum ct. perrieri, Cephalostachyum cf. viguieri, and Nastus elongatus) (16%), leaves from other plants (mainly lianas) (4%), fruits (5%), and other foods (3%). Parts of the bamboo plant eaten include young leaf bases, immature parts of pseudopetioles, branch shoots (new sprouts from the nodes), and shoots (new sprouts from the subterraneous rhizomes). Gray Bamboo Lemurs also eat soil daily as a supplement. In one study at Analamazaotra Special Reserve, bamboo of the genus Bambusa (Poaceae) made up 90% ofthe diet, but fruit, young leaves, leaf stems ofterrestrial grasses, small berries in the understory, and soil were also consumed.
Breeding. In Ranomafana National Park, most mating of Gray Bamboo Lemurs takes place in June-July, with subsequent births in October-November. Gestation is 137-140 days. Single infants are the rule, and the interbirth intervalis typically one year. An infant is first carried in its mother’s mouth and then on her back a few weeks after birth. Eventually she is able to park her infant for short periods while she forages.
Activity patterns. Gray Bamboo Lemurs are diurnal in Ranomafana National Park. They are possibly cathemeral in other locations, but other than in Ranomafana, no nocturnal studies have been conducted to confirm this. They are arboreal and use latrines for defecation in Analamazaotra Special Reserve.
Movements, Home range and Social organization. Home range size is 15-20 ha in Ranomafana National park and 6-10 ha in Analamazaotra Special Reserve. Group size is 2-7 individuals (average 4-5), and groups can contain more than one breeding female. Territories are defended by scent marking, vocal displays, and chasing. Daily movement of one group averaged 425 m. Males and females disperse from their natal groups. Density at Analamazaotra was estimated at 47-62 ind/km?,
Status and Conservation. CITES Appendix I. Classified as Vulnerable on The IUCN Red List. The subspecies griseus is also classified as Vulnerable and the subspecies gilberti as Data Deficient. However, at the IUCN/SSC Lemur Red-Listing Workshop held in July 2012, the subspecies gilberti was assessed as endangered due to a past and ongoing decline in the extent and quality ofits habitat, ranomafanensis as data deficient, whilst griseus was retained as vulnerable. Conservation status of ranomafanensis has not yet been assessed. Distribution of the Gray Bamboo Lemur extends through all remaining tropical moist lowland and montane forests in eastern Madagascar, from the latitude of Lake Alaotra in the north to Ranomafana in the south—wherever bamboo is present. Nevertheless, the geographic distributions of the three subspecies have been revised, resulting in much-reduced ranges for each of them. Main threats are habitat loss and hunting. The nominate subspecies occurs in two special reserves (Analamazaotra and Mangerivola), Mantadia National Park, and Betampona Strict Nature Reserve. The Ranomafana Bamboo Lemur occurs in two national parks (Tsingy de Bemaraha and Ranomafana), but the Beanamalao Bamboo Lemur is not known to occur in any protected areas.
Bibliography. Digby & Stevens (2007), Ganzhorn (1988, 1989b), Glanderet al. (1992), Grassi (2006), Haring & Davis (1998), Irwin et al. (2004), Mittermeier et al. (2010), Overdorff et al. (1997), Petter & Peyrieras (1970a, 1975), Pollock (1979b, 1986¢), Rabarivola et al. (2007), Rakotondravony et al. (1998), Santini-Palka (1994), Stafford et al. (1993), Sterling & Ramaroson (1996), Tan (1999, 2000, 2006), Terranova & Coffman (1997), Wright (1986a, 1988, 1990), Wright, Daniels et al. (1987).
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