Monday, 28 January 2013

Lemurs 4: Red-Bellied and Mongoose Lemurs

Red-Bellied Lemur
Not as familiar to the general public as many of their relatives, scattered through the forests of Madagascar are a multiplicity of forms of what might perhaps be determined the typical lemurs, Eulemur. As with the rest of Madagascar’s wildlife, increased study in recent years has greatly increased the number of named species, which currently stands at around twelve, possibly more if some subspecies are raised to specific rank.

Brown Lemur
All the Eulemur forms are of more or less similar size, at around 2-4kg, and are mainly herbivorous, feeding on fruit, flowers, and possibly some insects when available. There is some difference in the social structure, varying from small family groups of a pair plus a few offspring, up to as many as 20 in some populations of Brown lemur, E.fulvus. They usually have a single youngster each year, which remains with the parents until 3 or 4, at which point males tend to be evicted by the dominant male and females by the dominant female. In the group as a whole, as with many lemurs, the females are the dominant sex, and take first place in any feeding locations. In field studies, it is often fairly easy to tell the sexes apart as many Eulemur species have coloured fur and are dimorphic in colour, with various differences in coat colour between males and females, especially on the face.
Mongoose Lemur
Here at Bristol we currently hold two species, which can be seen in the Lemur Walk-Through (currently closed for the winter months). Our two Mongoose Lemurs, Orchis and Rufus, are actually mother and son so are obviously not being bred from, and are quite habituated to the public having been with us for many years. Orchis is probably too old to breed now, but her genes are sufficiently well represented in the wider captive population. They share the walk-through with the Ring-Tails, and mostly get on OK aside from a small amount of chasing when fed together in the walk through – they have separate sleeping quarters at night. Although Mongoose Lemurs come from fairly dry forest areas, they are noticeably more tolerant of cool and damp conditions than the Ring-Tails, who retreat to their inside area at the first cloud. This adaptability is probably what has enabled them to survive on the Comoros islands north of Madagascar. Almost certainly derived from escaped pets, Mongoose (and Brown) lemurs are the only non-native lemurs to have permanently established themselves as feral populations away from their native land.
Range of E.mongoz (Comoros in blue)
The other species only arrived late last year. As we have not kept them before, we have begun with being assigned two males by the stud book holder (generally females are far more valuable to a breeding program than males, so new holders tend to start with males). The two males are brothers, and at least at present seem to get on well. They seem more assertive than the Mongoose lemurs, even entering the inside quarters of the Ring-Tails, at least briefly, and this may reflect their social structure – Red-Bellied lemurs seem to be among the most strongly territorial of lemurs, even though their home ranges are quite small (around 20 hectares). They are true rain-forest lemurs, and (like Mongoose lemurs) exhibit cathemeral behaviour – active both day and night. As with other Eulemur species, their diet is quite wide-ranging, comprising fruit, nectar and insects, and is probably an important seed disperser as with other primates.

Red-bellied Lemur range
Unfortunately, the ongoing deforestation disaster in Madagascar has had serious impacts on both Mongoose and Red-Bellied lemur populations, which are all endangered as a result, As well as deforestation destroying their habitat, many are still hunted for food as well.

Blue-Eyed Black Lemur (female)
Bristol Zoo is currently working with AEECL in the Sahamalaza peninsula with another Eulemur species, the Blue-Eyed Black or Sclater’s Lemur, E.flavifrons in studies of the tiny wild population, which is an even worst state than the Mongoose and Red-Bellied lemurs as a result of its restricted range.

Next week, one of the more specialised of lemurs – the Lac Alaotra Gentle Lemur

(Images from wikipedia)