 |
Propithecus diadema edwardsi is one of the largest lemurs in Madagascar (and the largest lemur at RNP). The fur is mostly black (or dark brown) with one large white patch on its lower back, that extends to its sides like a saddle.
There are at least four P. diadema edwardsi groups in the Talatakely Trail System at RNP, some of which have been followed since 1986 by Patricia Wright and her guides. The following data are mostly from her work (Wright 1995), and from Claire Hemingway's study at Vato (Hemingway, 1995).
Group II's territory includes the research station and consists of GO (Green Orange) breeding female; P (Pink) breeding male and their offspring. Group I is adjacent and most often seen by tourists. TS (Teal Silver) is the breeding female; R (Red) is a twenty old male; YS (Yellow Silver), B (Brown) are younger males in the group.
 |
 |
|
|---|---|---|
| Head & Body Length | 48cm | 48cm |
| Tail Length | 44cm | 46cm |
| Weight (Glander,
1992) (fluctuates seasonally & yearly) |
5.6kg | 5.9kg |
|
|
P. d. edwardsi mates between Dec-Jan and gives birth in May-July (Wright 1995) (in a given year, the birth season is about 6-7 weeks, Hemingway, 1995) with a gestation period of 6 months. The sex ratio at birth is approximately 1:1. Infants are initially carried ventrally, but move to the back after 3 weeks at which point they also start eating independently. Any member of the group may carry the infant. By the 4th month infants start eating solid food, milk accounts for less than half their nourishment by the 6th month, and by the 7th month travel independently 80% of the time, after the 12th month infants were not observed to suckle (though one captive female continued to produce milk until 18 months) (Wright 1995). Births occur when food is scarce, as did early lactation, while weaning is coincident with the rise in food availability (Hemmingway, 1995, Wright 1999)
43% of infants die in their first year. Of 5 observed deaths of infants less than 3 months, 3 were from infanticide and 2 from predation by Cryptoprocta ferox. 67% died before reaching reproductive age.
Females can give birth every year, but generally do so every other year. They are only in estrus one day a year. (Wright 1995)
In Claire Hemingway's study at Vato a female gave birth to, on average, .42 infants per year. No females successfully reared 2 infants in 2 years, though several gave birth two years running if the first infant died early. Greatest likelihood of infant mortality occurred around the time of weaning. P.d.e.'s reproduction at Ranomafana is more similar to that of P. verreauxi verreauxi in the dry south than it is to the sympatric Eulemur species. (Hemingway, 1995)
Females are sexually mature at 4 years, males at 5. Males emigrate from their natal group at around 5 or 6 years, females may also emigrate at around 4 or 5 years. In Patricia Wright's study groups 2 maturing females disappeared (emigrated?) while 1 stayed in her natal group (her father had died) and bred there, one of the two that disappeared was the target of aggression from the resident breeding female; sub-adult males were not observed to be harassed. Migrating females have not appeared in adjacent groups while all observed migrating males have, implying that females migrate further than males. Males have been observed to move up to 4 times .(Wright 1995)
Of 4 observed male migrants, 2 have committed infanticide upon entering a new group (one committed two infanticides). The resident male did not attempt to defend the infants and was later observed grooming with the infanticidal male. In one instance a non-breeding female chased the immigrant male. (Wright 1995)
Some have lived to be more than 25 years old.
Locomotion is by vertical clinging and leaping, some suspensory (as in the picture of foraging above left).
 |
At Talatakely P. d. edwardsi eats leaves 53% of the time, flowers 25%. fruit 22%, they will eat about 20 plant species a day. (Wright 1995)
In Claire Hemingway's study, Group I ate 83 different species of plants, but only about 22% of the species accounted for more than 1% of the feeding time. Seeds were the preferred food source 38%, then fruit 29%, leaves 26% (19% immature, 6% mature leaves) and flowers 6%, dirt .4%, and underground fungus .2%. Group II ate 73 species, of which 16% contributed more than 1% feeding time, seeds were the preferred source 32%, fruit 32% and leaves 30%. Immature leaves were again preferred (17% to 13%), and immature fruit were preferred as seed and fruit sources (20% vs 12% and 18% vs. 14% respectively). Most feeding occurred in tree canopies, but all levels of the forest (including the ground) were used. Animals descended to the ground to feed on rotten fruit or fungus only a few months out of the year. (Hemingway, 1995)
When fruit and seeds are not available, leaves provide a staple, the major sources of leaves are Bakerella sp. (a mistletoe also consumed by Microcebus rufus, and by Philepitta castenea), Schefflera sp. (hemi-epiphyte), Plectaneia sp. (liana), and Strongylodon sp. (liana). (Hemingway, 1995)
Few sex differences are obvious for feeding duration on seeds, fruit or leaves, nor on top food species, nor in feeding rates, nor activity patterns. No plant part was consumed more by males than females on average, in some months there were differences (which were reversed in other months). In particular feeding differences were not greatest during months of food scarcity nor during greatest female energetic costs. Individual feeding variation is greater than inter-sexual variation. (Hemingway, 1995) Suggesting that feeding priority/dominance does not produce a better diet for females than males (one possible explanation for female dominance in lemurs).
Mothers allow infants and juveniles up to 2 years old to feed with them. (Wright 1995)
P. d. edwardsi is diurnal.
P. d. edwardsi has several adaptations for avoiding predators, most obviously their cryptic coloration. They have separate alarm calls for avian and ground (mammalian) predators. The avian call is much louder than the ground call, a great roaring bark that may last up to 15 minutes, one animal begins the call and the others stop what they were doing, look up, drop to the ground and join in.
No one has observed a raptor attack P.d.e., there is some debate as to whether any of the current raptors are large enough to do so. Sub-fossils of a large eagle (extinct for perhaps 500 years), Stephanoaetus mahery, have been found and that it may account for P.d.e.'s reaction to raptors (Goodman, 1994), on the other hand the raptors are certainly large enough to take infants and juveniles. P.d.e. will alarm call when sighting any of the large raptors in the park (Polyboroides radiatus, Eutriorchis astur, Accipiter henstii and Buteo brachypterus). Sub-adults and juveniles will occasionally make a mistake and alarm call at other large birds (ibis for example), but the adults will not join in.
During the day P.d.e. will descend into the lower canopy to rest, and then ascend again to feed, presumably this is a raptor avoidance strategy.
The ground predator alarm (which sounds to human ears like a sneeze) is directed at unknown terrestrial animals (including humans). One animal starts the call, and other animals join in and repeat for up to 8 minutes, after which they escape quickly. The one time a Cryptoprocta ferox was observed near a P.d.e. group, the group issued an alarm call, but most Cryptoprocta predation occurs at night when the animals are asleep and less vigilant. P.d.e. tries to minimize the possibility of nocturnal predation by: sleeping in a different site every night, sleeping high up in trees, sleeping either singly or in pairs (with the rest of the group in near-by trees, perhaps 16m between pairs) (Wright, 1998).
The greatest observed threat to adult P.d.e. comes from the Cryptoprocta ferox, while the greatest threat to small infants comes from immigrant infanticidal P.d.e. males.
Madagascar is subject to frequent cyclones and Ranomafana is no exception. These cyclones can hinder trees from fruiting, and kill immature lemurs (Hemingway, 1995; Wright, 1995)
Hemingway suggests that careless males (but not infanticidal ones) can drop infants and cause them harm (Hemingway, 1995)
P.d.e. is female dominant.
Female dominance does not prevent infanticide. (Wright 1995)
 |
Groups seem to contain 1 or 2 breeding males and 1 or 2 breeding females, with a group size between 3 and 9. The females may be related (mother daughter), males are probably unrelated.
Groups are fairly stable, and breeding pairs can remain together for 6-10 years.
The home range area is about 70ha, mean daily path 1km. (Wright 1995)
Propithecus diadema edwardsi groups defend their territories. These territories are relatively stable over the years, and appeared independent of the group size, presumably the territory size is set by maximal group size, but can be defended by a smaller number in case of need.
*
Approximate ranges of the three main P. d. e.
groupsM1
MCP areas are 69ha for Grp 1,
69ha for Grp 2, 43ha for Grp 3
Areas used are: 57ha for Grp
1, 43ha for Grp 2, 37ha for Grp 3
90% Contours: 26ha for Grp
1, 27ha for Grp 2, 27ha for Grp 3
(the 90% contour of group 2 consists of several contours)
(overlap between groups 1&2: MCP: 35ha, Area used: 10ha, 90% contour:
~3ha)
Mean Daily Path: 1.09km for Grp 1, 1.08km for Grp 2, .94km for Grp
3
Observed range for Group 1 over the years
Observed range size is correlated with hours of observation
Most hours in 90 and 95
|
Adult females do not play when they have infants under 3 months of age
(Grieser, 1992). Juveniles and sub-adults love
to play, both wrestling play with a
sibling
2.5Mb
V9 and acrobatic play
2.0Mb
V10
Males usually scent mark over places where females have already scent marked
4.3Mb
V12
Males will attempt to harass other males copulating with females. Juveniles have not been observed to do so. All observed copulations have been single mount. Both sexes have been observed to solicit copulations.
Both self grooming
.7Mb
V13 and mutual grooming are common
1Mb
V14, and a grooming session often will
turn into a play bout and back into grooming
2.5Mb
V9.
Mothers frequently sleep with their juveniles, and their mates. Breeding males will sleep with their offspring.
Propithecus diadema edwardsi is found in the rainforests of the south east coast of Madagascar. (Mittermeier et al, 1994).
Mammalia -> Primata (Strepsirrhini, Lemuriformes) -> (Indrioidea)Indriidae -> Propithecus diadema edwardsi (Grandidier, 1871)
There are four named subspecies of this species. (Tattersall, 1986), there was considered to be a fifth (P.d. holomelas) but this is now thought to be a variant of P.d.e.
Erhart, EM, Overdorff, DJ, 1998 "Infanticide in Propithecus diadema edwardsi: an evaluation of the sexual selection hypothesis", International Journal of Primatology, 19:(1) 73-81
Glander, KE, et al, 1992 "Morphometrics and testicle size of rainforest lemur species from southeastern Madagascar", Journal of Human Evolution, 22: 1-17
Goodman, SM, 1994 "Description of a new species of subfossil eagle from Madagascar. Stephanoaetus (Aves: Falconiformes) from the deposits of Ampasambazima", Procedings of the Biological Society, 107: p. 421-428
Grieser, B. 1992 "Infant development and Parental care in two species of Sifakas", Primates, 33:(3) 305-314
Hemingway, Claire Alison, 1995, "Feeding and Reproductive Strategies of the Milne-Edwards' Sifaka, Propithecus diadema edwardsi", Ph.D. dissertation, Duke University.
Hemingway, CA 1996. "Morphology and phenology of seeds and whole fruit eaten by Milne-Edward's sifaka, Propithecus diadema edwardsi in Ranomafana National Park." International Journal of Primatology 17: 637-659.
IUCN Conservation Monitoring Centre, viewed in July 2000, "Threatened Animals of the World", IUCN Red List of Threatened Animals
Mittermeier, Russell et al, 1994, The Lemurs of Madagascar, Conservation International
Rowe, Noel, 1996, The Pictorial Guide to the Living Primates, Pogonias Press
Tattersall, I., 1986, "Notes on the distribution and taxonomic status of some subspecies of Propithecus in Madagascar", Folia Primatologica, 46:51-63
Wright, P.C. 1999 "Lemur traits and Madagascar ecology: coping with an island environment." Yearbook of Physical Anthropology 42: 31-72.
Wright, PC, 1998, "Impact of Predation Risk on the Behavior of Propithecus diadema edwardsi in the Rainforest of Madagascar", Behaviour, 135(4): 483-512
Wright, P. C., et al 1997, "Predation on Milne Edwards Sifaka (Propithecus diadema edwardsi) by the fossa (Cryptoprocta ferox) in the rainforest of southeastern Madagascar", Folia Primatologica 68(1) 34-43.
Wright, PC, 1995 "Demography and Life History of Free-ranging Propithecus diadema edwardsi in Ranomafana National Park, Madagascar", International Journal of Primatology, 16:(5) 835-854
Wright, PC, 1988, "Social Behavior of Propithecus diadema edwardsi in Madagascar", American Journal of Physical Anthropology, 75(2) 289-289
Wright, PC, 1987, "Diet and Ranging Patterns of Propithecus diadema edwardsi in Madagascar", American Journal of Physical Anthropology, 72(2) 271-271
P.d.e..P7
-- RNP Main -- Other Lemurs at RNP -- Lemur Taxonomy -- Comments -- Copyright --
