Diadem Sifaka

Observations: Not much is known about the longevity of these animals. In the wild, they have been shown to live up to 21 years with no signs of reproductive senescence except for a slight increase in mortality with age (Pochron et al. 2004). Dental senescence has also been described in animals with more than 18 years of age. Considering the longevity of similar species, it has been estimated that they may live more than 27 years in the wild (King et al. 2005), which is possible but awaits confirmation.

Both P. diadema candidus and P. diadema perrieri are given IUCN critically endangered status. All subspecies are threatened by habitat destruction. This occurs mainly in the form of slash-and-burn agriculture, but also as timber extraction. Most are also hunted for food, even in protected areas. All subspecies occur in at least one protected area.

In response to these threats, several reserves have been established within the last few decades. Also, campaigns to educate locals and find better methods of agriculture have been persued (Wright, 1992; Mittermeier, 1994; Garbutt, 1999).

US Federal List: endangered

CITES: appendix i

IUCN Red List of Threatened Species: endangered

Individuals of all ages and both sexes are subject to predation. No documented cases of predation by reptiles or raptors exist, but suspected avian predators include Madagascar harrier-hawks and Henst's goshawks. The main predators of P. diadema are probably fossas, an ambush predator that takes advantage of any opportunities available.

Two alarm vocalizations are given in response to predators. The ground predator call is a "tzisk-tzisk-tzisk", and the aerial predator call is a "honk-honk-honk" (Wright, 1988, 1995; Garbutt, 1999; Mittermeier, 1994).

Known Predators:

• Cryptoprocta ferox
• Polyboroides radiatus
• Accipiter henstii

Members of the genus Propithecus reach lengths between 450 and 550 mm, with the tail adding an additional 432 to 560 mm. Propithecus diadema weighs between 5 and 7 kg.

Each subspecies is phenotypically unique. Propithecus diadema diadema is often reported to be the largest extant lemur. These animals have a white head, grey shoulders, tail, and back, and golden limbs. Propithecus diadema edwardsi is almost completely grey/black, with a white back. Propithecus diadema candidus has almost completely white pelage with tints of grey. Propithecus diadema perrieri is completely black. All subspecies have dark naked faces and red-orange eyes.

The only other animals with which these animals might be confused are indris. However, sifakas have a very long tail, which distinguishes them from short-tailed indris.

Range mass: 5 to 7 kg.

Range length: 450 to 550 mm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

The longevity of this species has not been reported. However, an individual of another species in the genus, Propithecus verreauxi, is reported to have lived beyon 23 years on captivity (Nowak, 1999). It is likely that P. diadema is capable of reaching similar ages.

Sifakas generally inhabit mid-altitude rainforests. These animals mainly occur at elevations above 800 meters. The range of P. diadema candidus extends into montane rainforest. Rainfall in sifaka habitat is variable, from 2000 to 4000 mm per year, with most rainfall occurring during the summer months (December through March) (Wright, 1995; Garbutt, 1999).

Range elevation: 800 (low) m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: rainforest ; mountains

Propithecus diadema, like all lemurs, occurs only in Madagascar. Although all sifakas occur on the eastern side of the island, each of the four described subspecies has a distinct range (Garbutt, 1999).

Biogeographic Regions: ethiopian (Native )

Other Geographic Terms: island endemic

Propithecus diadema is herbivorous, eating only leaves, flowers, fruits, and young shoots. Approximately 25 species of plants are consumed in each of the two subspecies that have been studied (P. diadema edwardsi and P. diadema diadema). Propithecus diadema edwardsi has also been seen eating soil, possibly to detoxify plant poisons or to supplement their diet with trace elements (Garbutt, 1999).

Plant Foods: leaves; fruit; flowers

Primary Diet: herbivore (Folivore , Frugivore )

As frugivores, these animals probably help to disperse seeds. As potential prey items, they may impact predator populations.

Ecosystem Impact: disperses seeds

The existence of this rare and endemic species, as well as the rest of Madagascar's unique flora and fauna, has stimulated a large amount of ecotourism for the area. This, along with the establishment of several reserves in Madagascar's remaining forests, has helped to bolster the economy of a severely depressed nation (Wright, 1992).

Positive Impacts: ecotourism

There is no known negative economic effect of this species on humans.

As in all primate species, communication is rich and varied. Vocalizations are used mainly in maintaining group cohesion. Two alarm vocalizations are given in response to predators. The ground predator call is a "tzisk-tzisk-tzisk", and the aerial predator call is a "honk-honk-honk" (Wright, 1988, 1995; Garbutt, 1999; Mittermeier, 1994).

Scent marking is common, and males scent mark twice as often as females. Scent marking frequency doubles when approaching the territorial boundaries (Wright, 1988, 1995; Garbutt, 1999; Mittermeier, 1994).

In addition to vocal and chemical communication, these animals use tactile communication, in the form of grooming, play, and aggression. Tactile communication is likely to be of high importance between mothers and their offspring, as well as between mates.

Although not specifically reported for these animals, we may assume that, like other diurnal primates, they use visual signals in their communication also. These include but are not limited to facial expressions and body postures (Nowak, 1999).

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: scent marks

Perception Channels: visual ; tactile ; acoustic ; chemical

All sifakas are amazing leapers, jumping distances of up to thirty feet. When on the ground, they move by leaping sideways on their hind limbs.

Neither P. diadema candidus and P. diadema perrieri have been formally studied, and therefore little is known of their ecology and behavior. They are both extremely rare, and so time is running out to find out about these creatures (Garbutt, 1999).

Strangely enough, leaping primates (including sifakas), do not take adavantage of the elasticity of the substrates on which they move. Therefore, unlike most things in nature, leaping locomotion is not an evolutionarily efficient locomotory strategy for large-bodied primates (Demes, 1995).

Our current understanding of the mating system of this species is limited. Mating occurs between resident males and resident females, with no recorded cases of invading males successfully copulating. There is a hierarchy system for mating, and it seems that only the dominant male copulates with the females. Submissive males may show aggression and attempt to keep the dominant male from mating.

Mating System: polygynous

The best data on reproduction exists for P. diadema edwardsi, but data for other subspecies suggest that they are similar. Copulations occur in summer, in the months of December and January. Gestation period is around 180 days (approximately six months). Females give birth to one or two offspring in the winter months (May, June, July).

Offspring are carried by their mother. The young may nurse up to the age of 2, although by this time, mother's milk does not provide them with a substantial amount of their nutrition. Sexual maturity is reached at four years for females and five years for males. Birth rates are approximately 0.5 offspring per female per year (Wright, 1995; Garbutt, 1999).

Breeding interval: Females are able to produce offspring every two years.

Breeding season: Copulations occur in summer, in the months of December and January

Range number of offspring: 1 to 2.

Average gestation period: 180 days.

Range weaning age: 24 (high) months.

Average age at sexual or reproductive maturity (female): 4 years.

Average age at sexual or reproductive maturity (male): 5 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous

Average birth mass: 145 g.

Average gestation period: 157 days.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)
Sex: male: 913 days.

Average age at sexual or reproductive maturity (female)
Sex: female: 1186 days.

Offspring initially cling to the mother's belly, switching to her back at around one month of age. Nursing begins to decrease from the age of two months, although the process of weaning is protracted. At six months of age, less than half of the offspring's diet consists of the mother's milk. At one year of age, suckling during the day ceases. Suckling during the night, however, may continue until the infant is two years old.

In addition to food, the mother provides her young with protection, grooming, and socialization.

The role of males in parental care has not been described.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Protecting: Female); extended period of juvenile learning

Sifakas are diurnal and spend almost all of their time in the trees (2). The majority of behavioural studies of this species have been carried out on Milne-Edward's sifaka and these are thought to be broadly similar for the 3 other subspecies (2). These sifakas occur in multi-male, multi-female groups of between 3 and 8 individuals (4), who occupy large, exclusive territories that are depicted by scent-markings at the boundaries. Births for Milne-Edward's sifaka occur in May and July although those for other subspecies may take place later in the year (4). A female will give birth to a single offspring every couple of years; the infant initially clings to its mothers belly before transferring to her back after a month (4). Sexual maturity is reached at 4 to 5 years of age and, whilst males disperse, females remain within their natal group and are the dominant sex in the group (4). Sifakas move through the trees by vertical clinging and leaping (2). Feeding takes place at all levels of the canopy, predominately on leaves, although fruit, young shoots and flowers may also be eaten in season (2). Individuals may alight on the ground to search for fallen fruit and to engage in play-fighting, some sifakas have also been seen to eat soil, possibly in an effort to rid themselves of toxins (4).

All of the diademed sifaka subspecies occur in a least one protected range; P. d. diadema has been confirmed from at least 5, whilst Perrier's sifaka is thought to be found only within the Analamera Special Reserve (4). Further research and protection is needed if these appealing and interesting primates are to be saved from extinction.

The diademed sifaka is one of the largest lemurs, with a lustrous, silky coat. These lemurs have long powerful legs and grasping hands and feet, which allow them to leap from one vertical trunk to another in their arboreal habitat. The species is currently thought to be composed of 4 distinct subspecies, each of which is very different in appearance (4). The diademed sifaka (Propithecus diadema diadema) from which the species name is derived is one of the most attractive and largest of the sifakas. The coat is white on the head with a dark crown; the rest of the body varies in shades of grey except for the rich golden-orange of the arms and legs, and the hands, feet and face, which are black (4). Perrier's sifaka (P. d. perrieri) in contrast, is the smallest of the 4 subspecies and the dense coat is completely black (4). Milne-Edward's sifaka (P. d. edwardsi) has soft chocolate-brown fur with a creamy-white saddle on the lower back, and piercing orange-red eyes, which stand out against the dark face (4). The long, sleek, creamy-white coat of the silky sifaka (P. d. candidus) is also striking; the face is usually black and the eyes orange-red, although some individuals lack dark pigment giving their skin a pink tinge (4).

Predominantly inhabits primary and montane rainforest, although Perrier's sifaka is also found in dry-deciduous forest (4).

The diademed sifaka is found in eastern Madagascar, in a range that extends from the Mananara River in the south to the northern tip of the island (3). Within this area the 4 subspecies appear to occupy non-overlapping ranges with Milne-Edwards sifaka in the south and Perrier's sifaka in the north; occupying the most restricted area (4). P. d. diadema has the largest range of the four, situated between Milne-Edward's sifaka and the silky sifaka (4).

Classified as Critically Endangered (CR - A2cd, B1+2c) on the IUCN Red List 2002 (1), and listed on Appendix I of CITES (6). Subspecies: Diademed sifaka (Propithecus diadema diadema) classified as Critically Endangered (CR - A1cd); Milne-Edwards's sifaka (P. d. edwardsi) classified as Endangered (EN - A1c); silky sifaka (P. d. candidus) classified as Critically Endangered (CR - A2cd, B1+2bc); Perrier's sifaka (P. d. perrieri) classified as Critically Endangered (CR - A2cd, B1+2c) (1).

Habitat destruction is the major cause of the decline of the diademed sifaka. Primary forests are being cleared to make way for agriculture, for the extraction of timber and for charcoal production (4). Some subspecies may also be hunted for food in parts of their range and deliberate fires further encroach on what is an already highly- fragmented habitat (4). Perrier's sifaka is the most endangered of the diademed sifakas, and possibly the most endangered of all the lemurs; estimates in 1998 put the population at around 2,000 individuals with none in captivity (5).

The diademed sifaka is one of the world's largest living lemurs, with a total adult length of @ 105 cm (41 in),[3] half of which is tail. It weighs 5-7 kg. Sifakas reach lengths of 45-55 cm, with the tail adding 43-56 cm. Its coat is moderately long, silky and luxuriant. It has long powerful legs and grasping hands and feet, enabling it to leap from one vertical trunk to another. It has a white head, grey shoulders, tail, and back and golden limbs. Russell Mittermeier says it is "one of the most colorful and attractive of all the lemurs" [4]. The diademed sifaka has a white head with a dark crown; the rest of the body varies in shades of grey except for the rich golden-orange of the arms and legs, and the black hands, feet and face (4). The long white fur encircling the muzzle and covering the cheeks, forehead and chin and the dark crown engenders the "diadem" or crown appearance. The eyes are reddish-brown, the muzzle is short and the darkish gray to jet black face is bare. The black crown fur often extends to the nape of the neck. The upper back and shoulder fur are slate grayish, but the lower back is lighter in colour attaining a silvery quality. The flanks and tail are paler gray, sometimes white, as is the ventral fur. The hands and feet are black; the arms, legs and tail base are yellowish-golden or rich golden-orange. Only the male has a large cutaneous gland at the exterior center of the throat; this is darkish gray to jet black.

The diademed sifaka is one of the mostly widely distributed sifakas [5]. It occurs in primary rainforests and smaller forest fragments at altitudes of 200-800 m throughout much of the eastern Madagascar lowland forests and at altitudes 800- 1,625 m in subhumid montane rainforests. The range extends to at least the Mananara Nord River in the north to the Onive and Mongoro Rivers in the south (11,12). The range is situated between those of the Milne-Edward's and silky sifakas (12). Earlier authors said it occurred between Antainambalana River near Maroantsetra and Mananara Nord River (13). Members of an anomalous outlier population of P. diadema in south central Madagascar show various colour markings, including an all black lemur. DNA analyses have not concluded if this group constitutes a new species.There is a clinal variation between P. diadema and P. edwardsi in the extreme southern portion of the range [6]. Specific locations for sighting the diademed sifaka are Mantadia National Park and in the forests of Tsinjoarivo.[7]

It lives in multi-male/multi-female groups of 2-10 individuals (4). Communication is rich and varied. The sifakas use scent-marking to defend home ranges of 20-50 ha (14). Males scent mark twice as often as females. Scent marking frequency doubles when approaching the territorial boundaries (10,15-17). Vocalizations are used mainly to maintain vocal and chemical communication. Sifakas use tactile communication, in the form of grooming, play, and aggression. This may be very important between mothers and their young, as well as between mates. Sifakas probably use facial expressions, body postures and other visual signals in their communication (18). The sifaka defends the group's territory strongly against other diademed sifakas, but shares territory with red-bellied and common brown lemur. It is thought to traverse the greatest daily path distance relative to other members of its family in its patrolling and foraging, attaining a typical travel distance in excess of 1.6 km a day.

It is thought that the diademed sifaka behaves like the related Milne-Edward's sifaka (2). The sifaka is diurnal and spends almost all its time in trees, being rarely seen on the ground; it is a vertical clinger and lateral leaper through the trees (2). It can achieve lateral aerial propulsion of up to 30 km per hour, due to muscular leg thrusting action pushing off from a vertical tree trunk. Individuals may alight on the ground to search for fallen fruit and to engage in play-fighting; some sifakas eat soil, possibly in an effort to rid themselves of toxins (4).

It is herbivorous, eating mainly verdant leaves, as well as flowers, seeds, fruits, and young shoots from @ 25 species of plants (2) at all levels of the canopy. As a frugivore, it probably helps to disperse seeds. As potential prey items, Individuals of all ages and both sexes may impact predator populations. are subject to predation. Suspected avian predators include Madagascar harrier-hawks and Henst's goshawks. The fossa is an ambush predator. The sifaka gives 2 alarm vocalizations in response to predators. The ground predator call is a "tzisk-tzisk-tzisk" or "kiss-sneeze" when a fossa, Nile crocodile or another terrestrial predator is perceived [8]. The aerial predator call is a "honk-honk-honk" (10,15-17). The sifaka high levels of activity is linked to a diet high in energy content, including a high consumption of two plants containing high concentrations of alkaloids.

Mating occurs between resident males and resident females, with no recorded cases of invading males successfully copulating. The female is probably receptive to mating few days per year. Being dominant, she has the greatest input to mate selection. There is a hierarchy system for mating; it seems that only the dominant male copulates with the females. Submissive males may show aggression and try to keep the dominant male from mating. Copulation occurs in summer (in December and January) and there is usually one offspring per female every 2 years. Gestation period is @ 157-180 days. Births for Milne-Edward's sifaka occur in May and July, but those for other species may occur later in the year (4). Females can produce 1-2 offspring in winter (May-July) every 2 years (10,16). The altricial newborn young weighs @ 145 g. The infant initially clings to its mothers belly before transferring to her back after a month (4). Nursing begins to decrease from the age of 2 months. At 1 year old, suckling during the day ceases. As well as continue until the infant is two years old. In addition to food, the mother provides her young with protection, grooming, and socialization. When the young is 2 years old, its mother's milk does not provide it with a substantial amount of their nutrition. Sexual maturity is reached at 4 years for females and 5 years for males. Sexual maturity is reached at 2-5 years of age; the male matures more slowly than the female. Males disperse, but females stay within their natal group and are the dominant sex in the group (4). Captive sifakas may live beyond 23 years in captivity (18). A wild sifaka may live up to 21 years with no signs of reproductive senescence except a slight increase in mortality with age (19). Dental senescence may occur described in animals over 18 years old. Wild sifakas may be able to live over 27 years in the wild (20).

The diademed sifaka is classified as Critically Endangered on the IUCN Red List and is listed on Appendix I of CITES. In 2002, population estimates for the species ranged from 6,000-10,000 individuals [9]. The primary threat is habitat reduction due to shifting cultivation by native peoples. This threat is also present within designated national parks, where it is hard for the government to enforce national laws protecting habitat. Pressures of overpopulation in central and eastern Madagascar cause many of the rural poor to seek subsistence by seizing forest lands, timber extraction and undertaking slash-and-burn tactics as their initial step in a shifting cultivation system (4). Deliberate fires encroach on the highly- fragmented habitat (4). Returns from such land use are usually meagre, yielding small amounts of charcoal, firewood or grass crop for grazing of zebu (4). Illegal rum production, involving planting sugar cane fields threatens populations in Tsinjoarivo. The species is thought to have undergone a reduction of more than 50% over the past 30 years due primarily to a decline in area and quality of habitat within its range of the species and due to levels of exploitation; the population trend is 'Decreasing'. It is hunted for food, even in protected areas (14). This species occurs in three national parks (Mananara-Nord, Mantadia, and Zahamena), two strict nature reserves (Betampona and Zahamena), and three special reserves (Ambatovaky, Mangerivola, and Marotandrano) (14). Additional populations have been identified in the Andriantantely Classified Forest, Tsinjoarivo Classified Forest, the Marokitay Forest Reserve, and in the unprotected forests of Anosibe, Anjozorobe, Didy, Iofa, Maromiza and Sandranantitra (14). The Tsinjoarivo Classified Forest has already been recommended as a new protected area. In response to threats, several reserves have been established within the last few decades, along with campaigns to educate locals and find better methods of agriculture (10,17,21). This species and other unique plants and animals have stimulated a large amount of ecotourism, helping to bolster the economy of a severely depressed nation (21). This species was represented in a zoological collection at the Duke University Primate Center in Durham, North Carolina, USA.

The diademed sifaka comprised 4 distinct subspecies, which are now classified as separate species (4) and form a tight species group within the Propithecus genus, but all have a distinct range (10). The other 4 species are the Milne-Edwards' sifaka (P. edwardsi), Perrier's sifaka (P. perrieri), golden-crowned sifaka, (P. tattersalli) and silky sifaka (P. candidus). They have luxuriant silky coats and are powerful leapers. They share similar characteristics of gestation length (4 months), age of sexual maturity, female dominance, life expectancy (18 years) and propensity for sunbathing while stretched out on a branch. They differ in colouration and markings, but have black, naked faces and red-orange eyes.

The diademed sifaka (Propithecus diadema), or diademed simpona, is an endangered species of sifaka, one of the lemurs endemic to certain rainforests in eastern Madagascar. Along with the indri, this species is one of the two largest living lemurs, with an average weight of 6.5 kg and a total adult length of approximately 105 centimetres (41 inches), half of which is its tail. Russell Mittermeier, one of the contemporary authorities on lemurs, describes the diademed sifaka as "one of the most colorful and attractive of all the lemurs", having a long and silky coat. P. diadema is also known by the Malagasy names simpona, simpony and ankomba joby. The term "diademed sifaka" is also used as a group species designation formerly encompassing four distinct subspecies.