Propithecus verreauxi, Grandidier, 1867

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Indriidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 142-175 : 169

10.

Verreaux’s Sitaka

Propithecus verreauxi

French: Sifaka de Verreaux / German: Kappensifaka / Spanish: Sifaca de Verreaux

Other common names: White Sifaka

Taxonomy. Propithecus verreaux: Grandidier, 1867 ,

Madagascar, Tsifanihy (N. of Cap Sainte-Marie).

A distinctive color variant was described as a subspecies and given the name major: by W. Rothschild in 1894, but most experts now consider it a melanistic form of Verreaux’s Sifaka. Monotypic.

Distribution. SW & S Madagascar, in the W up to the Tsiribihina River, in the SE it is found near to (just N of) Tolagnaro (= Fort-Dauphin) in the Nahampoana Reserve, although it was probably introduced there; the distributional limit in the SE is the transitional and spiny forest patches of the Mangatsiaka Parcel of Andohahela National Park.

Descriptive notes. Head-body 40-48 cm, tail 50-60 cm; weight 2-9 kg. Verreaux’s Sifaka is one of the smaller species of Propithecus . Its pelage is long and thick, with the predominant coat color, including the tail, being generally a lustrous white, often with a silvery or golden tint on the back and flanks. This contrasts sharply with the black face, muzzle, hands, and feet. It also contrasts with the dark reddish-brown, chocolatebrown, or black crown that extends down the nape of the neck in both sexes. The underside is sparsely furred, exposing the dark skin of the belly and giving the abdomen a grayish appearance. The snout is deep and narrow, and ears are slightly tufted with white. Males have a reddish-brown patch on the upper chest that is associated with a sternal gland, visible at the base of the throat. Juveniles are entirely white except for a dark brown spot on the crown and occasionally a rufous wash on the ventral side. A variant, originally considered a subspecies (majori), is also predominantly white, including its cheeks, ears, and forehead, but it has a chocolate-brown head cap and is brownish to brownish-black on the chest, back, inside of the limbs, and tail, except for its white tip. This variant is almost always found in groups of normally colored Verreaux’s Sifakas. Entirely white individuals also are occasionally observed with normally colored animals (e.g. in Berenty Reserve), and other variants may perhaps have maroon patches on the back, belly, or limbs.

Habitat. Typically tropical dry lowland and montane forest from sea level to elevations of 1300 m; also semi-arid spiny bush, brush-and-scrub thickets, deciduous gallery forest, riparian forest, and humid forests at low elevations.

Food and Feeding. Diets of Verreaux’s Sifaka are seasonally variable but consist mainly of young leaves, fruits, and flowers, supplemented with seeds, bark, dead wood, and termite soil. Leaves are the most important food item during the dry season, and fruits are most important during the wet season when parts of fewer plant species are eaten. Most seeds eaten are destroyed, meaning that Verreaux’s Sifaka is at least partly a seed predator. Survival of Verreaux’s Sifaka in Didiereaceae forest—including periods of severe drought—suggests that they do not need to drink. Water may be obtained indirectly during the dry season by eating bark and cambium of Operculicarya decaryi ( Anacardiaceae ).

Breeding. Reproduction of Verreaux’s Sifaka is seasonal and synchronized within groups and between them. Mating takes place in January-February. Females are receptive for only about a single day per year. A single dominant male monopolizes paternity in each group at Kirindy Forest, whereas paternity by extragroup males is common at Beza-Mahafaly Special Reserve. A single young is born in August-September after gestation of 162-170 days. The mothercarries her infant on her belly for the first three months, at which pointit shifts to her back. All group members interact with infants, with grooming, playing, carrying, and nursing being the most common alloparental behaviors. Infanticide has been reported. Young are almost completely independent at about six months. Age of sexual maturity varies by habitat; for example, in the spiny forests of Beza-Mahafaly, less than one-half of the females reproduced by six years of age, whereas three-year-old females at Berenty Reserve are routinely seen with newborns. Males are sexually mature at c.2-5 years old.

Activity patterns. Verreaux’s Sifakas are diurnal and mainly arboreal. They have the extraordinary ability to leap from one cactus-like Didiereaceae trunk to another—somehow managing to avoid the very hard, sharp spines of these tall, thin plants. Individuals regularly descend to the ground, where they proceed by a series of upright, usually slightly sideways, bipedal hops with arms raised above the head.

Movements, Home range and Social organization. Verreaux’s Sifakas tend to live in small to medium-sized, multimale-multifemale groups of 2-14 individuals (average 5-6). There are usually more males in a group than females. Home ranges may exceed 10 ha but are often much smaller. Rather than strict territorial boundaries, core areas and food resources of overlapping home ranges are defended against neighboring groups. Females appear to be dominant over males. Males fight with one another for dominance only during the mating season. Males disperse. Reported densities include 47 ind/km? in the degraded forests of Belaoka Marovato, 150-200 ind/km®at Berenty Reserve, and 400-500 ind/km?® at Antserananomby.

Status and Conservation. CITES Appendix I. Classified as Vulnerable on The IUCN Red List. However, at the IUCN/SSC Lemur Red-Listing Workshop in July 2012, P. verreauxi was assessed as endangered. Despite the large distribution of Verreaux’s Sifaka, the two principal habitats upon which it depends for survival—spiny forest and riparian or gallery forest—are under continual threat because of logging, slash-and-burn agriculture (especially for corn plantations), and charcoal and firewood collection. Although hunting is illegal and “fady” (taboo) to several ofthe tribes living within its distribution (e.g. Antandroy and Mahafaly), it is hunted for food by othertribes (e.g. Sakalava) and immigrants to the region. In the Isalo region, Verreaux’s Sifaka is known as “sifaka-bilany” (sifaka of the cooking pot), butitis unclear whetherthisis because ofits popularity as a food item or because of the sooty black appearance of individuals from this part of its range. It occurs in four national parks (Andohahela, Isalo, Tsimanampetsotsa, and Zombitse-Vohibasia), two special reserves (Andranomena and Beza-Mahafaly), and two private reserves (Analabe and Berenty Reserve). Populations of the Verreaux’s Sifaka also are found in the Kirindy Forest (part of the Menabe-Antimena Protected Area) and a number of unprotected classified forests and forest reserves. Significant variation in densities has been noted in different forest types; in general, densities are lower in areas of degraded habitat but even very small forest patches can support sizeable numbers of Verreaux’s Sifaka.

Bibliography. Benadi et al. (2008), Brockman (1999, 2003), Brockman & Whitten (1996), Brockman et al. (1998), Carrai & Lunardini (1996), Carrai et al. (2003), Erkert & Kappeler (2004), Fenn et al. (1999), Fichtel (2004), Fichtel & Kappeler (2002), Fichtel & van Schaik (2006), Goodman (1999b), Goodman & Raselimanana (2003), Goodman et al. (2004), Hawkins (1999), Howarth et al. (1986), Jolly, A. (1966, 1972, 1977), Jolly, A. et al. (1982), Kappeler (1991), Kappeler & Schaffler (2008), Karpanty & Goodman (1999), Lawler et al. (2003, 2005), Lewis & Kappeler (2005a, 2005b), Lewis et al. (2003), Mertl-Millhollen (1979), Mittermeier, Langrand et al. (2010), Mittermeier, Tattersall et al. (1994), Nicoll & Langrand (1989), Norscia & Palagi (2008), Norscia et al. (2005), O'Connor (1987), O'Connoret al. (1986, 1987), Oda (1998), Oda & Masataka (1996), Petter et al. (1977), Raharivololona & Ranaivosoa (2000), Ralisoamalala (1996), Rasoarimanana (2005), Rasoloarison et al. (1995), Richard (1974a, 1974b, 1976, 1977, 1978a, 1985, 1987, 1992, 2003), Richard & Nicoll (1987), Richard, Dewar et al. (2000, 2002), Richard, Rakotomanga & Schwartz (1991, 1993), Rumpler et al. (2011), Simmen et al. (2003), Sussman & Richard (1986), Sussman, Green et al. (2003), Sussman, Richard & Rakotomanga (1987), Tattersall (1982, 1986b), Trillmich et al. (2004).

Figures

On following pages: 12. Crowned Sifaka (Propithecus coronatus); 13. Coquerel’s Sifaka (Propithecus coquerell); 14. Tattersall’s Sifaka (Propithecus tattersall); 15. Diademed Sifaka (Propithecus diadema); 16. Milne-Edwards's Sifaka (Propithecus edwardsi); 17. Silky Sifaka (Propithecus candidus); 18. Perrier’s Sifaka (Propithecus perrieri).

Distribution. SW & S Madagascar, in the W up to the Tsiribihina River, in the SE it is found near to (just N of) Tolagnaro (= Fort-Dauphin) in the Nahampoana Reserve, although it was probably introduced there; the distributional limit in the SE is the transitional and spiny forest patches of the Mangatsiaka Parcel of Andohahela National Park.