Golden-crowned Sifaka

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Golden-crowned Sifaka[1]
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Indriidae
Genus: Propithecus
Species: P. tattersalli
Binomial name
Propithecus tattersalli
Simons, 1988

The Golden-crowned Sifaka (Propithecus tattersalli) is a medium-large lemur characterized by short, mostly white fur, prominent furry ears and a golden-orange crown. It weighs about 3.5 kg (7.7 lb) and is about 90 cm long. It is found in gallery, semi-evergreen and dry deciduous forest where it is mostly diurnal and sleeps in tall emergent trees. The Golden-crowned Sifaka is confined to a small area between the Manambato River and Loky River in northeast Madagascar. This critically endangered species has one of the smallest ranges and documented population sizes of any lemur.

Contents

[edit] Evolutionary Origins

The Golden-crowned Sifaka was first described in detail as a unique species by E.L. Simons of the Duke University Primate Center in 1988 after the animal was first witnessed by Ian Tattersall in 1974.[3] Simons and his team were the first to capture and observe this new group of lemurs, and due to its geographic isolation and unique appearance he deemed it a new species of the Propithecus genus. Traditionally, it has been accepted that P. tattersalli is one of the three recognized species of sifakas, along with the Diademed Sifaka (P. diadema) and Verreaux's Sifaka (P. verreauxi).[4] However, there have been conflicting studies regarding its taxonomic status. A 2001 genetic study concluded that based on its mitochondrial DNA, P. tattersalli is merely a subspecies of P. diadema.[5] A comparative study of the genetic karyotypes of the three traditional species of sifakas provided insight into the chromosomal arrangements of all three groups. This study found that P. tattersalli differs from P. verreauxi and P. diadema by 9 and 17 chromosomal rearrangements respectively, and conversely argued that the Golden-crowned Sifaka is indeed a separate species and is more closely related to P. verreauxi.[4] More recently, in 2007 a craniodental study provided evidence for 9 or 10 distinct sifaka species, with P. tattersalli being one of them.[6]

[edit] Physical description and ecology

The Golden-crowned Sifaka is the smallest of the three traditionally accepted sifaka species with an average weight of 3.5 kilograms and average body length of 90 centimeters.[7] It has a coat of white fur with prominent tufts of hair protruding from its ears and a characteristic bright orange-gold crown. Similar to other sifakas, this arboreal animal has long, strong legs that enable it to cling and leap between tree trunks and branches.[8]

It is primarily active during the day, however researchers have witnessed activity in the early morning and evening during the rainy season.[7] The diet of the Golden-crowned Sifaka consists of a wide variety of plant resources whose availability varies based on the season. Seeds are a year-round staple in its diet and when available, the Golden-crowned Sifaka eats both ripe and unripe fruit, flowers, and leaves.[9] Group size ranges from 3 to 10 adults and each group occupies a home range between 9 and 12 ha (.09 to .12 km2) which it marks with scent glands.[7] Each group defends a large home range, however on any given day this sifaka only travels between 400 and 1,200 meters.[10] The Golden-crowned Sifaka lives in densities ranging from 17 to 28 individuals per square kilometer.[7]

[edit] Reproduction and sociality

The Golden-crowned Sifaka requires a gestation period of a little less than 6 months, and therefore with a lactation period of 5 months, there is only one month in every twelve in which successfully reproductive females are likely to cycle and have the ability to conceive.[9] Research has indicated that reproduction is strategically linked with forest seasonality. Gestation starts in the later parts of the wet season and continues on through the middle of the dry season. Lactation then takes place from the middle of the dry season through the early part of the wet season.[9] After this eleven-month gestation and lactation period, the offspring is then weaned during the middle of the wet season when an abundance of immature leaves is available. It is thought that such reproductive timing exists to ensure adequate protein intake from the immature leaves for both mother and child at the end of the lactation period.[9]

Each Golden-crowned Sifaka group contains an average of 5 to 6 adults (both male and female), but only one female per group is reproductively successful in any given year. Sexual maturity is reached between 2 and 3 years of age and during the mating season males migrate between groups.[10] As with all primates, social dynamics plays an integral role in the lives of the Golden-crowned Sifaka. Each group is female-dominated and while the males move between groups, females remain in the same group throughout their entire lives and build strong social bonds with other females through grooming activities.[10]

It has been noted that the temperament of the Golden-crowned Sifaka is more volatile than that of other Propithecus species and, in the case of a dispute, this animal frequently emits a grunt-like vocalization that seems to signal annoyance.[3] Such aggressiveness has also been witnessed in territorial disputes. Although not physical, the aggressive confrontations when two groups meet include loud growling, territorial marking, and seemingly ritualistic leaping and movements.[11]

[edit] Habitat and species abundance

The Golden-crowned Sifaka lives in dry deciduous forests and is found at altitudes up to 700 meters.[8] Human activities have greatly decreased the amount of available habitat for the Golden-crowned Sifaka. Surveys have shown it to be limited to highly fragmented forests surrounding the town of Daraina in an area encircled by the Loky and Manambato rivers in Northeastern Madagascar.[7] Of the 75 total forest fragments studied by researchers, the presence of P. tattersalli could be definitively reported in only 44 fragments totaling 44,125 hectares. This study also estimated the total species population to be between 6,120 and 10,080 individuals with 2,520 to 3,960 reproductive adults.[7]

[edit] Threats

The Golden-crowned Sifaka faces very few natural threats, the most significant of which is predation. Due to its relatively large size however, the sifakas on the Eastern coast of Madagascar suffer lower predation pressure than other lemurs with their only predator being the carnivorous Fossa.[12]

While the Golden-crowned Sifaka faces few biological threats, it faces many significant anthropogenic threats. Although considered a western species of the Propithecus genus, its habitat has been reduced to only a small area in the northeastern portion of Madagascar. By 1985 it was estimated that 34% of the entire eastern rainforest of the island had disappeared, and by extrapolation it is predicted that at this rate of deforestation there will be no eastern rainforest left by 2020.[12] Illegal logging practices, slash-and-burn agriculture, gold mining, and clearing land for agricultural use have all significantly contributed to the massive habitat destruction witnessed in Madagascar and the ongoing decline of suitable habitat for Propithecus tattersalli.[7]

As population and subsequently the demand for agricultural lands increases, the Malagasy farmers continue to use fire to clear out forested lands. The fires sometimes burn out of control and destroy forest edges along with the natural flora, increasing the damage even further than intended.[7] This kind of fire damage is also a consequence of the slash and burn agricultural practices of Madagascar. These practices have been prominent for years and over time the people have been forced to decrease fallow periods in order to produce enough crops to meet subsistence levels. As the fertility of the land decreases, the people are forced to clear more land and the deforestation continues.[7]

Although coal is more efficient, the most affordable and prominent source of energy for the Malagasy people is timber. Wood is also used as a primary building material, only adding further incentive to remove trees from the forest. As the already dead trees are being quickly depleted from the forest patches, the people have begun to remove young, healthy trees. As would be expected, this type of devastation is most common in areas closest to villages.[7]

A newly emergent threat facing the Golden-crowned Sifaka is the threat of hunting by the gold miners moving into the region's forests.[8] There is a local fady, similar to a taboo, in Madagascar that protects sifakas from being hunted due to their likeness to humans.[12] So while the Malagasy people seldom hunt these animals, the gold miners who have immigrated to the area have begun to hunt the Golden-crowned Sifaka as a source of meat as it is one of the largest animals in their forests.[8] The miners themselves are not the only negative consequence of the gold mining taking place in the forested regions. The mining is often small-scale but the deep mining pits are often dug near or underneath large trees. This activity disturbs the extensive root systems and ultimately leads to the death of the trees in the area.[7]

[edit] Conservation

To date, there has been no formal conservation effort aimed solely at the Golden-crowned sifaka. As of 2007, P. tattersalli has been labeled as critically endangered by the IUCN.[2] Its habitat is extremely fragmented and none of the forested areas that it inhabits are part of a formally protected park or reserve.[7] Its preferred dry-forest environment is also an important agricultural and economical resource for the human population.[13] Propithecus tattersalli is a high-priority species for conservation, as its numbers are small and the entirety of its habitat that remains is unprotected and in danger of uncontrolled human exploitation.[7]

The Golden-crowned Sifaka is mainly threatened by anthropogenic disturbances, and the most glaringly obvious and urgent conservation agenda is the creation of and effective implementation of a national park or nature reserve.[13][7] The most important goal is to increase the amount and protection of suitable habitat available to the Golden-crowned Sifaka. A conservation study from 1989 calls for the creation of a national park that includes the forest of Binara as well as the dry forests to the north of Daraina.[13] On the other hand, a more recent study proposes a network of protected forest areas including areas outside of the village of Daraina, forests north of the Monambato River, and the northern forests that constitute the species' northern reservoir.[7]

The area inhabited by Propithecus tattersalli is highly fragmented and includes a significant human presence.[12] These citizens must be taken into account when considering further conservation efforts in other small forest patches. Besides the political obstacles associated with relocating citizens, conservation efforts must also overcome damage to land perpetrated by farming practices and out-of control brush fires.[13] It is important to recognize the human factor in the conservation equation, and it has been suggested that a system incorporating Conservation Gradients be instituted.[7] This would entail designing and enforcing different degrees of protection throughout the many forested patches of land in the region. Such a system would allow human activity and resource extraction in areas that have less conservation potential while strictly protecting areas critical to the species' survival. This type of compromise with the Malagasy people could also make them more inclined to cooperate with conservationists and possibly take a personal interest in the preservation of the Golden-crowned Sifaka.[7]

In terms of captive populations, there are only three individuals (all males) currently living in captivity at the Duke University Lemur Center in Durham, North Carolina.[14] The youngest male is five years old and he is the first Golden-crowned Sifaka to have ever been conceived in captivity and go on to survive in captivity. This animals does not seem to fare well in captivity, and unless more research can be done on captive populations, the possibility of future reintroductions or even successfully sustaining captive populations is questionable.

[edit] References

Wikispecies has information related to:
  1. ^ Groves, Colin (16 November 2005). in Wilson, D. E., and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press, 121. ISBN 0-801-88221-4. 
  2. ^ a b Ganzhorn, J. & Members of the Primate Specialist Group (2000). Propithecus tattersalli. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 2007-05-14.
  3. ^ a b Simons, E.L. (1988). "A new species of Propithecus (Primates) from northeast Madagascar". Folia Primatol 50: 143-151. 
  4. ^ a b Rumpler, Y., Andriaholinirina, N., Warter, S., Hauwy, M., Rabarivola, C. (2004). "Phylogenic history of the sifakas (Propithecus: Lemuriformes) derived from cytogenetic studies". Chromosome Research 12: 453-463. 
  5. ^ Pastorini, J., Forstner, M.R.J., Martin, R.D. year = 2001. "Phylogenic history of sifakas (Propithecus: Lemuriformes) derived from mtDNA sequences". American Journal of Primatology 53: 1-17. 
  6. ^ Groves, C.P. & Helgen, K.M. (2007). "Craniodental characters in the taxonomy of Propithecus". International Journal of Primatology 28: 1363-1383. 
  7. ^ a b c d e f g h i j k l m n o p q Vargas, A., Jimenez, I., Palomares, F., and Palacios, M.J. (2002). "Distribution, status, and conservation needs of the golden-crowned sifaka (Propithecus tattersalli)". Biological Conservation 108: 325-334. 
  8. ^ a b c d Mittermeier, R.A., Konstant, W.R., Hawkins, F., Louis, E.E., Langrand, O., Ratsimbazafy, J., Rasoloarison, R., et al. (2006). Lemurs of Madagascar. Colombia: Conservation International. 
  9. ^ a b c d Meyers, D.M. & Wright, P.C. (1993). "Resource tracking: food availability and Propithecus seasonal reproduction", in P.M. Kappeler. & J.U. Ganzhorn (Eds.): Lemur social systems and their ecological basis. New York: Plenum Press, pp. 179-192. 
  10. ^ a b c EDGE: The Zoological Society of London (n.d.). Golden-crowned sifakas (Propithecus tattersalli). EDGE Team of the Zoological Society of London. Retrieved on 2008-04-20.
  11. ^ Raynor, S. (2000). Propithecus tattersalli. Retrieved on 2008-04-20.
  12. ^ a b c d Irwin, M.T. (2006). "Ecologically enigmatic lemurs: the sifakas of the eastern forests (Propithecus candidus, P. diadema, P. edwardsi, P. perrieri, and P. tattersalli)", in L. Gould & M.L. Sauther (Eds.): Lemurs: ecology and adaptation. New York: Springer Science + Business Media LLC, pp. 305-324. 
  13. ^ a b c d Meyers, D.M. and Ratsirarson J. (1989). "Distribution and conservation of two endangered sifakas in northern Madagascar". Primate Conservation 10: 81-86. 
  14. ^ DLC: Animals: Golden-Crowned Sifaka