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The golden-crowned sifaka or Tattersall's sifaka (''Propithecus tattersalli'') is a medium-sized lemur characterized by mostly white fur, prominent furry ears, and a golden-orange crown. It is one of the smallest sifakas (genus ''Propithecus''), weighing around and measuring approximately from head to tail. Like all sifakas, it is a vertical clinger and leaper, and its diet includes mostly seeds and leaves. The golden-crowned sifaka is named after its discoverer, Ian Tattersall, who first spotted the species in 1974. However, it was not formally described until 1988, after a research team led by Elwyn L. Simons observed and captured some specimens for captive breeding. The golden-crowned sifaka most closely resembles the western forest sifakas of the ''P. verreauxi'' group, yet its karyotype suggests a closer relationship with the ''P. diadema'' group of eastern forest sifakas. Despite the similarities with both groups, more recent studies of its karyotype support its classification as a distinct species. Found in gallery, deciduous, and semi-evergreen forest, its restricted range includes 44 forest fragments, totaling an area of , centered on the town of Daraina in northeast Madagascar. Its estimated population is 18,000 individuals. It is primarily active during the day, although it also tends to be active at dawn and dusk during the rainy season. It sleeps in tall emergent trees and is preyed upon by the fossa. The golden-crowned sifaka lives in groups of around five to six individuals, containing a balanced number of adult males and females. Scent is used to mark territories, which are defended by growling, chasing, and ritualistic leaping displays. Reproduction is seasonal, with gestation lasting six months and lactation lasting five months. Infants are weaned during the wet season to ensure the best chances of survival. The small range and fragmented populations of this species weigh heavily on its survival. Forest fragmentation, habitat destruction, poaching, slash-and-burn agriculture, and other human factors threaten its existence. The golden-crowned sifaka is listed by the IUCN Red List as ''Endangered''. Its range was originally not covered by any national parks or protected areas in Madagascar, but a new protected area was established in 2005 to include a portion. Attempts have been made to keep the golden-crowned sifaka in captivity at the Duke Lemur Center in Durham, North Carolina. The small colony was maintained from 1988 to 2008. In Madagascar, lawlessness resulting from the 2009 political coup led to increased poaching of this species, and many were sold to local restaurants as a delicacy. ==Taxonomy and phylogeny== The golden-crowned or Tattersall's sifaka (''Propithecus tattersalli''), known locally as ''ankomba malandy'' (or ''akomba malandy'', meaning "white lemur"), was discovered in 1974 north of Vohemar in northeast Madagascar by Ian Tattersall, who observed but did not capture the animal. Unsure of its classification, Tattersall provisionally considered it a variant of the silky sifaka in his 1982 book, ''The Primates of Madagascar'', citing its mostly off-white to yellowish fur, but also noting its uncharacteristic orange crown patch and tufted ears. Driven by a report in 1986 that the forest where Tattersall had observed this unique sifaka was contracted to be clear-cut for charcoal production, a research team from the Duke Lemur Center, led by Elwyn L. Simons, obtained permits to capture specimens for a captive breeding program. Simons and his team were the first to capture and observe the golden-crowned sifaka, formally describing it as a new species in 1988 and naming it in honor of Tattersall. The specimens were found northeast of Daraina, a village in the northeast corner of Madagascar. There have been conflicting studies regarding the taxonomic status of the golden-crowned sifaka. When described by Simons in 1988, size, vocalizations, and karyotypes (the number and appearance of chromosomes) were compared with the other sifakas. In terms of size, general morphology, and vocalizations, the golden-crowned sifaka is more comparable to the western forest sifakas (known as the ''P. verreauxi'' group) in that it is smaller in length and weight. Its karyotype, however, is more similar to that of the eastern forest sifakas (known as the ''P. diadema'' group). The golden-crowned sifaka has 42 chromosomes (2n=42), 16 of which are autosomal pairs (not sex chromosomes) that are meta- or submetacentric (where chromosome arms are equal or unequal in length, respectively). The remaining autosomal pairs are smaller and acrocentric (with the shorter chromosome arm difficult to observe). Its X chromosome is metacentric, which is comparable to that of the ''P. diadema'' group, not the ''P. verreauxi'' group. Given the conflicting information, its geographic isolation, as well as the unique long fur tufts on the ears—a trait not shared by any other sifaka—the golden-crowned sifaka was recognized as a distinct species. In 1997, comparisons of repeated DNA sequences within the family Indriidae supported Simon's classification, placing the golden-crowned sifaka as a sister group to the other sifakas. In 2001, a study involving mitochondrial DNA suggested a very recent divergence between it and the Coquerel's sifaka, then considered a subspecies of the ''P. verreauxi'' group. If this were true, the golden-crowned sifaka would not merit species status and would form a subclade with the Coquerel's sifaka within the ''P. verreauxi'' group. In 2004, a comparative study of the karyotypes of the three traditional species of sifakas provided insight into the chromosomal arrangements of all three groups. This study found that the golden-crowned sifaka differs from ''P. verreauxi'' group and ''P. diadema'' group 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 the ''P. verreauxi'' group. More recently, in 2007 a craniodental (skull and tooth) study provided evidence for 9 or 10 distinct sifaka species, including the golden-crowned sifaka. It also placed the golden-crowned sifaka within the ''P. verreauxi'' group. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Golden-crowned sifaka」の詳細全文を読む スポンサード リンク
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