Золотой львиный тамарин: Экология и охрана исчезающего вида.

Species of New World monkey

The golden lion tamarin (Leontopithecus rosalia; mico leão dourado ˈmiku leˈɐ̃w do(w)ˈɾadu, liˈɐ̃w ), also known as the golden marmoset, is a small New World monkey of the family Callitrichidae. Endemic to the Atlantic coastal forests of Brazil, the golden lion tamarin is an endangered species. The range for wild individuals is spread across four places along southeastern Brazil, with a recent census estimating 3,200 individuals left in the wild and a captive population maintaining about 490 individuals among 150 zoos.

The golden lion tamarin gets its name from its bright reddish orange pelage and the extra long hairs around the face and ears which give it a distinctive mane. Its face is dark and hairless. The bright orange fur of this species does not contain carotenoids, which commonly produce bright orange colors in nature. The golden lion tamarin is the largest of the callitrichines. It is typically around and weighs around There is almost no size difference between males and females. As with all callitrichines, the golden lion tamarin has claw like nails, instead of the flat nails found in other monkeys and apes, although callitrichines do have a flat nail on the big toe. Tegulae enable tamarins to cling to the sides of tree trunks. It may also move quadrupedally along the small branches, whether through walking, running, leaping or bounding. This gives it a locomotion more similar to squirrels than primates.

The Golden Lion Tamarin has a very limited distribution range, as over time they have lost all but 2%–5% of their original habitat in Brazil rain forest. Today, this tamarin is confined to three small areas of the tropical rain forest in southeastern Brazil: Poço das Antas Biological Reserve, Fazenda União Biological Reserve, and private land through the Reintroduction Program. However, they have been successfully reintroduced to the municipalities of Rio das Ostras, Rio Bonito, and Casimiro de Abreu. Tamarins live in coastal lowland forests less than 300 m (984 ft) above sea level. They can be found in hilltop forests and swamp forests.

The golden lion tamarin is active for a maximum of 12 hours daily. It uses different sleeping dens each day. By frequently moving their sleeping nests around, groups minimize the scent left behind, reducing the likelihood of predators finding them. The first activities of the day are traveling and feeding on fruits. As the afternoon nears, tamarins focus more on insects. By late afternoon, they move to their night dens. Tamarin groups use hollow tree cavities, dense vines or epiphytes as sleeping sites. Sites that are between off the ground are preferred. The golden lion tamarin tends to be active earlier and retire later in the warmer, wetter times of the year as the days are longer. The golden lion tamarin has a diverse, omnivorous diet consisting of fruits, flowers, nectar, bird eggs, insects and small vertebrates. They rely on microhabitats for foraging and other daily activities and tamarins will use bromeliads, palm crowns, palm leaf sheaths, woody crevices, lianas, vine tangles, tree bark, rotten logs, and leaf litters. It is made possible by elongated hands and fingers. Insects make up to 10–15% of its diet. Much of the rest is made of small, sweet, pulpy fruits. During the rainy season, the golden lion tamarin mainly eats fruit; however, during drier times, it must eat more of other foods like nectar and gums. Other members include subadults, juveniles and infants of either sex. These individuals are typically the offspring of the adults. When there is more than one breeding adult in a group, one is usually dominant over the other and this is maintained through aggressive behavior. The dominance relationship between males and females depends on longevity in the group. A newly immigrated male is subordinate to the resident adult female who inherited her rank from her mother. Both males and females may leave their natal group at the age of four, however females may replace their mothers as the breeding adult, if they die, which will lead to the dispersal of the breeding male who is likely her father. This does not happen with males and their fathers. Dispersing males join groups with other males and remain in them until they find an opportunity to immigrate to a new group. The vast majority of recruits to groups are males. A male may find an opportunity to enter into a group when the resident male dies or disappears. Males may also aggressively displace resident males from their group; this is usually done by two immigrant males who are likely brothers. When this happens, only one of the new males will be able to breed and will suppress the reproduction of the other. A resident male may also leave a vacancy when his daughter becomes the breeding female and he must disperse to avoid inbreeding. Golden lion tamarins are highly territorial and groups will defend their home range boundaries and resources from other groups. Tamarins emit "whine" and "peep" calls, which are associated with alarm and alliances respectively. "Clucks" are made during foraging trips or during aggressive encounters, whether directed at conspecifics or predators. "Trills" are used to communicate over long distances to give away an individual's position. "Rasps" or "screeches" are usually associated with playful behavior. Tamarins communicate through chemicals marked throughout their territories. Reproductive males and females scent mark the most and their non reproductive counterparts rarely do so. Dominant males use scent marking to show their social status and may suppress the reproductive abilities of the other males.

The mating system of the golden lion tamarin is largely monogamous. When there are two adult males in a group only one of them will mate with the female. There are cases of a male mating with two females, usually a mother and daughter. Females are sexually mature between the ages of 15–20 months but it is not until they are 30 months old that they can reproduce. Males may reach puberty by 28 months. The younger members of the groups may lose breeding opportunities but they gain parental experience in helping to rear their younger siblings.

A study has shown that increased predation has caused significant decreases in the population numbers. A survey conducted in 1992 found the number of wild population of golden lion tamarins to be 562 individuals in 109 groups. Currently, the average group size includes 3.6 to 5.7 individuals and densities from 0.39 groups/km to 2.35 groups/km.

Threats to the golden lion tamarin population include illegal logging, poaching, mining, urbanization, deforestation, pet trading, and infrastructure development and the introduction of alien species. In 1969, the number of individuals in the Atlantic Forest was found to have dropped to a low of 150 individuals. In 1975 the golden lion tamarin was listed under Appendix I of CITES, given to animals threatened with extinction that may be or are being affected by trade. The species was listed as Endangered by the IUCN in 1982, but the IUCN warns that extreme habitat fragmentation from deforestation means the wild population has little potential for any further expansion. The first step of reintroduction begins with zoo free ranging programs, where tamarins have access to explore the entire zoo. However, they are kept on zoo grounds by the presence of a nest box, an ice box like container where their food is kept. When the tamarins are reintroduced in Poço das Antas Biological Reserve, they require a large amount of post release training and veterinary care. For the first 6–18 months the reintroduced groups are monitored. Additionally, 1 2 tamarins from each group are radio collared to allow careful monitoring, and all reintroduced tamarins are tattooed and dye marked for easy identification. The golden lion tamarins faced the potential of getting new diseases that they had not been previously exposed to. Many were exposed to callitrichid hepatitis, and contracted the disease. Despite the challenge of illness, the forty two translocated golden lion tamarins' population grew to over 200 in União Biological Reserve. The number of wild golden lion tamarins is now up in the thousands in all reserves and ranches combined in Brazil. These numbers were once down in the 200s in 1991. By 2025, the number of golden lion tamarins that are protected is projected to be greater than 2000. However, due to the deforestation and fragmentation of the Atlantic forest, their home ranges have decreased in size. This directly affects their areas of foraging and subsequently, the amount of resources available.

Additionally, this deforestation and fragmentation also leads to demographic instabilities, and an increased probability of inbreeding, consequently leading to inbreeding depression and a population decline. In the case of inbreeding, the problem lies in the increase of the isolated fragments where golden lion tamarins live. Inbreeding leads to low levels of genetic diversity and has a negative effect on survivorship; inbred offspring have a lower survivorship than non inbred offspring. Fragmentation leads to a decline in dispersal and as a result, a decline in breeding with individuals of other groups. Consequently, inbreeding depression is observed in these populations. With delay breeding, the decrease and shortage of territory puts pressure on golden lion tamarins to disperse in order to find necessary resources and areas suitable for their survival. However, dispersal is risky and requires a lot of energy that could have been used for reproduction instead.

A 2016 2018 yellow fever epidemic in southeastern Brazil had a significant impact on the golden lion tamarin population, reducing it by 32% to approximately 2,516 individuals. The tamarin population faced increased losses in forest areas that were of a larger size, with fewer edge zones and greater connectivity, all of which could create conditions conducive to the presence and spread of mosquitoes that transmit yellow fever. The impact of the outbreak was particularly devastating within the Poço das Antas Biological Reserve, with the population of around 400 tamarins dropping to only 32. The cause of this decline was attributed to human activities, such as the expansion of the BR 101 highway, which brings a constant flow of traffic into the area. Researchers noted that the rapid spread of the disease across Brazil, from north to south, was due to human mobility, as infected people carried the virus with them. In response to the epidemic, Brazilian scientists created a customized yellow fever vaccine specifically for golden lion tamarins. The vaccine campaign started in 2021 and had vaccinated over 300 tamarins by February 2023, with no reported adverse effects. The efficacy of the vaccine is similar to human vaccines, with 90 95% of retested monkeys showing immunity. By February 2023, the yellow fever outbreak had subsided, and the tamarin population had stabilized.