Friday 10 August 2012

Sumatran Rhinocerous

The Sumatran rhinoceros (Dicerorhinus sumatrensis) is a member of the family Rhinocerotidae and one of five extant rhinoceroses. It is the only extant species of the genus Dicerorhinus. It is the smallest rhinoceros, although is still a large mammal. This rhino stands 112–145 cm (3.67–4.76 ft) high at the shoulder, with a head-and-body length of 2.36–3.18 m (7.7–10.4 ft) and a tail of 35–70 cm (14–28 in). The weight is reported to range from 500 to 1,000 kg (1,100 to 2,200 lb), averaging 700–800 kg (1,500–1,800 lb), although there is a single record of a 2,000 kg (4,400 lb) specimen. Like the African species, it has two horns; the larger is the nasal horn, typically 15–25 centimetres (5.9–9.8 in), while the other horn is typically a stub. A coat of reddish-brown hair covers most of the Sumatran rhino's body.
Members of the species once inhabited rainforests, swamps and cloud forests in India, Bhutan, Bangladesh, Myanmar, Laos, Thailand, Malaysia, Indonesia, and China. In historical times they lived in southwest China, particularly in Sichuan. They are now critically endangered, with only six substantial populations in the wild: four on Sumatra, one on Borneo, and one in the Malay Peninsula. Their numbers are difficult to determine because they are solitary animals that are widely scattered across their range, but they are estimated to number fewer than 275. Survival of the Peninsular Malaysia population is in doubt, and one of the Sumatran populations may already be extinct. Total numbers today may be as low as 200. The decline in the number of Sumatran rhinoceros is attributed primarily to poaching for their horns, which are highly valued in traditional Chinese medicine, fetching as much as US$30,000 per kilogram on the black market.
The Sumatran rhino is a mostly solitary animal except for courtship and offspring-rearing. It is the most vocal rhino species and also communicates through marking soil with its feet, twisting saplings into patterns, and leaving excrement. The species is much better studied than the similarly reclusive Javan rhinoceros, in part because of a program that brought 40 Sumatran rhinos into captivity with the goal of preserving the species. The program was considered a disaster even by its initiator; most of the rhinos died and no offspring were produced for nearly 20 years, representing an even worse population decline than in the wild.

Taxonomy and naming


The first documented Sumatran rhinoceros was shot 16 kilometres (9.9 mi) outside Fort Marlborough, near the west coast of Sumatra, in 1793. Drawings of the animal, and a written description, were sent to the naturalist Joseph Banks, then president of the Royal Society of London, who published a paper on the specimen that year. It was not until 1814, however, that the species was given a scientific name, by Johann Fischer von Waldheim, a German scientist and curator of the State Darwin Museum in Moscow, Russia.
The scientific name Dicerorhinus sumatrensis comes from the Greek terms di (δι, meaning "two"), cero (κέρας, meaning "horn"), and rhinos (ρινος, meaning "nose"). Sumatrensis signifies "of Sumatra", the Indonesian island where the rhinos were first discovered. Carolus Linnaeus originally classified all rhinos in the genus Rhinoceros; therefore the species was originally identified as Rhinoceros sumatrensis. Joshua Brookes considered the Sumatran rhinoceros, with its two horns, a distinct genus from the one-horned Rhinoceros, and gave it the name Didermocerus in 1828. Constantin Wilhelm Lambert Gloger proposed the name Dicerorhinus in 1841. In 1868, John Edward Gray proposed the name Ceratorhinus. Normally the oldest name would be used, but a 1977 ruling by the International Commission on Zoological Nomenclature established the proper genus name as Dicerorhinus.
The three subspecies are:

D. s. sumatrensis, known as the western Sumatran rhinoceros, has only 170 to 230 rhinos remaining, mostly in the national parks of Bukit Barisan Selatan and Gunung Leuser in Sumatra. Around 75 may also live in Peninsular Malaysia. The main threats against this subspecies are habitat loss and illegal poaching. There is a slight genetic difference between the western and eastern Sumatran rhinos. The rhinos in Peninsular Malaysia were once known as D. s. niger, but were later recognized to be similar to the rhinos on western Sumatra.

D. s. harrissoni, known as the eastern Sumatran rhinoceros or Bornean rhinoceros, was once common throughout Borneo; now only about 50 individuals are estimated to survive. The known population on Borneo lives in Sabah. There are unconfirmed reports of animals surviving in Sarawak and Kalimantan. This subspecies is named after Tom Harrisson, who worked extensively with Bornean zoology and anthropology in the 1960s. The Bornean subspecies is markedly smaller than the other two.

D. s. lasiotis, known as the northern Sumatran rhinoceros, once roamed in India and Bangladesh, but has been declared extinct in these countries. Unconfirmed reports suggest there may be a small population still surviving in Burma, but the political situation in the country has prevented verification. The name lasiotis is derived from the Greek for "hairy-ears". Later studies showed their ear-hair was not longer than other Sumatran rhinos, but D. s. lasiotis remained a subspecies because it was significantly larger than the other subspecies.

Evolution


Ancestral rhinoceroses first diverged from other perissodactyls in the Early Eocene. Mitochondrial DNA comparison suggests the ancestors of modern rhinos split from the ancestors of Equidae around 50 million years ago. The extant family, the Rhinocerotidae, first appeared in the Late Eocene in Eurasia, and the ancestors of the extant rhino species dispersed from Asia beginning in the Miocene
The Sumatran rhinoceros is considered the least derived of the extant species, as it shares more traits with its Miocene ancestors.Paleontological evidence in the fossil record dates the genus Dicerorhinus to the Early Miocene, 23–16 million years ago. Many fossils have been classified as members of Dicerorhinus, but no other recent species are in the genus. Molecular dating suggests a split of Dicerorhinus from the four other extant species as far back as 25.9 ± 1.9 million years. Three hypotheses have been proposed for the relationship between the Sumatran rhinoceros and the other living species. One hypothesis suggests the Sumatran rhinoceros is closely related to the black and white rhinos in Africa, evidenced by the species having two horns, instead of one. Other taxonomists regard the Sumatran rhinoceros as a sister taxon of the Indian and Javan rhinoceros because their ranges overlap so closely. A third hypothesis, based on more recent analyses, however, suggests the two African rhinos, the two Asian rhinos and the Sumatran rhinoceros represent three essentially separate lineages that split around 25.9 million years ago, and it may therefore be unclear which group diverged first.
Because of morphological similarities, the Sumatran rhinoceros is believed to be closely related to the extinct woolly rhinoceros (Coelodonta antiquitatis). The woolly rhinoceros, so named for the coat of hair it shares with the Sumatran rhinoceros, first appeared in China, and by the Upper Pleistocene, ranged across the Eurasian continent from Korea to Spain. The woolly rhinoceros survived the last Ice Age, but like the woolly mammoth, most or all became extinct around 10,000 years ago. Although some morphological studies questioned the relationship, recent molecular analysis has supported the two species as sister taxa.

Description

 

Specimen in Cincinnati Zoo
 
A mature Sumatran rhino stands about 120–145 centimetres (3.9–4.76 ft) high at the shoulder, has a body length of around 250 centimetres (8.2 ft) and weighs 500–800 kilograms (1,100–1,800 lb), though the largest individuals in zoos have been known to weigh as much as 1,000 kilograms (2,200 lb). Like the African species, it has two horns. The larger is the nasal horn, typically only 15–25 centimetres (5.9–9.8 in), though the longest recorded specimen was much longer at 81 centimetres (32 in). The posterior horn is much smaller, usually less than 10 centimetres (3.9 in) long, and often little more than a knob. The larger nasal horn is also known as the anterior horn; the smaller posterior horn as the frontal horn. The horns are dark gray or black in color. The males have larger horns than the females, though the species is not otherwise sexually dimorphic. The Sumatran rhino lives an estimated 30–45 years in the wild, while the record time in captivity is a female D. lasiotis which lived for 32 years and 8 months before dying in the London Zoo in 1900.
Two thick folds of skin encircle the body behind the front legs and before the hind legs. The rhino has a smaller fold of skin around its neck. The skin itself is thin, 10–16 millimetres (0.39–0.63 in), and in the wild the rhino appears to have no subcutaneous fat. Hair can range from dense (the most dense hair in young calves) to scarce and is usually a reddish-brown. In the wild, this hair is hard to observe because the rhinos are often covered in mud. In captivity, however, the hair grows out and becomes much shaggier, likely because of less abrasion from walking through vegetation. The rhino has a patch of long hair around the ears and a thick clump of hair at the end of the tail. Like all rhinos, they have very poor vision. The Sumatran rhinoceros is fast and agile; it climbs mountains easily and comfortably traverses steep slopes and riverbanks. 

Distribution and habitat

 

The Taman Negara National Park contains the only known concentrated population of Sumatran rhinoceros on mainland Asia.
 
The Sumatran rhinoceros lives in both lowland and highland secondary rainforest, swamps and cloud forests. It inhabits hilly areas close to water, particularly steep upper valleys with a lot of undergrowth. The Sumatran rhinoceros once inhabited a continuous range as far north as Burma, eastern India and Bangladesh. Unconfirmed reports also placed it in Cambodia, Laos and Vietnam. All known living animals occur in Peninsular Malaysia, the island of Sumatra and Sabah, Borneo. Some conservationists hope Sumatran rhinos may still survive in Burma, though it is considered unlikely. Political turmoil in Burma has prevented any assessment or study of possible survivors. The last reports of stray animals from Indian limits were in 1990s.
The Sumatran rhino is widely scattered across its range, much more so than the other Asian rhinos, which has made it difficult for conservationists to protect members of the species effectively. Only six areas are known to contain communities of more than a handful of Sumatran rhinoceros: Bukit Barisan Selatan National Park, Gunung Leuser National Park, and Way Kambas National Park on Sumatra; Taman Negara National Park in Peninsular Malaysia; and the Tabin Wildlife Reserve in Sabah, Malaysia on the island of Borneo.
The Kerinci Seblat National Park, Sumatra's largest, was estimated to contain a population of around 500 rhinos in the 1980s, but due to poaching, this population is now considered extinct. The survival of any animals in Peninsula Malaysia is also in doubt.

A cloud forest in Sabah, Borneo
 
Genetic analysis of Sumatran rhino populations has identified three distinct genetic lineages. The channel between Sumatra and Malaysia was not as significant a barrier for the rhinos as the Barisan Mountains along the length of Sumatra, for rhinos in eastern Sumatra and Peninsular Malaysia are more closely related than the rhinos on the other side of the mountains in western Sumatra. In fact, the eastern Sumatra and Malaysia rhinos show so little genetic variance that the populations were likely not separate during the Pleistocene, when sea levels were much lower and Sumatra formed part of the mainland. Both populations of Sumatra and Malaysia, however, are close enough genetically that interbreeding would not be problematic. The rhinos of Borneo are sufficiently distinct that conservation geneticists have advised against crossing their lineages with the other populations. Conservation geneticists have recently begun to study the diversity of the gene pool within these populations by identifying microsatellite loci. The results of initial testing found levels of variability within Sumatran rhino populations comparable to those in the population of the less endangered African rhinos, but the genetic diversity of Sumatran rhinos is an area of continuing study.

Behaviour

 

Male of the extinct D. s. lasiotis with a very large front horn, London Zoo around 1904
 
Sumatran rhinoceroses are solitary creatures except for pairing before mating and during offspring rearing. Individuals have home ranges; bulls have territories as large as 50 km2 (19 sq mi), whereas females' ranges are 10–15 km2 (3.9–5.8 sq mi). The ranges of females appear to be spaced apart; males' ranges often overlap. There is no evidence Sumatran rhinos defend their territory through fighting. Marking their territory is done by scraping soil with their feet, bending saplings into distinctive patterns, and leaving excrement. The Sumatran rhino is usually most active when eating, at dawn, and just after dusk. During the day, the rhino wallows in mud baths to cool down and rest. In the rainy season, they move to higher elevations; in the cooler months, they return to lower areas in their range.
The rhino spends a large part of its day in wallows. When mud holes are unavailable, the rhino will deepen puddles with its feet and horns. The wallowing behaviour helps the rhino maintain its body temperature and protect its skin from ectoparasites and other insects. Captive specimens, deprived of adequate wallowing, have quickly developed broken and inflamed skins, suppurations, eye problems, inflamed nails, hair loss and have eventually died. One 20-month study of wallowing behavior found they will visit no more than three wallows at any given time. After two to 12 weeks using a particular wallow, the rhino will abandon it. Typically, the rhino will wallow around midday for two to three hours at a time before venturing out for food. Although in zoos the Sumatran rhino has been observed wallowing less than 45 minutes a day, the study of wild animals found 80–300 minutes (an average of 166 minutes) per day spent in wallows.

A Sumatran rhinoceros wallows in the mud at the Cincinnati Zoo.
 
There has been little opportunity to study epidemiology in the Sumatran rhinoceros. Ticks and gyrostigma were reported to cause deaths in captive animals in the 19th century. The rhino is also known to be vulnerable to the blood disease surra, which can be spread by horse-flies carrying parasitic trypanosomes; in 2004, all five rhinos at the Sumatran Rhinoceros Conservation Centre died over an 18-day period after becoming infected by the disease. The Sumatran rhino has no known predators other than humans. Tigers and wild dogs may be capable of killing a calf, but calves stay close to their mothers, and the frequency of such killings is unknown. Although the rhino's range overlaps with elephants and tapirs, the species do not appear to compete for food or habitat. Elephants (Elephas maximus) and Sumatran rhinos are even known to share trails, and many smaller species such as deer, boar and wild dogs will use the trails the rhinos and elephants create.
The Sumatran rhino maintains trails across its range. The trails fall into two types. Main trails will be used by generations of rhinos to travel between important areas in the rhino's range, such as between salt licks, or in corridors through inhospitable terrain that separates ranges. In feeding areas, the rhinos will make smaller trails, still covered by vegetation, to areas containing food the rhino eats. Sumatran rhino trails have been found that cross rivers deeper than 1.5 meters (5 ft) and about 50 meters (165 ft) across. The currents of these rivers are known to be strong, but the rhino is a strong swimmer. A relative absence of wallows near rivers in the range of the Sumatran rhinoceros indicates they may occasionally bathe in rivers in lieu of wallowing.

Diet

 

MallotesPhilipensis.jpg Garcinia mangostana fruit1.jpg
Eugenia1.jpg Ardisia crenata6.jpg
The Sumatran rhino eats a wide range of plants, such as: (clockwise from top left), Mallotus, mangosteens, Ardisia, and Eugenia.
Most feeding occurs just before nightfall and in the morning. The Sumatran rhino is a browser, with a diet of young saplings, leaves, fruits, twigs and shoots. The rhinos usually consume up to 50 kg (110 lb) of food a day. Primarily by measuring dung samples, researchers have identified more than 100 food species consumed by the Sumatran rhinoceros. The largest portion of the diet is tree saplings with a trunk diameter of 1–6 cm (0.4–2.4 inches). The rhinoceros typically pushes these saplings over with its body, walking over the sapling without stepping on it, to eat the leaves. Many of the plant species the rhino consumes exist in only small portions, which indicates the rhino is frequently changing its diet and feeding in different locations. Among the most common plants the rhino eats are many species from the Euphorbiaceae, Rubiaceae and Melastomataceae families. The most common species the rhino consumes is Eugenia.
The vegetal diet of the Sumatran rhinoceros is high in fiber and only moderate in protein. Salt licks are very important to the nutrition of the rhino. These licks can be small hot springs, seepages of salty water or mud-volcanoes. The salt licks also serve an important social purpose for the rhinos—males visit the licks to pick up the scent of females in oestrus. Some Sumatran rhinos, however, live in areas where salt licks are not readily available, or the rhinos have not been observed using the licks. These rhinos may get their necessary mineral requirements by consuming plants rich in minerals.

Communication

 




The Sumatran rhinoceros is the most vocal of the rhinoceros species. Observations of the species in zoos show the animal almost constantly vocalizing, and it is known to do so in the wild, as well. The rhino makes three distinct noises: eeps, whales, and whistle-blows. The eep, a short, one-second-long yelp, is the most common sound. The whale, named for its similarity to vocalizations of the humpback whale , is the most song-like vocalization and the second-most common. The whale varies in pitch and lasts from four to seven seconds. The whistle-blow is named because it consists of a two-second-long whistling noise and a burst of air in immediate succession. The whistle-blow is the loudest of the vocalizations, loud enough to make the iron bars in the zoo enclosure where the rhinos were studied vibrate. The purpose of the vocalizations is unknown, though they are theorized to convey danger, sexual readiness, and location, as do other ungulate vocalizations. The whistle-blow could be heard at a great distance, even in the dense brush in which the Sumatran rhino lives. A vocalization of similar volume from elephants has been shown to carry 9.8 km (6.1 mi) and thus the whistle-blow may carry as far. The Sumatran rhinoceros will sometimes twist the saplings they do not eat. This twisting behavior is believed to be used as a form of communication, frequently indicating a junction in a trail.

Reproduction

 

Adult with juvenile
 
Females become sexually mature at the age of six to seven years, while males become sexually mature at about 10 years old. The gestation period is around 15–16 months. The calf, which typically weighs 40–60 kg (88–132 lb), is weaned after about 15 months and stays with the mother for the first two to three years of its life. In the wild, the birth interval for this species is estimated to be four to five years; its natural offspring-rearing behavior is unstudied.
The reproductive habits of the Sumatran rhinoceros have been studied in captivity. Sexual relationships begin with a courtship period characterized by increased vocalization, tail raising, urination and increased physical contact, with both male and female using their snouts to bump the other in the head and genitals. The pattern of courtship is most similar to that of the black rhinoceros. Young Sumatran rhino males are often too aggressive with females, sometimes injuring and even killing them during the courtship. In the wild, the female could run away from an overly aggressive male, but in their smaller captive enclosures, they cannot; this inability to escape aggressive males may partly contribute to the low success rate of captive breeding programs.
The period of oestrus itself, when the female is receptive to the male, lasts about 24 hours, and observations have placed its recurrence between 21–25 days. Rhinos in the Cincinnati Zoo have been observed copulating for 30–50 minutes, similar in length to other rhinos; observations at the Sumatran rhinoceros Conservation Centre in Malaysia have shown a briefer copulation cycle. As the Cincinnati Zoo has had successful pregnancies, and other rhinos also have lengthy copulatory periods, a lengthy rut may be the natural behavior. Though researchers observed successful conceptions, all these pregnancies ended in failure for a variety of reasons until the first successful captive birth in 2001; studies of these failures at the Cincinnati Zoo discovered the Sumatran rhino's ovulation is induced by mating and it had unpredictable progesterone levels. Breeding success was finally achieved in 2001, 2004 and 2007 by providing a pregnant rhino with supplementary progestin. Recently, a calf was born in captivity of an endangered female in western Indonesia,only fifth such birth in one and a quarter century.

Conservation

 

D. s. sumatrensis "Rosa" in the Sumatran Rhino Sanctuary, Way Kambas National Park
 
Sumatran rhinoceroses were once quite numerous throughout Southeast Asia. It is now estimated that fewer than 275 individuals remain. The species is classed as critically endangered, primarily due to illegal poaching. Until the early 1990s, the population decline was estimated at more than 50% per decade, and the small, scattered populations now face high risks of inbreeding depression. Most remaining habitat is in relatively inaccessible mountainous areas of Indonesia.
Poaching of Sumatran rhinoceros is a cause for concern, as the price of its horn has been estimated as high as $30,000 per kilogram.This species has been overhunted for many centuries, leading to the current greatly reduced – and still declining – population. The rhinos are difficult to observe and hunt directly (one field researcher spent seven weeks in a treehide near a salt lick without ever observing a rhino directly), so poachers make use of spear traps and pit traps. In the 1970s, uses of the rhinoceros's body parts among the local people of Sumatra were documented, such as the use of rhino horns in amulets and a folk-belief that the horns offer some protection against poison. Dried rhinoceros meat was used as medicine for diarrhea, leprosy and tuberculosis. "Rhino-oil", a concoction made from leaving a rhino's skull in coconut oil for several weeks, may be used to treat skin diseases. The extent of use and belief in these practices is not known. It was once believed that rhinoceros horn was widely used as an aphrodisiac; in fact traditional Chinese medicine never used it for this purpose.Nevertheless, hunting in this species has primarily been driven by a demand for rhino horns with supposedly medicinal properties.

Close-up of specimen in Cincinnati Zoo
 
The rainforests of Indonesia and Malaysia, which the Sumatran rhino inhabits, are also targets for legal and illegal logging because of the desirability of their hardwoods. Rare woods like merbau, meranti and semaram are valuable on the international markets, fetching as much as $1,800 per m3 ($1,375 per cu yd). Enforcement of illegal-logging laws is difficult because humans live within or near many of the same forests as the rhino. The 2004 Indian Ocean earthquake has been used to justify new logging. Although the hardwoods in the rainforests of the Sumatran rhino are destined for international markets and not widely used in domestic construction, the number of logging permits for these woods has increased dramatically because of the tsunami. However, while it has been suggested that this species is highly sensible to habitat disturbance, it appears this is of little importance compared to hunting, as it can withstand more or less any forest condition.

In captivity


The female D. s. lasiotis "Begum", which was shown in London Zoo from 15 February 1872 to 31 August 1900
Though rare, Sumatran rhinoceroses have occasionally been exhibited in zoos for nearly a century and a half. The London Zoo acquired two Sumatran rhinoceros in 1872. One of these, a female named "Begum", was captured in Chittagong in 1868 and survived at the London Zoo until 1900, the record lifetime in captivity for a Sumatran rhino. Begum was also the type of the extinct subspecies D. s. lasiotis. At the time of their acquisition, Philip Sclater, the secretary of the Zoological Society of London, claimed the first Sumatran rhinoceros in zoos had been in the collection of the Zoological Garden of Hamburg since 1868. Before the extinction of the subspecies Dicerorhinus sumatrensis lasiotis, at least seven specimens were held in zoos and circuses. Sumatran rhinos, however, did not thrive outside their native habitats. A rhino in the Calcutta Zoo successfully gave birth in 1889, but for the entire 20th century, not one Sumatran rhino was born in a zoo. In 1972, Subur, the only Sumatran rhino remaining in captivity died at the Copenhagen Zoo.
Despite the species' persistent lack of reproductive success, in the early 1980s, some conservation organizations began a captive breeding program for the Sumatran rhinoceros. Between 1984 and 1996, this ex situ conservation program transported 40 Sumatran rhinos from their native habitat to zoos and reserves across the world. While hopes were initially high, and much research was conducted on the captive specimens, by the late 1990s, not a single rhino had been born in the program, and most of its proponents agreed the program had been a failure. In 1997, the IUCN's Asian rhino specialist group, which once endorsed the program, declared it had failed "even maintaining the species within acceptable limits of mortality", noting that, in addition to the lack of births, 20 of the captured rhinos had died. In 2004, a surra outbreak at the Sumatran Rhinoceros Conservation Centre killed all the captive rhinos in Peninsular Malaysia, reducing the population of captive rhinos to eight.

The taxidermied remains of the last Sumatran rhinoceros that lived in captivity by 1972, a female called "Subur"

Seven of these captive rhinos were sent to the United States (the other was kept in Southeast Asia), but by 1997, their numbers had dwindled to three: a female in the Los Angeles Zoo, a male in the Cincinnati Zoo, and a female in the Bronx Zoo. In a final effort, the three rhinos were united in Cincinnati. After years of failed attempts, the female from Los Angeles, "Emi", became pregnant for the sixth time, with the zoo's male "Ipuh". All five of her previous pregnancies ended in failure. But researchers at the zoo had learned from previous failures, and, with the aid of special hormone treatments, Emi gave birth to a healthy male calf named "Andalas" (an Indonesian literary word for "Sumatra") in September 2001. Andalas's birth was the first successful captive birth of a Sumatran rhino in 112 years. A female calf, named "Suci" (Indonesian for "pure"), followed on July 30, 2004. On April 29, 2007, Emi gave birth a third time, to her second male calf, named "Harapan" (Indonesian for "hope") or Harry. In 2007, Andalas, who had been living at the Los Angeles Zoo, was returned to Sumatra to take part in breeding programs with healthy females, leading to the siring and June 23, 2012 birth of male calf Andatu, the fourth captive-born calf of the era; Andalas had been mated with Ratu, a wild-born female living in the Rhino Sanctuary at Way Kambas National Park.
Despite the recent successes in Cincinnati, the captive breeding program has remained controversial. Proponents argue the zoos have aided the conservation effort by studying the reproductive habits, raising public awareness and education about the rhinos, and helping raise financial resources for conservation efforts in Sumatra. Opponents of the captive breeding program argue the losses are too great; the program is too expensive; removing rhinos from their habitat, even temporarily, alters their ecological role; and captive populations cannot match the rate of recovery seen in well-protected native habitats.

Cultural depictions


Aside from those few individuals kept in zoos and pictured in books, the Sumatran rhinoceros has remained little known, overshadowed by the more common Indian, black and white rhinos. Recently, however, video footage of the Sumatran rhinoceros in its native habitat and in breeding centers has been featured in several nature documentaries. Extensive footage can be found in an Asia Geographic documentary The Littlest Rhino. Natural History New Zealand showed footage of a Sumatran rhino, shot by freelance Indonesian-based cameraman Alain Compost, in the 2001 documentary The Forgotten Rhino, which featured mainly Javan and Indian rhinos.
Though documented by droppings and tracks, pictures of the Bornean rhinoceros were first taken and widely distributed by modern conservationists in April 2006, when camera traps photographed a healthy adult in the jungles of Sabah in Malaysian Borneo. On April 24, 2007 it was announced that cameras had captured the first-ever video footage of a wild Bornean rhino. The night-time footage showed the rhino eating, peering through jungle foliage, and sniffing the film equipment. The World Wildlife Fund, which took the video, has used it in efforts to convince local governments to turn the area into a rhino conservation zone. Monitoring has continued; 50 new cameras have been set up, and in February 2010, what appeared to be a pregnant rhino was filmed.
A number of folk tales about the Sumatran rhino were collected by colonial naturalists and hunters from the mid-19th century to early 20th century. In Burma, the belief was once widespread that the Sumatran rhino ate fire. Tales described the fire-eating rhino following smoke to its source, especially campfires, and then attacking the camp. There was also a Burmese belief that the best time to hunt was every July, when the Sumatran rhinos would congregate beneath the full moon. In Malaya, it was said that the rhino's horn was hollow and could be used as a sort of hose for breathing air and squirting water. In Malaya and Sumatra, it was once believed that the rhino shed its horn every year and buried it under the ground. In Borneo, the rhino was said to have a strange carnivorous practice: after defecating in a stream, it would turn around and eat fish that had been stupefied by the excrement.

Thursday 9 August 2012

Przewalski

Przewalski's horse or Dzungarian horse, is a rare and endangered subspecies of wild horse (Equus ferus) native to the steppes of central Asia, specifically Mongolia. At one time extinct in the wild (in Mongolia, the last wild Przewalski's horses had been seen in 1966), it has been reintroduced to its native habitat in Mongolia at the Khustain Nuruu National Park, Takhin Tal Nature Reserve  and Khomiin Tal. The taxonomic position is still debated, and some taxonomists treat Przewalski's horse as a species, Equus przewalskii.
Common names for this equine include Asian wild horse, Przewalski's Wild Horse,Mongolian wild horse and the Tahki. Historical but obsolete names include true tarpan and Mongolian tarpan. The horse is named after the Russian geographer and explorer Nikolai Przhevalsky.
Most "wild" horses today, such as the American Mustang or the Australian Brumby, are actually feral horses descended from domesticated animals that escaped and adapted to life in the wild. In contrast, Przewalski's horse has never been successfully domesticated and remains a truly wild animal today. Przewalski's horse is one of three known subspecies of Equus ferus, the others being the domesticated horse, Equus caballus and the extinct tarpan (Equus ferus ferus). The Przewalski's horse is considered the only remaining truly wild "horse" in the world and may be the closest living wild relative of the domesticated horse. There are still a number of other wild equines, including three species of zebra and various subspecies of the African wild ass, onager (including the Mongolian wild ass) and kiang.

Taxonomy

 

The Przewalski's horse was described in 1881 by L.S. Poliakov. The taxonomic position of Przewalski's horse has always been problematic and no consensus exists whether it is a full species (Equus przewalskii), a subspecies of the wild horse (Equus ferus przewalskii) or even a sub-population of the horse (Equus ferus). Studies using DNA have been inconclusive, in part due to crossing domestic horses into the Przewalski's horse as well as the limited genetic variation present in the founder population of the Przewalski's horse. A 2009 molecular study using ancient DNA (that is DNA recovered from archaeological finds like bones and teeth) places the Przewalski's horse in the middle of the domesticated horses, but more recent mitochondrial DNA analysis suggests that the Przewalski and the modern domestic horse diverged some 160,000 years ago. The karyotype of the domestic horse differs from that of Przewalski’s horse by an extra chromosome pair either because of the fission of domestic horse chromosome 5 in Przewalski’s horse or fusion of Przewalski’s horse chromosomes 23 and 24 in the domestic horse. In comparison, the chromosomal differences between domestic horses and zebras include numerous translocations, fusions, and inversions. Przewalski’s horse is known to have the highest diploid chromosome number among all equine species. Przewalski’s horse can interbreed with the domestic horse and produce fertile offspring (65 chromosomes) 

Population

 

The world population of these horses are all descended from 9 of the 31 horses in captivity in 1945. These nine horses were mostly descended from approximately 15 captured around 1900. A cooperative venture between the Zoological Society of London and Mongolian scientists has resulted in successful reintroduction of these horses from zoos into their natural habitat in Mongolia; and as of 2011 there is an estimated free-ranging population of over 300 in the wild. The total number of these horses according to a 2005 census was about 1,500.

Appearance

 

Przewalski's horse is stockily built in comparison to domesticated horses, with shorter legs. Typical height is about 13 hands (52 inches, 132 cm), length is about 2.1 m (6 ft 11 in). They weigh around 300 kilograms (660 lb). The coat is generally dun in color with pangaré features, varying from dark brown around the mane (which stands erect) to pale brown on the flanks and yellowish-white on the belly and around the muzzle. The legs of Przewalski's horse are often faintly striped, also typical of primitive markings. The tail is about 90 cm (35.43 in) long, with a longer dock and shorter hair than seen in domesticated horses.

Behavior

 

Przewalski's horses
In the wild, Przewalski's horses live in small, permanent family groups consisting of one adult stallion, one to three mares, and their common offspring. Offspring stay in the family group until they are no longer dependent, usually at 2 or 3 years old. Bachelor stallions, and sometimes old stallions, join bachelor groups. Family groups can join together to form a herd that move together.
The patterns of their daily lives exhibit horse behavior similar to that of feral horse herds. Stallions herd, drive and defend all members of their family, while the mare often displays leadership in the family. Stallions and mares stay with their preferred partner for years.
Horses maintain visual contact with their family and herd at all times and have a host of ways to communicate with one another, including vocalizations, scent marking, and a huge range of visual and tactile signals. Each kick, groom, tilt of the ear or other contact with another horse are means of communicating. This constant communication leads to complex social behaviors among Przewalski's horses. 

History

 

In the 15th century, Johann Schiltberger recorded one of the first European sightings of the horses in the journal of his trip to Mongolia as a prisoner of the Mongol Khan. The horse is named after the Russian colonel Nikolai Przhevalsky (1839–1888) (the name is of Polish origin and "Przewalski" is the Polish spelling). He was the explorer and naturalist who first described the horse in 1881, after having gone on an expedition to find it, based on rumors of its existence. Many of these horses were captured around 1900 by Carl Hagenbeck and placed in zoos. As noted above, about twelve to fifteen reproduced and formed today's population.


The native population declined in the 20th century due to a combination of factors, with the wild population in Mongolia dying out in the 1960s. The last herd was sighted in 1967 and the last individual horse in 1969. Expeditions after this failed to locate any horses, and the species was designated "extinct in the wild" for over 30 years.
After 1945 only two captive populations in zoos remained, in Munich and in Prague. The most valuable group, in Askania Nova, Ukraine, was shot by German soldiers during World War II occupation, and the group in the USA had died out.
By the end of the 1950s, only 12 individual Przewalski's horses were left in the world.

Przewalski's horses
 
In 1977, the Foundation for the Preservation and Protection of the Przewalski horse was founded in Rotterdam, the Netherlands, by Jan and Inge Bouman. The Foundation started a program of exchange between captive populations in zoos throughout the world to reduce inbreeding, and later began a breeding program of its own. As a result of such efforts, the extant herd has retained a far greater genetic diversity than its genetic bottleneck made likely.
In 1992, sixteen horses were released into the wild in Mongolia, followed by additional animals later on. One of the areas to which they were reintroduced became Khustain Nuruu National Park in 1998. Another reintroduction site is Great Gobi B Strictly Protected Area, located at the fringes of the Gobi desert. Lastly, in 2004 and 2005, 22 horses were released by the Association Takh to a third reintroduction site in the buffer zone of the Khar Us Nuur National Park, in the northern edge of the Gobi ecoregion.
The reintroduced horses successfully reproduced, and the status of the animal was changed from "extinct in the wild" to "endangered" in 2005. On the IUCN Red List, they were reclassified from "extinct in the wild" to "critically endangered" after a reassessment in 2008 and from "critically endangered" to "endangered" after a 2011 reassessment.

Preservation efforts

 

Close up image
 
While dozens of zoos worldwide have Przewalski's horses in small numbers, there are also specialized reserves dedicated primarily to the species.
The world's largest captive breeding program for Przewalski's horses is at the Askania Nova preserve in Ukraine. Several dozen Przewalski's horses were also released in the area evacuated after the Chernobyl accident, which now serves as a deserted de facto natural preserve.An intensely researched population of free-ranging animals was also introduced to the Hortobágy puszta in Hungary; data on social structure, behavior and diseases gathered from these animals is used to improve the Mongolian conservation effort.
Several American zoos also collaborated in breeding Equus ferus przewalskii from 1979 to 1982. Recent advances in equine reproductive science in the USA also have potential to further preserve and expand the gene pool. In October 2007, scientists at the Smithsonian Institution's National Zoo successfully reversed a vasectomy on a Przewalski's horse — the first operation of its kind on this species and possibly the first ever on any endangered species. While normally a vasectomy may be performed on an endangered animal under limited circumstances, particularly if an individual has already produced many offspring and its genes are overrepresented in the population, scientists realized the animal in question was one of the most genetically valuable Przewalski's horses in the North American breeding program.
Le Villaret, located in the Cevennes National Park in southern France and run by the Association Takh, is a breeding site for Przewalski Horses that was created to allow the free expression of natural Przewalski's horse behaviors. Eleven zoo born horses were brought to Le Villaret in 1993. Horses born there are adapted to life in the wild: they are free to choose their own mates and must forage on their own. Such a unique breeding site was necessary to produce the individuals that were reintroduced to Mongolia in 2004 and 2005. In 2012 there were 39 individuals at Le Villaret. 
The Przewalski's Horse Reintroduction Project of China was initiated in 1985 when 11 wild horses were imported from overseas. After more than two decades of effort, the Xinjiang Wild Horse Breeding Centre has bred a large number of the horses, of which 55 were released into the Kalamely Mountain area. The animals quickly adapted to their new environment. In 1988, six foals were born and survived, and by 2001 there were over 100 horses at the centre.

Wednesday 8 August 2012

Vaquita

The vaquita (Phocoena sinus) is a rare species of porpoise. It is endemic to the northern part of the Gulf of California. Estimates of the number of individuals alive range from 100  to 300. The word "vaquita" is Spanish for little cow. Since the baiji (Lipotes vexillifer) is believed to have gone extinct in 2006, the vaquita has taken on the title of the most endangered cetacean in the world.
Other names include Cochito, Gulf of California Harbor Porpoise, Gulf of California Porpoise, Gulf Porpoise, Hafenschweinswal, and Marsouin du Golfe de Californie

Biology

 

Physical description

 

The Vaquita has a classic porpoise shape (stocky and curved into a star shape when viewed from the side). It is the smallest of the porpoises, a group of marine mammals that differ from dolphins in their stockier, robust body, lack of an elongated beak, and their distinctively shaped teeth. Individuals may reach a mature size of 1.2-1.5 m (4-5 ft) and may weigh 40-55 kg (90-120 lb). They have large black eye rings and lip patches. The upper side of the body is medium to dark grey. The underside is off-white to light grey but the demarcation between the sides is indistinct. The flippers are proportionately larger than in other porpoises and the fin is taller and more falcate. The skull is smaller and the rostrum is shorter and broader than in other members of the genus.

Habitat

 

The habitat of the vaquita is thought to be restricted to the northern area of the Gulf of California. The vaquita lives in shallow, murky lagoons along the shoreline and is rarely seen in water much deeper than 30 meters; indeed, it can survive in lagoons so shallow that its back protrudes above the surface. The vaquita is most often sighted in water 11 to 50 metres deep, 11 to 25 kilometres from the coast, over silt and clay bottoms. Its habitat is characterised by turbid water with a high nutrient content. Other characteristics of its habitat are strong tidal mixing, convection processes and high primary and secondary productivity.

Behavior

 

There are very few records of the Vaquita in the wild. It appears to swim and feed in a leisurely manner, but is elusive and will avoid boats of any kind. It rises to breathe with a slow, forward-rolling movement that barely disturbs the surface of the water, and then disappears quickly, often for a long time. It has an indistinct blow, but makes a loud, sharp, puffing sound reminiscent of the Harbour Porpoise.

Schooling

 

Like other phocoenids, the vaquita occurs singly or in small groups, usually from 1 - 3 individuals but as many as 8 - 10.

Diet

 

All of the 17 fish species found in vaquita stomachs can be classified as demersal and or benthic species inhabiting relatively shallow water in the upper Gulf of California, and it appears that the vaquita is a rather non-selective feeder on small fishes and squids in this zone. Like other cetaceans, the vaquita produces high-frequency clicks which are used in echolocation. This may be used to locate their prey, but several of the fish species it feeds on are known to produce sound and so it is possible that the vaquita locates them by following their sound, rather than by echolocating.

Reproduction

 

Most calving apparently occurs in the spring. Gestation is probably 10–11 months. Maximum observed life span was 21 years.

Conservation

 

Vaquita have never been hunted directly. Indeed their continued existence was only confirmed by a dedicated survey in 1985. However, it is known that the vaquita population is declining. Estimates have placed the vaquita population at 567 in 1997 and 150 in 2007. The decline in the vaquita population is believed to be due to the animals becoming trapped in gillnets intended for capturing another species endemic to the Gulf, the totoaba. CIRVA, the Committee for the Recovery of the Vaquita, concluded in 2000 that between 39 and 84 individuals are killed each year by such gillnets. The Vaquita is listed by the IUCN and the Convention on International Trade in the Endangered Species of Wild Fauna and Flora in the most critical category at risk of extinction. In order to try to prevent extinction, the Mexican government has created a nature reserve covering the upper part of the Gulf of California and the Colorado River delta. CIRVA is recommending that this reserve be extended southwards to cover the full known area of the Vaquita's range and that trawlers be completely banned from the reserve area. Even if the number of Vaquita killed by fisheries is reduced to zero, concerns remain amongst conservationists. Use of chlorinated pesticides, reduced flow of freshwater from the Colorado River due to irrigation, and depression due to inbreeding may also have a detrimental effect.
The Vaquita is one of the top 100 EDGE Species, meaning "Evolutionarily Distinct, Globally Endangered". Evolutionarily distinct animals have no close relatives and represent proportionally more of the tree of life than other species, meaning they are top priority for conservation campaigns.
On October 28, 2008, Canada, Mexico, and the United States, under the jurisdiction of the NAFTA environmental organization, the Commission for Environmental Cooperation, launched the North American Conservation Action Plan (NACAP) for the Vaquita. The NACAP is a strategy to support Mexico’s efforts to recover the Vaquita, which is considered the world’s most-endangered marine mammal. The U.S. government has listed the vaquita as endangered under the Endangered Species Act.

Sunday 5 August 2012

Sumatran Orangutan

The Sumatran orangutan (Pongo abelii) is one of the two species of orangutans. Found only on the island of Sumatra, in Indonesia, it is rarer than the Bornean orangutan.

 

 

 

 

 

 

 

 

 

 

 

 

 

Physical description

 

The Sumatran orangutan grows to about 1.4 metres (4.6 ft) tall and 90 kilograms (200 lb) in males. Females are smaller, averaging 90 centimetres (3.0 ft) and 45 kilograms (99 lb). Compared to the Bornean species, Sumatran orangutans are thinner and have longer faces; their hair is longer with a paler red color.

Behaviour and ecology

 


Sumatran Orangutan at Bukit Lawang
Compared with the Bornean orangutan, the Sumatran orangutan tends to be more frugivorous and especially insectivorous. Preferred fruits include figs and jackfruits. It will also eat bird eggs and small vertebrates. Sumatran orangutans spend far less time feeding on the inner bark of trees.
Wild Sumatran orangutans in the Suaq Balimbing swamp have been observed using tools. An orangutan will break off a tree branch that is about a foot long, snap off the twigs and fray one end. It then will use the stick to dig in tree holes for termites. They will also use the stick to poke a bee's nest wall, move it around and catch the honey. In addition, orangutans use tools to eat fruit. When the fruit of the Neesia tree ripens, its hard, ridged husk softens until it falls open. Inside are seeds that the orangutans enjoy eating, but they are surrounded by fiberglass-like hairs that are painful if eaten. A Neesia-eating orangutan will select a five-inch stick, strip off its bark, and then carefully collect the hairs with it. Once the fruit is safe, the ape will eat the seeds using the stick or its fingers. Although similar swamps can be found in Borneo, wild Bornean orangutans have not been seen using these types of tools.
NHNZ filmed the Sumatran orangutan for its show Wild Asia: In the Realm of the Red Ape; it showed one of them using a simple tool, a twig, to pry food from difficult places. There is also a sequence of an animal using a large leaf as an umbrella in a tropical rainstorm.
The Sumatran orangutan is also more arboreal than its Bornean cousin; this could be because of the presence of large predators like the Sumatran Tiger. It moves through the trees by quadrumanous locomotion and semibrachiation.

Life cycle

 

The Sumatran orangutan is more social than its Bornean counterpart. Groups of these orangutans gather to feed on the mass amount of fruiting on the fig trees. However adult males generally avoid contact with other adult males. Sub-adult males will try to mate with any female, though they probably mostly fail to impregnate them since mature females are easily capable of fending them off. Mature females prefer to mate with mature males.
The average interbirth rates for the Sumatran orangutan is 9.3 years – the longest reported among the great apes, including the Bornean orangutan. Infant orangutans will stay close to their mother for up to three years. Even after that, the young will still associate with their mother. Both orangutan species are likely to live several decades; estimated longevity is more than 50 years. The average of the first reproduction of P. abelii is around 15.4 years old. There is no indication of menopause.

Conservation status


The Sumatran orangutan is endemic to Sumatra island and is particularly restricted to the north of the island. In the wild, Sumatran orangutans survive in the province of Nanggroe Aceh Darussalam (NAD), the northernmost tip of Sumatra. The primate was once more widespread, as they were found more to the south in the 19th century such as in Jambi and Padang. There are small populations in the North Sumatra province along the border with NAD, particularly in the Lake Toba forests. A survey in the Lake Toba region found only two inhabited areas, Bukit Lawang (defined as the animal sanctuary) and Gunung Leuser National Park. The species has been assessed as critically endangered on the IUCN Red List since 2000. It is considered one of "The World's 25 Most Endangered Primates."
A survey in 2004 estimated that around 7,300 Sumatran orangutans still live in the wild. Some of them are being protected in five areas in Gunung Leuser National Park; others live in unprotected areas: northwest and northeast Aceh block, West Batang Toru river, East Sarulla and Sidiangkat. A successful breeding program has been established in Bukit Tiga Puluh National Park in Jambi and Riau provinces.
Nonja, thought to be the world's oldest in captivity or the wild at the time of her death, died at the Miami MetroZoo at the age of 55.

Genomics

 

Orangutans have 48 chromosomes. The Sumatran orangutan genome was sequenced in January 2011, based on a captive female named Susie. Following humans and chimpanzees, the Sumatran Orangutan has become the third extant hominid species to have its genome sequenced.
The researchers also published less complete copies from ten wild orangutans, five from Borneo and five from Sumatra. It was found that genetic diversity was lower in Bornean Orangutans (Pongo pygmaeus) than in Sumatran ones (Pongo abelii), despite the fact that Borneo is home to six or seven times as many orangutans as Sumatra. The comparison has shown that these two species diverged around 400,000 years ago, more recently than was previously thought. It was also found that the orangutan genome has fewer rearrangements than the chimpanzee/human lineage.

Saturday 4 August 2012

Spix's Macaw

Spix's Macaw (Cyanopsitta spixii) is the only member of the parrot genus Cyanopsitta. They are critically endangered, possibly extinct in the wild (IUCN 3.1) The species is conserved through several breeding programs. It was found in Brazil, in parts of the Brazilian state of Bahia. It has a very restricted natural habitat due to its dependence on the Caraibeira (Tabebuia aurea) tree for nesting. If there are any left in the wild the population is assumed to be tiny. (Fewer than 50 individuals)

 

 

 

 

 

Description

 

Illustration of Glaucous Macaw (foreground) with Spix's Macaw in Hamburg, 1895
 
Spix's Macaw is 55–57 cm (21.5–23.5 in) long. It is various shades of blue, including a pale blue head, pale blue underparts, and vivid blue upperparts, wings, and tail. The underside of the wings and tail are black. They have a bare area of grey/black facial skin which sometimes fades to white when they are juveniles. The beak is entirely black except for juveniles which have a white stripe down the center of the beak. The white beak stripe and facial skin of juveniles disappears after 1–2 years. The birds' feet are light grey as juveniles, then become dark grey, and are almost black as adults. The eyes are dark as juveniles but fade to white as the birds mature.The mating call of Spix's Macaw can be described as the sound "whichaka". The sound is made by creating a low rumble in the abdomen bringing the sound up to a high pitch. Its voice is a repeated short grating. It also makes squawking noises.

History

 

Spix's Macaw was named after the German naturalist Johann Baptist von Spix, who discovered the species in 1817. The decline of the species is attributed to hunting and trapping of the birds, destruction of its habitat, and the introduction of the Africanized bee, which competes for nesting sites and kills breeding individuals at their nests. The last three birds were captured for trade in 1987 and 1988. A single male, paired with a female Blue-winged Macaw, was discovered at the site in 1990. A female Spix's Macaw released from captivity at the site in 1995 disappeared after seven weeks. The last wild male died at the site in October 2000. The species probably became extinct in the wild around 2000, when the last known wild bird died. No sightings of this macaw have been made in the wild since 2000, but part of the range has not been surveyed, so it can not be presumed to be extinct in the wild.

Conservation efforts

 

A drawing of 1824. It has the bill of a juvenile.


The Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA, Brazilian Institute of Environment and Renewable Natural Resources in English) established in 1990 the Permanent Committee for the Recovery of Spix’s Macaw, called CPRAA, and its the Ararinha Azul Project (Little Blue Macaw Project) in order to conserve the species. Other participants included BirdLife International, Birds International, WWF-Brazil, and the American Federation of Aviculture; most of the funding came from IBAMA and the Fundación Loro Parque (Loro Parque Foundation) of Spain. Several exchanges of birds were made between institutions and individuals for increasing the probability of breeding based on DNA analysis as part of the program. "The first breeding occurred in Brazil, in the aviaries of the late Alvaro Rossman Carvalhaes, a once prominent aviculturist from Santos. The number and years in which Carvalhaes has bred Spix's has been the subject of much confusion: Low (1984, 1986 and 1990) and Keller have both written that he kept a pair in the 1950's and that eight young were reared during this period. King (1978-1979), in a presumable reference to the breeding pair reported that they died in the 1970's." Birds International's efforts turned out to be the most successful: "Dr. Hammerli produced young Spix's macaws in 1984, however, Antonio de Dios has had the most successful breeding results at Birds International Inc. This collection has achieved a second generation breeding, a real breakthrough for the future survival of this species.". The committee was dissolved in 2002 due to irreconcilable differences between the parties involved. In 2004 a committee was re-formed and re-structured under the title of “The Working Group for the Recovery of the Spix’s Macaw”.

Captive population

 

As at year 2010 there are approximately 85 Spix’s Macaws in captivity. 77 of these are participating in an international breeding program managed by the Institute Chico Mendes of Biodiversity Conservation (ICMBio), the Natural Heritage Branch of the Brazilian Government. 60 of these are managed at Al Wabra Wildlife Preservation (AWWP), State of Qatar, which took over the population of Birds International and where a captive breeding program is guiding Spix’s Macaw a step closer to re-establishment back to its natural habitat in Brazil.


Institutions Males Females Unknown Total Bred in captivity in last 6 years
Al Wabra Wildlife Preservation (AWWP), Qatar, Persian Gulf, Middle East 22 34 0 60 31
Association for the Conservation of Threatened Parrots (ACTP), Berlin, Germany 1 1 4 6 4
Loro Parque Foundation (LPF), Tenerife, Canary Islands, Spain 3 5 0 8 5
Lymington Foundation (LF) São Paulo, Brazil 2 1 0 3 0
São Paulo Zoo (SPZ), São Paulo, Brazil 2 2 0 4 0
Total 30    43       4 81               40



All chicks bred at AWWP have been hand-reared by experienced staff, since it is considered a safer option than parent-rearing and the priority at the moment is to increase the population. When the captive population is considered more secure, breeding pairs will be given the opportunity to raise some of their own young. All Spix’s Macaw chicks bred are required to be close leg banded with a uniquely coded ring and at the time of their first health check, they are also to be implanted with a micro-chip transponder.

Popular culture

 

  • In the 1997 animated TV series Noah's Island, an episode focuses on Noah bringing a breeding pair of Spix's Macaws to his island from the Amazon rainforest, in the hope that they will breed. at first, the two Macaws are both very aggressive and fight with each other, but they eventually make up and fall in love.
  • In the opener of the Gorgo episode of Mystery Science Theater 3000, Crow finds that his head crown has become a nesting spot for two Spix's Macaw eggs. Later in the episode he reveals that the eggs have been taken away by Egg Protective Services after he accidentally made an omelet in front of them.
  • In the 2011 animated movie Rio, the main characters Blu (Jesse Eisenberg) and Jewel (Anne Hathaway) are the supposed last pair of Spix's Macaws in the world (although they're referred to as Blue Macaws). The movie even references their extinct-in-the-wild status and at one point ornithologist Túlio Monteiro mentions the species' scientific name.

Thursday 2 August 2012

Siamese Crocodile

Siamese crocodile (Crocodylus siamensis) is a freshwater crocodile native to Indonesia (Borneo and possibly Java), Brunei, East Malaysia, Laos, Cambodia, Burma, Thailand, and Vietnam. The species is critically endangered and already extirpated from many regions. Its other common names include: Siamese freshwater crocodile, Singapore small-grain, cocodrilo de Siam, crocodile du Siam, buaja, buaya kodok, jara kaenumchued, and soft-belly.

 


Description

 

The Siamese crocodile is a small, freshwater crocodilian (a group that also includes alligators, caimans and the gharial), with a relatively broad, smooth snout and an elevated, bony crest behind each eye. Overall, it is an olive-green color, with some variation to dark-green. Young specimens measure 1.2–1.5 m (3.9–4.9 ft) and weigh 6–12 kg (13–26 lb), growing up to 2.1 m (6.9 ft) and a weight of 40–70 kg (88–150 lb) as an adult. The largest specimens can measure 3.1 m (10 ft) and reportedly weigh "several hundred kilograms". It is one of the most endangered crocodiles in the wild, although it is extensively bred in captivity.

Distribution

 

The historic range of the Siamese crocodile included most of Southeast Asia. This species is now extinct in the wild or nearly extinct from most countries except Cambodia.Formerly it was found in Cambodia, Indonesia (Borneo and possibly Java), Laos, Malaysia, Thailand, Vietnam, Brunei, and Burma.

Ecology

 

Habitat

 

Siamese crocodiles occur in a wide range of freshwater habitats, including slow-moving rivers and streams, lakes, seasonal oxbow lakes, marshes and swamplands. Most adults do not exceed 3 m (10 ft) in length, although hybrids in captivity can grow much larger. Pure, unhybridised examples of this species are generally unaggressive towards humans, and unprovoked attacks are unknown.

Biology

 

Adults feed mainly on fish, but may also eat amphibians, reptiles and small mammals. Very little is known about the natural history of this species in the wild, but females do appear to build mound-nests constructed from scraped-up plant debris mixed with mud. In captivity, these crocodiles breed during the wet season (April to May), laying between 20 and 50 eggs, which are then guarded until they hatch. After incubation, the female will assist her young as they break out of their eggs and then carry the hatchlings to the water in her jaws.

Genetics

 

Three barcode sequences are available from BOLD and GenBank. Below is a sequence of the barcode region cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
Taxonomy ID: 68455
Genbank common name: Siamese crocodile
Inherited blast name: crocodiles
Rank: species
Genetic code: Translation table 1 (Standard)
Mitochondrial genetic code: Translation table 2 (Vertebrate Mitochondrial)
synonym: Crocodylus siamensis Schneider, 1801

Life history and behavior

 

Despite conservation concerns, many aspects of C. siamensis life history in the wild remain unknown, particularly regarding its reproductive biology.

Status

 

This crocodile is classified as critically endangered on the IUCN Red List, and is listed on Appendix I of CITES.

Threats

 

Siamese crocodiles are under threat from human disturbance and habitat occupation, which is forcing remaining populations to the edges of their former range. Extinct from 99% of its original range, the Siamese crocodile is considered one of the least studied and most critically endangered crocodilians in the world. Although few wild populations remain, more than 700,000 C. siamensis are held on commercial crocodile farms in Southeast Asia.
In 1992, it was believed to be extremely close to or fully extinct in the wild. Since then, a number of surveys have confirmed the presence of a tiny population in Thailand (possibly numbering as few as two individuals, discounting recent reintroductions), a small population in Vietnam (possibly less than 100 individuals), and more sizable populations in Burma, Laos and Cambodia. In March 2005, conservationists found a nest containing juvenile Siamese crocodiles in the southern Lao province of Savannakhet. There are no recent records from Malaysia or Brunei. A significant population of the crocodiles is known to be living in East Kalimantan, Indonesia.

Habitat degradation

 

Factors causing loss of habitat include: conversion of wetlands for agriculture, using chemical fertilizers, using pesticides in rice production, and an increase in the population of cattle.
Many river systems, including those in protected areas, have hydroelectric power dams approved or proposed, which are likely to cause the loss of about half of the remaining breeding colonies within the next ten years. One cause for habitat degradation via hydrological changes, for the Siamese crocodile, is the implementation of dams on the upper Mekong River and its major tributaries. Potential impacts of dam construction include wetland loss and altered flooding cycle with a dry season flow 50% greater than under natural conditions.

Exploitation and fragmentation

 

Illegal capture of wild crocodiles for supply to farms is an ongoing threat, as well as incidental capture/drowning in fishing nets and traps. C. siamensis currently has extremely low and fragmented remaining populations with little proven reproduction in the wild.
Siamese crocodiles have historically been captured for skins and to stock commercial crocodile farms. In 1945, skin hunting for commercial farms was banned by the French colonial administration of Cambodia. In the late 1940s, populations spurred the development of farms and harvesting wild crocodiles for stocking these farms. Protection was abolished by the Khmer Rouge (1975–79) but later reinstated under Article 18 of the Fishery Law of 1987, which "forbids the catching, selling, and transportation of...[wild] crocodiles..."
Crocodile farming now has a huge economic impact in the provinces surrounding Tonle Sap, where 396 farms held over 20,000 crocodiles in 1998. Also, many crocodiles were exported from Cambodia since the mid-1980s to stock commercial farms in Thailand, Vietnam, and China.
Despite legal protection, a profitable market exists for the capture and sale of crocodiles to farms since the early 1980s. This chronic overharvesting has led to the decline of the wild Siamese crocodile.

Conservation and management

 

The current situation of C. siamensis represents a significant improvement from the status reported in the 1992 Action Plan (effectively extinct in the wild), but poses major new challenges for quantitative survey and effective conservation action if the species is to survive. While the species remains critically endangered, there is a sufficient residual wild population, dispersed among many areas and countries, to provide a basis for recovery. If the pressures which have caused the virtual disappearance of this species in Thailand, Malaysia and Indonesia can be controlled or reversed, then the species is likely to survive.
The Siamese crocodile is relatively unthreatening to people (compared to C. porosus), and the possibility of people and crocodiles coexisting in natural settings seems possible. The powerful economic force of the commercial industry based on C. siamensis also needs to be mobilized and channelled for conservation advantage. Considerable effort and action is still required, but the species has a reasonable chance of survival if the necessary actions can be implemented.
Yayasan Ulin (The Ironwood Foundation) is running a small project to conserve an important wetland habitat in the area which is known to contain the crocodiles. Most of them, though, live in Cambodia, where isolated, small groups are present in several remote areas of the Cardamom Mountains, in the southwest of the country, and also in the Vireakchey National Park, in the northeast of the country.
Fauna and Flora International is running a program in the district of Thmo Bang, Koh Kong province, where villagers are financially encouraged to safeguard known crocodile nests. The Araeng River is considered to have the healthiest population of Siamese crocodiles in the world, although this may soon change after the completion of a massive dam in the river. Fauna and Flora international, in collaboration with several Cambodian government departments, is planning on capturing as many crocodiles as possible from this river and reintroducing them in another, ecologically suitable area, before the completion of the dam and the subsequent flooding of the whole area effectively renders their current habitat unsuitable. During the heavy monsoon period of June–November, Siamese crocodiles take advantage of the increase in water levels to move out of the river and onto large lakes and other local bodies of water, returning to their original habitat once water levels start receding back to their usual levels. A smaller population also is thought to exist in the Ta Tay River, and in the district of Thmo Bang. Poaching is a severe threat to the remaining wild population in the area, with the value of small specimens reaching hundreds of dollars in the black market, where they are normally taken into crocodile farms and mixed with other, larger species. The total wild population is unknown, since most groups are in isolated areas where access is extremely complicated. A number of captively held individuals are the result of hybridization with the saltwater crocodile, but several thousand "pure" individuals do exist in captivity, and are regularly bred at crocodile farms, especially in Thailand.
Bang Sida National Park in Thailand, near Cambodia, has a project to reintroduce Siamese crocodile into the wild. A number of young crocodiles have been released into a small and remote river in the park, not accessible to visitors.
The Phnom Tamao Wildlife Rescue Center in Cambodia conducted DNA analysis of 69 crocodiles in 2009, and found 35 of them were purebred C. siamensis. Conservationists from Fauna and Flora International and Wildlife Alliance plan to use these to launch a conservation breeding program in partnership with the Cambodian Forestry Administration.
The Wildlife Conservation Society (WCS) is working with the government of Lao PDR on a new program to save this critically endangered crocodile and its wetland habitat. In August, 2011, a press release announced the successful hatching of a clutch of 20 Siamese crocodiles. These eggs were then incubated at the Laos Zoo. This project represents a new effort by WCS to conserve the biodiversity and habitat of Laos’ Savannakhet Province, promotes conservation of biodiversity for the whole landscape, and relies on community involvement from local residents.

Priority projects

 

High priority projects include:
  • Status surveys and development of crocodile management and conservation programs in Cambodia and Lao PDR: These two countries appear to be the remaining stronghold of the species. Identifying key areas and populations, and obtaining quantitative estimates of population size as a precursor to initiating conservation programs is needed.
  • Implementation of protection of habitat and restocking in Thailand: Thailand has the best-organized protected-areas system, the largest source of farm-raised crocodiles for restocking, and the most-developed crocodile management program in the region. Although the species has virtually disappeared from the wild, re-establishment of viable populations in protected areas is feasible.
  • Protection of crocodile populations in Vietnam: A combination of habitat protection and captive breeding could prevent the complete loss of the species in Vietnam. Surveys, identification of suitable localities and the implementation of a conservation program coordinated with the captive breeding efforts of Vietnamese institutions is needed.
  • Investigation of the taxonomy of the freshwater crocodiles in Southeast Asia and the Indo-Malaysian Archipelago: The relationships among the freshwater crocodiles in the Indo-Malaysian Archipelago are poorly understood. Clarification of these relationships is of scientific interest and has important implications for conservation.

Other projects include:

  • Coordination of captive breeding, trade and conservation in the South east Asian region: Several countries in the region are already deeply involved in captive breeding programs for commercial use. Integration of this activity with necessary conservation actions for the wild populations (including funding surveys and conservation) could be a powerful force for conservation. A long term aim could be the re-establishment of viable wild populations and their sustainable use by ranching.
  • Maintain a stock of pure C. siamensis in crocodile farms: The bulk of the captives worldwide are maintained in several farms in Thailand where extensive interbreeding with C. porosus has taken place. Hybrids are preferred for their superior commercial qualities, but the hybridization threatens the genetic integrity of the most threatened species of crocodilians. Farms should be encouraged to segregate genetically pure Siamese crocodiles for conservation, in addition to the hybrids they are promoting for hide production.
  • Survey and protection of Siamese crocodiles in Indonesia: Verification of the presence of C. siamensis in Kalimantan and Java is a first step to developing protection for the species within the context of the developing crocodile management strategy in Indonesia.

Wednesday 1 August 2012

Saiga Antelope

The saiga (Saiga tatarica) is a Critically Endangered antelope which originally inhabited a vast area of the Eurasian steppe zone from the foothills of the Carpathians and Caucasus into Dzungaria and Mongolia. They also lived in North America during the Pleistocene. Today the nominate subspecies (Saiga tatarica tatarica) is only found in one location in Russia (steppes of the North-West Precaspian region) and three areas in Kazakhstan (the Ural, Ustiurt and Betpak-dala populations). A proportion of the Ustiurt population migrates south to Uzbekistan and occasionally Turkmenistan in winter. It is extinct in China and southwestern Mongolia. The Mongolian subspecies (Saiga tatarica mongolica) is found only in western Mongolia.


 

 

 

 

Physical characteristics



The saiga typically stands 0.6-0.8 meters at the shoulder and weighs between 36 and 63 kg. Their lifespan ranges from 6 to 10 years. Males are bigger than females and are the only sex to carry horns. The horns have some value as Chinese traditional medicine and for that reason Saiga are now endangered by poaching. The saiga is recognizable by an extremely unusual, over-sized, flexible nose structure.

Habitat and behavior

 

Saigas form very large herds that graze in semi-desert steppes eating several species of plants, including some that are poisonous to other animals. They can cover considerable distances and swim across rivers, but they avoid steep or rugged areas. The mating season starts in November, when stags fight for the possession of females. The winner leads a herd of 5-50 females. In springtime the mother gives birth to, in two thirds of all cases two, or in one third, one single foal.

Distribution

 


Stuffed saiga herd at The Museum of Zoology, St. Petersburg
During the Ice Age the saiga ranged from the British Isles through Central Asia and the Bering Strait into Alaska and the Yukon. At the beginning of the 18th century it was still distributed from the shores of the Black Sea, the Carpathian foothills and the northern edge of the Caucasus into Dzungaria and Mongolia.


Reconstructed range (white) and current distribution of the two subspecies Saiga tatarica tatarica (green) and Saiga tatarica mongolica (red)
After a rapid decline they were nearly completely exterminated in the 1920s, but they were able to recover and by 1950 there were again two million of them in the steppes of the USSR.
Its population fell drastically following the collapse of the Soviet Union, due to uncontrolled hunting and demand for its horns in Chinese medicine. At one point, some conservation groups, such as the World Wildlife Fund, encouraged the hunting of this species as its horn was presented as an alternative to that of a rhinoceros.
Today the populations have again shrunk enormously, as much as 95% in 15 years, and the saiga is classified as critically endangered by the IUCN. There is an estimated total number of 50,000 saigas today, which live in Kalmykia, three areas of Kazakhstan and in two isolated areas of Mongolia. Another small population in the Pre-Caspian region of Russia, remains under extreme threat.
Cherny Zemli Nature Reserve was created in Russia's Kalmykia Republic in 1990s to protect the local saiga population and the President of Russia's Kalmykia Republic, Kirsan Ilyumzhinov, announced year of 2010 in Kalmykia as Year of Saiga. In Kazakhstan, the number of saiga was recently found to be increasing, from around 21,000 at the begin of this millennium to around 81,000 in January 2010.
However, in May 2010, it was announced that an estimated 12,000 of the 26,000 Saiga population in the Ural region of Kazakhstan have been found dead. Although the deaths are currently being ascribed to pasteurellosis, an infectious disease that strikes the lungs and intestines, the underlying trigger remains to be identified.
Kazakhstan in November 2010 reaffirmed a ban on hunting saiga antelopes, and extended this ban until 2021, as the Central Asian nation seeks to save the endangered species.
The Mongolian saiga (Saiga tatarica mongolica) is found in a small area in western Mongolia around Sharga and Mankhan Nature Reserve.
Currently only the Moscow Zoo zoo and Askania-Nova keep saigas. Cologne and San Diego Zoos had them in the past. Pleistocene Park in northern Siberia plans to introduce the species.

Conservation

 

The Saiga Conservation Alliance was started back in the early 1990s as an informal network of researchers and conservationists to study and protect the critically endangered saiga antelope. The SCA was officially inaugurated in September 2006, and in November 2006 was granted Candidate Partner status by the Wildlife Conservation Network. SCA also publishes a quarterly newsletter with latest updates from the field and range countries.
The organization Rewilding Europe has plans for reintroducing saiga to Europe.
Among followers of traditional Chinese medicine, saiga horns can be sold for as much as $150.