Orangutan (Pongo pygmaeus)

The orangutan is the only great ape that occurs outside Africa, and is the largest arboreal mammal in the world. Orangutans are extremely intelligent, and have shown evidence of tool use and culture - traits once believed to be uniquely human. Despite being one of our closest relatives, human activities are having a devastating impact on the species. Orangutans are the slowest breeding of all mammal species, giving birth to a single young every 6-8 years. With such a low reproductive rate even a small decrease in numbers can lead to extinction. Scientists predict that unless immediate action is taken, this peaceful primate could be the first great ape to become extinct in the wild.

Evolutionary Distinctiveness

Order: Primates

Family: Hominidae

The family Hominidae comprises seven living species in four genera: Homo (humans), Gorilla (gorillas), Pan (chimpanzees) and Pongo (orangutans). Apes are thought to have diverged from Old World monkeys between 22 and 30 million years ago (mya). They were confined to Africa until around 15-17 mya, when they colonised Eurasia across a newly formed land bridge between the two continents. Here they underwent rapid dispersal and diversification, with the evolution of many new species including the ancestors of modern orangutans. This Eurasian ape radiation also includes the extinct genusSivapithecus (formerly known as Ramapithecus), which was once thought to be one of the earliest human ancestors. Out of all the great apes, orangutans are the least closely related to humans, having split off from the early hominid lineage 10 to 12 million years ago. Gorillas were the next lineage to diverge, followed finally by the chimpanzee-bonobo lineage.

Description

Size: Head and body length: 1.25-1.50 m Arm span: 2.25 m

Weight: Male: 50-90 kg Female: 30-50 kg

The orangutan is the only great ape found outside Africa, and the largest arboreal mammal in the world. It has a coarse, shaggy reddish-brown coat, and long, powerful arms which can reach up to 2 m in length. Both the thumbs and the large toes are opposable, allowing the ape to grasp branches with both its hands and feet. The orangutan is highly sexually dimorphic, with males growing to about twice the size of females. When sexually mature, males develop flanges on either side of their faces, known as ‘cheekpads’. These are deposits of subcutaneous fat bound by connective tissue. Adult males also develop throat sacs, which can be inflated to add resonance to the male’s loud ‘long-call’. The two species of orangutan differ slightly in appearance and behaviour. Sumatran orangutans tend to be lighter in colour and have longer fur around their faces than the Bornean species. Bornean orangutans have wider faces, particularly the males, which have wider cheek pads than their Sumatran relatives.

Ecology

Orangutans eat, sleep and travel in the trees. They are active during the day, and spend the majority of their time searching for and consuming food. Fruit such as figs, durians, jackfruit, lychees, mangosteens and mangos are eaten when available, along with smaller quantities of leaves, seeds, ants, termites and bark. Individuals tend to switch to eating these lower quality foods when fruit is scarce, rather than move to another area. In some areas over 400 different types of food have been recorded as part of the species’ diet. At night, individuals sleep in a nest made of twigs or leaves high up in the trees. They generally make a new nest each night, although old nests are occasionally re-used. Unlike other diurnal primates – which are social and gregarious – orangutans lead a semi-solitary lifestyle. This is thought to be primarily due to the scattered distribution of their food. There is generally not enough fruit in an area at any one time to support a large group of orangutans. Adult males of both species occupy large, overlapping home ranges, which encompass those of several females. They spend almost all of their time alone, coming together with females only to mate. Although males are not territorial, they are generally hostile to one another. Confrontations are rare, as the male’s long-call is thought to serve to repel rivals, as well as advertise his availability to sexually receptive females. Female orangutans are slightly more social than the males. They maintain small, overlapping home ranges, and occasionally come together to feed when food is plentiful. Social behaviour has been observed more frequently in the Sumatran species. In particular, it coincides with the simultaneous (or “mast”) fruiting of fig trees, which does not occur in Borneo. Juvenile males and females of both species display the most social behaviour, and are often observed feeding, playing and travelling together in groups. The fact that Sumatran orangutans have more opportunity to come together to eat fruit that the Bornean species has enabled greater sociality among individuals. This in turn has enabled them to learn tool-using behaviour from one another. Orangutans play an important role in their forest habitat; they act as seed dispersers and help to open up the forest canopy which allows light to reach the forest floor so that the forest can regenerate. The orangutan is the slowest breeding of all mammal species. Females reach sexual maturity at around 10-15 years of age, and generally give birth to a single young every 6-8 years thereafter, depending on the quality of the habitat. Infants are totally dependent on their mothers, and are carried constantly for the first two to three years of their lives. Weaning occurs at around 3.5 years, but the infant will remain close to its mother for at least another three years, learning the spatial and temporal patterns of fruiting in the forest. When the young disperse, females usually set up a home range adjacent to their mothers, while males tend to travel further afield. Life expectancy in the wild is thought to be 45-50 years. The incredibly long inter-birth period means that a female orangutan can produce a maximum of four surviving young during her lifetime.

Habitat

Known from primary and secondary forest, typically in lowland dipterocarp, freshwater and peat swamp forests. Orangutans are rarely found above 1000 m.

Distribution

Fossil evidence indicates that orangutans once ranged throughout south-east Asia as far north as China. Today, they are only found in pockets of forests on the islands of Borneo and Sumatra. The Sumatran orangutan is restricted to remaining patches of rainforest in northern Sumatra. Most remaining populations occur in and around Gunung Leuser National Park near Aceh, a protected area around 9,460 km² in area. Populations of the Bornean orangutan are found in both Malaysian and Indonesian Borneo: P. p. pygmaeus (northwest Kalimantan to Sarawak), P. p. wurmbii (southwest Kalimantan) and P. p. morio (northeast Kalimantan to Sabah).

Population Estimate

Orangutan population sizes are difficult to estimate with precision. The most recent estimates of total surviving numbers for the Sumatran and Bornean orangutans are around 7,300 and 57,000 respectively.

Population Trend

Densities and population sizes are in decline across the species' range, and forest continues to be lost at a rapid rate.

Status

The Bornean orangutan is classified as Endangered (EN A2cd) on the 2006 IUCN Red List of Threatened Species. The Sumatran orangutan is listed as Critically Endangered (CR A2bcd).

Threats

Orangutan populations have crashed during the past 200 years, as a result of deforestation of their habitat. Today the species continues to be threatened by habitat loss, degradation and fragmentation as a result of legal and illegal logging, forest fires, illegal gold mining, and conversion to agriculture, in particular oil palm plantations. The species’ highly arboreal lifestyle makes them particularly vulnerable to habitat fragmentation, as they rarely travel long distances on the ground. More than 80% of orangutan habitat has been altered or destroyed by these factors. If this alarming rate of habitat loss continues then the orangutan may become extinct in the wild in as little as 10 years. Individuals that have lost their natural habitat sometimes enter oil palm estates, where they are often shot as pests. Mothers with babies are particularly vulnerable. They are often killed and the infants sold into the illegal pet trade. It is estimated that at least three orangutans are killed for each one that is captured and transported. The species is also hunted for meat in some areas. With such a low reproductive rate, the orangutan is particularly vulnerable to these threats. Small, fragmented populations are at considerable risk. Many of the remaining populations, particularly in Sumatra number fewer than 250 individuals. These small, isolated populations do not have the capacity to recover from population declines. A slight rise in female mortality rate of just 1-2% can drive a local population to extinction.

Conservation Underway

Orangutans are protected by law in Malaysia and Indonesia, and listed on Appendix I of CITES, which prohibits international trade. However, weak law enforcement in both countries means that the species continues to be at risk from the above threats. Populations occur in a number of national parks and other protected areas, although illegal logging is still a problem in many of these areas. The Orangutan Conservation Forum is a consortium of groups working to stop illegal logging and hunting by patrolling protected areas, increasing sustainable economic alternatives for communities surrounding critical orangutan habitat, raising awareness, and releasing ex-captive orangutans into suitable protected habitat. There are currently three orangutan rehabilitation centres in Kalimantan, one in Sabah, one in Sarawak and one in Sumatra.

Anderson's Salamander (Ambystoma andersoni)

Anderson’s salamander exhibits some highly unusual and distinct features, indicative of its evolutionary distinctiveness, including its rare “neotenous” life history, whereby the species never develops into an adult but instead retains its juvenile characteristics throughout life, essentially achieving reproductive maturity whilst still in its undeveloped larval form. This would be akin to a tadpole being able to breed without ever turning into a frog. The species is totally aquatic, spending its whole life in the same body of water (Lake Zacapu). This lake is currently suffering from pollution which poses a major threat to the survival of the species.

Evolutionary Distinctiveness
Order: Caudata
Family: Ambystomatidae
The family Ambystomatidae or “the mole salamanders” is included within the four earliest or most primitive family lineages of the order “Caudata” (the salamanders), diverging from all other salamanders in the Early Cretaceous period over 140 million years ago, around five million years before the koala and dolphin lineages diverged from their common ancestor. The small number of species that represent the genus Ambystoma are highly evolutionarily distinct members of both the salamanders and the amphibians as a whole.Anderson’s salamander exhibits some highly unusual and distinct features, indicative of its evolutionary distinctiveness, including its rare “neotenous” life history, whereby the species never develops into an adult but instead retains its juvenile characteristics throughout life, essentially achieving reproductive maturity whilst still in its undeveloped larval form. There are a couple of theories for why neoteny (also referred to as paedomorphosis) develops in some mole salamanders. One idea is that the production or effectiveness of the hormone thyroxine is compromised, either by the species living in water bodies containing insufficient iodine (which is required in the manufacture of thyroxine by the body) or in water temperatures that are too cold for the thyroxine to be effective. This impacts upon the development of the species and sexually mature adults never develop adult characteristics but remain in the larval form. A second theory suggests that species evolving in pools surrounded by hostile terrestrial environments develop aquatic lives to obviate the need to exit the relative safety of their watery home. This is a common trait in species that inhabit high-elevation ponds.

Description
Anderson’s salamander is an Ambystomatid or mole salamander found only in Lake Zacapu near Zacapu, Mexico at an elevation of 2,000 meters above sea level. Mole salamanders are medium to large, stocky salamanders, usually measuring between 90 to 350mm from the tip of the nose to the end of the tail, which salamanders retain throughout their life. Males are often larger than females, owing to their longer tails. Ambystomatids generally exhibit both aquatic “neotenic” larval (or aquatic and permanently juvenile in form with external, feathery gills) and terrestrial “metamorphosed” (or ground-dwelling, fully developed adult in form with reduced gills) stages in their wild populations. Ambystomatids are often boldly patterned as adults, with well-developed “costal” grooves (successive vertical grooves along the sides of the body), especially the metamorphosing varieties. They have a rather flattened body with a wide, flattened head, a large mouth and smooth skin with many glands. The tail is roundish or laterally compressed, and, during the breeding season, males have a very swollen cloacal zone (the region around the reproductory and excretory opening in amphibians located underneath the base of the tail).Like all neotenic Ambystoma species, Anderson’s salamander retains its larval features into adulthood. The mature salamander has medium-sized external gills with bright red filaments, and a prominent caudal (or tail) fin. It grows to a length of around 214 mm, with the tail accounting for about 40% of this measurement. A dorsal fin extends as a low ridge from the base of the gill rakers along the back to the base of the tail, where it rises about 13 mm to form the dorsal tail fin. This species has a large head and small, stocky limbs, as do the larvae. The toes are short and pointed with a slight degree of webbing. The skin colouration is a complex pattern of black blotches (some interconnected) on a red-brown base.

Ecology
Anderson’s salamanders are totally aquatic and spend their whole lives in the same body of water. The species is paedomorphic (or permanently juvenile in physical characteristics), and reaches sexual maturity whilst still having the appearance of a larval salamander. This would be akin to a tadpole being able to breed without ever turning into a frog. It requires a clean, cool aquatic habitat and is found only in Lake Zacapu and the spring-fed streams and canals associated with the lake. Once the eggs are laid in water they are left to develop with no further participation by either parent. This species does not exhibit parental care.Anderson’s salamanders do not metamorphosise from larval to adult form in nature, and individuals that have been artificially induced to metamorphosise with thyroid hormone in the laboratory do not thrive. The diet consists largely of snails and crawfish.

Habitat
Its habitat is that of Lake Zacapu, a small lake near Zacapu, sitting at an altitude of 2000 meters above sea level. The lake is located within the Mesa Central portion of Mexico, an area home to many neotenic Ambystoma species. Lake Zacapu (or Lago de Zacapu) is temperate, with low salinity, and the Anderson’s salamander inhabits the main body of the lake and the spring-fed streams and canals associated with it, requiring a clean, cool aquatic habitat in order to survive.
Distribution
Lake Zacapu (Lago Zacapu) and its surrounding streams near Zacapu, located in north-western Michoacan within the Mesa Central portion of Mexico at an altitude of 2000 metres above sea level.
Population Estimate
Unknown.
Population Trend
Anderson’s salamander is not currently rare in its small area of occupancy, but it is considered to be in decline by the IUCN Red List of Threatened Species.

Status
Listed as Critically Endangered in the IUCN Red List of Threatened Species because its extent of occurrence is less than 100km sq. and its area of occupancy is less than 10km sq., all individuals are in a single subpopulation, and there is continuing decline in the extent and quality of the lake habitat around the city of Zacapu.
Threats
The major threat to the wild population is the pollution of Lake Zacapu, its sole habitat location. Additionally, the animals are heavily fished for food and predatory fish have been introduced into the lake which may pose a severe problem if they prey extensively on the declining populations of Anderson’s salamander.
Conservation Underway
Anderson’s salamander does not occur in any protected area but the species could undergo a population recovery if Lake Zacapu can be kept clean and its ecosystem restored, including the control of introduced predatory fish and general levels of resource extraction from the lake and its associated streams and canals. Studies are needed to evaluate the sustainability of the harvest as well as on the impacts of introduced predatory fish. The species is protected under the category Pr (Special Protection) by the Government of Mexico.

Bactrian camel (Camelus bactrianus)

This camel is probably the ancestor of all domestic two-humped camels. It is superbly adapted to life in the harsh Gobi Desert, one of the most hostile and fragile regions on the planet. The species can withstand drought, food shortages and even radiation from nuclear weapons testing. Less than 1,000 individuals survive today in only four locations. Classified as Critically Endangered, these animals continue to be threatened by hunting, habitat loss, and competition for resources with introduced livestock.

Evolutionary Distinctiveness
Order: Artiodactyla
Family: Camelidae
Camelids (llamas, vicuñas, alpacas, guanacos and camels) evolved in North America during the Eocene Epoch, over 46 million years ago. They differ from all other mammals in the shape of their red blood cells, which are oval instead of circular. There are six living species in three genera (the Old World Camelus, and the New World Lama and Vicugna). The ancestors of the true camels migrated across the Bering Strait land bridge to Asia some 3-4 million years ago. Camelids also crossed to South America after the formation of the Isthmus of Panama around 3 million years ago. Camels disappeared from North America completely around 10,000 years ago. Today, only two species of camel are generally recognised to survive: Camelus bactrianus (Bactrian or two-humped camel) and C. dromedarius (dromedary or one-humped camel).
Description
Size:

Head and body length: 225-345 cm

Shoulder height: 180-230 cm

Tail length: 35-55 cm
Weight: 300-690 kg
The two-humped Bactrian camel is smaller and more slender than its domestic relative, and is superbly adapted to life in the harsh Gobi Desert. It has a double row of long eyelashes and hairs inside the ears to protect against damage from sand, and the camel’s long slit-like nostrils can be closed for further protection during sandstorms. The foot has a tough undivided sole consisting of two large toes, which spread apart widely for efficient travel across the shifting desert sands. The camel’s fur, which is a light brown or beige colour, is thick and shaggy during the harsh winters and is shed rapidly in the spring.

Ecology
Wild camels are diurnal, sleeping at night in open spaces and foraging for food during the day. Shrubs and grass form the bulk of the diet, with the animals being well adapted to feed on thorns, dry vegetation and salty plants, which other herbivores avoid. Excess fat is stored in the humps and used as a reserve when food is scarce. This enables the camels to go for several days at a time without eating or drinking. Upon finding water they will drink vast quantities rapidly to replace what is missing from their bodies - they can take in as much as 57 litres of water to restore the normal amount of body fluid. If no fresh water is available, the species can drink salty or brackish water with no ill effects (camels are the only land mammals adapted for this). Group size is largely dependent on the amount of food available. Usually the camels can be found travelling in small herds of between 6 and 20 related individuals, led by a single adult male, although larger groups will sometimes congregate around water. The distribution is normally widely scattered, with estimates of population density as low as 5/100 sq km. The camels are highly migratory, and will travel vast distances in search of food and water sources. Breeding usually occurs in winter, often overlapping with the rainy season. Females give birth to their first calf at around 5 years of age and the interbirth interval is usually at least 2 years. Wild camels are thought to live up to 40 years of age.
Habitat
The camels are migratory, and their habitat ranges from rocky mountain massifs to flat arid desert, stony planes and sand dunes. Conditions are extremely harsh – vegetation is sparse, water sources are limited and temperatures are extreme, ranging from as low as -40°C in winter to 40°C in summer. The camels’ distribution is linked to the availability of water, with large groups congregating near rivers after rain or at the foot of the mountains, where water can be obtained from springs in the summer months, and in the form of snow during the winter.

Distribution
The species has suffered a drastic reduction in its range. It now occurs only in three separated habitats in northwest China (Lake Lob, Taklimikan desert and the ranges of Arjin Shan) and one in the Trans-Altai Gobi desert of southwest Mongolia. The largest population lives in the Gashun Gobi (Lop Nur) Desert in Xinjiang Province, China, which was for 45 years used as a test site for nuclear weapons.
Population Estimate
There are approximately 600 individuals surviving in China and 350 in Mongolia. In contrast, there are over 2 million domestic Bactrian camels currently living in Central Asia.
Population Trend
Population size is decreasing. The Mongolian population has almost halved in the last twenty years and there is every indication that the situation is just as serious for the Chinese populations.
Status
Classified as Critically Endangered (CR A3de+4ade) on the 2006 IUCN Red List of Threatened Species.
Threats
The species has suffered greatly at the hands of humans. It has lost habitat to mining and industrial development, and has been forced to compete with introduced livestock for food and water. Farmers hunt the camel for this reason, and many individuals are lost every year when the camels migrate out of protected areas and onto land set aside for grazing. Domestic Bactrian camels are amongst the animals introduced to these areas. They graze alongside reserves containing their wild relatives, and there is much concern that interbreeding and subsequent hybridisation will lead to the loss of the genetically distinct wild camel.

Conservation Underway
The species is listed on Appendix I of the Convention on Migratory Species (CMS or the Bonn Convention). The governments of China and Mongolia have agreed to cooperate in order to protect the species and its fragile desert ecosystem. Assisted by the Wild Camel Protection Foundation (WCPF), the two governments have adopted an ecosystem-based management programme which aims to protect the biodiversity of the Great Gobi Desert. Two reserves have been created – the ‘Great Gobi Reserve A’ in Mongolia in 1982, and the Arjin Shan Lop Nur Nature Reserve in China in 2000. These reserves provide a safe habitat for a wide range of endangered desert animals and plants, as well as the wild camels. The WCPF also aims to increase the population of the species through captive breeding. In 2003 it established a sanctuary in Zakhyn-Us, Mongolia, which has some of the last non-hybridised herds of Bactrian camels. Initial breeding attempts have been successful, with several calves having been born since the programme’s inception.

Black rhinoceros (Diceros bicornis)

Black rhinos and white rhinos are not named for their colours, but for the shape of their lips. The black rhino has a prehensile (or grasping) upper lip, which it uses to draw plant material into its mouth. This two-horned rhinoceros has a reputation for being unpredictable and dangerous. As a result it has suffered much more persecution than other rhinos. The total population decreased by a massive 96% between 1970 and 1992, the largest decline of any of the rhino species. Four subspecies are recognised, of which three are considered Critically Endangered.

Evolutionary Distinctiveness
Order: Perissodactyla
Family: Rhinocerotidae
Together with equids (horses, zebras and asses) and tapirs, rhinos are the only surviving members of an ancient and formerly diverse group of ungulates, which originated in the Eocene around 50 million years ago. The ancestors of the black and white rhinos reached Africa about 10 million years ago, at the end of the Miocene. The black rhino diverged from the white rhino between four and five million years ago, and is considered to be the more primitive of the two. It is the only species in the genus Diceros.
Description
Size: Head and body length: 300-375 cm

Shoulder height: 140-180 cm

Tail length: 70 cm

Horn length: 500 mm (anterior horn)
Weight: 800-1,400 kg
The black rhino is not black at all, but a yellow-brown or grey colour. It acquired its name to separate it from confusion with the other African species, the white rhino. While it is slightly darker in colour than the white rhino, its main distinguishing feature is its prehensile, or grasping, upper lip. This hook-shaped lip sticks out beyond the lower one and is used to draw food into the mouth. The rhino has two horns made from keratin (the same protein found in human hair and nails). The longest of these horns can grow to over 50 cm in length.

Ecology
The species is a browser. Its diet is made up of a wide variety of plant material, such as leaves and twigs of woody plants and legumes, supplemented with minerals obtained from salt-licks. Individuals prefer to feed during the early morning and evening, and spend the day wallowing in mud or water holes to keep cool. The species is generally solitary, although small groups often congregate at wallows and salt-licks. Females often have overlapping home ranges and will sometimes form temporary groups that move and feed together. Females usually have their first calf at around 6 or 7 years old, and will give birth every 2-5 years thereafter. Life expectancy for the species is around 40-50 years.

Habitat
Found in a variety of habitats, including grasslands, savannas and shrublands, although the preferred habitat is the transitional zone between grassland and forest. The species is restricted to areas within 25 km of a permanent water source.
Distribution
Black rhinos were once found throughout sub-Saharan Africa with the exception of the Congo Basin. Today the main populations live in reserves in South Africa, Namibia, Zimbabwe, Tanzania and Kenya.

Population Estimate
There are currently approximately 3,610 surviving black rhinos.
Population Trend
Population size collapsed during the last century, from an estimated 65,000 animals in 1970 to a mere 2,300 in the 1990s. Rhino numbers are now increasing, but recovery is slow and the western subspecies in particular is still very much in danger of becoming extinct.
Status
Classified as Critically Endangered (CR A2abc) on the 2006 IUCN Red List of Threatened Species. Listed on Appendix I of CITES.
Threats
The black rhino has a reputation for being unpredictable and dangerous, and has suffered much persecution as a result. Over the years, it has been killed for sport, and for its hide and meat. However, the main threat to the rhino has been the demand for its horn, and this remains the case today. In the 1970s there was huge demand for rhino horn from Yemen, where it was used to make handles for traditional daggers worn by the wealthy as status symbols. Rhino numbers plummeted as a result of subsequent poaching. Although this demand has now subsided, rhino horn is still being illegally exported to Asia for use in traditional medicine. Currently almost all rhino deaths are caused by poaching to obtain the horn. It has a huge market value, and as a result of civil unrest and wars, many poverty-stricken African farmers have been left with little option but to turn to poaching as a means of survival.
Conservation Underway
Several organisations are working to help save this species. Conservation efforts are concentrating on reducing demand for rhino horn, while at the same time increasing protection for wild populations. At present, all trade in rhino horn is prohibited, and the extent of illegal trade is monitored by TRAFFIC (the wildlife trade monitoring network of the IUCN and WWF). Conservation organisations are also working in consumer countries to draw attention to the link between the use of rhino horn and the suffering of wild rhinos, and to investigate suitable alternatives for use in traditional medicine. At the same time, national and international conservation groups have been working with African governments to develop and implement effective national conservation and management strategies, under the co-ordination of the African Rhino Specialist Group of the IUCN which has developed a detailed Action Plan for conservation of the African rhinos. Most key wild populations are now protected in reserves, which are patrolled regularly by anti-poaching teams, and a de-horning programme has been introduced in some areas in an attempt to deter poachers. Regular monitoring takes place, and attempts to reintroduce rhinos to areas of their former range have been largely successful. A captive breeding programme is also underway to safeguard against any unforeseen catastrophes occurring within the vulnerable wild populations.

Blunt-headed Salamander (Ambystoma amblycephalum)

The blunt-headed salamander is a metamorphosing species of mole salamander, which means that it can make the full transition from aquatic larval form to a terrestrial adult form in its lifetime. The adult spends the majority of its time on land in a mosaic of natural grasslands and pine-oak forests. It is highly evolutionarily distinct, the family diverging from all other salamanders in the Early Cretaceous period over 140 million years ago, around five million years before the koala and dolphin lineages diverged from their common ancestor. Today, the desiccation, pollution and conversion of former ponds, small reservoirs, and open habitat to row crops, represents the main threat to the species’ survival.

Evolutionary Distinctiveness
Order: Caudata
Family: Ambystomatidae
The family Ambystomatidae or “the mole salamanders” is included within the four earliest or most primitive family lineages of the order “Caudata” (the salamanders), diverging from all other salamanders in the Early Cretaceous period over 140 million years ago, around five million years before the koala and dolphin lineages diverged from their common ancestor. The small number of species that represent the genus Ambystoma are highly evolutionarily distinct members of both the salamanders and the amphibians as a whole.The blunt-headed salamander is capable of reaching sexual maturity in its neotenous form, retaining its aquatic larval characteristics such as fins and gills throughout its life. However, it is also able to metamorphose into the adult form and live a terrestrial life. Although this species has been little-studied, there are a couple of theories that may explain why some populations of the blunt-headed salamander do not metamorphose. One idea is that the production or effectiveness of the hormone thyroxine is compromised, either by the species living in water bodies containing insufficient iodine (which is required in the manufacture of thyroxine by the body) or in water temperatures that are too cold for the thyroxine to be effective. This impacts upon the development of the species and sexually mature adults never develop adult characteristics but remain in the larval form. A second theory suggests that species evolving in pools surrounded by hostile terrestrial environments develop aquatic lives to obviate the need to exit the relative safety of their watery home. This is a common trait in species that inhabit high-elevation ponds. Since the blunt-headed salamander inhabits various ponds across its range, and is able to disperse between them in its metamorphosed form, it is possible that the conditions in some of these ponds are not conducive to metamorphosis.
Description
The blunt-headed salamander is an Ambystomatid or mole salamander from high elevations (2,000m above sea level) 15 miles west of Morelia in Michoacán, Mexico. Mole salamanders are medium to large, stocky salamanders, measuring between 90 to 350mm from the tip of the nose to the end of the tail, which salamanders retain throughout their life. Males are often larger than females, partly due to their longer tails. Ambystomatids generally exhibit both aquatic “neotenic” larval (or aquatic and permanently juvenile in form with external, feathery gills) and terrestrial “metamorphosed” (or ground-dwelling, fully developed adult in form with reduced gills) stages in their wild populations. Ambystomatids are often boldly patterned as adults, with well-developed “costal” grooves (successive vertical grooves along the sides of the body), especially the metamorphosing varieties. They have a rather flattened body with a wide, flattened head, a large mouth and smooth skin with many glands. The tail is roundish or laterally compressed, and, during the breeding season, males display a very swollen cloacal zone (the region around the reproductory and excretory opening in amphibians located underneath the base of the tail).The blunt-headed salamander has both neotenic and fully developed terrestrial (or ground-dwelling) populations. Neotenic populations retain their gills and fins throughout their life, whereas metamorphosed individuals develop adult traits, such as the lack of gills, functioning lungs, eyelids and no fins. These so-called “neotene” individuals are very long with extremely short, blunt heads and round eyes. They are about 150-160 mm in length, with a tail length of around 60-70 mm. The neotenous adults have a dorsal fin along the tail and relatively short, thick gills, although metamorphosed adults lack both fins and gills. The digits are semi-webbed. The colouring of this species is blackish-brown on the dorsal (or upper) surfaces, with a lighter grey under-belly. The end of the tail is darker than the base. The chest and throat have some cream markings. They also display small, dark marks on their head and back.
Ecology
The blunt-headed salamander is a metamorphosing species of mole salamander, which means that it can make the full transition from aquatic larval form to a terrestrial adult form in its lifetime in the wild. The adult blunt-headed salamander spends the majority of its time on land in a mosaic of natural grasslands and pine-oak forests.Once the eggs are laid in water they are left to develop with no further participation by either parent. This species does not exhibit parental care.
Habitat
The blunt-headed salamander inhabits a mosaic landscape of natural grasslands and pine-oak forest, occurring at about 2,000m above sea level in its small range area around Tacicuaro, north-western Michoacan, to the west of the Morelia City in Mexico. Blunt-headed salamanders require ponds of moderate depth in which to breed, and are able to survive in some types of modified landscape, taking advantage of cattle ponds for larval development.
Distribution
Found in the neotropics in a small area around Tacicuaro, north-western Michoacan, to the west of Morelia City in Mexico. It occurs at about 2,000m above sea level.
Population Estimate
There is very little information on the species' population status; there has been limited fieldwork carried out on this species since the early 1980s.
Population Trend
The IUCN Red List of Threatened Species indicates that the blunt-headed salamander’s total population size is generally in decline.
Status
Listed as Critically Endangered on the IUCN Red List of Threatened Species because its extent of occurrence is less than 100km sq. and its area of occupancy is less than 10km sq., its distribution is severely fragmented, and there is continuing decline in the number of mature individuals and in the extent and quality of its habitat around the city of Morelia.
Threats
The desiccation, pollution, and conversion of former ponds, small reservoirs, and open habitat to row crops, represents the main threat to the blunt-headed salamander, coupled with urban expansion of Morelia and Uruapan. Introduced predatory fish are also a major concern, both in ponds and small streams as these may prey extensively on the declining populations of blunt-headed salamanders.
Conservation Underway
The blunt-headed salamander does not occur in any protected areas, although it is protected under the category Pr (Special Protection) by the Government of Mexico.

Axolotl (Ambystoma mexicanum)

The name “axolotl” is thought to have originated from the Aztecs, derived from two words: atl, meaning “water”, and xolotl meaning “monster”. Axolotls do not develop adult characteristics but retain their gills, fins and other larval characteristics throughout their life. They live permanently in water, in the wetlands and canals associated with Lake Xochimilco and Lake Chalco, adjacent to Mexico City. Once eaten as a delicacy in Mexico City, they are now a protected species in Mexico and Critically Endangered in the wild.

Evolutionary Distinctiveness
Order: Caudata
Family: Ambystomatidae
The family Ambystomatidae or “the mole salamanders” is included within the four earliest or most primitive family lineages of the order “Caudata” (the salamanders), diverging from all other salamanders in the Early Cretaceous period over 140 million years ago, around five million years before the koala and dolphin lineages diverged from their common ancestor. The small number of species that represent the genus Ambystoma are highly evolutionarily distinct members of both the salamanders and the amphibians as a whole.The axolotl exhibits some highly unusual and distinct features, indicative of its evolutionary distinctiveness, including its rare “neotenous” life history, whereby the species never develops into an adult but instead retains its juvenile characteristics throughout life, essentially achieving reproductive maturity whilst still in its undeveloped larval form. There are a couple of theories for why neoteny (also referred to a paedomorphosis) develops in some mole salamanders. One idea is that the production or effectiveness of the hormone thyroxine is compromised, either by the species living in water bodies containing insufficient iodine (which is required in the manufacture of thyroxine by the body) or in water temperatures that are too cold for the thyroxine to be effective. This impacts upon the development of the species and sexually mature adults never develop adult characteristics but remain in the larval form. A second theory suggests that species evolving in pools surrounded by hostile terrestrial environments develop aquatic lives to obviate the need to exit the relative safety of their watery home. This is a common trait in species that inhabit high-elevation ponds.

Description
The axolotl is an Ambystomatid or mole salamander found only in the Laguna Alchichica in eastern Puebla, Mexico at an elevation of 2,290m above sea level. Mole salamanders are medium to large, stocky salamanders, usually measuring between 90 to 350mm from the tip of the nose to the end of the tail, which salamanders retain throughout their life. Males are often larger than females, owing to their longer tails. Ambystomatids generally exhibit both aquatic “neotenic” larval (or aquatic and permanently juvenile in form with external, feathery gills) and terrestrial “metamorphosed” (or ground-dwelling, fully developed adult in form with reduced gills) stages in their wild populations. Ambystomatids are often boldly patterned as adults, with well-developed costal grooves (successive vertical grooves along the sides of the body), especially the metamorphosing varieties. They have a rather flattened body with a wide, flattened head, a large mouth and smooth skin with many glands. The tail is roundish or laterally compressed, and, during the breeding season, males have a very swollen cloacal zone (the region around the reproductory and excretory opening in amphibians located underneath the base of the tail).Like all neotenic Ambystoma species, the axolotl retains its larval features into adulthood. A fully grown axolotl (at age 18–24 months) ranges in length from 150–450mm, although a size close to 230mm is typical and axolotls measuring more than 300mm nose to tail are rarely observed. The axolotl grows much larger than a normal larval or neotenic salamander species, and it reaches sexual maturity in this larval stage. Axolotls have distinctive fern-like gill structures that are uncovered or external – usually three stalks on each side of the head. They have tiny teeth which are used to grip food rather than to tear and chew it. In body colour, axolotls range from albino or white (the leucistic variety) to black, through greys, tans and browns. However, leucistic axolotls are rarely found in the wild.
Ecology
The most notable feature of the life history of the axolotl is that the species exhibits an extreme form of neoteny. Axolotls remain in their aquatic larval form throughout their entire lives, which means that when they reach sexual maturity at approximately one and a half years of age, they remain in all other respects a large larva. This would be akin to a tadpole being able to breed without ever turning into a frog. Neoteny involves the retention of “paedomorphic” features (referring to those features which pertain to the juvenile form) such as external gills that persist through life, a state described as “perennibranchiate”. The paedomorphic characteristics found in adult axolotls include the maintenance of external gills, fins, non-protruding eyes, no eyelids and an associated permanently aquatic lifestyle. Young axolotls feed on algae, but as adults their diet predominantly consists of aquatic insects.During reproduction in axolotls, the male releases sperm packets which are taken up by the female for internal fertilisation. Fertilised eggs are attached by the female to structures such as plants and hatching generally occurs after 2-3 weeks. In the wild, axolotls can live for ten to 12 years. The major predators of the axolotl are predatory birds such as herons.Axolotls famously have a fast regeneration rate which can allow them to regrow limbs and organs. In addition to respiring via their external fearthery gills, axolotls are able to breathe through their skin and also possess lungs.

Habitat
The axolotl is native to the ancient system of water channels and lakes in Mexico City. This species requires deep-water lakes and water bodies (including both natural and artificial canals) with abundant aquatic vegetation. The axolotl depends upon vegetation and other suitable structures for the attachment of their eggs, following fertilisation. Lake Xochimilco is known for its “floating gardens,” or “chinampas,” which are strips of land between drainage channels where local people grow vegetables and flowers for the market. Axolotls may be found in these channels, as well as remaining lake areas.

Distribution
The axolotl is known only from central Mexico, on the southern edge of Mexico City, in canals and wetlands in the general vicinity of Xochimilco (including outside of Xochimilco proper, around the Chalco wetland). The axolotl lives only in wetlands and canals associated with Lake Xochimilco and Lake Chalco, both adjacent to Mexico City. Xochimilco and Chalco are part of a complex of five lakes, among which the Aztecs built Mexico City and around which the city has since expanded. Axolotls are not regularly distributed throughout their range but instead congregate in places where the habitat is still conducive for the survival and breeding of the axolotl.
Population Estimate
An accurate population estimate is currently unavailable for the species, although the surviving wild population of axolotls is known to be very small despite a large captive population. Although populations are difficult to assess, recent surveys covering almost all of its known distribution range have usually captured less than 100 individuals and during 2002-2003, following more than 1,800 net casts along Xochimilco canals covering 39,173m2, the resultant catch was just 42 individuals. A recent scientific survey in 2004 revealed no axolotls in the species’ range. However, wild-caught animals are still found in local markets, indicating that the local fishermen still know where to find them. There has not been a density study of the Chalco population, but evidence suggests that this population is small and, furthermore, Chalco is a highly unstable system which runs the risk of disappearing in the near future.
Population Trend
Exact population data are currently unavailable for the axolotl, although the population trend is assumed to be in decline in the IUCN Red List of Threatened Species based on notable declines in survey catches performed since 2002 along a 39,173m2 area of the Xochimilco canals.
Status
Listed as Critically Endangered in the IUCN Red List of Threatened Species because its area of occupancy is less than 10 km sq., its distribution is severely fragmented, there is a continuing decline in the extent and quality of its habitat and a sustained decline in the number of mature individuals.
Threats
Axolotl populations are suffering as a result of land drainage and the growth of Mexico City. Various efforts at flood control and sewage disposal starting in the seventeenth century have led to serious damage to the Xochimilco and Chalco lake complex. The digging of wells for the burgeoning population of Mexico City has also caused drying of the valley in which the lakes are located. The largest of these lakes, Texcoco, has been greatly diminished in size, while Lake Chalco has all but disappeared. Xochimilco has likewise suffered a decline in size and water quality. The major threat to the survival of the axolotl is therefore the desiccation, pollution and general degradation of the canal system and lakes in Xochimilco and Chalco, as a result of urbanization. The species is under pressure from traditional harvesting for consumption by local people and axolotls are also captured for medicinal purposes. The harvesting is targeted at animals that are less than one year old, and therefore generally before the individuals have had the opportunity to breed since axolotls reach sexual maturity at approximately one and a half years of age. Formerly, axolotls have also been captured for the international pet trade, although it is thought that no axolotls commercially available today are wild caught since doing so is strictly forbidden. The majority of axolotls currently available on the international market probably originated from captive or laboratory populations.Introduced predatory fish (such as tilapia and carp) have increased to high abundances – a recent study collected 600kg of tilapia in one small channel using a 100m net. These introduced fish species have had a negative impact upon axolotl populations through competition and predation. The species is also being adversely affected by poor water quality, arising from factors such as pollution and disease, probably spread via invasive species. Although the water regime has changed in the last ten years, and it is reported that pollution levels are decreasing, factors such as very high levels of bacterial contamination could still pose a serious threat to axolotls in the wild.
Conservation Underway
Conservation action to protect axolotl populations in the wild is focusing on raising the profile of Lake Xochimilco through conservation education and a nature tourism initiative, coupled with work on habitat restoration and bioremediation. A species action plan is in draft. This species is protected under the category Pr (Special Protection) by the Government of Mexico and is in the process of being amended to a higher risk category. The axolotl is currently on Appendix II of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), restricting its international trade to protect this species from over-harvesting in the wild, where it has been listed since 1975. However, it is currently under the process of "Periodic Review of Species included in CITES Appendices".A Darwin project was recently completed focusing on the conservation of the axolotl, led by the Durrell Institute of Conservation and Ecology. This was designed to assist Mexico in the development of a sustainable development programme to conserve the axolotl and other endemic fauna and flora of Xochimilco through the promotion of nature tourism.

Sumatran rhinoceros (Dicerorhinus sumatrensis)

This two-horned rhino is the smallest and most threatened of the five living rhinoceros species. It is sometimes referred to as the ‘hairy rhino’ because of the long coarse hair that covers its body. The species leads a solitary life deep in the rainforests of South East Asia, where it has survived virtually unchanged for a million years. Sadly, human activities have brought the species to brink of extinction. Extensive deforestation and poaching for the horn have caused a dramatic decline in rhino numbers, and it is estimated that fewer than 275 individuals survive today in very small and highly fragmented populations.

Evolutionary Distinctiveness
Order: Perissodactyla
Family: Rhinocerotidae
Together with equids (horses, zebras and asses) and tapirs, rhinos are the only surviving members of an ancient and formerly diverse group of ungulates, which originated in the Eocene around 50 million years ago. The Sumatran rhino is the only surviving member of the most primitive group of rhinos, the Dicerorhinini, which emerged during the Miocene, 15-20 million years ago. It is closely related to the extinct woolly rhinoceros (Coelodonta antiquitatis), which lived in Europe and Asia until 10,000 years ago. Ancestral members of this clade are thought to have migrated into Africa and evolved into the two species now found in this continent, the black rhino and the white rhino. The Sumatran rhino is therefore thought to be more closely related to these species than to either of the one-horned Asian species.

Description
Size: Head and body length: 236-318 cm

Shoulder height: 112-145 cm
Weight: 600 - 950 kg
Often referred to as the ‘hairy rhino’, the Sumatran rhino is the smallest of the five living rhinoceros species. It has a sparse covering of long coarse hair on its body and tufts of hair on its ears. The skin is reddish-brown and deeply folded behind the front legs and in front of the hind legs. It is the only Asian rhino to have two horns, although the posterior horn is usually very small and often absent in females.
Ecology
The species is a browser, feeding on a wide variety of plant material, including fruit, leaves, bark, shrubs and vines. Most of the 50 kg of food the rhino consumes each day comes from saplings, which it breaks down in order to reach young leaves and shoots. The rhino is particularly fond of wild mangos, bamboo and figs, and obtains essential minerals from salt-licks. Individuals prefer to travel and feed at dawn or dusk or during the night, when it is cooler. Days are usually spent resting and wallowing in mud to keep the skin cool and insects at bay. The rhinos are solitary creatures and tend avoid each other, coming together only for breeding. Females maintain stable, partially overlapping home ranges, while males are slightly more nomadic. The large ranges of males overlap extensively, but there appear to be small, exclusive core areas. Both sexes mark their territories with faeces, urine and soil scrapes. In some areas the rhinos have been seen to exhibit seasonal movements, moving to higher ground during the wet season to escape flooding and descending again once the rains have finished. The lifespan of the Sumatran rhino is thought to be similar to that of other rhinos, at around 35-40 years. Sexual maturity is reached at 6-8 years of age and females give birth to a single calf every 3 to 4 years.

Habitat
Mainly found in hilly country near water. It inhabits both tropical rainforest and mountain moss forest. The species is thought to prefer lowland secondary forest, where the canopy is broken and the smaller shrubs and vines on which it feeds are more abundant. Individuals can, however, be found in a wide variety of habitats. An agile climber, it is sometimes forced up into higher altitudes due to lowland flooding or human pressures. The rhino is quite capable of surviving in such areas providing there is sufficiently thick undergrowth and a salt-lick (essential for every home range).
Distribution
Once found throughout south-east Asia, the species now exists only as small, highly fragmented populations scattered throughout its former range. The largest concentration of the western subspecies is thought to be in Sumatra and Peninsular Malaysia (with possibly a few surviving in Thailand along the border with Malaysia). There have also been unconfirmed reports of the rhinos in Cambodia, Laos and Vietnam. The eastern subspecies is currently found only in Sabah in Malaysian Borneo, although there is also speculation that it may exist in the neighbouring state of Sarawak and in Kalimantan (Indonesian Borneo). The subspecies D. s. lasiotis is probably extinct, although a few individuals may possibly survive in the forests of Burma.

Population Estimate
The population size is critically low. There are thought to be as few as 275 Sumatran rhinos surviving in the wild.
Population Trend
Numbers have halved over the last decade, although this decline appears to have been slowed and numbers seem to be stabilising in most of the core areas.
Status
Both the Eastern and Western Sumatran rhino are classified as Critically Endangered on the 2006 IUCN Red List of Threatened Species, and D. s. lasiotis is classified as Extinct. The species is listed on Appendix I of CITES.
Threats
Hunting has been a major factor in the decline of the species. Rhino horn, along with various other body parts, has been used in traditional Asian medicine for centuries to treat a variety of ailments, including fevers and strokes. Although hunting is now illegal, poaching continues, with animals continuing to be trapped and killed for their horns. Loss of habitat as a result of logging and conversion of land to other uses is the other main threat. As areas of suitable habitat become fewer, the rhino populations are pushed together into small, fragmented subpopulations that may be too small to be viable. Stranded in these remaining pockets of forest, the rhinos become even more susceptible to disease, environmental disasters and poaching.
Conservation Underway
Surviving rhino populations are being intensively protected by anti-poaching patrol teams, which have proved very effective at reducing illegal poaching. The teams are also involved in monitoring rhino populations, with the information gathered being used by the Indonesian and Malaysian governments to develop effective management programmes. Some of these programmes have involved creating breeding sanctuaries where the rhinos can be protected and maintained under conditions most suitable for reproductive success. The governments are assisted in their work by several national and international conservation organisations which are also restoring habitat in heavily encroached areas.The IUCN/SSC Asian Rhino Specialist Group (AsRSG), the co-ordinating body for rhino conservation work, has developed an Action Plan for conservating this species. This plan recognises the importance of involving local communities in their work, so that they can learn about the rhino's plight and benefit from its conservation. Such communities are also being encouraged to adopt sustainable methods by which they can effectively manage natural resources without causing further harm to the rhino or its habitat. In addition to these measures, conservation groups are trying to reduce the demand for rhino horn by conducting awareness campaigns in consumer countries, and investigating possible alternatives to rhino horn in traditional medicine. At present, all trade in rhino horn is prohibited, and the extent of illegal trade is investigated by TRAFFIC (the wildlife trade monitoring network of the WWF and IUCN).