andrew revkin reports : http://dotearth.blogs.nytimes.com/2011/11/12/extinct-western-black-rhinoceros/
This follows on the extinction of the northern white rhino, the last few of which I saw in Garamba National Park, in the northeastern corner of the Democratic Republic of Congo, on the Sudan Border, as I reported in Dispatch #2. Despite the heroic efforts of Kes and Fraser Hillman-Smith, with whom I flew there, they were wiped out by the Lord’s Resistance Army. By 2006 none were left in the wild. But there was still six left in the Dv?r Králové Zoo in Czech Republic. In 2009 four of them were flown down to the Ol Pejeta Conservancy in Kenya in a last bid to save their species. They arrived at the conservancy after an air and road trip on 20 December 2009, and seem to be integrating very well in their new home.
So this leaves 5000 or so of the eastern subspecies of southern black rhino, and there are still 15,000 southern white rhinos, the last representative of the largest, most abundant species remaining, and the Javan (the last one in Vietnam was just shot, so there’s another extinction; the only ones left now are in Indonesia), and the Sumatran, found in Sumatra and Borneo.
Here’s a rundown on the remaining five species from Wikipedia.
The White Rhino has an immense body and large head, a short neck and broad chest. This rhino can exceed 3,500 kg (7,700 lb), have a head-and-body length of 3.5–4.6 m (11–15 ft) and a shoulder height of 1.8–2 m (5.9–6.6 ft). The record-sized White Rhinoceros was about 4,500 kg (10,000 lb). On its snout it has two horns. The front horn is larger than the other horn and averages 90 cm (35 in) in length and can reach 150 cm (59 in). The White Rhinoceros also has a prominent muscular hump that supports its relatively large head. The colour of this animal can range from yellowish brown to slate grey. Most of its body hair is found on the ear fringes and tail bristles with the rest distributed rather sparsely over the rest of the body. White Rhinos have the distinctive flat broad mouth which is used for grazing.
 Black Rhinoceros
The name Black Rhinoceros (Diceros bicornis) was chosen to distinguish this species from the White Rhinoceros (Ceratotherium simum). This can be confusing, as those two species are not really distinguishable by colour. There are four subspecies of black rhino: South-central (Diceros bicornis minor), the most numerous, which once ranged from central Tanzania south through Zambia, Zimbabwe and Mozambique to northern and eastern South Africa; South-western (Diceros bicornis bicornis) which are better adapted to the arid and semi-arid savannas of Namibia, southern Angola, western Botswana and western South Africa; East African (Diceros bicornis michaeli), primarily in Tanzania; and West African (Diceros bicornis longipes) which was declared extinct in November 2011. The native Tswanan name Keitloa is used to describe a South African variation of the black rhino in which the posterior horn is equal to or longer than the anterior horn.
An adult Black Rhinoceros stands 150–175 cm (59–69 in) high at the shoulder and is 3.5–3.9 m (11–13 ft) in length. An adult weighs from 850 to 1,600 kg (1,900 to 3,500 lb), exceptionally to 1,800 kg (4,000 lb), with the females being smaller than the males. Two horns on the skull are made of keratin with the larger front horn typically 50 cm long, exceptionally up to 140 cm. Sometimes, a third smaller horn may develop. The Black Rhino is much smaller than the White Rhino, and has a pointed mouth, which they use to grasp leaves and twigs when feeding.
 Indian Rhinoceros
The Indian Rhinoceros or the Greater One-horned Rhinoceros (Rhinoceros unicornis) is now found almost exclusively in Nepal and North-Eastern India. The rhino once inhabited many areas of Pakistan to Burma and may have even roamed in China. But because of human influence their range has shrunk and now they only exist in several protected areas of India (in Assam, West Bengal, Gujarat and a few pairs in Uttar Pradesh) and Nepal, plus a few pairs in Lal Suhanra National Park in Pakistan. It is confined to the tall grasslands and forests in the foothills of the Himalayas.
The Indian Rhinoceros has thick, silver-brown skin which creates huge folds all over its body. Its upper legs and shoulders are covered in wart-like bumps, and it has very little body hair. Fully grown males are larger than females in the wild, weighing from 2,500–3,200 kg (5,500–7,100 lb).The Indian rhino stands at 1.75–2.0 metres (5.75–6.5 ft). Female Indian rhinos weigh about 1,900 kg and are 3–4 metres long. The record-sized specimen of this rhino was approximately 3,800 kg. The Indian Rhino has a single horn that reaches a length of between 20 and 100 cm. Its size is comparable to that of the White Rhino in Africa.
 Javan Rhinoceros
The Javan Rhinoceros (Rhinoceros sondaicus) is one of the rarest and most endangered large mammals anywhere in the world. According to 2002 estimates, only about 60 remain, in Java (Indonesia) and Vietnam. Of all the rhino species, the least is known of the Javan Rhino. These animals prefer dense lowland rain forest, tall grass and reed beds that are plentiful with large floodplains and mud wallows. Though once widespread throughout Asia, by the 1930s the rhinoceros was nearly hunted to extinction in India, Burma, Peninsular Malaysia, and Sumatra for the supposed medical powers of its horn and blood. As of 2009, there are only 40 of them remaining in Ujung Kulon Conservation, Java, Indonesia. The last rhinoceros in Vietnam was reportedly killed in 2010.
Like the closely related larger Indian Rhinoceros, the Javan rhinoceros has only a single horn. Its hairless, hazy gray skin falls into folds into the shoulder, back, and rump giving it an armored-like appearance. The Javan rhino’s body length reaches up to 3.1–3.2 m (10–10 ft), including its head and a height of 1.5–1.7 m (4 ft 10 in–5 ft 7 in) tall. Adults are variously reported to weigh between 900–1,400 kg or 1,360-2,000 kg. Male horns can reach 26 cm in length while in females they are knobs or are not present at all.
 Sumatran Rhinoceros
The Sumatran Rhinoceros (Dicerorhinus sumatrensis) is the smallest extant rhinoceros species, as well as the one with the most fur, which allows it to survive at very high altitudes in Borneo and Sumatra. Due to habitat loss and poaching, its numbers have declined and it is one of the world’s rarest mammals. About 275 Sumatran Rhinos are believed to remain.
Typically a mature Sumatran rhino stands about 130 cm (51 in) high at the shoulder, a body length of 240–315 cm (94–124 in) and weighs around 700 kg (1,500 lb), though the largest individuals have been known to weigh as much as 1,000 kilograms. Like the African species, it has two horns; the largest is the front (25–79 cm) and the smaller being the second, which is usually less than 10 cm long. The males have much larger horns than the females. Hair can range from dense (the densest hair in young calves) to scarce. The color of these rhinos is reddish brown. The body is short and has stubby legs. They also have a prehensile lip.
The southeastern black rhino is under intense poaching pressure. 120 were just airlifted, aerially relocated, to Limpopo Province, South Africa. Here’s an NPR story about it : http://www.npr.org/blogs/pictureshow/2011/11/09/142033170/flying-rhinos-photos-you-dont-see-every-day