How Long Can a Rhino's Horn Grow?

Fast Facts About Rhinos and Their Horns

By Sectionov, Indonesia Liaison, IRF

The horn on a rhinoceros is very different from that of a sheep or antelope. A rhino’s horn is not attached to the skull. Rhino horn is made of compressed keratin fibers, the same material that is found in fingernails and hair! Some people believe that rhino horn has powerful medicinal uses, ranging from stopping nosebleeds and headaches to curing diphtheria and food poisoning, but there is no scientific evidence that this is true. The use of rhino horn for medical purposes has been illegal since 1993. Trade continues, however, and is driving the illegal poaching of endangered rhinos. Asian rhino horns are more highly prized than African horns; consumers believe that their smaller size means that they are more concentrated, and therefore more potent. One repeated misconception is that rhinoceros horn in powdered form is used as an aphrodisiac in traditional Chinese medicine. It is, in fact, generally prescribed for fevers and convulsions. The horns are also valued as dagger handles in Middle Eastern countries like Yemen, where they are known as “jambiyas.”
To prevent poaching in certain areas, rhinos have been tranquilized and their horns removed. Many rhino range states have stockpiles of rhino horn, which needs to be carefully managed.  
The African and the Asian rhinoceroses have some distinct characteristics. Morphologically, one obvious difference is that both African varieties have two horns in tandem, while the Sumatran rhino has two horns, but one typically is a stub, and the other two Asian types, Greater one-horned and Javan rhinos, have a single horn. Behaviorally, it has been found that African rhinos are more aggressive than Asian rhinos. African rhinos fight with their horns, using them to impale and throw their adversaries, while the Asian rhino fights with its bottom teeth, using them in a slashing motion. Their feeding habits vary as well. African rhinos feed low to the ground, whereas the Asian rhino browses on leaves that are higher.
The White Rhino has an immense body and large head, with a short neck and broad chest. This rhino can exceed 3,500 kg (7,700 lb), has 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 largest White Rhinoceros on record was about 4,600 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.
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), with particularly large rhinos weighing up to 1,800 kg (4,000 lb), and the females are smaller than the males. Two horns on the skull are made of keratin with the larger front horn typically 50 cm long (20 inches), but sometimes up to 140 cm (55 inches). Sometimes, a third smaller horn may develop. The Black Rhino is much smaller than the white rhino, and has a pointed mouth, which it uses to grasp leaves and twigs when feeding.
The Greater One-Horned (or 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 meters (5.75-6.5 ft). Female Indian rhinos weigh about 1,900 kg (4,200 lb). The Indian Rhino is from 3–4 metres (10 – 14 feet) long. The record-sized specimen of this rhino was approximately 3,800 kg (8,377 lb). The Indian Rhino has a single horn that reaches a length of between 20 and 100 cm (8 – 39 inches). Its size is comparable to that of the White Rhino in Africa.
The Javan rhino‘s body length reaches up to 3.2 m (10 ft), including its head, and is 1.5–1.7 m (4 ft 10 in–5 ft 7 in) tall. Adults are variously reported to weigh between 900–2,000 kg (2,000 – 4,400 lbs). Male horns can reach 26 cm (10 inches) in length while in females they are knobs or are not present at all.
Typically a mature Sumatran rhino stands about 130 cm (51 in) high at the shoulder, with 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 (2,200 lb). Like the African species, it has two horns; the largest is the front (25–79 cm or 10 – 31 inches) and the smaller is second, and is usually less than 10 cm (4 inches) long. The males have much larger horns than the females. Hair can range from dense (the most dense hair is 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. 
World Record Rhino Horns
According to a study by Dr. Nico van Strien in 2006, the longest rhino horn ever recorded was a 150 cm (59 inch) white rhino horn. This means the rhino’s horn alone was longer that the average adult pig! This horn was found before 1900 in South Africa and it was owned by Sir William Gordons Cummings, but according to the most recent information, the horn was stolen and its whereabouts are unknown.
The longest black rhino horn on record was 130 cm (51 inches) long; it was found in Kenya in 1928. The world record rhino horn for the Greater one-horned rhino is 57 cm (23 inches), and was found in Assam in 1909, and the world record Sumatran rhino horn is 60 cm (23 inches). Both of these horns are currently housed at the British Museum, which also has several Javan rhino horns.