It’s estimated that a rhino is poached every 8 hours. At this rate, rhinos could become extinct in 15 years.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/nola-e1430856504251.jpg)
In total, there are less than 30,000 rhinos remaining on Earth.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/T07_0620_147-e1430857150735.jpg)
A group of rhinos is sometimes called a “crash.”
Rhinos may look indestructible, but their skin is actually quite sensitive, especially to sunburn and biting insects.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/mudbath-e1430856976395.jpg)
All rhinos are herbivores.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/sumatran-e1430857326341.jpg)
Rhino gestation lasts 15 to 16 months. The only animal with a longer pregnancy is the elephant.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/8207536616_56331a0728_b-e1430858153985.jpg)
Newborn calves are able to stand on their feet and start to nurse two to three hours after birth.
Because rhinos are very nearsighted, they often charge when startled; in the wild, rhinos have been observed charging at boulders or trees.
The biggest threat to rhinos is humans; civil war in their native lands and poaching for their horns has decimated wild populations.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/horn-e1430857542774.jpg)
Rhino horn is made of keratin, the same material as our fingernails.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/T06-0140-083-e1430857660361.jpg)
The demand for rhino horn has gone from subsistence hunting by locals to highly organized international crime rings.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/T15_0032_004-e1430862242647.jpg)
In 2014, the toll from poaching was the worst yet: a horrifying 1,215 rhinos were killed in South Africa.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/Angi-e1430857987832.jpg)
Close to 100 known rhino species have existed. Today, only five continue the line: two native to Africa (black and white) and three native to Asia (Greater one-horned, Javan and Sumatran).
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The rhino’s ancestors walked the Earth 55 million years ago.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/T09_0719_006-e1430857446332.jpg)
Black, white and Sumatran rhinos have two horns; Javan and greater one-horned rhinos have one.
Despite their name, black rhinos and white rhinos are the same color – brownish gray.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/14706927953_a6c6d810cc_o-e1430863672388.jpg)
Black rhinos can reach speeds of up to 40 miles per hour (64 kilometers per hour).
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/T08-0630-039.jpg)
Standing at up to 6 feet (1.8 meters) at the shoulder, white rhinos are the largest rhino species and the second largest land mammal.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/T11_0389_115-e1430864303239.jpg)
White rhino males can be persistent, with courtship lasting 5 to 20 days.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/9043725431_06bf8b63fb_b-e1430858346678.jpg)
There are only 3 northern white rhinos remaining on the planet.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/15595525775_da2f3abf33_o-e1430861583811.jpg)
The three Asian rhinos use enlarged incisors or tusks, rather than their horns, when fighting or defending territory.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/7228886450_a4a65b59bc_z-e1430862033529.jpg)
All three Asian rhino species are excellent swimmers.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/15259365665_b525994860_k-e1430859107109.jpg)
Sumatran rhinos are the smallest of the five rhino species and the only type covered with a coat of shaggy hair.
![25 Rhino Facts You Should Know](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/sumatran2-e1430859174531.jpg)
Through collaborative, science-based, multidisciplinary conservation efforts at the Safari Park, we have successfully added the births of 96 southern white rhinos, 70 greater one-horned rhinos, and 13 black rhinos to the worldwide population.
Lend a hand to save rhinos. Write “STOP KILLING RHINOS” on your hand and post your photo to Instagram or Twitter with the #Rally4Rhinos hashtag. Learn more HERE.
![#Rally4Rhinos](http://blogs2015.sandiegozoo.org/wp-content/uploads/2015/05/bws-e1430863890754.jpg)
Jenn Beening is a communications specialist for San Diego Zoo Global. See her previous post, Best of Vine: Safari Park.