Five Rhino Facts with IRF’s New Communications Director
By Jim Cronin
Rhinos are evolutionary wonders. From skin that can be two inches thick to their iconic horns and massive size, there’s a lot to know about the five species of rhino.
As IRF’s new Communications Director, I’m excited to discover everything I can about the amazing animals we work every day to protect. Here are five topics I was interested in learning more about.
Q: What purpose do rhino horns serve?
A: We all know rhinos have horns, and they play an important part in their lives. Black, white and Sumatran rhinos have two horns, while greater one-horned rhinos (obviously) and Javan rhinos have just one. Rhinos wield their weaponry in defense against other rhinos in disputes over territory, as well as against would-be predators. Which leads to my next question …
Q: Do rhinos have predators?
A: Some rhino species can weigh more than 6,000 pounds and run up to 34 miles per hour. Along with their thick skin and horns, adult rhinos are nearly impervious to attack. Adult rhinos have no natural predators – except humans looking to kill them, cut off their horns and sell them to the highest bidder. However, rhino calves are vulnerable to predation by lions, crocodiles, tigers, hyenas and wild dogs, especially if they become separated from their mothers.
Q: How big are rhino babies when they are born?
A: They are very big! Weighing from 100 to 150 pounds at birth, white rhino newborns are among the world’s largest terrestrial mammal babies. Greater one-horned rhinos also weigh anywhere from 100 to 150 pounds when they are born. Black rhino calves are around 75 to 100 pounds at birth. Newborn Javan rhinos tend to weigh between 85 and 140 pounds, while Sumatran calves are 90 to 110 pounds at birth.
Q: Why do Sumatran rhinos have thick coats of hair when the others don’t?
A: Critically endangered Sumatran rhinos, the smallest of all existing rhinos, have an estimated 34 to 47 individuals left in the world, according to data from the International Union for Conservation of Nature. While most rhinos have some hair, Sumatran rhinos are covered with long hair at birth. Scientists think that could be because they are more closely related to extinct woolly rhinos than any of the other four rhino species alive today. The dense coat Sumatran rhino calves are born with eventually becomes more sparse as they age.
Q: What do rhinos eat?
A: Rhinos are herbivores, so they only eat plants. They are among the largest land animals in the world and are considered “megaherbivores.” Rhinos and similar megafauna are so large and eat so much that their feeding habits have a major impact on the structure and function of the ecosystems where they live. These ecosystem engineers create and maintain habitats for other species. They create water holes and mud wallows that provide water and mud for other animals. Their hungry grazing creates and maintains short-grass lawns that benefit species that rely on those habitats.
White rhinos are known as grazers and can feed on grass all day thanks to their wide squared lips. Black rhinos are browsers that eat leafy plants, foliage from low-growing trees and bushes, shoots and fruit. The browsing Sumatran rhino forages for a variety of foods including fruits, leaves, twigs and bark. As primarily browsers, Javan rhinos have a varied diet of shoots, fallen fruit, twigs and foliage, along with grasses. Finally, greater one-horned rhinos are primarily grazers that feed on tall grass, aquatic plants, farm crops, fruits and leaves.
To learn more about the five rhino species, click here. If you’d like to join the fight to protect these incredible animals, please consider supporting our work.