Male giraffe's age can be predictable by just looking at their coat, according to a research.
Researchers from the Primate Research Institute and Wildlife Research Centre, Kyoto University, Japan have discovered that giraffe's brown patches darken with age.
Researchers had been documenting giraffe since it first became a park ranger in the 1970s. Now after several decades, scientists have got link between the giraffe age and patches.
"It's pretty amazing that he's simply written down tons of stuff for over three decades that we are now able to turn into scientific papers," the BBC has quoted Fred B. Bercovitch, professor at the Primate Research Institute, as saying.
Researchers believe that all the species of giraffe are known to develop darker brown coats as they become older but the exact timing of the changes were unknown. Until now, researchers claim that darkening patches in male giraffes coat could be associated with changes in testosterone at puberty. Male giraffe reach sexual maturity at the age of 10 years.
"Given the timing of the darkening, my hunch is that it's linked to testosterone upsurges associated with puberty," said Prof Bercovitch.
Researchers found that male giraffe coats first started to change colour at seven to eight years of age and brown blotches transformed to coal-black within some years.
"I suspect that the blackening of the blotches is a public announcement to the other giraffe that a male is going through puberty; something like adolescent boys flexing their muscles to impress the opposite sex," said Prof Bercovitch.
Generally, male giraffe is around 16 to 18 feet tall and it weighs around 2000 pounds. Female giraffes usually have light patches and they are about two feet shorter compared to the male giraffe. Giraffe inhibits in savannas, grasslands, open woodlands. They usually prefer plenty of acacia trees to eat.
Female giraffes conceive for the first time in their fifth year. With a gestation period of 15 months, a mean interval between births of 20 months, and a maximum longevity of 25 years, a cow may produce up to 12 calves in her lifetime. Newborn calves usually stand 6 feet and weigh approx. 150 lbs. After being dropped about 6 feet to the ground, they stand on wobbly legs about 20 minutes after birth and begin to nurse within 1 hour. Male calves are weaned at about 15 months, female calves a couple of months later, according to Honolulu zoo researchers.