Rare twin giraffes born in Kenya

Twins have been born to a Maasai giraffe in Nairobi's national park, which Kenyan wildlife minister Najib Balala described as "an extremely rare occurrence" as he posted a picture of the mother watching over her offspring.

The world's tallest species is listed as "vulnerable to extinction" by the International Union for Conservation of Nature.

Only about 117,000 remain in the wild, and numbers of the gentle long-necked giant have plummeted by 30 percent in 30 years. Kenya is home to three subspecies of giraffe: Maasai, reticulated and Rothschild.

At 15 months, giraffes have one of the longest gestation periods for mammals. They give birth standing up, which means calves fall nearly two meters to the ground. This startling introduction to life gets them up and running around within an hour.

Only a handful of twin births have been documented, with most calves not surviving to live for up to 25 years.