The world’s population of rare greater one-horned rhino’s has just got a tiny boost, after Asha, at Chester Zoo in the UK, gave birth to a male calf.The vulnerable species had as few as 200 members at the end of the 20th century, the World Wildlife Fund said, but numbers worldwide are now at around 3,500.The zoo reported that labor took just 20 minutes after a 16-month gestation period.Video from the zoo shows the calf up and about and taking his first steps shortly after the birth. Credit: Chester Zoo via Storyful