At more than 140 years old, Hong Kong zoo is home to almost 400 animals, including three-year-old twin orang-utans and one very bored-looking sloth. Little seems to have changed since the Hong Kong Zoological and Botanical Gardens' inception in 1871, according to the Society for the Prevention of Cruelty to Animals. But the city is studying how to modernise it. "It's like a menagerie from the turn of the last century," said Dr Jane Grey, the deputy director of the SPCA. "The facilities are very outdated, inadequate and overcrowded."