Bristol Zoo's baby gorilla Kukena holds onto his mother's arm as he ventures out of his enclosure at Bristol Zoo's Gorilla Island on May 4, 2012 in Bristol, England. The seven-month-old western lowland gorilla is starting to find his feet as he learns to walk having been born at the zoo in September. Kukena joins a family of gorillas at the zoo that are part of an international conservation breeding programme for the western lowland gorilla, which is a critically endangered species. (Photo by Matt Cardy)