Jim Cronin started working with primates by working as a zoo keeper in various zoos. He came to the UK, where he got a job as a zoo keeper at John Aspinall's zoo at Howletts, where he perfected his skills of primate rehabilitation and care, in 1980. John Aspinall had set up a breeding programme for gorillas which were an endangered species. Jim Cronin's passion for working with primates made him quite successful in his career and encouraged him to wish to eventually build a safe haven for primates that were treated badly. During his years working at John Aspinall's Zoo, he gave himself the necessary experience of dealing with apes on a daily basis in his career path of working with them as well as small monkeys and their complex life needs.