Complex sentence: Its headquarters are at Les Augrès Manor on the isle of Jersey in the English Channel, where what was originally called the Jersey Zoo, now the Durrell Wildlife Park, was established by Gerald Durrell in 1959 as a sanctuary and breeding centre for endangered species.
Split into simpler sentences: Its headquarters are at Les Augrès Manor on the isle of Jersey in the English Channel. The grounds of Les Augrès Manor form the Durrell Wildlife Park, which originally established by Gerald Durrell in 1959 as a sanctuary and breeding centre for endangered species.