Answer:
The primary threat to the sulphur-crested cockatoo is the common farmer.
Sulphur crested cockatoos are prolific throughout eastern and northern Australia, in the country's most fertile agricultural areas. These birds are considered a pest, as they can descend on a crop and cause considerable damage.
Although sulphur-crested cockatoos are a protected native species, farmers with permits may shoot the birds or do whatever they deem necessary to protect their crops.