A 700lb or 900lb gorilla would be equally entitled to sleep wherever he wants to. Interestingly, the Wikipedia entry for Gorilla states that the average male gorilla weighs about 400lb, occasionally reaching 500lb in the wild. Only obese gorillas in captivity have attained weights of 600lb. So the number doesn't even seem to be related to gorilla biology (except that it is safely larger than any known gorilla, save King Kong).