MEMPHIS, Tenn. (AP) - The Memphis Zoo is celebrating the birthdays of its two polar bears, "Payton" and "Haley." The zoo says a birthday party is planned for Saturday at the Northwest Passage exhibit. The celebration includes readings of the book "Snow Bear," a polar bear feeding and a birthday card signing. Payton, a male, turns 10 years old on Friday. Haley, a female, will be 11 years old on Nov. 15. The birthday celebration is part of Polar Bears International's polar bear week.