Near the end, Tim's on the computer and watches as three raptors jump up on the balcony (p. 349) Now skip ahead to when Grant's in the hatchery with the THREE raptors. On page 356 after Grant thinks 'That's one' In the next paragraph, it says 'One cocked its head, then another, and another' Add 'em up, that's three, plus the dying one which makes four raptors.