Said the FAA spokesperson, in an email to Huffpost, "The FAA can't stop people from throwing live turkeys out of planes....Federal Regulations do not specifically prohibit dropping live animals from aircraft. This does not mean we endorse the practice...."
FAR §91.15 Dropping objects.
No pilot in command of a civil aircraft may allow any object to be dropped from that aircraft in flight that creates a hazard to persons or property. However, this section does not prohibit the dropping of any object if reasonable precautions are taken to avoid injury or damage to persons or property.