Federal and state wildlife officials are investigating after a dog killed a protected piping plover chick on a Scarborough beach. A spokesman for the Maine Department of Inland Fisheries and Wildlife says a woman spotted an unleashed dog on Pine Point Beach on Monday morning approaching a plover nest. She warned the dog’s owner, who allegedly paid no attention, allowing the dog to kill a chick. The witness brought the chick to The Audubon Society, but volunteers there did not get her name. Plovers are endangered and protected under federal law. Authorities want to talk to the witness because the dog’s owner could face charges.