Birthday celebration: Saturday, March 12 - The Patuxent Research Refuge will be celebrating the 102nd birthday of the National Wildlife Refuge System from 10 a.m. to 3 p.m. at the National Wildlife Visitor Center, off Powder Mill Road in Laurel. Activities will include live animals, tram tours, guided hikes, puppet shows and children's activities. 301-497-5760 or http://patuxent.fws.gov.