BAR HARBOR — College of the Atlantic’s George B. Dorr Museum of Natural History opens two new exhibits, on Monday, May 21 with a reception from 4 to 5:30 p.m.: “The Human Ecology of Weeds” by Meg Trau and a large-scale painting of Little and Great Duck islands, “The Duck Islands: A Study of Museum Diorama Painting,” by Becca Berezuk. Both are senior project exhibits.