We captured and radio-tagged 29 harbor seals in spring 2001 in Chatham, MA, and off Rockland, ME. Male and female seals of all ages were captured in Chatham, compared to mostly juveniles in Maine. Seventy-five percent (9/12) of the Chatham seals moved to the Maine coast in spring and summer during the pupping, breeding, and moult seasons. Similarly, seventy-one percent (12/17) of seals tagged in western Penobscot Bay remained in the mid-Maine coastal region during these seasons. These short-term movement patterns suggest that Penobscot Bay may be the source for some of the seals overwintering in southern New England.