PORTLAND, Ore. (AP) - The only moose herd in Oregon appears to have doubled in size in recent years, despite deaths in recent years from a parasite. The herd numbers about 60 animals today, compared to 30 in 2006. The carotid worm problem was discovered in about 2010 when biologists captured a moose in Wallowa County to fit it with a radio collar. The moose died as it was being captured. The worms were found during a necropsy. The moose are the smallest subspecies in North America, with females weighing up to 800 pounds and males weighing up to 1,000 pounds. Alaska and Yukon moose are the largest subspecies in North America, weighing about 1500 pounds.