More Monarch butterflies appear to have made the long flight from the U.S. and Canada to their winter nesting ground in western Mexico, raising hopes after their number dropped to a record low last year. But experts still fear that unusual cold temperatures will threaten the orange and black insects.
While an official census won’t be ready until mid-January, observers are seeing healthy populations of butterflies bunched together on fir and pine trees in protected sanctuaries, said Gloria Talavera, director of the official monarch butterfly reserve.
