Favorable weather along the monarch butterfly’s migratory route and in its U.S. and Canadian summer habitat have spurred one of the imperiled insect’s largest summer populations in recent years, raising conservationists’ hopes for a bumper population in the butterfly’s Mexican wintering grounds.  Citizen scientists and experts report large numbers of monarchs making the fall migration from the northeastern United States and southeastern Canada to their upland, oyamel fir (Abies religiosa) overwintering habitat in the Mexican states of Michoacán and Mexico. (A small percentage of West Coast monarchs also migrate to wintering grounds in California.) Based on fall migration counts taken so far, experts say, the winter population in Mexico will likely occupy some five hectares (12 acres) of forest this year, up from 2.48... [Log in to read more]