10 Nov '11, 10pm
Monarch butterflies decline at wintering grounds in Mexico, Texas drought adds to stress to migration via @mongabay
Monarch butterflies decline at wintering grounds in Mexico, Texas drought adds to stress to migration Sarah Jane Keller, special to mongabay.com November 10, 2011 Every fall, millions of monarch butterflies travel south to Mexico and take refuge in twelve mountain sanctuaries of oyamel fir forests. Now, declining numbers of the overwintering butterflies expose the migration’s vulnerability and raise questions about threats throughout the monarch’s lifecycle. A study published online last spring in Insect Conservation and Diversity shows a decrease in Mexico’s overwintering monarch butterflies between 1994 and 2011. The butterflies face loss of wintering habitat in Mexico and breeding habitat in the United States. Extreme weather, like winter storms in Mexico and the ongoing drought in Texas, adds yet another challenge. The seeds of the decline date back more than 40 years ...