Based upon the Journey North reports of high hundreds or thousands of clustering monarchs in the Bt corn and Roundup Ready soybean growing regions of southern Minnesota, Iowa and neighboring States last September I thought the overwintering populations in Mexico this winter would be the same or higher than in 2007. I recently received the following report written by Biologist Meza Felipe Martinez, assigned to the area of Biodiversity Research and the Management of the Reserve of the Monarch Butterfly Biosphere in Mexico:
"During this season of hibernation there were 11 colonies of Monarch butterfly that occupied 5.06 hectares of forest in the states of Mexico and Michoacan which represents an increase of 8.89% compared to 4.61 hectares in December 2007. Again this year there were colonies at San Francisco Oxtotilpan and Contepec. The colony with the largest occupied area was the Ejido El Rosario with 2.37 hectares followed by the colony Cerro Prieto in the Sierra Chincua (1.0 hectare). Notable is the absence of colonies was the region of Cerro Pelon, compared with the previous season, because in this season only the colony in Ejido Nicolas Romero was occupied. During this season there has been significant frost, but with no rain or winter storms, which has contributed to the good of the populations of the butterfly."