|Estela Romero reports from the monarch overwintering region:
"We continue to have terribly rainy, gray, cold days! The sanctuaries are practically without tourists. Last weekend, with a little rain and soft hail falling, I went up to the sanctuary to conduct an interview for you. I hope you enjoy seeing how some local people work with the monarchs!"
This graph shows average low temperatures at the overwinering sites. Now that it's mid-February, monarchs
have survived what's typically the coldest part of the winter season.
really critical time for the monarchs is January and early February,"
says Dr. Lincoln Brower. "The lethal combination for the butterflies is to be wetted by a winter storm, and then subjected to freezing temperatures caused by intense radiant heat loss when the sky clears."
Counting Cold Fronts
The 34th cold front of the season entered Mexico this week. How can cold fronts affect overwintering monarchs? They can bring cold, polar air masses into central Mexico. Cold air, interacting with moisture from the Pacific, often results in sub-freezing temperatures, wind, hail, snow and ice in the butterfly colonies. Meteorologists predict Mexico will have 50 cold fronts this season. Watch the weather maps. How many more fronts will reach the monarch region?
Risks and Benefits?
This picture reveals clues about ways cold can affect monarchs. Why are so many on the ground? Are they in danger? This week, learn about the risks monarchs face—and the benefits they receive—from their cold winter habitat.