Monarch Migration Update: February 14, 2013
Please Report
Your Sightings!
Report Your Sightings
The monarch's winter home in Mexico is surprisingly cold. Temperatures often fall to freezing! This week, explore how the cool habitat meets the monarchs' needs for survival. Estela tells about life for people in the region.

This Week's Update Includes:

Image of the Week
Monarch butterfly habitat in Mexico: Risks and benefits of cold?
Risks and Benefits?
Image: Dr. Lincoln Brower
News: A Critical Time is Passing
It's mid-February now and temperatures are starting to rise. Monarchs have survived the coldest part of the overwintering season.

"The 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."

Living in a Cold Climate
People are welcoming the recent change to warmer temperature says Estela Romero. Winter nights get cold because houses are not heated. When going to bed at night, people wear warm pajamas and pile blankets on their beds.

  • In this week's report, Estela visits the town market where children often help with the family business.

Today's Temperatures?
How are temperatures affecting monarchs today? You can track real-time weather information at the monarch overwintering region. Watch how temperatures change as spring migration approaches:

Graph of annual temperature in the monarch region
Temperatures Rising
Adapted from L.P. Brower
Seven blankets at night!
Seven Blankets!
Image: Estela Romero
Map of Monarch Butterfly Sanctuaries in Mexico
Monarch Sanctuaries
Slideshow: Temperature and Survival
It can be warm during the day at the monarch's winter home in Mexico, but at night it's as cold as the inside of your refrigerator. This slideshow explores a key question:

Essential Question
What temperatures do overwintering monarchs need to survive?


Journal page

The Migration: Maps and Journal
Seeing Monarchs or Milkweed?
Not all monarchs go to Mexico! Before spring migration begins, please help us document where monarchs are located this winter and where milkweed is available.


Seeing Monarchs?
When you see a monarch, we want to know about it.
Monarch butterfly migration map Map of milkweed emergence: Spring 2013

Map of Monarch Butterfly Sanctuaries in Mexico

(map | animation | sightings)
(map | animation | sightings)
The next update will be posted on February 21, 2013.