Monarch Migration News: January, 2015
By Elizabeth Howard
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Your Sightings!
Report Your Sightings
The overwintering season in Mexico is now underway. Scientists measure the population in late December and announce the results by March. Will the population have increased from last year's record low?

Monarch Butterflies
November 16, 2014    El Rosario Sanctuary    Estela Romero

News: Waiting for Population Measurements
An Increase Predicted
The results of the annual population measurements — taken in late December — are typically released by March. We predict the population will have doubled from last year's record low, based on this fall's migration data and from overall impressions during the breeding season.

A Lucky Break
Weather conditions during this year's breeding season were ideal, following the two bad years that led to the population crash. If this year's population does double — to 66 million butterflies — it would still be only 20% of the long term average.

How Many Needed?
If last year's record-low population had encountered poor breeding conditions, we don't know if the population could have recovered. What does the target population size need to be to preserve the migration? Scientists simply don't know the extinction threshold.

Monarch Butterflies
Population Size
Monarch Butterflies
Wintering Sites
Winter in Mexico: Month-by-month Highlights
November   December
Monarch Butterflies arriving in Mexico   Scientists visit the 12 wintering sites and measure the surface area the colonies cover.
Throughout the month, monarchs continue to arrive from the north and settle in at the 12 traditional wintering sites.
  Being Counted
Scientists visit the 12 wintering sites and measure the surface area the colonies cover. Results will be released by March, 2015.
January   February
Monarch Butterflies wintering in Mexico   Monarch Butterflies wintering in Mexico
Surviving Cold
Watch the weather! At this coldest time of year, monarchs are at the greatest risk of mortality from deadly winter storms.
  Preparing to Migrate
Monarchs that survive four winter months will mate and begin the journey north in March. Join us for weekly updates on Feb. 5, 2015.
Maps: Report Your Sightings
Please continue to report your sightings. Help document how long fall migration lasts and where monarchs found this winter.
Winter Monarchs?
When you see a monarch, we want to know about it.

What to Report to Track Fall Migration

Monarch Butterfly: Adult Sighted Monarch Butterfly: Egg or Larva Sighted
What to Report Adult Butterflies
map | list
Eggs and Larvae
map | list
Monarch Butterfly Migration Map: Fall Roosts, Fall 2014 Monarch Butterfly Migration Map: Peak Migration Fall 2014 How You Can Help
Fall Roosts
map | list | archives
Peak Migration
map | list
Journal and Activities
  • Slideshow: Why So Special for Monarchs?
  • Journal: Why important to conserve oyamel forest?
  • Journal: Explore monarch overwintering region.
Next Update February 5, 2015