Monarch Butterfly News: August, 2013
Please Report
Your Sightings!
Report Your Sightings
Get ready for fall migration! With low numbers this breeding season, how many monarchs will be migrating to Mexico?

This Month's News:

Image of the Week
Monarch Butterfly laying egg on milkweed
Migration Season
Image: E. McCormick
Fall Migration Starts in August
On August 1st, we open the Journey South database for sightings. When you see a monarch—nectaring, flying, roosting, or breeding—we want to know about it.

Note: Report any monarch you see. You do not need to know whether or not it's migrating.

What to Report to Track Fall Migration
Spotlight: Where Are the Monarchs?
Monarchs have been scarce this summer across their breeding range. Many people didn't see their first monarch of the year until July. Two key factors led to this situation:

1. Record Low Last Winter
There were only 60 million monarchs wintering in Mexico last winter, 80% below the 350 million monarch average. The area of forest covered with monarchs was only 3 acres, compared to the 17-acre average. Why so few? Drought and excessive heat during summer 2012 resulted in low reproduction last year.

2. Cold Spring, Slow Migration
This spring's unusually cold temperatures across the middle section of the country delayed the migration northward. The season's first monarch generation was slow to develop in the southern U.S. and late to migrate northward.

What's Happening Now?
Low numbers, cold temperatures, and slow spring migration meant few monarchs across the north in June. The trend continued throughout July. Monarchs must have a productive breeding season this summer for the population to recover.

Summer Breeding
During the breeding season, monarchs can produce a new generation in about 30 days, resulting in four generations. The monarchs that migrate to Mexico this fall will be the great-great-grandchildren of those who left Mexico last spring.

A Missing Generation?
By arriving late this spring across their breeding range, monarchs may not have time to complete four generations. Since numbers increase with each generation, this could result in a small fall migration and low numbers in Mexico again next winter.

Let's see what happens when the migration season begins. Please report your monarch sightings to help document the status of the population.

Monarch Butterfly in Texas
Record Low Last Winter
Monarch Butterfly Development Time: Life Cycle Timing
Cold Spring
Monarch Butterfly egg

Monarch Egg
Image: Holli Hearn

Monarch Butterfly eggs in New Jersey
Annual Cycle
First Fall Update August 22, 2013