Monarch Butterfly Migration News

Monarch Butterflies

Departure Imminent
March 9, 2017 by Elizabeth Howard

As the monarchs prepare to depart for spring migration, tags and wings are being recovered for clues about where the butterflies originated last fall.

"The flying and constant bursting were spectacularly fantastic. I cannot find any other words to describe this weekend’s experience," wrote Estela after her visit to Sierra Chincua on March 5th.

Collecting Tags and Wings
This week, Estela accompanied Monarch Watch volunteers to collect tags. New this year, the wings are also being collected for research. Volunteer Diane Pruden describes the process:

"Over the winter, local people comb the forests and look for dead monarchs with tags. The tags are then removed and each person has a different method of storing them." Read more...

News From the Sanctuaries
Colony break-up is underway as monarchs continue to move down the mountains in search of water. It was last year at this time — as the monarchs were about to depart — that the devastating late-season storm struck.

Estela visited four sanctuaries last week with the team. She said the butterflies at Sierra Chincua were truly stunning.

"As we reached the center of the colony, we got paralyzed. One could not believe one’s eyes. I last saw this huge population in Sierra Chincua years and years ago now." Read more...

Cerro Pelon Sanctuary
Ellen Sharp, who lives and runs a hotel near the sanctuary, shares her impressions of the season. The monarchs appear to have started a slow, staggered departure.

"Overall higher temperatures have left us asking if our colony will stay with us until the March 20 equinox as it has in seasons past." Read more...

Get Ready for Migration!
On March 1st, Estela sent this exciting news:

"I need to tell you while driving from Querétaro to Angangueo we saw perhaps a couple dozen monarchs flying north! They were already 80 km (50 miles) from the sanctuary!"

Tag — and Wing!

Monarch Butterfly Tags Found at Mexico Overwintering Sanctuary

Tag Found

Monarch butterfly at sanctuary in Mexico in snow.

Letter from Estela

Letter from Ellen Sharp at Cerro Pelon

Research and Conservation: Wings Reveal Origins

Using wings collected at the sanctuaries, researchers discovered where overwintering butterflies in Mexico originated. Their map shows the proportion of butterflies from six breeding regions in the U.S. and Canada. Lead author Tyler Flockhart was surprised by the findings:

"We expected the vast majority of monarch butterflies to be found in the Midwestern states. However, just 38 per cent come from that part of the U.S.A. If we just focus conservation activities on that area, our research shows we will be missing a large number of butterflies born elsewhere in North America."

Wings Reveal Origins of Monarch Butterflies Overwintering in Mexico

Origins Revealed
Map | Journal

If you were a monarch biologist, how would you use this map for conservation planning?

Report Your Sightings


Report all monarchs you see — adults, eggs, larvae.

What to Report	Adults report \| map \| list	Eggs report \| map \| list

Larvae report \| map \| list	Milkweed report \| map \| list	Other Observations report \| map \| list

Next March 16, 2017