Monarchs on the Move!

It has been an interesting week if you have been following the BlūMorpho tagged monarchs at the overwintering sanctuaries in Mexico! If you aren’t familiar with BlūMorpho tags, the tiny solar radio tags allow the paths of individual monarchs to be detected; you can find more information in previous blog posts (Feb. 16).

I’ve been eagerly watching for northward movement by the monarchs tagged during the fall migration. I was excited to see movements by XSTI and JMU011. XSTI was tagged on Oct. 6 in Stillwater, Oklahoma. XSTI went undetected from Nov. 11 to Jan. 3 and then was detected multiple times in January. XSTI then traveled about 40 miles north on Feb. 20 before stopping at the northeast corner of the Monarch Butterfly Biosphere Reserve. XSTI was then recorded 35 miles west by the end of the day on Feb. 22:

JMU011 was tagged on Sept. 26 in Harrisonburg, Virginia then recorded just north of the Monarch Butterfly Biosphere Reserve on Feb. 20 and traveled about 68 miles to the northwest by the end of the day on Feb. 22:

And then, I noticed PP0017 and CHI007. PP0017 was tagged on Oct. 3 at Point Pelee in Ontario, Canada, while CHI007 was tagged on Feb. 11 at Sierra Chincua. They both ended up about 120 miles west from where they were last detected on Feb. 21 to where they were detected at the end of the day on Feb. 22:

That is a lot of westward movement! I previously posted about the challenging winds during the fall migration and there appear to be similar challenges in the spring. Stay tuned as we watch for path corrections and wait for the first arrivals in Texas. We will be learning lots from the BlūMorpho tagged monarchs over the next few months! Join us in following the spring migration in real time using the free Project Monarch Science mobile app (download via your device’s app store).

These detailed insights into monarch biology are possible thanks to the Project Monarch Collaboration, which is led by Cellular Tracking Technologies (CTT) and the Cape May Point Arts & Science Center (CMPASC). More than 25 organizations make up the Project Monarch Collaboration:

Logos of 2025 Project Monarch Partners.