Monarch Watch Blog

Fast-paced migration this year

Wednesday, September 9th, 2020 at 11:40 am by Chip Taylor
Filed under Monarch Migration | Comments Off on Fast-paced migration this year

If you are a monarch tagger located north of 35N (e.g. Oklahoma City), tag when you can. This will be a fast-paced migration compared to recent years. If you hesitate, you could miss the opportunity to tag.

Last year we experienced the latest migration in the last 28 years. It was too warm in the Upper Midwest with daytime highs in the 80s and 90s for much of the month. Monarchs prefer to migrate when the temperatures are in the 60s and 70s and that is what is shaping up for the Upper Midwest and much of the northern breeding area over the rest of the month.

Once this cold surge passes after Friday and Saturday, monarchs will be on the move. This migration will be more like those seen in the late 1990s and early 2000s in the northern breeding area. The population will advance at a steady pace into the South region and it is likely that this migration will be more compressed with few stragglers.

Thus, the opportunities to tag will be more limited than over the last 5 warm Septembers. This temperature shift also means that late developing monarchs will be left behind in larger numbers than in recent years. That happens, and there is nothing we can do about it that will affect the number of monarchs reaching Mexico. Monarchs have dealt with these swings in the weather for a very long time.

Enjoy the tagging and thanks for your assistance in helping us all learn more about the monarch migration.

Sorry, comments for this entry are closed at this time.