Five years ago my wife and I joined other local citizen scientists at Willow Lake for an enjoyable afternoon catching and tagging monarch butterflies. The tags are small stickers with ID numbers. They don't impair the butterfly's ability to fly, but they do let us humans track where they fly to!
 |
| A monarch in the hand. |
The Southwest Monarch Study group recently updated their map showing the location of recovered tags. The straight lines indicate starting and ending locations, not necessarily the meandering paths monarchs take to migrate across the landscape.
 |
| Image from Southwest Monarch Study. |
Over the ensuing years, those tagged butterflies have turned up as far away as the monarch's overwintering grounds in Mexico. Interestingly, they also visit California overwintering sites. Most monarch populations can be neatly divided into Eastern and Western populations based on where they spend the winter; Eastern go to Mexico and Western go to California. But it seems AZ monarchs can go to either, which raises the fascinating question: how do they decide where to go? Is AZ a meeting spot for different populations, and each return to their home wintering sites, or is AZ a melting pot, a single population where individuals decide each year where to overwinter?
Hopefully this citizen science research will help resolve some of the question marks on monarch migration maps.
 |
| Monarch migration map from Xerces. |
 |
| Monarch migration map from Monarch Watch. |
No comments:
Post a Comment