Flight of the Monarchs

Several years ago I discovered a citizen science group called Monarch Watch that is "dedicated to education, conservation, and research" of the monarch butterfly.  What I was really excited about was that I could purchase tags to put on migrating monarch butterflies!  Tagging monarchs was nothing new to me.  I spent several years in graduate school banding birds.  This included spending three months as the songbird banding intern at Kiptopeke State Park on the Eastern Shore of Virginia; the group that runs the banding station also employs a monarch tagger.  I guess I just kind of assumed that tagging butterflies was similar to banding birds.  Bird capture and banding requires permits.  I was thrilled that tagging butterflies does not!  I've missed bird banding, and tagging butterflies has been a wonderful alternative.

Tagging allows Monarch Watch to track monarch movements and migration (each year monarchs from portions of Canada and the northern United States east of the Rocky Mountains migrate to Mexico).  When a butterfly is tagged the tagger records the tag number (each tag has a unique combination of 3 letters and 3 numbers), the date the butterfly was tagged, the sex of the butterfly (males have scent glands on their hind wings, females do not), whether the monarch was captured as a wild butterfly or raised from the egg or caterpillar stage, and where it was tagged.  The tag also lists a telephone number and an email address where a person who might find the butterfly later can contact Monarch Watch to give them the tag number and let them know where the butterfly was recovered.  This fall Addisyn and I tagged 50 butterflies.  During the last 2 days before our tags ran out we tagged 31 monarchs!

Obviously there were a ton of monarchs around during our last two days of tagging.  Each day we were seeing hundreds of butterflies.  I was so excited to have found my first roost!  Butterflies do not maintain a constant body temperature, rather they rely on their environment to keep them warm enough to fly.  So, in the evening as the temperature drops and the sun goes down monarchs land in trees and stay there throughout the night, often in groups - this is called roosting.  The first roost I found consisted of about 30 monarchs in a single tree - I was thrilled!  

Two days later I found a HUGE roost!  During an evening walk I spotted a bush with close to 100 monarchs on it.  I returned just as the sun was coming up the following morning and the bush was empty, but there were at least 200 monarchs in the trees surrounding the bush!  I think I spent a good hour and a half down there watching the butterflies warm up and being to take flight.  Some simply opened and closed their wings a few time before taking flight, others spent several minutes "shivering" their wings in an attempt to warm themselves up.  Of course the butterflies on the sunny side of the trees were the first to take to the air.  As I watched, many of the monarchs from the shaded portions of the trees warmed up enough to fly, and then flew around to the sunny side of the trees to spend some more time warming themselves.  The next morning there were only 2 monarchs there.