The butterflies are kept in an envelope in a cooler while waiting to be tagged. In this pic the naturalist is demonstrating how a small amount of the butterfly's scales are removed (with a lovely painted fingernail) in order to make room for the tagging sticker to be attached.
She explained that each tag has a unique number and the address where to send the butterfly (or the tag) should it be recovered. 3M makes the stickers just for tagging and they don't hinder the butterfly's ability to fly at all.
Each butterfly is weighed and measured and a general assesment of its body condition is made. All of this info is recorded along with the tag number. With that, the butterfly is ready to be released and to resume its journey to Mexico. All that is needed is a cute little girl with nimble fingers.
The hand off. Ready...
The monarch lingered for a moment or two on the little girl's palm before flying to the shrubbery nearby to warm in the sun.
Yearly counts and census info, as well as a brief history of the project, is available from NJ Audubon at this link. Certainly worth a read if you're interested in more information.