Science News Article on Monarchs

[Sunsol Daniels]

Hi!

Did anybody read about this amazing new tagging effort?  Instead of using 
tags applied by humans, they are using naturally available water tags.  
Water in different parts of the country has different amounts of 
deuterium.  The plants take it up, the caterpillars eat the plants, and 
then they are marked.  By sampling the isotope tag of the overwintering 
adult, scientists can figure out where it spent its caterpillarhood.

s