1 August 2012
In Waterton Lakes National Park, Alberta, my students and I camped under the shade of cottonwood trees…
But some of the cottonwoods’ branches were looking a little thin… Caterpillars were munching on their leaves.
And some trees had been completely denuded by the voracious little larvae:
All three photos are taken on roughly the same scale (note the Moon as a reference point in each!).