Regarding the first sounds of tree frogs last year, I read my notes wrong. I had written 22 July 08, but somehow read that as July 8. If you saw my notes, written on the corner of an envelope, you would understand how that could happen.

 

This relates to climate change in an obvious way: if the event is later this year than last year, that might be a sign of a cooler summer, assuming there needs to be a certain number of days in which the air temperature reaches a certain level in order for the frog chorus to begin. (I think climatologists refer to this as degree-days.)

 

So the date to watch for, at my location near the center of Des Moines, is July 22.

 

Phenology, as I'm sure you all know, is the study of the dates when natural events occur during the year; events such as buds on oak trees opening in the spring. Not to be confused with phrenology, a discredited pseudo-science popular in the 19th Century that supposedly enabled "experts" in the field to derive information about a person's character from the shape of the bones in their cranium.

 

By the way, Aldo Leopold kept excellent phenology records at his farm in Wisconsin back in the 1930s and '40s that are proving useful today.

 

I hope to be able to keep you all posted on the tree frog singing this year.

 

Tom