Sunday, March 25, 2012

March Madness - Eary Arrival of Anax junius.

Unless you have been living in a cave, you have to be amazed by the warm weather we have been getting in the Great Lakes region this year. I have not examined the data, but from November through February it has been far warmer than typical in Michigan. In January, we had days in the 50s, and rarely did we have snow for more than a few days anytime during the winter. March as been phenomenal as well. We have had a stretch of days when it has been over 70 degrees F, sometimes reaching into the 80s last week. Plants grow and flower according to accumulated degree days, so it is no wonder that our flowers and shrubs are already at a point where we would see them in mid to late April during a "typical" year. At the same time, many ode watchers were wondering when the first Common Green Darners (CGD), Anax junius, were going to arrive. During a "typical" year, we start seeing CGDs around mid-April. Usually, it is some warm front pushing infrom the S, bringing CGDs with it. This year, we are about 2 to 3 weeks earlier, as the map below shows with green dots for the locality, and the date of observation. Considering that one has to be out at a pond to see Anax junius, it is possible that there are some even earlier arrivals that just were not observed. In my case, I saw at least four at a small pond in Pittsfield Twp., with one pair in tandem, and the female was ovipositing. That was on Friday, March 23, the first day when I had a chance to be outside in the middle of the day at a place where I could look for CGDs. I expect that they had arrived there at least a few days earlier, given that the temps had been above 70 all week.

Thanks to Carl Freeman for the Benzie Co. data, Jeff Sommer for the Saginaw Co. data (and the nice photograph of A flying Anax junius), and Julie Craves for passing along the Wayne County record. At some point, we will compile a list of earliest records for Anax junius, but I suspect that these late March records will hold up for some time.

Keep watching and recording!

1 comment:

Darrin O'Brien said...

I finally saw my 1st on 4/12/12 and vouchered one in Oakland County today (4/13/12).