December 20th aerial survey

We flew the waterfowl inventory on Tuesday, December 19th . Nearly all of the ice that formed over the last couple of weeks was gone, and we still had a bunch of ducks around for the 3rd week in December. We estimated 184,710 total ducks in the Illinois River valley, which was 31% down from last week but 30% above the 10-yr average. Similarly, mallards (153,935) were down 22% from last week but still 35% above the 10-yr average. Total ducks (796,480) on the Mississippi River dropped 8% from last week but were 142% above average. Likewise, mallards were abundant (417,185), especially in St. Charles County, MO, and were nearly double (96%) the 10-yr average.

However, the real story this week was the huge number of canvasbacks observed on Pool 19 of the Mississippi River. We estimated 246,125 canvasbacks between Nauvoo, IL and Fort Madison, IA. This raft of ducks stretched 5 miles in length and in spots approached a mile wide. This was a phenomenal number of canvasbacks when you consider this year’s breeding population of canvasbacks from the U.S. and Canada was estimated at 732,500 ducks. Even when we consider this year’s recruitment of ducklings, we very likely have less than 1 million birds in the population. So, this impressive raft of canvasbacks likely exceeded 25% of our continental population of canvasbacks. Now that’s a bunch of divers!

We tried to capture a video of the canvasbacks with a cell phone (What would we do without cell phones?). I will post the video on the Forbes Biological Station Facebook page for your viewing. Sorry for the bouncing video but that’s what it is like in the plane! Enjoy! Thanks to Joe Lancaster for the video!

Stay tuned for more updates next week…