• Aaron Yetter

Aaron Yetter & aerial surveys: Ruddy ducks & more

In prime time with duck and Canada goose seasons opening on Saturday Illinois' central zone, here is Aaron Yetter's latest blog entry from his aerial surveys for the Illinois Natural History Survey. Survey numbers are posted at

The Illinois Department of Natural Resources links the surveys on their site at

Here is his blog:

October 22th, 2015 – Aerial Waterfowl Inventory Blog

The cold weather and north winds that passed through the prairies and Illinois during the weekend of October 9-11 brought some migrant waterfowl. Duck numbers in the Illinois River valley (IRV) jumped to 204,035 birds which was 32% above average for this time of year. The vast majority (77%) of these birds were non-mallard dabbling ducks comprised of pintail, shoveler, gadwall, wigeon, and green-winged teal. However, the ducks were not evenly distributed in the IRV; 43% were found within 9 miles of Havana at the Emiquon complex and Chautauqua NWR. Waterfowl abundance was 70% above average along the Mississippi River and estimated at 166,350 ducks. Like the Illinois, 76% of the total numbers were attributed to those non-mallard dabblers. Interestingly, we observed a record number (28,295) of ruddy ducks this week along the Mississippi. One impressive raft of ruddy ducks was observed between Nauvoo and Hamilton, IL. This weekend (October 24th) marks the duck season opener in the central zone of Illinois. Hopefully, the above average numbers of ducks will lend to some quality recreation for our central zone hunters. Good luck and be safe out there!

Just a reminder – we’ve started our second year of “grid” surveys along the Illinois River

so you may see the survey plane two days each week this fall. The Illinois Natural

History Survey and Illinois Department of Natural Resources are evaluating this

experimental waterfowl “grid” survey (1-mi2 plots) from Hennepin to Meredosia.

The new grid survey will allow us to determine the detection probability of observing

ducks from the airplane; which in turn will allow us to determine confidence intervals

about our estimates of waterfowl in the IRV. We will also be able to generate

“thunderstorm” maps from the data yielding a visual perspective of where the ducks

are in the Illinois Valley. For this reason, you may see us flying in locations outside

the 23 refuges of the traditional waterfowl survey. Please be patient with us as we

embark on this new survey design. For more information check out our

Research tab at

Stay tuned for more updates next week…….

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