Due to some technical delays we missed some of Aaron Yetter’s earlier blogs off the long-running aerial waterfowl surveys. But we get started again with his latest and it includes some interesting insights on the movement of ducks off the water and the meaning of radar to waterfowl migration.
Here is Yetter’s latest blog:
November 8th, 2019 – Aerial Waterfowl Inventory Blog
We flew the waterfowl survey on Tuesday, November 5th, 2019. Weather radar indicated a large movement of birds out of the Illinois River valley (IRV) on Monday evening (November 4th) shortly after sunset. Total duck abundance was up 11% from the previous week and stands at 250,455; however, we are down 36% from the 10-year average (393,373 ducks). The Mississippi River was up 19% from last week, and we estimated 212,970 ducks. Like the IRV, total ducks were down 37% from average (339,497) for the first week of November.
Weather radar indicated another big movement of birds out of the IRV on Thursday evening (November 7th) as illustrated by Dr. Ben O’Neal at Franklin College in Indiana (https://www.facebook.com/134920053228058/videos/1380611302098987/?q=franklin%20college). Dr. O’Neal is a former graduate student of the Forbes Biological Station and University of Illinois. Ben’s Ph.D research investigated using weather radar to track movements of waterfowl. Thursday’s radar also revealed the departure of ducks from the Grafton area near the confluence of the Illinois and Mississippi rivers. The green colors on the radar are actually birds departing the refuges. Current weather patterns are putting these ducks on the move. Let’s hope more are arriving from the Prairies than are departing for warmer areas to the south.
This week we observed an increase in the number of diving ducks along both rivers. In fact, lesser scaup numbers increased to 19,500 along the central Mississippi River. We found the largest concentration of scaup at Henderson Creek Conservation Area just south of Oquawka, IL. Ring-necked ducks jumped this week as well. We estimated over 11,000 at Chautauqua NWR and 30,000 ring-necks at Two Rivers NWR near Grafton, IL. As you can see in the photos, diving ducks differ from dabbling ducks in that they need a running start on the surface of the water before taking flight. Dabbling ducks spring from the water and are able to take flight a little quicker than divers. The photos show the ripples from the dark colored ring-necked ducks as they scamper across the water’s surface. Northern pintails don’t leave the water trail as they flush up from the water.
I wish you the best of luck in the duck blind. Stay warm! It looks like it will be a cold one next week. For more information about the waterfowl survey, check out our webpage at www.bellrose.org. Stay tuned for more updates next week…….
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