Saturday, March 31, 2012. 1:15-2:30 pm. Overcast. Temperature 58 degrees F. Moderate breeze from the south. A thunderstorm Thursday evening about dumped about an inch of rain on the park. The shallow pond in the middle wetland complex that has been nearly dry most of the winter now is about half full. However, the water level is not yet high enough to flow into the south lake. The south lake has risen about 6 inches since I was last here but no water is flowing through the outlet to the Skunk River.
Starting at the Ding Darling rock, I walked clockwise around the south lake. Waterfowl on the lake: 15 Canada Geese, 30 Gadwall, 7 Shovellers, 10 Mallards, and 5 Ruddy Ducks. Also, one Pied-bill Grebe. As I rounded the bend at the main outlet, I saw 10 Double-crested Cormorants fly in from the south and land in the lake just east of the bluff. About 15 minutes later, they all got up and flew due north.
Other birds seen: Red-winged Blackbird, Common Grackle, Red-bellied Woodpecker, Flicker, Red-tailed Hawk, American Crow, Black-capped Chickadee, Brown-headed Cowbird, Robin, Cardinal, and a Fox Sparrow.
There were 16 Blue-winged Teal swimming in the half-filled pond on the middle wetland. Fourteen of these were paired and two were bachelor males. Blue-winged Teal are unusual among migratory waterfowl in that they travel all the way to South America for the winter. Most of our waterfowl go only as far as the Gulf Coast. Thus, Blue-wings can be thought of as neo-tropical migrants. Unlike geese, ducks to not mate for life, but form new pairs each spring. Blue-wings mate during their spring migration and will begin nesting as soon as they arrive on their chosen breeding grounds. A few pairs of Blue-winged Teal may nest in Story County but most continue on north to the Prairie Pothole Region. The most common duck species nesting in northern Iowa wetlands are Mallards and Blue-winged Teal.
The prairie next to Stonebrooke has been treated with a prescribed burn recently. The burn revealed several mounds constructed by mound-building ants, a common species in Iowa's native prairies (see photo above).