For ground-nesting birds, high-water levels present another threat to their survival, the Minnesota Department of Natural Resources said.
In southern Minnesota, grassland ground-nesting birds like pheasants, meadowlarks, dickcissels, bobolinks, native sparrows, and ground-nesting ducks like the blue-winged teal lay their eggs on or near the ground. When nests become submerged, the eggs get too cold and incubation is aborted. If there are very small chicks already in the nest, they too could become too cold and wet and die from hypothermia or drowning.
“Wet conditions during nesting times are always rough, but this year has been an exceptionally difficult one,” said Carrol Henderson, Nongame Wildlife Program supervisor. “After the long, cold winter we had, the birds didn’t have much time to take advantage of mild, dry conditions they need for success.”
If the nests are flooded before the eggs hatch, the birds will likely re-nest and hatch a brood of young later in the summer. If the chicks have already hatched and die from exposure from being soaked by the rains, the birds typically will not re-nest and they are done for the year.
Early-nesting waterfowl like Canada geese and Trumpeter swans should be hatched by now and the young should be old enough to survive higher water conditions. However, overall it is a tough year for ground-nesting wildlife as well as for the farmers, landowners, and communities affected by the heavy rains.