Time is Short and the Water Rises

Immature sora photographed in Cook County, Illinois by Carolyn Fields.

For the last several years, I have been doing bird surveys at an area called  the Des Plaines River Wetland Demonstration Project in Wadsworth, Illinois. It is the brainchild of Donald Hey whose organization, Wetlands Research, Inc., manages the project. Old quarries and scrubby woods were converted into marsh and sedge meadow as an outdoor laboratory to study the biological and physical aspects of wetlands. Over the last two years, work has begun to expand the wetlands out of what use to be an old golf course and more recently an area for paintball shooters. These new areas will be part of a wetland bank, whereby developers can compensate for destroying small low quality wetlands by contributing to the creation of larger and higher quality ones. That is the rational anyway, and as far as I know that is what occurs here in northern Illinois.

My work at Wadsworth consists of censusing water birds during spring and fall migration and breeding birds in June and July I just completed my last breeding survey of the season on July 10. And it was an interesting year. According to Brad Semel of the Illinois Department of Natural Resources, 25 years of data show that every wetland in northeastern Illinois eventually loses its conservative birds. By those I mean species like moorhens, black terns, least bitterns, yellow-headed blackbirds, and to a lesser extent pied-billed grebes and Virginia rails. That has certainly happened to the Des Plaines wetlands where a number of these species used to nest regularly. But in the last few years the best I have come up with was one least bittern on one occasion in each of two summers. Because I have never had it twice in one season, I can’t say whether the species is breeding here or not.

The first visit this summer (June 6)  was extraordinary, yielding a least bittern, pied-billed grebe, and two soras, a wonderful collection of potential nesters. Almost a week later, however, the only species that could be located was the grebe. And then just before the third visit, there was a prodigious rain that flooded the whole site. Roads covered with twelve inches of water became impassible, so I was forced to access spots on foot. While the extra exercise was undoubtedly good for me, I am sure that any rail or bittern would have been flooded out. I did find one Virginia rail that day, but in an area that has been dry before the rain. This suggests that birds did relocate- nests were probably destroyed which forced birds to find other places. Whether any young would be produced under such a scenario is open to question. (And two weeks later, that location was dry again, as waters receded.)

Another species affected by the rise in water levels is sandhill crane. Sightings suggest that two pairs of cranes nest on the property every year. In 2008, one nest was in a very conspicuous place and was flooded out. Someone reported seeing a colt after that but I saw the adults several times and they were sans young. This year a nest was also inundated and again all I have seen since are the adults.

But another pair may well have done better. The highlight of this year’s surveys was my observation of a pair of cranes with their colt feeding along a flooded bike path. When they saw me, the adults started squawking and the colt made a beeline for the thick marsh vegetation. One bird flew off to perhaps rendezvous with youngster, but the other continued to forage. Unfortunately, it incurred the wrath of a redwing which actually landed on the crane and vigorously pecked at it. The blackbird moved off for a moment giving the crane an opportunity to adopt a new strategy- it hunched down to assume a lower profile, no doubt hoping to become less annoying to the blackbird (“Nothing to see here, redwing. Move along.”)

A pair of sandhill cranes photographed in Jasper County, Indiana by Carolyn Fields.

          

Tags: sandhill crane, wetlands