It is not uncommon to run into fellow photographers along the river wetlands. It’s fun to exchange tips, information and stories. Eagle season triples the probability of these collaborative encounters and if you talk to enough amateur river naturalists, you get good data about eagle migration.
January is the best month to scout the river for our national bird.
Typically, the Illinois River is frozen (except for the shipping channel). As we slide into colder weather, the birds fly south from Wisconsin, Minnesota and points north in search of some open water and good fishing.
Dam spillways are especially popular. A photographer I met on the Bartonville boat ramp told me some years he has spotted as many as 50 eagles at the locks just north of the ramp area.
If you drive along the river, you can occasionally spot eagles standing way out on the ice watching the open water,
or see them wheeling overhead getting ready for a dive.
Morning and evening they tend to roost in trees along the bank,
fluffing out their feathers to conserve warmth. 
Occasionally, you might see one fly to a branch with a fish in its claw,
and sometimes you can watch one rip into its meal.
Eating is sometimes messy,
as you can see looking at this eagle after his meal ...
Juvenile eagles (less than 3 yrs old) are a motley brown in color, and if you look carefully around the adults you might spot several 
younger birds.
I've decided that the juveniles have the best camouflage because they resemble squirrel nests from a distance. Adult eagles look more like squirrel nests with a bit of snow on top, and are easier to spot in warmer weather.
Last year I caught the eagle bug after Christmas. I’d heard from an old timer that Chillicothe had its share, so I cruised the river road there and within a mile I saw nine roosting eagles that allowed me to take great shots from the car. (This was a good thing as it was 5 degrees F at the time, and both I and the camera tend to slow down at that temperature.) I spooked one of the birds by accident and followed him to a little marina which held three eagles, twenty great blue herons,
and a zillion ring-billed gulls. The light was low but I grabbed a few shots before sunset. The river was above flood stage and frozen river water covered parts of the road.
This year, the river was low and froze early in December, but by the time we got pulled together after Christmas it had warmed up a lot. Daily highs of 50 degrees F have been common; it was a record breaking thaw for January.
The consensus among the eagle watchers is a lot of the birds have not come south or have returned north. I spotted about 20 eagles in late January over a period of 4 days. Of these at least six are birds that nest in the wetlands at Rice and Chautauqua.
I saw six others 50 miles north at Starved Rock State park. While we undoubtedly have northern visitors, a substantial percentage of the birds we are seeing are local eagles.
So, global warming seems to be affecting eagle migration. Will it be harder to see eagles in future years? I am comforted a little by the fact that eagle numbers have generally increased with the ban of DDT and our resident populations seem to be increasing slowly. However, there are still only fifty-two documented eagle nests along the entire Illinois River.
Other bird species have also been affected by the warm weather. Robins have visited my feeder all winter. I photographed a bluebird at 
Banner Marsh on January 19, 2006. I think I need to take on a new project and follow the sightings and Audubon counts of these species over the next several years to track the change in winter ranges. Global warming seems scary on the larger scale, but investigating it locally could at least be interesting. We have a unique chance to document the effects of climate change on local animal populations.
