Environmental Almanac: Spring migration high point of the birding year
People who pay attention to the weather understand that knowing the average high temperature for May 18 doesn't tell you what the actual high temperature will be. In the same way, people who pay attention to the migrations of birds understand that knowing the average date of arrival for Baltimore orioles in Champaign doesn't tell you which day they're actually going to get here.
Much of the pleasure of birding derives from learning the general patterns of bird behavior and observing the variations on those patterns that occur over the course of time.
No birds that occur in East Central Illinois are more reliable in the timing of their migration than chimney swifts. In spring, they arrive here from South America within a few days of April 15, like clockwork, year after year after year. They then depart almost exactly six months later, in the middle of October. For now, you can see them in the sky throughout the day. Chimney swifts are recognized by their quick, acrobatic manner of flight, their stubby, dark cigar-shaped bodies and tapering, swept-back wings.
Other birds have completely ignored the migration schedule this spring. Two species that typically occupy East Central Illinois only during the winter, pine siskins and red-breasted nuthatches, are still being observed here regularly. Will they come to their senses and head for the northern forest to breed? For now, nobody knows.
The oddest local stopover so far this spring was a common loon that recently spent five days in the retention pond in front of Menard's in Champaign. It's not that migrating loons are unusual in Illinois; they're regularly seen on larger bodies of water. What was unusual was that the Menard's loon landed on such a small pond. Loons typically stop on larger lakes because they need up to a quarter mile of water surface for a "runway" to get airborne. Fortunately, a strong headwind seems to have enabled our wayward loon to get back into the air and resume its trek north.
The flooded agricultural fields that have hampered local farmers this spring have benefited both migrating shorebirds and bird-watchers. One day in late April, birders discovered thousands of pectoral sandpipers in fields southwest of town. Think of it. These are birds that winter in South America and then go all the way to the arctic to breed. And thousands of them spent a day or more feeding in Champaign County.
Other shorebirds that can be seen here and there around flooded fields range from the tiny least sandpiper to the relatively bulky greater yellowlegs.
For many birders, no aspect of spring migration compares to the waves of warblers passing through. More than 30 species of these most colorful little birds can be observed here. Ironically, the highly fragmented nature of the central Illinois landscape makes for great warbler watching. Warblers need trees to feed in, so when they stop over in our part of the world, they are concentrated in urban areas and the isolated woodlands that remain here.
Many warblers feed on insects in the crowns of mature trees and flit from branch to branch quickly, so it's best to start warbler watching with an experienced guide. One way you could do this is to take advantage of the two remaining Sunday morning bird walks led by members of the Champaign County Audubon Society.
These walks —one this Sunday (May 19) and one next Sunday — start at 7:30 a.m., departing from the Anita Purves Nature Center, 1505 N. Broadway, U.
Environmental Almanac is a service of the University of Illinois School of Earth, Society and Environment, where Rob Kanter is communications coordinator. Environmental Almanac can be heard on WILL-AM 580 at 4:45 and 6:45 p.m. on Thursdays.