4/22 IL Migration Report

Tonight we watch the ominous approach of another cold front from the Northwest, one that in some

Note the incoming cold front

ways is similar to the one that passed through IL leaving us with 6 to 8 more inches of water. Fortunately, this front shouldn't leave us with as much precipitation, but it will likely span the length of the U.S. in a couple days. This front will bring with it 2 things that pertain to migration. The first and most obvious is storms, and as they just barely move into NW Illinois tonight, we have the potential for light and localized fallout as migrants are forced down when flying north into the storm system. This means that tomorrow, if you are in NW IL, there could be an increased concentration of migrants in your local patch. The second

The irregular green shapes are storms surrounded by the
diffuse blue sphere of birds migrating
thing this storm will bring is westerly winds. Right now, Illinois is experiencing southeasterly winds, which is propelling much of the migration you see above. Note that this front will probably begin moving through Illinois itself tomorrow during the day, and in 24 hours it looks like the state will again be cut in half, with the northern half experiencing some form of westerly winds, and the southern half still experiencing southerly or southeasterly winds. More on this to come.

To continue the possibly uncalled-for emphasis on warblers, today saw the predicted movement of warblers, with birds moving northward into and north from Southern and Central IL, where between 15 and 20 species of warblers have been present. This is one thing I failed to clarify in yesterday's melodramatic report--warblers are packed into some places in the southern and central thirds of the state, with many of them having arrived early if anything, but are now held up by currently insufficient conditions (mainly cold temps) further north. It is the northern third of the state that is still largely missing out on the warbler fun, though there are certainly places in central IL that still haven't seen much warbler movement. Thanks go to those who followed up on this. These species include PROTHONOTARY, PRAIRIE, WORM-EATING, PINE, NASHVILLE, YELLOW, HOODED, YELLOW-RUMPED, PALM, YELLOW-THROATED, ORANGE-CROWNED, BLACK-THROATED GREEN, WILSON'S, and TENNESSEE WARBLERS + both WATERTHRUSHES, COMMON YELLOWTHROAT, OVENBIRD, and AMERICAN REDSTART. As trees slowly but surely start budding and insect prey necessary for passerine movement begin to present themselves more in N IL, we continue to see numbers of species like PALM, PINE, YELLOW-RUMPED, and ORANGE-CROWNED WARBLERS increase gradually. Other than warblers, today saw arrivals and influxes of species like AMERICAN BITTERN, more SWAINSON'S HAWKS, BROAD-WINGED HAWK, OSPREY, SPOTTED SANDPIPER, both YELLOWLEGS, CHIMNEY SWIFT, PURPLE MARTINS, GRAY CATBIRD, EASTERN KINGBIRD, both KINGLETS, BLUE-GRAY GNATCATCHER, WOOD THRUSH, SWAINSON'S THRUSH, ROSE-BREASTED GROSBEAK, and INDIGO BUNTING. For a taste if the best that Illinois has to offer including some species I've omitted here, check out Tyler Funk's report from his IOS Yellow Rail trip if you haven't seen it already: http://bit.ly/15CZlJv. What a great day.

It will be interesting to see how the incoming cold front affects bird migration, but it will likely slow it down significantly until it passes. It may be a few days before we have favorable southerly winds again, but regardless, keep an eye out for all of the above species in addition to BLACK-CROWNED NIGHT-HERONS, GREEN HERONS, SORAS, VIRGINIA RAILS, maybe SEMIPALMATED PLOVERS, PECTORAL, SPOTTED, LEAST, and SOLITARY SANDPIPER, DUNLIN, UPLAND SANDPIPERS, WILLET, FORSTER'S TERNS, COMMON NIGHTHAWKS, RUBY-THROATED HUMMINGBIRDS, EASTERN WOOD-PEWEE, GREAT CRESTED FLYCATCHERS (and maybe even some Leasts), BLUE-HEADED, WHITE-EYED, WARBLING and RED-EYED VIREOS, HOUSE WRENS, MARSH WRENS, all the expected swallows, all the expected sparrows (especially take note of LE CONTE'S SPARROWS, GRASSHOPPER SPARROWS, and LARK SPARROWS), for warblers, see above,  SCARLET and SUMMER TANAGERS, ORCHARD and BALTIMORE ORIOLES, BREWER'S, RUSTY, and YELLOW-HEADED BLACKBIRDS, and possibly early DICKCISSELS or BOBOLINKS.