It’s a birding bonanza as neotropical migrants wing theirway north from Central America and the Caribbean.
Spring Migration in Illinois
Story By Jeff WalkPhotos By Jerry Kumery
14 / OutdoorIllinois May 2007
and the Yucatan to our forests, fieldsand streams, on their way to the north-woods and the Land of the Midnight Sun.
May is when birders criss-cross thestate, soaking up the feathered richnessof two continents, happily sufferingthrough inconveniences like “warblerneck,” a soreness from looking up intotreetops for hours.
May is when you don’t have to goanywhere at all to see migration; birdscan be anywhere. Or everywhere. Allyou need to do is look.
Most people think of spring as when“our” birds return home from their winterretreats to set about the business ofnesting and raising young. But in all fair-ness, May is the month when tropical
Spring migration.
It starts in dead of winter, onsunny days when male gold-eneyes, dodging ice floes onrivers, start throwing their headsback in mating displays. Thecurtain call is a few yellowlegsand sandpipers lingering intoJune, so late—and just two or
three weeks before the first migrants arealready winging back south—that nine-teenth century naturalist E.W. Nelsonwas convinced these Arctic nesting-species must breed in Chicagoland.
Ah, but May is when spring migrationreaches a fevered pitch. The skies of Illi-nois are teeming with millions of birds,carrying fresh memories of Argentina
Male yellowthroats, a type of
warbler, can be identified by their
black masks.
A brilliant vermilion-colored body
and black wings are the marks of a
male scarlet tanager.
(Cop
yrig
htC
.C.L
ockw
ood.
)
For ages, people have marveled atmigration. Today, we have a much bet-ter understanding of how birds migrate,which makes the feat more incredible.Neotropical migratory birds—humming-birds, wood-warblers, vireos, tanagersand orioles—seen in Illinois in latespring are at or near the end of theirtrek, and the most amazing leg of theirjourney was completed weeks earlier. Atdusk on days in March and April, birdstake off in hoards from the YucatanPeninsula, flying north and northeast ona 600- to 1,000-mile nonstop flight to theGulf Coast. With a good tail wind, birdscan ride the “Yucatan Express” andmake land fall in as little as 20 hours.
The migrants moving through Illinoisare usually on a more leisurely pace.Most songbirds migrate at night, whentemperatures are cooler and humidity ishigher, reducing the risks of overheatingand dehydration. By day, they feed andrefuel for the next leg of their journey.Other birds, like hawks, move by daywhen they can take advantage of ther-
mal updrafts that enable a lower-energy,“solar-powered” migration.
Weather certainly affects the short-term timing and speed of migration, withbirds opportunistically using tail winds totheir advantage. Spring conditions thatproduce thunderstorms—warm, souther-ly flows slamming into colder air—canalso produce spectacular “fallouts,”
In contrast with her orange-
and-black mate, drab colors
help camouflage nesting female
Baltimore orioles.
May 2007 OutdoorIllinois / 15
birds come through Illinois, often head-ed farther north, to take advantage ofthe short-lived flourish of spring thatmakes it possible to nest and raiseyoung. Looking at the spectacularplumages of the wood-warblers, vireos,tanagers, grosbeaks and orioles, it’seasy to understand these are tropicalbirds. And when the first cool windsblow from the north in August, they willbegin heading home to Central Americaand the Carribean.
From the spring woodland canopy
come the buzzing trills of Northern
parulas (left) and the Robin-like
songs of red-eyed vireos (right).
(Pho
toB
yA
dele
Hod
de.)
when birds riding the southerly windsare forced to the ground along frontalboundaries. If you are lucky enough tobe under a migration fallout, at dawnyou are likely to be treated to as manybirds in a few hours as many people seein an entire season.
Length of daylight is the broader cuethat choreographs migration. As daysgrow longer, birds’ bodies literallychange as production of different hor-mones directs birds to store fat formigration and exhibit zugunruhe ormigratory restlessness. Many birds onspring migration are only 10 or 11months old, and rely on hard-wiredinstincts rather than experience to guide
them to their summer homes. Theseinstincts, linked to day length, areincredibly precise. Each year, festivalgoers count on swallows to return to theMission at San Juan Capistrano in Cali-fornia on March 19. Less famous are the“buzzards” (turkey vultures) of Hinckley,Ohio, that have returned to their sum-mer roost each year on March 15 since1818, when a great hunt left behindunwanted parts of game animals for thescavengers to feast on. Just as reliably,
Baltimore orioles return to central Illinoisthe last week of April and bobolinks tonorthern Illinois the first week of May.
Unlike waterfowl and shorebirdmigration, with apparent flyways andstopover locations, the migration of bil-lions of songbirds is a huge advancingcloud that eventually blankets all ofNorth America. Finding migrating birdsis as simple as finding the places thatoffer food and security.
In southern Illinois, the difficulty is notfinding habitat, but finding the best view-ing opportunities. The Garden of theGods Wilderness Area in the easternShawnee National Forest allows birdersto climb rock features and get to eyelevel with treetop birds.
16 / OutdoorIllinois May 2007
Birders enjoy searching the wood-
land canopy for summer residents,
including summer tanagers. Males
share in the feeding of nestlings.
Colorful markings—rusty cheeks on
the male Cape May warbler or the
breast on the male rose-breasted
grosbeak—provide identification clues.
(Pho
toB
yA
dele
Hod
de.)
The Emiquon and ChautauquaNational Wildlife Refuges near Havanaare representatives of the best water-fowl and shorebird locations on the Illi-nois River. Pool 19 of the MississippiRiver near Nauvoo is the place to seespectacular concentrations of scaup,canvasback and other diving ducks inthe early spring.
Stuck between a rock and a hardplace, with Lake Michigan to the eastand a scarcity of remnant natural habitatto the west, migrant birds on the Chica-go lakefront pack into “migrant traps,”such as Jackson Park and the “MagicHedge” at Montrose Harbor.
Experience and effort are at least asimportant as location. On a good day inMay, it is possible to see more than 100species in any county in Illinois. So grabyour hiking boots, field guide and binoc-ulars, and get outdoors!
The Illinois Breeding Bird Atlas
From 1986-1991, ornithologists
spent a collective 45,000 hours
surveying nesting birds in nearly
1,300 blocks (roughly 10 square miles
each), systematically located across
Illinois. The result is an incredibly
detailed portrait of the breeding distri-
bution of birds in Illinois. Each species
account includes information on nat-
ural history, historical changes in
abundance and distribution, and
abundance trends at the Illinois and
Midwestern scale.
To purchase ($25.95 plus 25 per-
cent for shipping and handling) a copy
of this useful reference, contact the
Illinois Natural History Survey Publi-
cations office at (217) 333-6880, and
request a copy of The Illinois Breed-
ing Bird Atlas, by Vernon Kleen, Liane
Cordle and Robert Montgomery (Spe-
cial Publication 26).
Dr. Jeffery Walk had worked as a sci-entist with the Illinois Natural HistorySurvey and coordinated the Compre-hensive Wildlife Conservation Plan forDNR, and recently accepted a positionwith The Nature Conservancy.
Radar image not only track storm
systems but also migrating birds,
bats and insects.
Canada warblers (below right)
have a distinct eye ring while
solitary vireos have “spectacles.”
May 2007 OutdoorIllinois / 17
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eath
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