BLOOMINGTON -- Twenty whooping cranes led by four ultra-light aircraft are poised to fly over Central Illinois on their way to wintering grounds in Florida.

Liz Condie, a spokesman for Wisconsin-based Operation Migration, says the geese may be able to make the next leg of their flight as early as Saturday, but weather could stall them in northern Illinois for a number of days.

The geese need calm skies to fly daily legs averaging 50 miles, and warm temperatures mean southerly headwinds that slow their progress. They spent Friday in Winnebago County.

The next rest point is scheduled for LaSalle County, and a Livingston County stop is scheduled to follow a day later.