|"The direction and strength of the winds largely determine the progress of the migration," says monarch biologist Dr. Bill Calvert. Monarchs rely on the wind to get to Mexico, but it's also a major migration hazard as observers on the Great Lakes witnessed this week.
Crossing to Safety
Only when the wind is right can monarchs cross the expansive Great Lakes safely. On Lake Erie, a waterfront park in downtown Cleveland was a welcome refuge for tired monarchs that had just made a 50-mile crossing.
"This past weekend, after crossing Lake Erie, thousands upon thousands of the dazzling butterflies arrived on Ohio shores to meet a powerful cold front pushing along the lakefront. High winds and rain forced an extraordinary number of monarchs to seek shelter from the inclement weather," said Cleveland Metropark's naturalis, Jen Brumfieldt.
For a migratory species, stopover habitat like Cleveland's may only be used for a single day but is essential for survival.
Following the Shoreline
Wind influences the pathways monarchs travel. By flying along the Great Lake's shorelines monarchs can avoid the dangers of crossing open water.
Coastlines are a great place to watch fall migration because the wind often blows large numbers of monarchs there. Many people reported a parade of monarchs traveling along the Great Lakes' this week.
Each fall, Frank Apsey conducts a point count survey on the shore of Lake Huron. This year's observations raise questions: were the monarchs crossing the lake or following the shoreline?
"We observed 481 monarchs migrating at Harrisville State Park. We noticed that the monarchs were coming EAST off the lake and heading due west. They were flying high from 50 to 200 feet as they came off the lake. We could see them quite far out as they approached. Instead of landing on the beach as they usually do, they just kept on going west with fast and steady wing beats. Here is the hour by hour count."
Watch the wind map to see what happens this week as a strong cold front makes its way across the continent. Predict when and where monarchs will travel.