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Hurricanes: A Fall Migration Hazard

September, 2008
Hurricane Ike: How Were Monarchs Affected?

Ike's direct impact on the monarch population should be small thanks to its timing: When the storm struck, the migration was heading toward Texas, but most of the monarchs were still over 700 miles away. Look at the migration map and notice that peak migration was occurring across Iowa on September 12th, and the migration's leading edge was entering Kansas.

Over the next month, the entire population will pass through Texas, and the Texas Gulf Coast is one of the main pathways monarchs will travel. The impact of a hurricane during peak migration in Texas could be enormous. This picture of a huge monarch roost was taken last October on the Bolivar Peninsula, a community that was leveled by Hurricane Ike on Saturday.

Mr. Harlen Aschen, who lives on the Gulf Coast and has weathered many hurricanes, made these observations:

"We've watched monarchs out the window clinging to the stems of plants when the winds were topping 50 mph. We also saw monarchs flying the day after Hurricane Claudette when we had had 105 mph winds, so they are tougher than I am ... or know what to do outside! They 'hunker-down' until the weather is favorable again."

Now that Ike has passed Mr. Aschen has noted sea-salt damage to the flowers monarchs use during migration along the coast.

Ruby-throated Hummingbirds at Peak Migration
Mr. Aschen is worried about the impact Ike had on another migratory species, the ruby-throated hummingbird.

"We were at the peak of the ruby-throated hummingbird migration down here. Think of all the hummingbirds that are leaving our coast this week to migrate across the Gulf of Mexico to the Yucatan."

"Essentially, all the ruby-throated hummingbirds that breed in the eastern half of the United States and Canada, estimated at a population of 7.3 million individuals, migrate along the shores of the Gulf of Mexico each fall," John Arvin, research biologist for the Gulf Coast Bird Observatory, told the Houston Chronicle.

Whooping Crane Winter Habitat Narrowly Missed
The winter habitat of the world's only natural flock of Whooping cranes was narrowly missed by Hurricane Ike. It's less than 150 miles down the coast from the site of Ike's landfall. Because the entire western flock resides in one place, scientists know a single storm can threaten their surivial. An oil or chemical spill in the Gulf of Mexico is one of the top concerns.

Realted Links: Hurricanes and Monarch Migration

  • Tagged monarch blown by Hurricane Katrina? A tagged monarch was evidently blown 165 miles in the wrong direction by Hurricane Katrina, northwest from Ohio to Ontario. (See story.)
  • Monarchs in England after gale winds: More than 170 monarchs appeared on the south coast of England in the fall of 1995. Weather backtracking suggests the monarchs could have been carried across the Atlantic Ocean by the wind for four days. (See story.)
  • Can a monarch fly across Atlantic Ocean? (See lesson.)

Hurricane Ike hit the Texas Gulf Coast the night of September 12, 2008.
The migration was heading toward Texas, but most of the monarchs were still 700 miles away.
This September storm was fortunate timing for monarchs. Peak migration on the Texas Gulf Coast is in October, as shown in this picture from October, 2007.

Ruby-throated hummingbird migration was at peak on the Texas Coast when the hurricane hit.
Whooping Crane habitat, narrowly missed by Ike, remains safe.