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.)
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