The census flight on April 13th only found 10 whooping cranes at
Aransas, fewer than I expected. The migration seems to be about
a week on the early side this year, with some cranes starting to
cross the border into Canada. The 11 radio-banded cranes with
satellite transmitters that let us know their exact whereabouts
spread out between Nebraska and North Dakota.
Who's Left at Aransas?
The 10 cranes still at Aransas included two family groups. I expect
them to depart in the next week since they have
to leave soon
in order to get up to Wood Buffalo National Park in time to nest.
So by next week, Aransas will be down to—at most—3
whooping cranes. Those 3 could stay into early May, and occasionally
two fails to migrate and could spend the summer at Aransas.
the 3 are young birds not yet old enough to breed, so they have
no sense of urgency to get to Canada to defend a territory
Migrate 2,500 Miles to Nest?
The blue crabs at Aransas are happy, no longer having to face
the menacing 5-foot-tall great white cranes that stalk them
the winter. The marshes seem empty to me with the whooping cranes
gone. Yet the species has evolved so that their best chance of
producing young and increasing the size of the flock lies
in making that 2,500-mile
migration and nesting in the highly productive marshes of Canada
where there are many fewer predators than there would be if the
cranes remained at Aransas to nest.
Stehn, Whooping Crane Coordinator
Aransas National Wildlife Refuge