Dear
Journey North,
On
April
10 I finally flew over the refuge to count cranes. I
found a total of 34 whooping cranes during the 3-hour flight.
The rest of the flock has started migration!
More about the count results >>
Off
to Canada!
I estimate that 87% of the whooping crane flock of 266 has
started migration. Seventeen groups of whooping cranes
have been reported
so far — all the way from
central Texas to South Dakota. Most sightings have come from Kansas and Nebraska.
Amazingly, the cranes currently
as far north as Nebraska will be held up by a snow storm and unfavorable
winds in that state over the next few days!
An Early Migration: Why?
At Aransas, all 34 cranes
still present may be subadults We saw only one duo that could
have been an adult breeding pair. Thus, the breeding pairs have
started
the
migration earlier this year than in years past, since some adult
cranes often wait until mid-April to take off. What might explain
an earlier departure?
I think
this earlier migration may be tied to the good
food resources
that were available to the cranes throughout most of the
winter, leaving them in good condition to start the migration.
The pre-migration
body condition of the cranes at Aransas is very important since
the 3-4 week migration to Canada will not include much feeding.
Also, conditions may be still very cold, with
only limited food available when they
first reach the nesting grounds. Migration
is generally
a hard time for wildlife species. Their long-distance movements
allow little time to find food to eat.
A Hot Job
The whooping crane survey was conducted in a Cessna
210 piloted by Gary Ritchey of Air Logistic Solutions of San
Antonio, Texas
with me and USFWS observer Darrin Welchert as passengers. It
was incredibly hot
in the airplane during today's flight,
with full sunshine coming through the windows and of course
no air conditioning. Outside
temperature
was 86 degrees and probably above 90 in the plane with
us dressed in fire proof full-length clothing and helmets.
We occasionally
opened a window, but not for long because the wind
noise interfered so much with our radio communications through
our headsets. (Sometimes
being a wildlife biologist is not fun and games, but I still
think it beats most alternatives.)
Next
Flight April 22
The
next census flight is scheduled for April 22. How many cranes
do you think I'll find then?
Tom Stehn
Aransas National Wildlife Refuge
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