An aerial whooping crane census of the Aransas National Wildlife Refuge and surrounding areas was conducted on 10 April by contract pilot Gary Ritchey of Air Logistic Solutions, San Antonio, Texas with observer Tom Stehn.
P.S. Two days after my count, a Whooping Crane tour boat captain (and his excited passengers) saw another 15 cranes leave. They headed north at 10 AM with perfect migration conditions: winds SE at 10, skies clear, temperature in the upper 70's.
| adults + young |  |
|
| Refuge | 09 + 1 | |
| Lamar | 00 + 0 | |
| San Jose | 13 + 4 | |
| Matatgorda | 32 + 6 | |
| Welder Flats | 07 + 0 | |
| Total | 61 + 11 = 72 | |
Whooping
cranes have started the migration from
all parts of the crane range. April 6 seemed to be the day when a noticeable
number of cranes departed Aransas, although some had departed before
that. Sightings in the migration
corridor indicate the whooping cranes are currently spread out across the U.S.
as far north as North Dakota. The total flock size remains estimated at 237 with
no mortality documented during the 2006-07 winter.
Some of the crane range was empty or practically empty. All of the cranes
had departed from the Lamar Peninsula, and only 1 crane was found on
the north half of Matagorda Island north of Panther Point. Based on the
locations and groupings observed, I estimated that only 11 adult pairs
are left on the wintering grounds out of the approximately 66 adult pairs
that
were present during the winter. Four of the seven wintering “twin” families
have started the migration.
On San Jose, one crane grouping of two turned out to be 2 juveniles with
no other cranes around. The parents of the E. Spalding Cove twin chicks
hadstarted the migration, leaving their youngsters behind. This happens
occasionally at Aransas. The juveniles will be fine and are able to migrate
back to Wood Buffalo National Park in Canada on their own.
In
some locations on the winter range, the cranes were bunched up. For example,
7 cranes were on the refuge’s Ayres/Roddy Island and 8 cranes were
just north of Long Reef on San Jose. This is sometimes observed prior
to the migration.
Tides were very high on today’s flight with all tidal flats covered
with water. No cranes were seen on uplands, prescribed burns, open bays
or at sources of freshwater. Recent rains have dramatically lowered bay salinities
so the marshes are relatively fresh.
The next census flight is scheduled for April 19th. Today’s flight
was conducted in the afternoon because of morning fog. Visibility during
the flight was excellent with full sunshine. The entire crane range was
covered in 4 hours of flight time. The Cessna 210 is a faster airplane
with speeds from 80 to 140 knots utilized during the census, depending
on the expected crane density.
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