Dear
Journey North Kids,
This
has been a better than expected winter for the whooping cranes.
On a census flight at Aransas conducted January 5th, I counted
264 whooping cranes! I am absolutely thrilled. Yes, the
264 is down 6 birds from the record high of 270 last winter, but
we were
expecting much fewer than the 264. We only had 247 birds in the
flock in spring 2009 after 23 birds died during the winter. (See
last report.)
Another
Decade Dip
Every 10 years, the population
drops right close to the start of a new decade. This drop is related
to some
unknown factor affecting the number of chicks produced on the
nesting grounds. In summer 2009, chick production was down and
only 20
chicks survived. This was a big dip from from the 38
chicks produced in 2008. Once the current dip ends, mathematical
analysis predicts
the population
should turn around and show an increase for the rest of the decade.
(See? There is a use for that math you are studying.)
Help From Mother Nature
We knew food for the cranes was going to be in short supply at
Aransas due to the drought over the past 2 years. Since whooping
cranes are so tied to marshes, they suffer when drought hurts
their habitat. There are fewer blue crabs, their favorite food,
for the cranes to eat. However, Mother Nature turned on the
faucet and the rains began to come in September. Rains have
kept coming,
breaking the record-making drought of the past 2 years. Many
parts of the refuge are flooded. The cranes are feeding, maybe
eating snails, in these
flooded
areas.
How Many Cranes at Aransas Today?
On my next census flight (January 21), I could see that one adult
pair had lost their chick. We could not find the dead chick
and do not know why it died, but I knew something bad had
happened since I saw the parent cranes without their youngster
anywhere
around. So that means 263 whooping cranes are currently in
the
Aransas flock.
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Can
you find
a Whooping crane juvenile and adult? A sandhill crane?
Enlarge |
Things
are Looking Up Even though food was short this winter,
the marshes were not very salty due to all the rains. The
cranes could drink
right
from the
marsh and did not have to fly every day to find fresh
water to drink. Thus, with additional areas available to
feed
in as the
rains produced flooded areas, the cranes are doing okay,
and only the one has died this winter. This is such good
news compared
to
the 23 cranes that died last winter when everything was
so dry and the marshes were too salty. Things are looking
up for this
very endangered species.
Tom Stehn
Aransas National Wildlife Refuge
Austwell, Texas
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