Dear
Journey North Kids,
Guess Who's Here?
|
|
|
Photographer
Diane Loyd captured something she'd never seen before: a juvenile
crane playing with a hunk of seaweed at Aransas NWR. The young
bird and its parents had migrated more than 2,500 miles from
the summer nesting grounds in Canada, where there is no seaweed!
What actions is the playful crane doing as he learns about
seaweed? It looks like the Seaweed Stomp-and-Catch… |
Counting
the Cranes: Not Easy
Every
winter, my most important goal is to figure out how many whooping
cranes are in the Aransas-Wood Buffalo flock (Western flock) that
winters on the Texas coast. I fly with the pilot in a small
aircraft
and try to find every whooping crane.
The
whooping cranes in winter, as in summer, are spread out over
a range of about 50 miles. We methodically fly transects about 5
miles
long by 1⁄4-mile wide until all the crane winter range
(about 54,600 acres!) is covered. This takes about 8 hours. I
plot all
whooping cranes sighted on 9 aerial photos of the crane marshes
attached to a clipboard on my lap. Research has shown that on
average, we find about 95% of the flock on any given flight.
It's not as easy as it sounds. We have thousands of white objects to
sort through at Aransas. I sometimes think that every white pelican, great
and snowy egret for miles around flies to Aransas every week just to get
counted. Throw in the occasional piece of white styrofoam trash washed up
into the marsh
along with white refuge boundary signs, and it's hard for our to find all
the whooping cranes. At least there
are
no trees at Aransas. In fact, Aransas salt marsh is unique: Nothing
here is
taller than a 5-foot whooping crane, the tallest bird in North America. The
cranes have no place to hide from us at Aransas.
Still, the cranes have figured out how to throw off my count.
We can spot a pair of cranes, only to have them take off and
fly up to 3 miles to a prescribed
burn to feed on acorns — or to a freshwater pond to get a drink.
That is why we fly often
and wait until we get consistent counts before the final
tally for the flock size is announced.
How Many Cranes at Aransas Now?
At this point I'm
estimating 270 cranes but I think there are more. We celebrate
the 45 chicks that are here. But I'm worried about flock
mortality
until the time
comes
that
I can
find
more than 270. With the summer's good nesting and
zero mortality, we could have been at 263 + 45 = 308 whooping cranes—WOW!
(But there is always some mortality between spring and fall.)
Serious
News
Migratory
whooping cranes have made
a remarkable comeback from only 15 birds
in 1941, but one thing that makes my job so fascinating is
that no one knows how this comeback story is going to end. Only
with continuing
efforts to protect the species and provide the habitat that it needs
can we expect the species to survive for generations to come. In
the latest news:
- The
new Eastern flock has grown from zero to 107 in its ten years.
But many challenges are many and the latest
peril
is
guns.
Three
of the Direct Autumn Release chicks were shot in Georgia in
December.
In January, one of the new flock's good fathers (#412), was
shot in Alabama. All
four deaths are under investigation, with reward money offered.
An agency you may not know about is helping:
The Forensic
Laboratory of the US Fish & Wildlife Service is
the only lab in the world dedicated to crimes against wildlife.
Scientists at the lab in Ashland, Oregon are examining crane
#412's carcass in hopes of turning up more clues. |
- In
better news, we are starting a new nonmigratory flock in Louisiana
this month! We hope to have the Windway Corporation fly 10
young whooping cranes from Patuxent WRC in Maryland to White
Lake, Louisiana.
This location is where the species last
nested in 1939. The last of that flock was wiped out by
a hurricane, so these whoopers will be the first in many years.
That flight
is scheduled for February 15th, weather permitting.
Sara Zimorski has moved there to take charge.
The
best news is that I expect a record-tying or record-breaking year
for the Aransas flock. Stay tuned! In my next reports you'll meet
some of the amazing cranes
that return here year after year.
Tom Stehn
Aransas National Wildlife Refuge
Austwell, Texas
|