wrong with this picture?
is a closer look. Now do you notice anything unusual about the crane's
again and compare to these cranes (#
find the answer below...
biologist Tom Stehn explains:
is a family (2 adults:1 young) of whoopers that have stayed on the
River in Nebraska since 10/23. As you can see, they are stained on the
legs and belly—with what, we don't know. The most popular theory seems
to be oil.
don't know if the black staining was caused by oil but for now we have
no other theories. The 3 cranes all apparently walked or landed
in water containing the substance that was deep enough to coat their
from contaminants expert Peter Albers at Patuxent Wildlife
Research Center provides a positive outlook to what we think is an
unprecedented situation. So far, the behavior of the birds is considered
durability of the staining and the uniform pattern on all three birds
are compatible with some type of oil-based staining that occurred as
the birds were wading through water. The dark brown (almost black) color
would indicate exposure to either crude oil (oil field waste ponds),
lubricating oils from waste water retention ponds (industrial or refining
complexes), or one of the heavier fuel oils (Nos. 4-6). Gasoline and
kerosene would have produced little visible stain and diesel fuel would
have left a light brown stain. There is probably little to worry about
if the cranes continue to look and behave normally. I would begin to
worry if their feathers start looking unkempt and the birds become lethargic."
Peter H. Albers
USGS Patuxent Wildlife
Research Center, Beltsville Lab
personnel monitoring the crane family have collected a fecal sample, but
have been unable to find any 'stained' feathers at the roost site. We'll
planning to get the fecal sample analyzed to see if it contains any oil-based
substances. Right now the situation calls for continued monitoring!
October 27, 2006
. .What Happened Next?
The "stained" family group arrived at
Aransas National Wildlife Center in Texas for the winter. "A
family group that is stained brown on the legs and bellies that may
have walked into a pond containing an oily
substance sometime during the migration was located on their territory
on Matagorda Island," reported Tom Stehn. "One of the adults was
banded YbY-Y in 1987 and was last observed on November 7th at Salt
Refuge in northern Oklahoma. This family was believed present at
Aransas on the November 15th flight, but on that day we were unable
to fly low enough to see the staining on the legs. Although the discoloration
is clearly evident, it is difficult to see from the air as you’re
looking down on the birds. From my brief look from the air, the
family seemed to behave just like any other cranes."
North is pleased to feature this educational adventure presented in cooperation
with the Whooping Crane Eastern