Goes Where? Dividing the Flock
team began separating
the birds into two groups headed for two wintering
areas: the original winter home at Florida's Chassahowitzka NWR and
a second home at Florida's St. Marks NWR.
Flock will be divided before arrival.
the group? There are many threats to Whooping
cranes; both the Whooping Crane Recovery Team and the
Whooping Crane Eastern Partnership wanted to test a new site by dividing
the flock. They could not forget loss of 17
of the 18 Class of 2006 cranes at Chass after a severe storm in
More crane habitat is available at
St. Marks and storm-driven tides are rare. Splitting the flock between
the two sites is wise. It
allows a new site to be tested without putting all the birds at risk.
At the same time it cuts the risk of another loss of an entire generation
such as happened with the Class of 2006. With so many adults in the
flock now, they believe it will be safer for
space and privacy from the territorial older birds. (The older birds
often return to "their" winter pen site for free food — or
to pick on the youngest birds.)
will the team decide who goes where? They consider five important
factors: gender, siblings, dominance, genetic value, and migration
group should have the same number of females.
- Any siblings
of the opposite gender will be kept together; siblings of the same gender
will be apart.*
in each group must get along with one another and have a balanced dominance
order. Birds with social problems must be evenly divided or separated.
valuable birds must be evenly divided.
that missed parts of the fall migration due to dropping out or not
being able to fly on some of the fly days should be evenly divided.
Try This: Journal or Discussion Questions
group that winters at Chass will need to fly a greater distance in
the spring than the group from St. Marks. Could this affect the
decision of how the birds are divided? If so, how?
of this year's" ultra-cranes" would you put into each of
final decision for which birds go in each group is made by
the Operation Migration team. Other WCEP experts
can provide input. Why
do you think many opinions are being considered?
have to do some guess work. Some experts believe it is more important
to split any brother-sister cranes. Then
if something bad happens to one group, the whole family isn't
reared together, the brother and sister would view each other
more as siblings and not be likely to pair with each other later.
it is more
the same gender.
Why is the question of gender of such great concern? How might the
scientists get more information to help their decision making?
your teacher assigns seats or groups in your classroom, how do you
think those choices are made?