BRINGING BACK BIRDIE
Currently, there is only one self-sustaining flock of wild whooping
cranes left in the world. Unlike Florida’s non-migratory
group, these individuals migrate between Canada‘s Wood Buffalo
National Park and Aransas National Wildlife Refuge in Texas. As
the only wild flock in existence, the livelihood of the entire
group is at risk from disease, natural disasters, natural predation,
and human threats. To ensure its survival, non-profit organizations
and public agencies from both countries joined forces in 1998 to
form the Whooping Crane Eastern Partnership. Their goal
is to provide population recovery for this species by establishing
an eastern migratory flock.
COME FLY WITH ME
For cranes, migration is a learned skill. Therefore, those born and
raised in captivity must be taught where and when to fly. To establish
a second migratory population of whooping cranes, young whoopers
are trained to follow a handler along a predetermined route. Ultralight
aircrafts are used to guide the birds and are considered an extension
of the caretaker. Cranes chosen for this task are hatched in captivity
and reared by people in crane costumes to minimize human contact.
Prior to hatching, audio recordings of the aircraft are played
in hopes that the birds will associate these sounds with the handler.
Those lucky enough to make the fall journey will travel from Necedah
National Wildlife Refuge in Wisconsin to Chassahowitzka National
Wildlife Refuge on Florida’s gulf coast.
Because a majority of ideal habitat along the route lies on private
lands, a key element for successful reintroduction has been the cooperation
of local landowners. Operation Migration, which works in
conjunction with Whooping Crane Eastern Partnership, spearheaded
the first reintroduction of migratory cranes using the ultralight
HAVE YOU HEARD?
Recorded calls are helping scientists understand how cranes use vocal
sounds to communicate among themselves. These acoustic fingerprints
allow experts to identify individuals and even crane pairs. This
method creates less stress than bird banding because there is minimal
human contact. Operation Migration also uses recorded
calls to safely guide and control birds along the migration route.
The voice prints are played through large megaphones which are
attached to ultralight planes. On the ground, these recordings
are heard via speakers concealed within a handler’s costume.
A SECOND CHANCE
Direct Autumn Release or DAR is a reintroduction technique
used as a supplement to the ultralight aircraft-led method. The
DAR process releases costumed reared chicks (Whooping cranes) in
areas containing older cranes that have successfully migrated in
the past. The hope is that young whoopers will learn the migration
route from the older birds. Scientists believe this technique is
important because it provides a second chance at life in the wild
for those chicks found unsuitable for the primary technique (ultralight-led
migration). Therefore, Direct Autumn Release has the potential
to augment crane populations in North America.
Resources for this article have been provided by
American Crane Working Group and the Florida
Fish and Wildlife Conservation Commission.