|
Questions
and Answers About
the Whooping Crane Reintroduction

History and Background
Why is there
a plan to reintroduce a migratory flock of whooping cranes to the eastern
U.S.?
Wild whooping
cranes currently exist in two flocks, a non-migratory flock in Florida
and one migratory flock that summers in Wood Buffalo National Park in
Canada and winters near and at Aransas National Wildlife Refuge (NWR)
in Texas along the Gulf coast. It is possible that all or most of these
birds could be wiped out from a single event such as a hurricane, disease
outbreak, toxic spill, or prolonged drought. This makes the species vulnerable
to extinction. To ensure that the whooping crane survives, the International
Whooping Crane Recovery Team has recommended that an additional flock
of whooping cranes be established that is separate from the single remaining
natural wild migratory population. If successful, this project will result
in the establishment of the second migratory population.
Who
is responsible for the reintroduction?
In 1985, the Director-General of the Canadian Wildlife Service and the
Director of the U.S. Fish and Wildlife Service signed a memorandum of
understanding (MOU) entitled "Conservation of the Whooping Crane
Related to Coordinated Management Activities." The MOU was revised
and signed in 1990. The U.S. Geological Survey-Biological Resources Division
(Patuxent) and Parks Canada (Wood Buffalo National Park) were added signatories
in 1995. The MOU discusses disposition of birds and eggs, postmortem analysis,
population restoration and objectives, new population sites, international
management, recovery plans, and consultation and coordination. All captive
whooping cranes and their future progeny are the joint responsibility
of the U.S. Fish and Wildlife Service and the Canadian Wildlife Service.
Consequently, both nations are involved in recovery decisions.
In
1996 the whooping crane recovery teams of Canada and the United States
were merged into an international team, now known as the International
Whooping Crane Recovery Team. This Team developed a recovery plan that
calls for the establishment of a second migratory whooping crane population
in the eastern U.S. With that goal in mind, the Whooping Crane Eastern
Partnership was formed in 1998 under the leadership of the U.S. Fish and
Wildlife Service.
Who
is the Whooping Crane Eastern Partnership?
The Whooping Crane Eastern Partnership is a consortium of non-profit organizations
and public agencies working under the authority of the Endangered Species
Act to provide for recovery of the whooping crane by establishing an eastern
migratory flock. Founding partners include the U.S. Fish and Wildlife
Service, Operation Migration, Inc., the U.S. Geological Survey's Patuxent
Wildlife Research Center, the International Crane Foundation, the Wisconsin
Department of Natural Resources, National Fish and Wildlife Foundation
and the Natural Resources Foundation of Wisconsin. Many other flyway States,
private individuals and conservation groups have joined with and support
WCEP, and have donated resources, funds and personnel.
Why
not relocate some of the migratory whooping cranes from the Aransas/Wood
Buffalo flock?
Since the Aransas/Wood Buffalo flock is the only self-sustaining wild
migratory population, it is too risky to do anything that might harm this
population. Instead, reintroduction efforts will focus on using young
hatched from whooping cranes already in captivity at captive breeding
centers. It is also not practical to take eggs from the wild flock because
the wild flock is located in a remote area that poses serious logistical
obstacles to egg collection. The wild flock also lay their eggs too late
in the year to use for ultralight aircraft training in Wisconsin.
How
much will this project cost?
The current cost estimate is $1.3 million, with more than 50 percent
of that amount coming from private donors. Most of the remainder is not
new government expenditures.
Why
was Wisconsin chosen as the site for the reintroduction?
Wisconsin was chosen for several reasons. Wisconsin is within the
historic breeding area of migratory whooping cranes and the reintroduced
Wisconsin flock will be separated from the existing migratory flock. In
addition, suitable habitat on Federal, State, and private lands is available.
Wisconsin's long tradition of environmental commitment and support from
the public increases the chances for success within the state.
If
this reintroduction is successful, will the whooping crane be taken off
the endangered species list?
If this reintroduction is successful and the ongoing reintroduction of
a non-migratory whooping crane population in Florida also is successful,
the Federal status of the species could be changed, eventually, from endangered
to threatened. This is a less restrictive designation for species that
still need the protection of the Endangered Species Act, but are not in
danger of extinction in the foreseeable future. While it may be possible
in the long term to fully recover the species, removal of the whooping
crane from the Federal list of threatened and endangered species would
require further steps. Even if the whooping crane is removed from the
Endangered Species list, it will still be federally protected under the
Migratory Bird Treaty Act.
Rearing
Crane Chicks for Reintroduction
Where
do the chicks for the whooping crane reintroduction come from?
The chicks come from existing captive breeding flocks. The three primary
captive breeding centers are located at the U.S. Geologic Survey's Patuxent
Research Facility in Maryland, the International Crane Foundation in Wisconsin,
and the Calgary Zoo in Alberta, Canada.
Where
are the cranes used for the reintroduction being reared?
The crane chicks are being captive-reared at the U.S. Geological Survey's
Patuxent Wildlife Research Center until they are 40 to 60 days old. Training
started from just before hatch with exposure of the eggs to sounds of
crane calls and ultralight aircraft engine noise. At Patuxent, chicks
will be trained to follow the ultralights in the protected captive environment
and later in the out-of-doors pens at the center. When the chicks no longer
need heat and protection from the elements, they will be moved to Necedah
National Wildlife Refuge for flight training behind the ultralight.
What
happens to the chicks after they arrive at Necedah National Wildlife Refuge?
To promote wildness in the birds, every attempt is made to provide as
natural an experience as possible. At the refuge, the birds were housed
in pens painted natural colors and disguised with trees. Feed and water
containers were made of natural materials and all human paraphernalia
removed. The enclosures were constructed in the bird's natural wetland
habitat and access by people restricted. Personnel from Operation Migration,
Inc. conducted most of the conditioning after the cranes arrive at Necedah
NWR.
Why
do the people rearing the cranes wear costumes?
When teaching cranes to follow an ultralight aircraft they can easily
become overly tame. If this happened, they could suffer an "identity
crisis" when they reach breeding age and not recognize other whooping
cranes, or become a nuisance because they associate people with a source
of food. While interacting with the birds, the Operation Migration handlers
minimize human contact time. They work in silence while covered head to
toe in gray fabric costumes that disguise the human form. This is done
so that the cranes will not be familiar with the normally dressed humans
they may encounter after they are released.
Will
the fact that researchers have worn costumes make a difference in how
the birds perceive humans?
We hope that by avoiding talking and disguising the human form the birds
will not be familiar with the normally dressed humans that they may encounter
in the wild. Their natural fear of the unknown will keep them from approaching
people and aid in maintaining their wildness.
How
are the cranes being fed? What do they eat?
The birds are being fed a pelletized food that was developed by USGS/Patuxent
Wildlife Research Center and commercially produced. It contains all the
minerals, proteins and vitamins needed by the growing birds as well as
medication to prevent parasites. The chicks will also be allowed to forage
on natural foods as they grow older so that they could make the transition
to survival in the wild. We will use special treats (mealworms, crickets,
and kernel corn) as aids in training the birds.
During
training at Necedah National Wildlife Refuge when the birds begin to be
allowed their freedom during the day, we will practice "controlled
food withholding" to encourage them to return to the pen in the evening.
This will help avoid unnecessary handling of the cranes.
During
the migration, we will mix the pelletized feed with whole corn. The birds
will be fed from metal feeders that would hang in the pen and would be
painted earth tones to make them look more natural. We will use two or
more feeders at all times so one dominant bird could not monopolize a
single food source.
How
will cranes at Necedah National Wildlife Refuge be protected from predators?
The bottom section of the pen is buried in the ground and the entire structure
covered in wire mesh. The pen has a net over the top and several strands
of electric fence wire would protect the perimeter to deter predators.
Handlers will monitor the pen area several times daily.
After
the cranes have learned to fly and before they migrate, is there a chance
that they would leave the Refuge and fly to nearby wetlands?
At that early stage of life the birds are still immature. They associate
the handlers, the aircraft and the pen area with security and comfort.
When they are released during the day they may wander but they do not
go far. This behavior is natural as the birds learn about their environment
and begin to explore.
Migration Aspects
Why
do the cranes have to be taught to migrate?
Cranes learn the migration route from the previous generation. Chicks
hatched on the nesting grounds learn to fly with their parents, following
them in the fall to the wintering grounds. Their destinations and the
route they use may have evolved for thousands of years but it exists only
in the memories of the birds that use it. If all individuals of a species
are lost from a region, the route is lost forever. Birds that are raised
in captivity lack an older generation to teach them and they tend to become
resident, staying the entire year in the same location.
Why
use ultralights to lead the birds?
Several methods have been used in an effort to reintroduce birds in a
migratory situation. Whooping crane chicks have been placed with adult
sandhill cranes in a cross-fostering program. Birds have been conditioned
to follow handlers in a truck and led along a predetermined route. Also,
birds have been released with a similar wild species prior to migration
in hopes they would follow them south. In another study, cranes were transported
to a staging area and allowed to fly free. They were then recaptured and
moved farther south and again released. This was repeated along the entire
route in hopes the birds could connect-the-dots during the return migration.
All of these methods have resulted in varying degrees of success but none
have been as successful as the ultralight-led technique. It most closely
replicates the natural process of a parent leading the offspring south.
Ultralights are the only type of aircraft that can fly slow enough (and
not stall) to enable birds to follow. Operation Migration, Inc. has conducted
ten migration studies with three species of birds and worked with the
Patuxent Wildlife Research Center to establish the protocol that would
be used to reintroduce whooping cranes into eastern North America.
How
do you train the cranes to follow the ultralight?
The process is based on the bird=s natural instinct to imprint. Once hatched,
the chick is attracted to the first creature that nurtures it, normally
the parent. This is nature's way of ensuring the offspring stays close
and is protected by the adults. The procedure we follow replaces the parent
bird with the handler and so the birds imprint on the surrogate parent.
Prior to hatching, a recording of the aircraft engine is played to the
chicks. They are introduced to the ultralight at about seven days of age
and they soon associate it with the handler. The birds are not trained
to follow the aircraft; instead they are conditioned to it as an extension
of the handler. After they arrive on the wintering grounds and reach the
sub-adult stage, they become independent (much like human teenage offspring)
and they no longer look to the handler and aircraft for security and comfort.
Unlike training, the conditioning diminishes with maturity.
Will
ultralights lead the cranes back in the spring?
The cranes learn the migration route during the trip south. In the wild
they often leave the parent birds during the course of the winter, yet
still return to the summering area in the spring. Based on previous research
with sandhill cranes, a closely related species, whooping cranes are expected
to migrate back to Wisconsin on their own, the next spring. This spring,
10 of the 11 cranes that made it successfully to Florida in the Fall of
2000 were observed at Necedah.
What
role will state wildlife agencies have in the states along the migration
route?
Our state wildlife agency partners identified stakeholder concerns related
to the project, proposed migration stopover locations and will help coordinate
the migration with private and public landowners. Some of the migration
stopover locations are located on prime state-owned wildlife lands. States
have been kept fully informed of progress made by the migration team.
The Whooping Crane Eastern Partnership obtained the support and approval
for the sandhill crane migration study in 2000 from all the states within
the NEP designation area.
Will
people be able to watch or view the cranes during the migration?
During migration it may be possible to see the birds from a distance when
they land or take off from an overnight location. But the need to keep
the cranes from imprinting on humans means that all efforts are taken
to keep people out of the birds' range of vision. No one - not even project
leaders or participants - would be allowed to approach the birds. The
ultralight pilots take measures to ensure that they are never seen by
the birds out of costume, even while they are flying. In addition, video
footage and still photographs of the flights and the birds would be available
to the public through the news media, on the Whooping Crane Eastern Partnership
website, and on the websites of the individual organizations that are
part of the Partnership. The public will also be able to track the birds'
progress by visiting the WCEP website.
In
the summer of 2000, two whooping cranes from the experimental flock in
Florida population migrated more than 1,000 miles on their own to rural
Michigan. Does this mean that the project is unnecessary?
This unexpected development resulted in the first whooping crane sighting
in Michigan in more than 100 years. Although not technically called a
migration, the birds' movements were encouraging. Even though two cranes
moved to Michigan last summer, only the female made it safely back to
Florida. There is no indication that another journey will be initiated
next year. If the migration to Michigan were to become an annual event,
it offers another migration route in the east for whooping cranes. Having
multiple populations on different migration routes decreases the chance
that a disease outbreak, habitat loss or bad weather in a given area may
wipe out the entire population of cranes.
Crane
Biology
How
are whooping cranes different from sandhill cranes?
Whooping cranes stand 5-1/2 feet tall, and are the tallest birds in North
America. Sandhill crane adults are about 4 feet tall. Adult whooping crane
plumage is white with black wing tips, whereas adult sandhills are grey
or sometimes grey and tan. They both have a bald spot - a red, bare patch
of skin on their forehead. Whooping cranes are aquatic birds, spending
virtually all of the time in wetlands. Sandhill cranes will use wetlands,
but also feed in upland habitats. Whereas sandhill cranes have adapted
to human agriculture and feed extensively on grain, seeds and tubers,
whooping cranes prefer marsh habitat and prefer to eat crabs, invertebrates,
frogs and minnows. And of course, sandhill cranes are much more common
than the endangered whooping crane. Sandhill cranes occur throughout much
of North America and number in the tens of thousands. Whooping cranes
are known from a limited area in North America and the total world population
is about 400 individuals.
What
is the current status of the whooping crane - is it in danger of extinction?
The whooping crane is a federally endangered species in the United States.
It is one of the world's rarest birds. The species was thought to number
"in the thousands" in North America before European settlement
caused population declines. Archival evidence suggests that by 1865, its
population was 700 to 1,400. Their numbers dropped rapidly and by 1890
the whooping crane had disappeared from the heart of its breeding range
in the north central United States. By 1938, only two small flocks remained
- one non-migratory flock in southwest Louisiana, and one migratory flock
that nested in Canada and wintered in Texas. In 1941, there were only
21 whooping cranes in North America.
From
near extinction 60 years ago, captive breeding efforts and the protection
provided by the Endangered Species Act have enabled whooping crane populations
to slowly increase. There are now 384 whooping cranes in North America
- approximately 174 in the only migratory flock, which breeds in Canada
and winters in Texas; 86 non-migratory birds in central Florida; 120 in
captivity, and two in the Rocky Mountains.
While
whooping cranes are not in immediate danger of extinction, extinction
in the wild without reintroductions would be likely because of the small
size of the single wild natural migratory flock. For this reason, multiple
efforts are underway to reduce the danger of extinction by increasing
populations in the wild, including a new migratory population in the East.
What
caused the whooping crane's near extinction?
Several factors contributed to the historic decline of whooping cranes.
Much of their wetland habitat was drained and converted to farm land.
The migratory populations in the central U.S. and Canada lost large portions
of their breeding and wintering habitat in the late 1800s and early 1900s.
Then the non-migratory population lost much of its habitat in the coastal
marshes and prairies of Louisiana and Texas as wetlands were converted
for rice production. In addition to outright habitat loss, these activities
increased the amount of human disturbance, which may have had adverse
effects on crane behavior. At the same time, hunting, egg collecting,
and specimen collecting were a substantial drain on the population, particularly
from 1870 to 1920.
Are
there currently threats to whooping cranes?
The wild flock winters in a small area in Texas where all the birds could
be lost to a catastrophic event like a hurricane, red tide, or a contaminant
spill which could destroy their habitat, eradicate their food or kill
the birds directly as a result of ingestion of toxins. For example, a
hurricane in 1940 contributed to the loss of half the population of nonmigratory
whooping cranes residing in Louisiana at that time. The population never
recovered from that loss and the last bird was captured and moved to Aransas
National Wildlife Refuge in Texas in 1949.
The
principal threat continues to be a contaminant spill along the Gulf Intracoastal
Waterway that bisects the winter range. It is one of the busiest waterways
in the world and much of the commercial barge traffic is petrochemical
products including crude petroleum, gasoline, benzene, and basic industrial
chemicals. Each of these cargoes is chronically to acutely toxic.
Why
doesn't the flock of whooping cranes in Florida migrate?
The non-migratory whooping crane population in Florida was reintroduced
in 1993, a product of captive breeding and reintroduction efforts. Since
migration is a behavior that must be learned by cranes, the Florida whooping
cranes are expected to remain in areas near where they were released.
The recent dispersal of two cranes that wandered as far away as Michigan
in the summer of 2000 is thought to have occurred as a result of a severe
drought in Florida which made their home marshes unsuitable for breeding.
The dispersal observed in those two cranes is expected to be an infrequent
and unpredictable event in the future.
What
habitats do whooping cranes use?
Whooping cranes spend most of their time in shallow water wetlands where
they feed and nest. Nests are built on small islands of bulrushes, cattails,
and sedges that provide protection from predators. At night (when not
incubating), whooping cranes stand (roost) in shallow water where they
are safe from coyotes and bobcats.
During
migration, the wild population uses a variety of feeding and roosting
habitats, including croplands, marshes, and submerged sandbars in rivers.
They winter in bays and coastal marshes in and near the Aransas National
Wildlife Refuge on the Texas Gulf Coast. The experimental non-migratory
population inhabits palmetto grasslands, savannahs, and shallow marshes
in the Florida's Kissimmee Prairie region.
What
do whooping cranes eat?
Whooping cranes feed in shallow water wetlands and eat insects, minnows,
crabs, clams, crayfish, and frogs. During migration and on their wintering
grounds they sometimes feed in upland areas, especially in areas that
have been flooded or burned. There they forage for acorns, snails, insects,
rodents, and other food items.
How
long do whooping cranes live?
Whooping cranes may live up 25 years in the wild. Captive birds have lived
up to 40 years.
How
many young does each whooping crane pair produce each year?
In Wood Buffalo Park, 50 pairs of cranes produce from 15 to 30 chicks
each year. Whooping cranes do not start breeding until they are four or
five years old even though they have their adult plumage by the time they
are a little over one year old. When they do mate, they are monogamous
and have the same mate for life. If one of the pairs dies, the remaining
bird will mate with another. Whooping cranes usually nest once each year,
but sometimes they will lay a second clutch of eggs if their first is
destroyed. Occasionally a pair will skip a nesting season if conditions
are unsuitable or for no apparent reason.
Whooping
crane pairs lay two eggs in late April to mid-May, with hatching one month
later. The parents share incubation and rearing duties although the female
takes the primary role in feeding and caring for the young. Most often,
successful nesting pairs raise one young each year. As a rule, fierce
competition between the two chicks usually results in the death of the
smaller, weaker sibling. Occasionally, when food supplies are abundant
and the chicks are perhaps more evenly matched in size and strength, whooping
cranes have been known to successfully raise two chicks.
Are
the remaining whooping cranes genetically diverse enough to survive into
the future?
The population reached a low of 21 birds in 1945-46 which resulted in
a decline in diversity and changes in gene frequencies. However, the population
continues to expand and genetic diversity, though reduced, appears to
be comparable to many other crane populations.
Eastern
Population Designation
The
U.S. Fish & Wildlife Service, in cooperation with other partners,
continues to address possible concerns about the reintroduction of an
endangered species. Migratory whooping cranes reintroduced east of the
Mississippi River are designated as "experimental" because they
are isolated from other whooping crane populations. They are also "nonessential"
because the survival of the species is not dependant on these individuals
at this time. These designations relax the restrictions of the Endangered
Species Act and lessen possible conflicts between people and whooping
crane conservation. Whooping cranes are still fully covered under the
Migratory Bird Treaty Act. A public comment period was held to allow input
on the proposed federal rule designating the flock as an "experimental,
nonessential" population. The comments were incorporated into a final
document that was sent to Washington, D.C.. Final approval to proceed
with the reintroduction project was granted upon publication of the final
rule on June 26, 2001. Prior to advancing with the project, two flyway
councils, seven states directly on the flight path, and 13 adjacent states
approved easements for the crane project.
Home
|