Captive breeding means
that members of a wild species are captured, then bred and raised
in a special facility under the care of wildlife biologists and other
experts.
Captive Breeding as a Conservation Tool
Captive
breeding is expensive and doesn't always work. (Some species, such
as giant pandas, rarely breed successfully in captivity.) But
captive breeding has some amazing success stories and several good
reasons to try it. Bringing an animal into captivity may represent
the last chance to preserve a species
in the wild in these situations:
- When
a population drops dangerously, captive breeding can boost
numbers. Captive-produced young can sometimes be released
into the wild where populations have diminished or disappeared,
yet where suitable habitat remains to support them. For example,
the very low numbers of wild Whooping Cranes caused biologists
to try
safeguarding the species through captive breeding. Starting
in 1967, eggs were collected from the the last remaining natural
migratory flock. Eggs were collected for several years by
biologists. These eggs became the birds of small captive populations
that now
provide chicks for projects to help bring Whooping Cranes back
from the brink of extinction.
Thanks
to captive breeding, experts began in 2001 to establish a second
wild migratory flock of Whooping Cranes to safeguard this highly
endangered species.
- When
all of the existing habitat is poor quality or other environmental
problems occur, a captive population can be maintained until
the problems can be solved or another appropriate habitat can
be found for the animal in the wild. This kind of project allows
us to bank a species. The California condor is an example
of a bird that has been temporarily banked in captivity.
- When
the existing habitat is fragmented, as in the case of the extremely
rare Philippine eagle, captive breeding combined with management
of the wild eagle may provide the only hope for survival by providing
opportunities for genetic mixing. This eagle has been
known to exist on only four of the 7,000-plus islands that make
up the Republic of the Philippines, and captive breeding programs
try to maintain separate genetic lines. Through the addition
and exchanges of young captive birds, scientists can help prevent
inbreeding by mixing the birds on each island genetically.
- When
a group of birds stays in one area of degraded habitat because
they are behaviorally trapped, captive breeding and release programs
can help them to expand their range. Mauritius kestrels
appeared to be doomed when they did not leave their small area
of diminishing natural forest. But captive-bred young Mauritius
kestrels were released into other areas and habitats on Mauritius,
where they quickly adapted and thrived.
- By
holding and breeding birds in captivity we learn a great deal
about them that may be difficult or impossible to accomplish
in the wild. Sometimes this scientific research provides
some of the information necessary to save a species.
Try
This! Journaling Questions and Activities
-
Prepare
a list of questions to ask about captive breeding if you could
interview an expert. What special challenges are faced by captive
breeding facilities and researchers? Why is captive breeding a
decision that should not be taken lightly? How could you get answers
to your questions? Next spring, send your toughest question about
captive breeding of whooping cranes to Journey North's Ask the
Crane Expert.
-
Create
presentations about endangered species for which captive breeding
programs are underway or have proved successful. For example, the
USGS Patuxent Wildlife Research Center in Maryland has captive
breeding programs for several species. The International Crane
Foundation in Baraboo, Wisconsin has captive breeding facilities
for many crane species. The World Center for Birds of Prey in Boise,
Idaho captive breeds endangered raptors such as the harpy eagle
and peregrine falcon.
-
Interested
students may wish to investigate an unfolding captive-breeding
success story and report on the status of black-footed ferret today.
The quest to save black-footed ferrets (Mustela nigripes)
has been called the environmental detective story of the 1980s.
Until a Wyoming ranch dog brought home a dead black-footed ferret
in 1981, many experts thought this rare mammal was extinct. Then,
when diseases were wiping out both ferret prey and the ferrets
themselves, the Wyoming Game and Fish Department and the U.S. Fish
and Wildlife Service faced an emergency. Unless they did something
fast, ferrets would go extinct. (What would YOU do?) By February
1987 the last known member of the world's only free-ranging ferret
colony was captured. With these 18 captive ferrets, the species
had a chance for survival. Since then, ferrets have been released
back into the wild. Conduct research to find out how they're doing!
National
Science Education Standards
- All
organisms must be able to obtain and use resources, grow, reproduce,
and maintain stable internal conditions in a constantly changing
external environment.
- Environments
are the spaces, conditions, and factors that affect an individual's
and a population's ability to survive and their quality of
life.
- Scientists
use different kinds of investigations depending on the questions
they are trying to answer.
- People
have always had problems and invented tools and techniques to solve
problems.
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