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A Brief History
of Wildlife Fertility Control
The concept of wildlife fertility
control is not new and research has been carried out for many
years. Most of this work was based on the fruits of human
contraceptive research and therefore mirrored human contraceptive
technologies. This in turn meant that until recently, the
most common approach to wildlife contraception was through
the use of steroid hormones, and particularly natural and
synthetic estrogens, progestins, and androgens, similar to
those found or used in humans. Zoos really led the way, administering
these compounds to captive animals, where delivery was not
an issue, but their use in free-roaming wildlife was another
issue. These compounds often worked in a pharmacological sense
but they fell far short of the standards that permit them
to be used with free-roaming wildlife. Basically, they failed
because
1. they had to be given in extremely large quantities, ruling
out remote delivery
2. they had to be administered too often
3. they caused a variety of pathologies in treated animals
4. the cost was relatively high
5. they often had profound effects upon social behaviors
6. they were often unsafe to administer to pregnant animals
7. they passed through the food chain to predators - human
and otherwise - and scavengers.
Because of these shortcomings, there was little hope that
they would ever be publicly-acceptable for use in free-roaming
wildlife by regulatory agencies. For more extensive reading
on the history of wildlife contraception we suggest Kirkpatrick
and Turner, 1985, 1991, 1995; Seal 1991 (referenced in the
Bibliography).
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