To perhaps one-day combat the effects of such inbreeding, many captive tigers - especially those in zoos - are managed very carefully with respect to their breeding patterns. Detailed records of the history of each tiger involved in an organized breeding program are kept in what is known as a studbook. Tigers can thereby be matched for breeding specifically according to their ancestries, for the sake of producing new generations of tigers that manifest the richest possible genetic heritage. This technique sometimes means that certain tigers whose genetic ancestry is either uncertain or impure are less "valuable" in terms of breeding strategy than others. It's very important to remember that not all captive tigers participate in an organized conservation-breeding operation. In fact, most captive tigers do not. Tigers used for specialized exhibitions such as circuses and magic shows are often bred more for looks than for genetic purity. Even zoos are sometimes willing to house tigers that are more beautiful than they are genetically viable. (White
tigers in particular present a dilemma for exhibitors who hope to support
both conservation breeding and public interest. White tigers are not considered
to be genetically valuable for conservation breeding due to their interbred
genealogies. But the public loves to see white tigers, and zoos, therefore,
must make a choice between housing genetically valuable tigers for conservation
breeding purposes or displaying physically beautiful tigers that appeal
to the general public - and sometimes attract conservation dollars.) Behind
all this lies a quest to preserve the genetic diversity of each of the
remaining five, or perhaps four, tiger subspecies. These captive tigers
may well be an insurance policy in the event conditions deteriorate for
their wild cousins.
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