Dingo CARE Network [Captive Breed]

The Captive Breeding Strategy


Although the keeping of wild animals in domestic settings is not ideal, a key component of the Dingo CARE Network's conservation strategy is to encourage and assist the captive breeding of dingoes that are DNA tested to be pure. The objective of this approach is to ensure that a population of dingoes can be preserved until such time as safe re-release into the natural environment is possible. The strategy is analogous to the idea of Noah's Ark , whereby a limited number of threatened animals are taken into safe keeping for release after the immediate threat to their existence has passed.
It must be recognised, however, that the captive breeding of wild animals for release at a later date has inherent problems and success is often difficult to achieve. A constant threat to the viability of animals bred in captivity is that of inadvertent domestication. It is easy for breeders to unconsciously select for tameness -- to breed from animals that are more manageable. Over a number of generations this can lead to a captive animal stock with diminished viability for survival in the wild. Another problem is that the relatively low genetic diversity of small captive populations can render its members susceptible to disease. Any acute susceptibility to a new disease can potentially wipe out a captive population (New, 2000: 300-203).
Undesirable genetic change over the life of the captive program can occur due to: ‘loss of variation due to limited population size’ and due to ‘genetic adaptation to the captive environment’ (New, 2000: 303). The first type of change can occur as a result of ‘genetic drift’ whereby random genetic mutations might come to characterise an entire small captive population in a way that would not occur in a large population. Such changes may not always be benign in terms of ability to survive in the wild. The second type of genetic change involves the affects of selection pressures arising from the captive environment.
Characteristics important to survival in the wild can become ‘relaxed’ within a domestic environment, such as the relaxation of the instinct to hunt in a situation where food is supplied without the exercise of this instinct. In the wild, animals with significantly reduced hunting instincts or drive would not likely survive to reproduce. In captivity, such animals are likely to reproduce and in a small population this reduced viability may pervade a captive population within relatively few generations (New, 2000: 303-304).Tim New sums up the problems posed by limited genetic variability in captive populations in the following way:
Genetically based variability reflects the variety of individual capabilities and tolerances among the members of a population. Populations that lack or lose this variability may suffer from some form of reduced ‘fitness’… irrespective of the suitability of their environment. (New, 2000: 304) The difficulty in avoiding the degeneration of ‘fitness’ for survival in the wild amongst captive populations, and the rapidity with which this can occur, provides a strong argument for supplementing captive breeding with the cryopreservation of reproductive material from DNA pure dingoes which are either born in the wild or are the product of only a generation or two of captive breeding. Potentially, frozen sperm and eggs could be used to slow the loss of ‘fitness’ of captive dingo populations. New, T. Conservation Biology, an Introduction for Southern Australia , Melbourne , Oxford University Press, 2000