Review of the management of feral animals and their impact on ...

total exclusion <strong>of</strong> goats is required, adequate fences are likely to remain unacceptably
<strong>and</strong> prohinitively expensive. Since fences usually do not permanently stop <strong>the</strong>
movement <strong>of</strong> all goats, <strong>the</strong>y should only be used as a tactical technique in a
<strong>management</strong> program (Parkes 1990). They may be useful for excluding goats from
l<strong>and</strong> containing flora <strong>of</strong> high conservation value when used in conjuction with a
controlled buffer zone <strong>and</strong> continual monitoring.
Shooting
Aerial shooting has been successfully used to control goats (Mahood 1985, Naismith
1992, Maas & Choquenot 1995, Pople et al. 1996). In pastoral areas this method is
mostly used to control inaccessible populations, manage low density populations or
remove survivors from o<strong>the</strong>r control campaigns (Parkes et al. 1996). It may also be
<strong>the</strong> only technique to achieve broad scale reductions when goat prices are low. It
generally involves using helicopters as a shooting platform with light aircraft
occasionally acting as 'spotters'. This method is costly, but allows difficult terrain to
be covered quickly <strong>and</strong> gives culling rates far in excess <strong>of</strong> o<strong>the</strong>r control methods (Lim
et al. 1992). The costs <strong>of</strong> this technique vary greatly, but tend to rise exponentially
with decreasing goat density (Parkes 1993b, Maas & Choquenot 1995).
Ground based shooting is not commonly used as a control strategy for <strong>feral</strong> goats in
<strong>the</strong> pastoral areas <strong>of</strong> Australia due to its labour intensity <strong>and</strong> variable efficiency
dependent upon climatic conditions (Dodd & Hartwig 1992, Edwards et al. 1994).
Shooting goats from <strong>the</strong> ground is mainly used in forested areas, <strong>and</strong> in such areas,
ground hunters may also use trained dogs to indicate, track, or bail goats (Parkes
1990).
Volunteer shooters have been successfully used to conduct ground shooting as part <strong>of</strong>
<strong>the</strong> control methods within Bounceback 2000. The success with volunteer shooters in
this case has been achieved by having well defined objectives <strong>and</strong> an effective system
<strong>of</strong> coordinating <strong>the</strong>ir activities to maximise <strong>the</strong> level <strong>of</strong> control achieved. In one
example from <strong>the</strong> Gammon Ranges National Park (South Australia), 78 volunteer
hunters killed over 3400 goats in about 1000 square kilometres <strong>of</strong> rugged country at a
cost (excluding labour) <strong>of</strong> about $10 per square kilometre (Dodd & Hartwig 1992).
Judas goat
This technique involves attaching a radio collar to a <strong>feral</strong> goat <strong>and</strong> releasing it in <strong>the</strong>
expectation that it will join up with o<strong>the</strong>r goats. The goat is <strong>the</strong>n tracked down <strong>and</strong> <strong>the</strong>
herd which it has joined is killed. Judas goats are generally used where <strong>the</strong>re is a low
density population; to locate survivors <strong>of</strong> o<strong>the</strong>r control campaigns (Parkes et al. 1996)
<strong>and</strong> to monitor areas thought to be free <strong>of</strong> goats (Taylor & Katahira 1988). However,
this technique is expensive as it requires costly equipment <strong>and</strong> skilled staff. It may be
warranted only in areas where extremely low goat densities are identified as being
necessary to protect conservation values or where eradication <strong>of</strong> goats is a feasible
option. This technique has not been used to eradicate goats in flatter semi-arid
pastoral areas. The use <strong>of</strong> helicopters to locate <strong>and</strong> shoot <strong>animals</strong> associating with <strong>the</strong>
Judas goat has not been trialled in Australia, but is used with success in high altitude
grassl<strong>and</strong>/scrub habitats in New Zeal<strong>and</strong> (Hondelink 1992).
Fertility control
The use <strong>of</strong> contraceptive control through hormone treatment is not considered a viable
option for managing <strong>feral</strong> goat populations as <strong>the</strong>re are no practical methods <strong>of</strong>
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