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

Cats are <strong>of</strong>ten thought to pose a serious threat to birds, yet dietary studies show that
cats eat far more rabbits, rodents <strong>and</strong> reptiles than birds (Potter 1991). Garnett <strong>and</strong>
Crowley (2000) assessed <strong>the</strong> conservation status <strong>of</strong> all declining birds in Australia,
<strong>and</strong> listed Cats as a potential threat to only one species within <strong>the</strong> Rangel<strong>and</strong>s, <strong>the</strong>
enigmatic night parrot. O<strong>the</strong>r potential threats to this bird include foxes, rabbits,
camels, overgrazing by stock, <strong>and</strong> altered fire regimes, <strong>and</strong> cats are not clearly
implicated. Because Garnett <strong>and</strong> Crowley drew upon a large pool <strong>of</strong> bird experts, <strong>the</strong>ir
report is here considered more credible than that <strong>of</strong> Dickman (1996), who proposed
on <strong>the</strong>oretical grounds that cats pose a threat to a significant number <strong>of</strong> declining
birds. The perception that cats pose a dire threat to birds has arisen partly because
many people see pet cats catching birds in gardens. But garden birds usually belong to
abundant species, none <strong>of</strong> which are threatened by predation.
Cats in arid areas eat large numbers <strong>of</strong> reptiles, but Australia’s reptiles appear to be
remarkably resilient to new <strong>impact</strong>s, <strong>and</strong> very few species are listed as threatened.
The Great Desert skink (Egernia kintorei) is one that may be threatened at some sites
by cats.
Cats may also pose an indirect threat to native mammals by transmitting <strong>the</strong>
protozoan parasite Toxosplasmosis. There are suggestions that Toxosplasmosis
contributed to declines in quoll species (Abbott 2002), <strong>and</strong> <strong>the</strong> disease also infects
b<strong>and</strong>icoots.
Cats can multiply quickly. They have a higher reproductive potential than foxes or
dingoes, first breeding at ten months <strong>of</strong> age <strong>and</strong> breeding continuously under good
conditions <strong>and</strong> at any time <strong>of</strong> year. They can build up numbers quickly after droughts
break or during rabbit <strong>and</strong> rat plagues. They can produce three litters in a year with a
litter containing as many as eight kittens. Unlike dingoes <strong>the</strong>y do not need to drink.
They will take prey weighing up to two kilograms, but <strong>impact</strong> falls most heavily on
smaller species, especially those weighing