There weren't ever too many Dingoes in this part of the State/Country, and now, no wild or feral dogs, altho a few of thousand years ago, or maybe as much as 10,000 years ago, there was a larger population of Thylacines (commonly called Tasmanian Tigers - considered completely extinct here for at least 2,000 years, and likely extinct in Tasmania now too) but even in Tasmania, where they were more prevalent until early last century, they never had much to do with rabbits (they just weren't ever really interested in them, then their population was decimated pretty effectively before the rabbit invasion truly began, so they never had much effect!)
Even when Europeans first arrived here and the climate was a bit colder, milder, and wetter, Dingoes were largely found further out in the drier areas to the North and to a lesser extent, on the open plains to the South East of the Adelaide Hills, but they were never really prevalent in the Hills themselves. Apparently, the bush was too thick and the climate was a little too cold and wet around here for them (the Hills were somewhat colder and wetter back then than they are now, even in my lifetime, often seeing significant snow in the Winter time), so when rabbits arrived, there weren't really any large-ish predators to keep their numbers in check (well, none except for the Drop Bears, Bunyips, & Carnivorous Kangaroos, most of which had died out locally thousands of years if not millennia ago, leaving those big carnivores considered extremely rare around here... until the Europeans brought in another imported feral species as prey, the Tourist; and when
that prey population boomed, the local predator populations of those animals also boomed!
)
All our locally endemic Owls are pretty small too, never growing too much larger than the average adult human's hand sorta size, so they haven't ever and still don't have much of an impact on rabbits; but as I mentioned earlier, the local Kite, Hawk, and Eagle populations are extremely well fed/gorged on rabbits atm. Their numbers are breeding up, but they don't breed and grow numbers anywhere near as fast as rabbits! So the entire population of predator avian species is having about as much the same impact on the booming rabbit populations as a single vegetarian mouse would have on trying to eat a herd of dead Elephants, especially if the herd of dead Elephants miraculously doubled in size on an almost nightly basis like the rabbit population appears to be doubling - the numbers of rabbits are well beyond just 'exponentially increasing' now!
IIRC, rabbits can become fertile as young as 2-3 months old; the gestation period for a female rabbit, a doe, is about 30 days, and she can have up to 12 kits per litter and up to 12 litters per year (altho the average of both is only about 6); she can then become pregnant again within 24 hours; and even if only half of her offspring are females (altho there's growing evidence that more females than males are generally born per litter!) if you do some basic arithmetic, you should be able to see how the population can increase exponentially rapidly! Just
One breeding pair can produce a million breeding offspring in a couple of years or less, and we started here with significantly more than one breeding pair significantly more than 4 years ago, so there's very likely many,
many,
MANY more rabbits than that around now!! And in the 'almost perfect conditions for them' that we've been experiencing for the last decade or so, they're clearly breeding like only rabbits can!!
The only real impact we've had on rabbit numbers lately has been thru introduced diseases, like myxomatosis and Rabbit Haemorrhagic Disease (calicivirus) but those really only spread rapidly thru the population when the conditions are right for increased mosquito & flea populations; only thru a number of factors, including deliberate breeding with vaccinated domesticate rabbits (they might make cute pets, but breeding/keeping domestic rabbits during these times should be banned!) it only takes a few years for the rabbit population to start building an immunity to a particular strain. All of that adds up to a need to develop and test a new variant of those diseases every few years, then test them to make sure they can't spread to other populations &/or people, before releasing them into the wild rabbit population.
I'm beginning to think we've lost this round, simply by not getting on top of it soon enough, so we probably won't see the rabbit population fall too much until they either eat themselves (and probably us too!) into starvation, or some other disease is developed to cut the numbers!! And as a result of their boom and bust cycle, we'll have following boom and bust cycles in what few species of predators we have left! Who knows, maybe the cane toads will spread this far South and somehow have an impact; but for now, after a sleepless night due to the incessant barking at the rabbits of all the dogs in the neighbourhood, and cos they've completely ignored the ultra-sonic 'rabbit scarer' that I've had out there for a day or so; then this morning, going out to see my 'new', laboriously (& expensively!) installed, just over a metre high, double layered and
electrified wire netting fence completely collapsed onto what's left of my lawn by the pure weight of numbers in the dawn rush of at least a couple of hundred rabbits (the fence was still standing at 04:00, altho there were 20 odd rabbits of at least 6 generations inside it by then anyway, obviously the best jumpers. I cleared them out then, only getting bit by the fence once, much to the Child Bride's amusement and the neighbours sudden awakening to the loud and not so deleted expletives!
), I think I'm gonna hafta give up on trying to save the lawn &/or keep it green for now.
