The Weekly Times are reporting (paywall) on concerns that recent aerial culls of sambar in the Victorian alps could be exacerbating problems with wild dogs.
Whilst it is clear and unarguable that wild dogs to visit and feed on carcasses, the extent to which they do so and to which this would supplement their diet rather than compensate for deficiencies is mostly unknown and open to guesswork.
A study in 2014 looked at how carnivores (wild dogs, foxes and cats) used culled sambar deer carcasses placed at intervals and monitored with camera traps. The findings were surprising to many, including the researchers.
“Although wild dog pups sometimes spent long periods at sambar deer carcasses, we were surprised that wild dogs did not spend more time feeding at sambar deer carcasses and did not contribute more to the removal of edible biomass from carcasses. There are several possible explanations for this. First, our study sites had been subject to wild dog control for many years and hence wild dog abundances were likely low, particularly close to farms (see above), relative to what they would be in the absence of control. Low frequencies of visits to carcasses by wild dogs, particularly adults, suggest that this species was at low density. Wild dogs form large packs in the absence of control and the presence of abundant food, with small packs considered a product of control. Second, the availability of more preferred alternative prey may have meant that wild dogs did not ‘need’ to eat sambar deer carcasses. The diet of wild dogs in south-eastern Australia is dominated by macropods and wombats. The low rate of visits involving feeding supports this hypothesis. Indeed, Fleming et al. considered wild dogs to be “specialist” hunters rather than “opportunistic generalists”. Third, and related to the previous point, the spatially and temporally unpredictable distribution of carcasses in the landscape means that wild dogs (and foxes) may have been using these areas less than other parts of the landscape.”
This is just one, relatively limited study – it is not a conclusive answer to the question and the dynamics involved in wildlife control mean that were it replicated at a different time or in a different place, it may well get a vastly different result.
Another factor to consider is that the deer in the forest will die (and therefore their biomass will be available for scavenging) regardless of whether or not hunters or cullers shoot them.
Hunters and farmers alike don’t like seeing useful animals shot to waste. A survey of 670 landowners in New South Wales and Victoria in 2018 found that even where overabundant wild deer were a problem, hardly any landowners agreed with wasting the carcasses.
All wild deer control should be based on a clear understanding of the impact that needs to be addressed and should include clear and transparent monitoring to determine success or failure. Where public money is involved we should be able to expect nothing less.