A 2019 paper by Erin Hill and colleagues published in Ecology and Evolution has become something of a touchstone in discussions about the conservation status of Victoria’s wild hog deer (Axis Porcinus) population. The paper’s finding that Victorian hog deer show evidence of historical hybridisation with chital (Axis axis) has been widely cited as evidence that the population is of limited conservation value, a conclusion that, on closer reading, the paper’s own authors did not actually reach, and which emerging genetic research suggests may be even less warranted than previously thought.
What Hill et al. actually said
Hill used mitochondrial and nuclear markers to assess the genetic composition of Victoria’s hog deer population, finding that the mitochondrial DNA of Victorian animals clusters with chital rather than with native Axis Porcinus populations from South Asia. This was interpreted as evidence of historical hybridisation, most likely occurring either in captivity prior to the animals’ release in the 1860s or in the early wild population before chital became locally extinct in Victoria in the 1920s.
The paper’s conclusions regarding conservation value were, however, carefully qualified. The authors explicitly noted that the population “may still be beneficial for future translocations within the native range” and that more in-depth analysis was necessary before any firm conclusions could be drawn. Crucially, they included a specific and important condition: that if natural hybrid zones between hog deer and chital were not detected in the native range after thorough investigation, this would lend weight to the idea that hybridisation between the species occurs only in captivity, which would in turn narrow the possibilities for where and how hybridisation occurred in the Victorian population, and potentially alter the conservation calculus considerably.
This is not a minor caveat. It is a substantive qualifier that conditions the paper’s central conservation conclusion on empirical questions that, at the time of publication, remained entirely unresolved.
Newer research complicates the picture
A more recent study by Arif et al, published in the Pakistan Journal of Zoology in 2024, examined genetic diversity in hog deer using mitochondrial ATPase 6/8 genes and found, consistent with Hill, that Axis Porcinus and Axis Axis cluster closely together phylogenetically. Importantly, however, the Pakistani samples (drawn from zoo-held animals) displayed considerably greater intraspecific genetic variation than the Victorian population, with one sample showing notable divergence from the others.
While the Arif study does not directly test for natural hybridisation between hog deer and chital in wild Pakistani populations, it underscores a point that Hill acknowledged: the genetics of native range hog deer populations remain substantially undercharacterised. The native range question, whether natural hybrid zones exist where the two species’ ranges overlap in northern India, has simply not been answered. And without that answer, the condition at the heart of Hill’s conservation assessment remains open.
To present Hill’s findings as a settled verdict on the Victorian population’s conservation worthlessness is therefore to misrepresent the science.
A convenient misreading?
It is worth asking why a nuanced, conditional scientific paper has so often been reduced to a simpler and more dismissive narrative. The answer may lie less in the science itself than in the policy environment surrounding wild deer management in Australia.
Victoria’s hog deer occupy an uncomfortable position in that environment. As a non-native species, they attract the automatic suspicion that attaches to all introduced fauna, regardless of the specific circumstances of their introduction or their subsequent ecological and conservation significance. At the same time, wild deer as a category have become increasingly subject to broad-brush management approaches that prioritise population reduction across all species.
The problem is that this categorical approach sits poorly with the genuine complexity of the hog deer’s situation. Victoria’s hog deer population is a stable, geographically bounded group representing the largest wild population of an endangered species anywhere outside its native range. The conservation case for treating this population differently is real, scientifically grounded, and explicitly acknowledged in the peer-reviewed literature.
When that case is inconvenient, when it complicates the simplistic narrative of managing all deer the same way, there is at least a temptation to lean on the hybridisation finding as a reason to set it aside. Hill’s paper, selectively read, offers a superficially scientific basis for doing so. More carefully read, it does not.
The stakes
None of this is an argument against responsible management of hog deer in Victoria, nor a suggestion that their ecological impacts should be ignored. It is an argument for honesty about what the science actually says. A population that may represent a genetically significant reservoir of an endangered species deserves to be assessed on the full weight of the evidence, including the evidence that the hybridisation question is more complex than a simple reading of one paper suggests, and that the native range genetic research necessary to resolve it has not yet been done.
Science that is selectively cited to support predetermined policy outcomes is not being used as science. It is being used as cover. The Victorian hog deer deserve better than that, and so does the conservation community’s credibility.
