Monday, November 11, 2019

Loaded ‘Study’ About Savannah Cats and Hybrids is BAD Science

"Cat Envy" by travis_warren123 is licensed under CC BY-NC 2.0 

 Posted October 30, 2019 on the website of the University of Sydney is a pathetic little blog post inciting enough fear mongering and moral panic fit for Halloween.

“Study shows impact exotic cats would have had on the environment” the post proclaims with confidence, as though the cited study had definitively proven something. 

The study being referred to is “Assessing Risks to Wildlife from Free-Roaming Hybrid Cats: The proposed Introduction of Pet Savannah Cats to Australia as a Case Study”, which was led by Professor Chris Dickman. It addresses the 2008 ban of Savannah cats which was the government’s response to a pet breeder’s application to import the hybrids into Australia, and ultimately concludes that the hastily concocted permanent ban was justified. Professor Dickman states in the post:

“This research assessed the impact that wild populations of savannah cats would have had on Australian mammals. Reptiles and birds would also have been affected.”

Then, he has the absolutely audacity to say this self-congratulatory nonsense:

“This research shows that Australian wildlife dodged a bullet…”
So, is this true?

It should be noted that I have no issue with regulating or prohibiting certain species that pose a real, logical threat to the unique and fragile ecosystem of Australia. There is a long list of species that could pose a significant threat there, or there is a lack of real world examples to examine to justify the risk.

It should also be noted that most of the study is not technically ‘incorrect’. While I’m sure that there are many highly respected intellectuals involved with this research, it remains irrefutable that their interpretations of these results are rife with non-scientific bias against pet ownership.  

Why is this research bad science? 

Properly-conducted scientific research involves the pursuit of objective information about the world. What science should not do is seek to confirm the preexisting belief of the scientist with the formation of a manipulative methodology that will ultimately serve that scientist’s agenda.

First of all, while Professor Dickman states that the study assesses what impacts free-roaming Savannahs would have had, he should have said MIGHT have had, which is more correct. His language continues to slip like this throughout the article.

 Dickman’s study conducted no experiments. Instead, essentially, the study looked at the diet and behavior of servals, and the diet and behavior of domesticated cats, speculated what both species would probably hunt in Australia based on their size and geographical range, combined them, and drew their conclusion with that, as Savannah cats have DNA from both species [3].

What the study gets right is that there is the potential for Savannah cats to escape, just like with any animal (perhaps other than fish). The researchers actually looked to the United States and other places where Savannah cats are owned as evidence of this. Savannah cats, just like servals and domesticated cats, also hunt animals when they escape; these things are true. In addition, something I admittedly learned is that servals prefer to hunt in wetter environments than domesticated cats, potentially expanding their hunting range and prey types [3].

This, combined with their size and climbing ability, was the reasoning the researchers gave to conclude that Savannah cats could cause considerably more damage than regular cats IF they become established. IF.

Which leads me to this next burning question: what are the chances that Savannah cats, which aren’t even a ‘species’ but a hybrid that cannot exist without human intervention, will become established in Australia?

 Absent from this ‘study’ is any attempt to answer this question other than suggesting that the cats are capable of escaping and a quick mention of the Bomford risk assessment model used by the Australian government, which judges the cats propensity for establishment only by climate matching, taxonomic class, migratory behavior, diet, and ability to live in a disturbed habitat [1]. These factors, supposedly used by the Australian government to conclude that Savannahs have an "extreme risk of establishment"[1], ignores exceptionally pertinent information, and would likely conclude the same of the legal F5 Bengal cats that seem to be causing no trouble.

Also presented is a claim that exotic cat sanctuaries are ‘overwhelmed’ with surrenders of these hybrids, referencing a page from The Wildcat Sanctuary, but the link provided shows the main breed being discussed is the much more common (and legal in Australia) Bengal cat that is NOT the same size as the more expensive F1-F3 Savannah cat, nor do the researchers look to the many countries where hybrid cats (in addition to pure exotic cats) are owned in the study.

While the researchers found it appropriate to use escaped Savannahs in the United States as evidence of a claim that backed the conclusion they preferred, did they also take into account the United States’ complete and utter absence of an established and invasive bionic population of Savannah cats in a wide array of climates and biomes? 

Did they assess the many other countries where Savannah cats and other hybrid cats are owned and their presumable lack of invasive hybrid cats? Did they conduct a more detailed assessment of how many of the ‘higher’ content Savannah cats (those which pose the threat based on their increased weight, according to the study) exist relative to the lower generation Savannahs due to their rarity, expense, and difficultly of producing?

 Did they take into account that rates of intentional release of cats that typically range anywhere from $1500 to $20,000 USD (the taller and ‘more bad’ for the environment the cat is, the higher the price) in cost may differ from ‘regular’ cats worth practically nothing?
Of course not. It doesn’t take a rocket scientist to deduct that these conservationists do not like hybrid cats (this mindset is more frustratingly evident in the government's assessment, where they sink so low that they use their personal opinions as some of the criteria to deny the cats entry), or any exotic pets being owned, and therefore they were destined to reach a certain conclusion so they can propose to employ their flagrant bias as ‘framework’ to ban even more animals from entering Australia in the future (“Subsequently, we propose a decision–framework that could be used to evaluate the potential risk to native fauna that is posed by the importation of hybrid cats—and, by extension, other novel taxa…”) [3]. 


Why the Research Is Inherently Flawed and Biased


The people conducting this so-called study should first be asking and addressing this one simple question: Are there ANY species that would not be a potential threat to Australia’s native fauna if they were to establish a feral population?

The absolute shadiest aspect of this ‘risk assessment’ is the fact that it is based on a loaded question that serves the bias of anti-exotic pet ‘conservationists’.


A feral population, or invasive  species, is inherently bad for the environment even if we don't know what the damaging effects are as of present. There are no ‘desirable’ or ‘proven harmless’ invasive species, as since an introduced species doesn’t belong there, it will have the capacity to compete for resources against native fauna, have the potential to introduce novel diseases, and have other impacts that we have yet to discover in a fragile ecosystem.

Without answering the extremely important question of how likely it is for Savannah cats to form feral populations, this ludicrous risk assessment is essentially saying “we concluded that in the completely hypothetical event of something bad happening, something bad is likely to happen”

Let’s set up an answer to a question in the same format of this ‘what if?’ scenario with a pet dog.

While it is very unlikely that your dog will try to kill you, let’s hypothesize what would happen if it did? In this assessment, we found out that your dog has teeth, and other dog attacks have resulted in serious injury and death. Given this capacity, as dog attacks have occurred, it would be reasonable to assume that the same can happen with your friendly golden retriever, despite the evidence of any such disposition in the actual animal in question. We have concluded that if your dog does decide to attack you, there is a strong risk that injury will result. Given the severity of this risk, you shouldn’t have your dog.

*Owner gets rid of their dog*

Follow up report: “Looks like you dodged a bullet”. Authors and ‘scientists’ proceed to congratulate each other on their ‘findings’ that saved the dog owner. “That’s good science!”

See how dumb that is?

Ironically in this example, a dog with no aggression in its history is still probably more likely to randomly attack than there is the potential for the existence of a feral population of tall Savannah cats.

Assessing the Likelihood of  'Tall' Savannah Cats (3.5-8kg) Becoming Established

1.    Have there been any confirmed births of wild-born Savannah cats at all? Even once?
2.    The fecundity of ‘tall’ (F3-F1) Savannah cats.
3.    Relative density of ‘tall’ Savannahs given their expense and rarity within the populace.
4.    Assess the number of ‘tall’ Savannah cats that have gone missing, instead of speculating that they have similar rates to domestic cats.
5.    Assess the histories of introduction for successfully established mammals and compare.

What really needs a lot more study is how often mammals in general become established in an environment, and how. As previously stated, I have no problem with banning a species if there is solid evidence it should be banned. I used to think raccoon dogs were an example of this, until I did research about the Federally banned (in the U.S.) animal when writing an article. It turns out that the ‘highly invasive’ raccoon dogs were intentionally released by the thousands. While they had incredible migration rates once introduced, it was the goal of fur producers to establish raccoon dogs in the environment so they can be hunted, and they succeeded…shocker. Yet somehow this means that raccoon dogs are invasive animals. 

 The red fox is another invader of Australia that was, again, intentionally introduced. The extremely destructive invasion of European rabbits in Australia was—again—the fault of an intentional introduction for sport hunters [4]. The European carp was brought up in the Australian government's assessment as an example of ‘hybrid vigor’, in which a different strain of carp was added to a preexisting population of the fish, which then resulted in a rapid increase of the animals in the 1970’s [2]. This was also an intentional introduction, and unlike servals and domesticated cats, these two carps were the same species, and the invasive strain was highly adaptive due to its development for farming conditions.  

Would these animals be so destructive if they were brought into the country in a controlled and mindful manner along with lack of pre-Industrial Revolution ignorance to the potential damage that an introduced species can cause? That would be a more useful study to pursue.

Risk Vs. Benefit

Of course, I understand that even if the risk of something is incredibly small, if the risk is potentially catastrophic, then it’s better to be safe than sorry. That’s why so many exotic pets are killed if they bite or scratch someone to be tested for rabies; the risk is so incredibly small that, to my knowledge, this protocol has never resulted in rabies being found, but it is done because rabies is almost 100% fatal once symptoms begin.

 An established population of larger cats would be catastrophic for Australia, as would pretty much any exotic invader would be, and potentially irreversible.
However, if it is true that there are no known feral populations of Savannahs or other hybrid cats where they are popular, and if it is true that a single wild-born Savannah cat has never been documented, the risks that this would suddenly be a problem in Australia are likely as close to 0 as it can get.

Add to this that larger Savannahs are not popular compared to ‘regular’ cats. Much of Australia’s introduced species, like the fox and rabbit, began with the simultaneous release of several breeding animals at once. Established populations of mammals from escaped individuals also tend to be species that are pervasive and widely owned (such as domesticated cats, horses, and other common livestock, which of course, are legal in Australia). 

Established populations of mammals that were not domesticated that started solely from escaped or released (without intention of establishment) captive animals seem to be very uncommon, as can be shown here in a list I created of all the invasive species in the United States I could find that originated from the exotic pet trade. Pay special attention to the mammalian list at the very bottom, because it is pathetically tiny, and none of them are widespread. Also in (Bomford, 2006), successfully established mammals in Australia are mostly widespread domesticated animals and 'semi-domesticated' ungulates used in agriculture or sport [1][5].

 As no one is trying to intentionally introduce these pricey cats into the wild, could this man-made ‘breed’ have enough escaped individuals at one time to result in (presumably, unless I'm wrong) the world’s first and only feral Savannah cat population? And could these feral animals avoid the now educated and ready Australian government’s anti-invasive animal defenses to take over in the same vein that the European rabbit did 1788?

These questions should have been addressed by the study. My layperson opinion is heck no, and that the government has no right to deprive citizens of these animals with the lousy ‘evidence’ presented here. Especially when they allow the importation of other domestic cats, do not ban the roaming of domestic cats, and even allow F5 Bengal cats, probably on the basis of their popularity only (“The Department accepts this to be a legacy issue”[3]). 

Unfortunately, pet ownership is not perceived as having any worth or significance for people who love to do it. It sounds preposterous to take any 'risk' for pet owners to people who, surprisingly, have no interest in keeping pets. The 'risk-benefit' assessment is generally controlled by these individuals.

These researchers need to at least acknowledge that their ‘assessments’ are just double standards designed to keep out ‘newcomers’ because popularity rules the roost (this is euphemistically referred to as ‘heritage’[2]) and dictates who gets their rights. If the issue is that Savannah cats haven't been around long enough to determine the effects of their presence, Australia should consider the cats for import in the future. Unfortunately, this sanctioned ‘study’ has eroded my trust in the science of conservation.  


To Summarize: 

•    The information presented in the study does not suggest Australia “dodged a bullet” or "validate the decision to ban Savannah cats from Australia”, nor does the framework present “the likely risks that are posed by the arrival of other hybrid cats or hybrids of other animals” because it doesn’t provide any evidence that there is anything more than a negligible risk that Savannah cats will become established in the environment.
•    The study provides evidence under the presupposition that Savannah cats will be harmful and concludes from this that they will be harmful.
•    The study fails to properly assess the fecundity, density, and cultural attitudes regarding the keeping practices of more valuable cats as well as address feral hybrid cats in other countries.
•    The study suggests that the ‘taller’ Savannah cats that pose the biggest threat to wildlife are as commonly surrendered or intentionally released as domesticated and similarly-sized hybrid cats with no evidence at all.
•    The study seems to inadvertently suggest that other animals approved for import into Australia would have little or no impacts if established, when the reality is that conservationists would not support taking the risk with any exotic species that are not already present and popular in Australia.


1.      Bomford, Mary. "Risk assessment for the establishment of exotic vertebrates in Australia: recalibration and refinement of models." Bureau of Rural Sciences, Canberra (2006).

2.      Department of the Environment, Water, Heritage and the Arts. Final Environmental Assessment of the Suitability of the Import of the Savannah Cat (Domestic Cat × Serval Hybrid Specimens) into Australia; Australian Government: Canberra, Australia, 2008.

3.      Dickman, Christopher R., Sarah M. Legge, and John CZ Woinarski. "Assessing Risks to Wildlife from Free-Roaming Hybrid Cats: The Proposed Introduction of Pet Savannah Cats to Australia as a Case Study." Animals 9.10 (2019): 795.  

4.      Fenner, F. "Deliberate introduction of the European rabbit, Oryctolagus cuniculus, into Australia." Revue scientifique et technique 29.1 (2010): 103.

5.      Reddiex, Ben, and David M. Forsyth. Review of existing red fox, feral cat, feral rabbit, feral pig and feral goat control in Australia. II. Information gaps. Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Melbourne. http://www. deh. gov. au/biodiversity/invasive/publications/information-gaps/pubs/information-gaps-final. pdf (Accessed December 2006), 2004. 

Prices of Savannah Cats:


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