Tetrapod Zoology

The mastiff cat hypothesis

i-07acc3ef3e1b949027034bcaeb700084-cat country.jpg

In the previous post I discussed some of the interesting goings-on that happened at the 1st Annual Big Cats in Britain Conference, held at Hull between the 23rd and 25th March. If you found any of the stuff I covered interesting, then you’ll be pleased and (hopefully) intrigued to know that I didn’t even get round to writing about the stuff I found really interesting. As promised, there are some revelations which – if valid – are just jaw-slackeningly amazing…

In the previous post I wrote briefly about Kellas cats, a population of melanistic felids first discovered in 1984 and now known from several specimens, some dead, some alive (one of which is pictured below). Kellas cats – generally regarded as introgressive wildcat x domestic cat hybrids – are not much bigger than either wildcats or domestic cats, and are nothing to do with the much larger species that also inhabit the British countryside (lynxes, leopards and pumas), despite the efforts of journalists and TV people to claim that they are. The first Kellas cat specimen to be obtained was shot dead near Kellas, West Moray, in 1983 and appeared in the national press in the October of 1984. Another black felid specimen, dubbed the Revack cat, had appeared in the press in June 1984 and is usually regarded as the first Kellas cat specimen to be brought to attention. Di Francis – the mystery cat researcher I introduced in the previous post – investigated these specimens. The Revack cat then disappeared, being known only from photos for years, until Di tracked down the taxidermist it had been given to. Luckily he still owned the skin, though it lacks a tail. The Kellas specimen, shot by Tomas Christie, did not go missing and is, today, a relatively famous taxiderm mount widely figured in the literature (Shuker 1989, 1990, Francis 1993a, b). Remember all this, as we’ll be returning to in the next post.


As anyone who has read Di’s books or articles will know, it is ironic that her involvement with these small black felids resulted from her search for the larger mystery felid that she thinks inhabits the British Isles. As explained in her 1983 book Cat County, Di has concluded that Britain is home to a large felid of a new species. It is purportedly diverse in coloration, with females being brownish or greyish, juveniles being striped, and males being black and, while superficially puma-like, it has a unique manual morphology, large, subtriangular ears and a distinctive pug-like squashed rhinarium (Francis 1983). Myself and colleagues have taken to calling this semi-hypothetical felid the Mastiff cat (in part for reasons that I can’t yet discuss).

If this idea is new to you then you may well consider it ridiculous. I personally cannot take seriously the idea that Britain might harbour an undiscovered species of large mammal, and indeed Di’s hypothesis has not gone down well among other mystery cat researchers. Not only is there no evidence for a new large British felid in the fossil record, it’s been mostly concluded that the diverse morphology she described for mastiff cats reflects the fact that the creature is a composite, based on sightings of species as diverse as feral domestic cats, jungle cats, lynxes, pumas and leopards. A mastiff cat ‘cub’ photographed in Wales looks almost identical to a big tabby, like the late Toby in the photo below [from my flickr site]. Di points to several good eyewitness reports – made at close range, sometimes by experienced observers – that describe a cat in great detail, the problem being that that cat does not match with any known species. I admit that this is indeed a problem, especially given that the reports in question are consistent.

I will end there on this subject, though I’ll say that this is not the end of the story. Most photos depicting the corpses of large British felids clearly show known species, including jungle cats, leopard cats and lynxes. However, as revealed at the conference there are some corpse photos that don’t match any known species. I cannot say any more and will stop there. As I’ve said, I personally find it just about impossible to think that Britain – or, indeed, the whole of Europe – might harbour an unknown mammal as large as a puma but then, remember that personal incredulity doesn’t count for much. It’s worth noting that, of the more than 30 new mammals described from Europe in the last 100 years, the biggest is a hare (go here for discussion of these species).


Based on the new evidence revealed at the conference, I was interested enough in this issue to take a vote. Yes, I know that science doesn’t work like that, but it’s still worth finding out which way opinions are going. Out of the 24 or so people there to participate, a clear majority (c. 20) thought that Di’s mastiff cat hypothesis was at least worthy of consideration as a hypothesis. And of those c. 20, c. 6 – including myself – had previously thought that Di’s hypothesis was not worthy of serious consideration. Among this number were most of the more experienced, qualified researchers present. Incidentally, the numbers are approximate because I can’t count.

And that’s not all. More to come.

Refs – -

Francis, D. 1983. Cat Country. David and Charles, Newton Abbot.

- . 1993a. The Beast of Exmoor and Other Mystery Predators of Britain. Jonathan Cape, London.

- . 1993b. My Highland Kellas Cats. Jonathan Cape, London.

Shuker, K. P. N. 1989. Mystery Cats of the World. Robert Hale, London.

- . 1990. The Kellas cat: reviewing an enigma. Cryptozoology 9, 26-40.


  1. #1 Mike
    March 29, 2007

    “Remember all this, as we’ll be returning to in the next post.”

    “for reasons that I can’t yet discuss”

    “I will end there on this subject, though I’ll say that this is not the end of the story.”

    “I cannot say any more”.

    Darren Naish: The Gypsy Rose Lee of vertebrate zoology. :-)

  2. #2 Monado
    March 29, 2007

    A few years ago, I read that slender black cats had been found on an island in Egypt, in the Nile River. There was a photo. Supposedly they look a lot like the Egyptian cat statues. Have you heard of them?

  3. #3 Christopher Taylor
    March 29, 2007

    My immediate thought is that even if the “mastiff cat” should turn out to be a new species (though I’d be waiting for the physical specimen, personally) it may not necessarily be native to Britain. Certainly in invertebrates there’s a reasonable list of species which were originally described from anthropogenic populations outside their native ranges (for some of which, the original habitat has not yet been discovered). Of course, vetebrates are usually a bit harder to miss, but I believe at least some species were originally described from zoo specimens?

  4. #4 Markk
    March 29, 2007

    More to come, indeed. You are such a tease.

  5. #5 Curious in Cornwall
    March 30, 2007

    As promised, there are some revelations which – if valid – are just jaw-slackeningly amazing…

    Sorry in advance for asking this. I’m genuinely curious, and I really don’t mean to be an asshole. But what are the revelations you speak of? Di Francis thinks there’s an unknown species of big cat roaming around. Hardly anyone else thinks this is the case. What’s new about this? What’s revelatory? And most importantly, what evidence is all this founded on?

    Again, I’m sorry, but to an interested outsider this looks like pure hearsay, and not particularly fresh hearsay at that.

    (please don’t kill me)

  6. #6 Sordes
    March 30, 2007

    The existence of an native unknown species of big animal in GB is really zero, even in most other parts of Europe. The humans managed to whip out nearly all native carnivores from most parts of Europe, not only bears and wolfs, but also smaller ones like lynxes and even wildcats. There were armees of hunters over the centuries, and famers have also a strong tendency to shoot things dead, which could be harmful to their lifestock. If there would be a native species of big cat, there would be tracks in ancient hunting records. There are such records which lists thousands of animals which were shot dead by (mostly aristocratic) hunters, including even every marten or hare, and not only from the last century, but also from older times. If even wildcats had a very hard time to survive, because they were often killed by hunters, it is impossible that there were no recogniced kills of an unknown species.

  7. #7 Mark Lees
    March 30, 2007

    On the matter about there being no fossil evidence for a puma like cat, what about Viretailurus schaubi. This is variously referred to as the ‘European Puma’ or the ‘Short-faced Leopard’ (the latter is interesting in the context of references to cats being ‘pug faced’). I know the fossils are from France and are from Pleistocene strata (I think mid Pleistocene) – but in the meantime Britain has been connected to mainland Europe, and it at least provides precedent for a cat of the right size and general type in western Europe.

    Personally I am highly sceptical that a totally new species of large cat is resident in the UK, but remain open minded. The idea that lynx may have not ever have been totally extirpated from the UK is one I have toyed with for a few years. I think the idea is plausible, but the evidence not convincing. However, if the lynx did hang on, albeit with a tiny dispersed population, what effect would that have on them? It occurs to me that otherwise low frequency phenotypes may come to comprise a higher proportion of the population. Possibly (and I am aware that there are way to many possiblies in this) melanistic or unspotted individuals may explain some of the other cat sightings. I must emphasise that I am not saying that this is likely, just that it seems more likely than a completely new species.

  8. #8 Darren Naish
    March 30, 2007

    Thanks to all for comments. Let me apologise unreservedly for all the annoying references to withheld data. Two points:-

    (1) One of the most interesting animals discussed at the conference is to be covered in the next blog post, hence my reluctance so far to discuss it. I regret that, if you’re familiar with British mystery felids, it won’t be anything new. However, such people account for perhaps 4% of the readership.

    (2) Regarding the mastiff cat, what I’m getting it is that new data was presented at the conference but, because it is strictly embargoed, I’m not allowed to discuss it. Sorry, but this partly explains those cryptic references.

    To Curious in Cornwall: let me begin, again, by apologising sincerely for the extreme and gratuitous hyperbole that I’ve used in my posts so far. They don’t reflect attempts to mislead or be dishonest but – seriously – reflect the genuine enthusiasm I’ve felt since attending the meeting. As just mentioned, the ‘amazing discoveries’ I keep harping on about will not be tremendously new to anyone familiar with the British ABC story, and if you’re a member of that minority then, sorry, but you might be disappointed. I’ve just explained why I can’t talk about one of the animals in question: the second will be new to most readers, and will be discussed in the next post as promised. I will say that no hearsay is involved, however.

    So, sorry; I’ve been gushing and have used lots of hyperbole, but that’s not because I’m trying to mislead, at least not deliberately anyway.

    Sordes: as I stated in the article, ‘I personally cannot take seriously the idea that Britain might harbour an undiscovered species of large mammal’, so I totally agree with you. Indeed most zoologists think that even the small wildcat and pine marten were virtually eradicated from the British Isles by hunting. But, alas, I am now more open-minded on this subject than I was before. Again, it’s due to that data that I can’t yet discuss.

    Mark: yes, Schaub’s panther has not been lost on me. Yikes, I suppose I should have mentioned it..

  9. #9 TheBrummell
    March 30, 2007

    OK, this is interesting, much more so than discussions of rare sightings of what were most likely individuals of non-breeding ‘populations’ originating from human introduction (accidental or otherwise) to the UK.

    Not interesting: Jaguar escapes, eats a deer, is spotted by bird-watchers in Scotland
    Interesting: Lynx may or may not have survived as a UK native species into the modern era, but it is most likely that there is a breeding population resident in the UK
    Very interesting: an undescribed species of felid may be present in the UK, and may or may not constitute a “native” species.

    Annoying: embargoed data. Is it embargoed because the relevant peer-reviewed manuscript is still in preparation or review? Has an expected embargo-lifting date been announced?

  10. #10 Darren Naish
    March 30, 2007

    Thanks for comments Martin. Minor points… photographic and eyewitness data indicates that the alien felids here are breeding, in which case we have established populations. And, contra what you say, I personally think that the presence of an alien species – whether introduced accidentally or deliberately – is interesting. Come on, you know this. Cane toad, fire ant, brown tree snake, Japanese knotweed, ruddy duck… How alien felids fit into the ecosystem of an archipelago that’s apparently been lacking macropredators for hundreds of years is indeed a fascinating subject that we’re only just starting to gather data on.

    Embargoed data is indeed frustrating. There is no peer-reviewed publication unless I (yes, I) push hard to get one produced. There is, instead, a book.. but I don’t know the release date. We will come back to this topic when we can.

  11. #11 Dr Vector
    March 31, 2007

    There is no peer-reviewed publication unless I (yes, I) push hard to get one produced. There is, instead, a book..

    ABC workers who refuse to submit their evidence to peer-reviewed journals have ZERO reason to complain that other scientists are ignoring their findings. IMHO, they can publish or STFU.

    I can’t even imagine why they aren’t doing this. Their science is suffering, capital-S Science is suffering. It’s a lose-lose situation. Please, someone explain to me why publishing books and/or not publishing at all are better strategies for getting people to take you seriously than just writing a damn paper.

  12. #12 Darren Naish
    March 31, 2007

    Thanks for the thoughts Matt.

    My take on this issue is that the people involved are either (1) blissfully unaware of the significance of peer-reviewed literature, or (2) incapable of, and/or uninterested in, technical writing. Having said that, this is all a new area of research and just two days ago I was shown a draft of a semi-technical article, in press, on the subject of field evidence for ABCs.

    By and large I have a really hard time getting people involved in mystery animal research to understand the significance of publishing data and results in the technical literature, and other academics interested in the field have had the same experience. As a general rule mystery animal researchers all seem to think that any new data they have must be put into a book or popular magaziney-type article. Yes cryptozoologists I’m talking to YOU. I have tried on several occasions to get the relevant parties to use me as a clearing house, but I think the problem then is that they feel that they’re losing intellectual rights on their research. Plus, of course, no-one makes money by writing technical papers.

  13. #13 barndad
    March 31, 2007

    Viretailurus schaubi has been known by quite a few different names including, Panthera schaubi, but is now known to be synonymous with Puma pardoides, and therefore a good contender for ancestor of the american puma. If i remember rightly though the sparse records only go to middle pleistocene and there is zero chance that something like this would not have been spotted. Think of how quickly people noticed pumas in the new world when they first arrived. Could something of similar size and habitat have been unobserved for over 2000 years of recorded history in somewhere as densely populated as Europe? I reckon this mastiff cat is most likely to be a composite from inexperienced observers seeing dogs at a distance or domestic cats with no frame of reference for size.

  14. #14 TheBrummell
    April 2, 2007

    Darren politely replied to me with: Minor points… photographic and eyewitness data indicates that the alien felids here are breeding, in which case we have established populations. And, contra what you say, I personally think that the presence of an alien species – whether introduced accidentally or deliberately – is interesting.

    I agree! I agree! I agree! Except with your contention that those points count as “minor”. Breeding populations of alien species, particularly things that sit on top of big food chains, are very interesting. My point was rather that non-breeding psuedopopulations of escapees are boring – they would certainly have an impact on local ecology, but without persistence through generations, not much. How much do we learn about evolution, ethology, ecology, et cetera by discovering a shoddy cage in some fool’s back garden? And a few escapees, dying childless in the wilderness, tells us very little about within-individual behavioural ‘adaptation’ to novel habitats.

    The other examples you list are all considered invasive species because they’ve established breeding populations in novel environments, and have had consequences upon the local environments. Cane toads et alia did not escape from a poorly-run zoo, munch a few deer, and mysteriously disappear – that’s why we care about them (at least, that’s why I occassionally read an article in The Journal of Biogeography).

  15. #15 Peter Jack
    August 22, 2011

    There has been no mention of a TV documentary I saw about twenty five years ago about the black cats of Scotland. I was amazed when they actually caught a specimen, and how spectacularly fierce it looked – flashing eyes, jet black body and showing all is teeth in a constant snarl. I have tried to get more information on the programme, but have been unsuccessful.