Sunday book review – Cat Wars by Peter P. Marra and Chris Santella

k10809I’m not a cat person; I’m not a dog person either; I’m not really a pet person at all.  I prefer my animals wild and free, or cooked and on a plate. And so I enter this subject, the impacts of domesticated and feral cats on wildlife, with a slight preference for hearing that cats are a problem and that careless cat-owners are to blame, rather than hoping to read that cats have had no impacts on the natural world.

This book will be slightly uncomfortable reading for many cat-lovers – and so I recommend it very strongly to them, and pretty strongly to everyone else as it is a fascinating story and one that is well written to boot.

The book opens with the story of the extinction of the Stephens Island Wren (not a wren really, but, yes, it lived on Stephens Island, off New Zealand). The last of very few species of flightless passerines to have survived on Earth until a cat arrived on the island, it seems a pregnant cat, and then very soon there were lots of cats and no Stephens Island Wrens.

There are lots of such stories of avian extinctions and taken together they weigh heavily in the litany of evidence against introducing predators into places where they have never previously occurred.  Rats and cats have caused lots of problems – of course, it was we who took them to these places and we who released them (no rat or cat has ever sought out predator-free islands and sought deliberately to eat its way through a flightless endemic mammal, bird, reptile or amphibian).

But how about continental systems where there are plenty of predators already, or maybe there used to be before we bumped them off, how do cats perform in those circumstances?

We all have anecdotes on this subject, don’t we? Both my next door neighbours changed last year (was it something I said or didn’t say?). This led to a very noticeable change in cat visits to my garden. On one side I now have an active dog and two active children yapping away in the garden which must make it a less attractive route for passing cats, and on the other side the former cats’ home is now a cat-free and child-rich zone. I see far fewer cats in my garden and my strong impression is that I now see more birds, and the nesting Blackbirds of this year were a first. Coincidence? Maybe, maybe not.

But we can do much better than anecdotes, and this book gathers together a large number of studies, many from North America and rather few from Europe or the UK.  This is something of a relief actually, I find it easier to read about the science of feral and domestic cats in Wisconsin in a moderately dispassionate way than I do to read about the issues here at home.  Clearly, although we all know that cats kill a lots of small vertebrates, and eat some of them, an awful lot of small vertebrates die every year anyway; if they didn’t then we would soon be knee-deep in frogs, lizards, voles and Great Tits and the world would be a very different place.  So the search for the impact of cat predation on wildlife has to tackle the issue of whether the deaths at the paws of cats are ‘additive’ or ‘compensatory’ in the inadequate jargon of science (‘compensatory’ is a particularly inadequate phrase but it’s the one used the most).  It’s not enough to say ‘cats kill lots of animals, therefore they must cause declines in animal populations’ because that doesn’t show that the mortality is extra mortality, nor does it, of itself, show that it is enough mortality to cause a population decline.

So ideally, we need lots of data and some clever modelling to assess the likelihood of measured losses of animals to cats being sufficient explanations for changes in animal abundance or more ideally we need experiments where we manipulate predation pressure by cats and see what happens. Introducing cats onto Stephens Island was like a badly designed and badly monitored experiment – but very convincing nonetheless. We know that the Stephens Island Wren was vulnerable to predation by being flightless, small and unevolved to cope with this new pressure; we know that the cats killed and ate the Wrens, and we know that, having survived there for thousands of years, the Stephens Island Wren disappeared from Stephens Island in a very few years after Tibbles the cat arrived. It’s not an experiment but it is convincing. Ideally we would have lots of islands where we introduced cats in different years and saw what happened but that would be rather unethical and practically difficult anyway since there is only one Stephens Island.

My observations in my back garden would be useful if they were more structured (like if I had some numbers to back up my impressions of cat abundance and bird abundance) and if they were replicated over many gardens, over longer time periods, and ideally (again) if cat numbers were experimentally increased after a period to see whether the impacts were reversed.

This book takes you through these areas and you are likely to come out the other side believing that cats can, and do, make a difference to the abundance of other species (their prey species) in a variety of places and situations; sometimes a big difference and sometimes a smaller difference, but often a difference. But if you are very keen on Tibbles then you may find room for quibbles.

We are then taken on a journey through potential routes to solve the problem of roaming cats and these range through keeping them indoors more, through fitting them with bells and bleepers to TNR (trap-neuter-release of feral cats) and on to killing the cuddly critters.  All of these approaches are evaluated.

The book ends with a series of passages that could be summarised with the question ‘Why bother?’, which is always asked about restoration of a more natural and usually richer ecology. The authors answer it well. In fact, the authors do everything well in this book. It is a contentious subject which is dealt with very sensibly, and it involves some quite challenging science which is explained well. And it is a good read and not the least bit dry (nor sensational). We move from place to place and we are introduced to  a variety of scientists and players in the story.

I enjoyed this book a lot, and rather more than I thought I might.

Cat Wars: the devastating consequences of a cuddly killer by Peter P. Marra and Chris Santella is published by Princeton University Press.


Inglorious: conflict in the uplands by Mark Avery is published by Bloomsbury – for reviews see here.  Updated paperback edition now out.

Remarkable Birds by Mark Avery is published by Thames and Hudson.

Website Pin Facebook Twitter Myspace Friendfeed Technorati Digg Google StumbleUpon Premium Responsive

Get email notifications of new blog posts

Registration confirmation will be emailed to you.

18 Replies to “Sunday book review – Cat Wars by Peter P. Marra and Chris Santella”

  1. I also reviewed this book and found several flaws especially when we come to the cost of the removal of rats and mice especially as 'bird feeding' is one of the main cases of rats especially in Urban settings!

    The modern day solution to this is poison! Deadly poison which also causes secondary poisoning in a lot of species like Barn Owls, Red Kites, Polecats and even causes cancer in cats and dogs. One incident in USA where the book is mainly based showed that a grain shipment from China which could have been used in human consumption killed over 1000 dogs as it was contaminated with this poison. So this poison is close to getting into the human food chain and at what cost!

    The book gives some great indications about the use of Coyotes to remove 'feral' cats but does not expand on it especially as Coyotes are a very much expanding species in the USA.

    As far as extinctions can you blame the cat or MAN for introducing them in the first place!
    Ps the new British law on the use of this poison will not make any difference especially as the things they try to poison actually can move away from the place where the poison is baited!

  2. A few decades ago it was commonplace for dogs to be allowed to roam the streets and take themselves for walks, fouling the pavements as they went. That is no longer acceptable. The same re-education is possible with cats. My cat has free access from the house to an outside run when we are not at home and access to the garden when we are in. He knows he must not leave the confines of the garden and very rarely does. He has caught the odd frog and mouse which we have released unharmed and his only kills have been two baby sparrows which fell from the nest too soon. It is perfectly possible to be a responsible cat owner but it needs a huge change of attitude.

  3. People are very quick to throw out the 'Stephens Island Wren' story as an example. True, the cat discovered the species, true the cat brought the last one ever seen in to the lighthouse keeper. But few people remember that as part of the building of the lighthouse most of the islands tree cover was removed and grazing livestock brought in to sustain the lightkeepers! My view is that without the cat, we would have lost the 'wren' anyway and never would have known of its existence. Ultimately, human impact is to blame.

  4. When my kids were little (we're talking nearly 20 years ago) I had to patrol the garden before I could let them play. On one occasion, I had to remove 15 piles of cat faeces. Not nice.

    Now (at a different house) I'd love to feed the birds in my garden, but we are still overrun with cats, making it quite impossible. The smell of cat urine at times can be overpowering.

    Cats seem to be the perfect pets for the irresponsible. You get to stroke them etc., then they go off and defecate and urinate in other people's gardens.

    Any suggestions on how to prevent this gratefully received. By the way, 'buying a dog' is not an option!

    1. Don't waste your money on one of the high-pitched-noise cat scarers - they don't work! Try to avoid bare patches of friable soil in your garden, 'cause that's where they poo; keep it well-vegetated or with hard trampled/compacted soil. Don't have any loose gravel on driveways because they'll use that. But if the weather is dry and the soil is hard they'll poo on your grass surfaces anyway. It isn't a good idea to shoo the cat away accompanied by swear words when your neighbours, the owners, are out in their garden and hear you - it doesn't go down well!

    2. 'Any suggestions on how to prevent this gratefully received'

      Take your pick:

      1. It is as illegal to get caught shooting at cats, even with an air rifle, as it is at raptors. Although I'll admit, the police seem a trifle more motivated to find who shot at the bloody stinking moggie than the raptor.

  5. My concern is that pointing the finger at domestic cats absolutely plays into the hands of the shooters 'you'll never have any wildlife in this country if you allow predators to survive' message.
    BTO data suggest that most of the species regularly taken by cats are doing not too badly - often better than rural species more exposed to farming activities.

    1. Precisely - and like it or not, cats are doing what their instincts tell them to do.

      Just as hen harriers are, when they take grouse chicks or, maybe, rarer birds.

      But we all love hen harriers!

      1. 'cats are doing what their instincts tell them to do.'


        All the more reason not to have them then. Introducing a non native predator into an eco system is going to have an adverse effect.To then give the non native predator legal protection is perverse. The problem is that cat owners are too stupid, ignorant or inconsiderate to accept the harm their pets cause.

        1. One of the very nice things about both Mark and his blog is the friendly and constructive tone that usually prevails, even when people are really cross about things. Let's not lose that.
          The comment by Alan (no relation) below is very interesting. Despite my efforts to prevent it, birds quite often fly into my windows, and some of them die. I guess I'm just too stupid, ignorant and inconsiderate to brick them all up.

          1. Alan Two - very kind of you to say so. I try to be friendly - and sometimes fail but quite often succeed. You should see the responses that get written and never posted!

          2. Maybe as well as being nice, we should also try to remain logical and rational. That generally is helpful when you are trying to present a case or arguing for change.

          3. De omnibus dubitandum - thank you - I try that too. But I'm not sure there is a lot of evidence to back up that claim.

  6. I've found making up a catnip "tea" is very helpful in redirecting cats. Drop a few cat toys in a bucket full of water and then on a nice hot dry evening, tip the whole thing whereever you want to redirect the cats to. They'll roll around getting high in it and losing all sense of self and setting.

    I dump it on the gravel drive two doors up, where the inhabitant has several moggies which they let loose. The next day I never know which is louder, the wails of the cats as fight for a spot there or the wail of the inhabitant who struggles to remove a dozen cats long enough to get their car in and out of the garage. On more than one occasion I've heard them bemoan that their cats are supposed to go into other people's garden not have other people's cats come to them. Sadly as it comes to winter there will be less and less suitable dry evenings to dose it.

    The spent cat toys go in the pooper-scooper bin down the road after soaking, of course.

  7. Hmm. Cat's have been associated with humans for about 7,000 years. So suddenly they are causing new problems? 'Wars' even? In Europe, I'd expect their effect has long since been factored in. Of course the number of domestic cats in the UK has probably doubled over (say) the last 50 years but equally the number of cats whose task it is to kill 'vermin' has gone down. Most domestic cats have no need to hunt, and given that cats' hunting skills are not wholly innate - they need to be taught or failing that significant opportunity to learn and practice - most Tibbles owners have no need to fear that their pet is a threat to the natural environment.

    In the USA, estimates for the number of non-natural deaths of birds range widely, but probably about the same number are killed by windows as by cats. 'Window Wars' anyone?

    Almost everywhere, including eg Australia and New Zealand which have more acute problems, all the evidence is that it is feral cats that are the problem. But if we are to go with the science, that is the issue to be addressed - according to context, including the impact on mesopredators - without demonizing domestic pets.

    The serious literature on cats is quite limited. I've read a couple of offerings and I guess I will read this one too, despite its decidedly emotive, unscientific and attention seeking title, which of course will be the fault of the publisher and not the authors.


Comments are closed.