Why would you want a field guide to all of the carninvores? They live everywhere, so there is no reason to carry around a field identification guide with ALL of them unless you were going everywhere in the whole world on one trip!
Yet, there is such a field guide, Carnivores of the World (Princeton Field Guides), and the truth is, this is ONE OF THE COOLEST BOOKS I’VE EVER SEEN! All the carnivores (almost) in one book. Interestingly, it turns out to be possible. There are fewer than three hundred species of terrestrial carnivore in the whole world, and that is fittable in a single book.
That itself is an interesting fact, in proper context. Indeed, when I went through this book, spending a bit of time on each and every page, a number of interesting thoughts about carnivores came to mind….
Regarding taxonomy, diversity, and disparity (the former = number of species, the latter = how different they are), carnivores are fairly unique, but in a way that applies as well to primates. Looking only at the regular terrestrial carnivores first, they are all very similar in certain respects yet there is a fair amount of variation among them, including a huge range of body size from the smallest carnivore that could easily hang out in an open soda can to the largest being the northern Bears (either polar or brown, depending on how you measure a species “size”). There are almost 30 orders of Mammalia, and Carnivora is about the fifth most speciose. Yet, Carnivora has fewer than 300 species. Compared to some other animal Classes (Mammalia is a Class). the mammals, for all the interest we have in them, are fairly low density in respect to species (there are something like 10,000 Birds!), high in disparity (the “hooved animals” includes whales and bats fly like birds!) and are rather cryptic with respect to how visible they are on the landscape (compared, again, to birds, which are always rather in your face).
Carnivores, relative to some of the more common mammal Classes, are both ubiquitous and thinly distributed. As you track mammals across the landscape, you might find that certain mammals are highly concentrated here and there, almost absent in other places. The total biomass of bovids in northern climes varies dramatically as you go from herds of bison to forests with thinly distributed deer to tundra or mountain slopes where the highly specialized forms occur in small groups with big gaps between. But everywhere you go, you will be within the territory of a carnivore. In fact, as a rule, you’ll be within the territory of between two and four carnivores, as they tend to divide themselves up by size class, with the classes sometimes competing with each other. In one place there may be otters or minks (small) and coyotes (medium) and either a cougar or a wolf pack (large), or there may be lots of coyotes (large) and otherwise mainly stoats and the like (small). In much of Africa, there will be one large cat (lion) one small cat (golden, wild-house, or sand?) one hyena and two or more mongoose-getet-civet-like creatures that are different from each other in size covering the exact spot you are standing. You’re standing there looking at some bird, and off in the bush there are five carnivores looking at you. In the ancient middle east, there would be lion, leopard, a smaller cat, and an even smaller cat. And so on.
Don’t think about that too much … it is just a rule of thumb. The point is, most space is occupied by carnivores, yet at the same time they are way spread out because of their territorial habits which arose for a number of reasons including the fact that they eat other animals and thus are limited. And, this means that as they disperse during their own carnivoresque personal development cycle, they tend to disperse over very long distances, maybe not during all generations but certainly some. Therefore, some carnivore species have huge ranges, or if they have diversified a bit, some carnivore groups of species have huge ranges. And, for many types of carnivores, there are both tropical and template’s and in between forms. This is not typical of the other orders of mammals.
This is why we get interesting patterns such as the fact that the New World cougar and the Cheetah are close relatives, having differentiated in North America. The Cougar did not spread from North America probably (this is just an educated guess) because medium+ size cats were already everywhere, but the Cheetah was rather a novelty … a doggish cat that could run as fast as the fastest antelope or pronghorn … so it did spread. Subsequent events left the Cheetah only in Africa but it was once more widely dispersed (as a type of cat, not necessarily the same species).
The lion was probably the one mammal among all mammals, other than humans, that has the largest range of all mammals ever, having been spread across North America, Europe, Asia and Africa not too long ago. And so on and so forth.
The result of these patterns of adaptation, dispersal, and ecology is what you see in Carnivores of the World (Princeton Field Guides). When you look at the carnivores organized more or less by taxonomy and then pay attention to the geography, your mind will be blown and you will demand an explanation! How the hell did we get the same basic animal living in the woods of North America (wolverine) and the nearby prairies (badgers) as we have across Europe and Asia and Africa (the honey badger) with about dozen or so other versions all over the place? And you will see other patterns as well; As you thumb through the pages, you will repeatedly see size grading among the carnivores, but most of the size grading is localized. It isn’t like Asia has large otter-mink-stoat critters and Africa small ones .. everywhere gets a range from small to large. Also, as you thumb through the pages, every here and there you’ll see “Crab Eating X” where “X” is some kind of animal (dog, badger, cat, whatever). Either carnivores like them their crabs or carnivore namers are regularly surprised enough to see crab eating that they tend to name anything they see eating a crab after that behavior, even if some of them actually rarely do. (Had I named coyotes after my first extended wild encounters with them, they would be the “crab eating dog”!)
Hunter’s book does not cover the fish. Yes, folks, just as the “hooved animals” gave rise to several fish (whales) and other groups have given rise to fish (hippos, etc.) the carnivores has a fish branch as well (walrus, seals, sea lions). I think it would be cool if Carnivores of the World (Princeton Field Guides) included these critters as well. Including them would make important points about evolution. I respect the fact that this book is written by an expert on land carnivores, so having seals and such in there with the terrestrial forms may be inappropriate. But in a future edition of the book, I would love to see five pages dedicated to the Fish nee Carnivores, not all species but just a nod to the families of seals, walrus, and sea lions.
The other thing that is missing from this book that I would very much like to see and that I must insist (as if I could) be included in the next edition is range maps. I have ideas as to how to make them fit. It is important. (But see below)
Luke Hunter is an Australian who has done research in South Africa and elsewhere. He heads the Panthera Corporation and formerly headed Great Cats and the Wildlife CosnervationSociety.
The Panthera Foundation web site has lots of information about carnivores, and in particular, you can download the range maps that are missing from the book, here!