Category Archives: Dogs

How Dogs Won The World

Years ago I proposed a theory (not anywhere in print, just in seminars and talks) that went roughly like this. Humans hunt. Dogs hunt. Prey animals get hunted. Each species (or set of species) has a number of characteristics such as the ability to stalk, track, kill, run away, form herds, etc. Now imagine a landscape with humans, wolves, and game animals all carrying out these behaviors, facilitated with various physical traits. Then, go back to the drawing board and redesign the system.

The hunting abilities of humans and dogs, the tendency of game animals to herd up or take other actions to avoid predation, etc., if disassembled and reassembled with the same actors playing somewhat different roles, give you a sheep herder, a protecting breed of dogs (like the Great Pyrenees or other mastiff type breeds), a herding dog (like a border collie) and a bunch of sheep, cattle, or goats.

Even human hunting with dogs (not herding domesticated animals) involves a reorganization of tasks and abilities, all present in non-dog-owning human ancestors and wolves (dog ancestors), but where the game are, as far as we know, unchanged. Human hunters documented in the ethnographic record, all around the world, had or have dogs, and those dogs are essential for many hunting types. The Efe Pygmies, with whom I lived in the Congo for a time, use dogs in their group hunting, where they spook animals into view for killing by archers, or drive them into nets that slow the game down long enough to be killed. The Efe actually get a lot of their game by ambush hunting, where a solitary man waits in a tree for a game animal to visit a nearby food source. He shoots the animal from the tree with an arrow. But, even then, the dog plays a role, because the wounded animal runs away. The trick to successful ambush hunting is to do it fairly near camp so you can call for help when an animal is wounded. Someone sends out a dog, and the dog runs the animal to ground. And so forth.

Scientist and science writer Pat Shipman has proposed another important element that addresses a key question in human evolution. Neanderthals, who were pretty much human like we are in most respect, and our own subspecies (or species, of you like) coexisted, but the Neanderthals were probably better adapted to the cooler European and West Asian environment they lived in. But, humans outcompeted them, or at least, replaced them, in this region very quickly once they arrived. Shipman suggests that it was the emerging dog-human association, with humans domesticating wolves, that allowed this to work. Most remarkably, and either very insightfully or totally fancifully (depending on where the data eventually lead), Shipman suggests that is was the unique human ability to communicate with their gaze that allowed this to happen, or at least, facilitated the human-dog relationship to make it really work. We don’t know if Neanderthals had this ability or not, but humans do and are unique among primates. We have whites around our Irises, which allow others to see what we are looking at, looking for, and looking like. We can and do communicate quite effectively, and by the way generally viscerally and honestly, with our glance. This, Shipman proposes, could have been the key bit of glue (or lubricant?) that made the human-dog cooperation happen, or at least, rise to a remarkable level.

The Invaders: How humans and their dogs drove Neanderthals to extinction, by Pat Shipman, outlines this theory. But that is only part of this new book. Shipman also provides a totally up to date and extremely readable, and enjoyable, overview of Neanderthal and contemporary modern human evolution. Shipman incorporates the vast evidence from archaeology, physical anthropology, and genetics to do so, and her book may be the best current source for all of this.

This is a fantastic book, and I highly recommend it. Shipman also wrote “The Animal Connection,” “The Evolution of Racism,” “The Wisdom of the Bones: In Search of Human Origins,” and several other excellent books on human evolution and other topics. Shipman, prior to becoming mainly a science writer, pioneered work in the science of Taphonomy, developing methods for analyzing marks on bones recovered from archaeological and paleontologic sites, such as those marks that may have been left by early hominins using stone tools to butcher animals.

Seriously, go read The Invaders: How humans and their dogs drove Neanderthals to extinction.

Can Dogs Transmit Ebola? And, should Excalibur be put down? they put down Excalibur.

UPDATE: They killed the dog.

UPDATE: I’m adding this here because it is my current post on Ebola. Thomas Eric Duncan, the person who became symptomatic with Ebola in Dallas, had died at the Texas Health Presbyterian Hospital (according to news alerts).

A nurse’s assistant in Spain caring for Spanish nationals returned with Ebola from West Africa contracted the disease, gaining the dubious distinction of being the first person to be infected with Ebola outside of that disease’s normal range in West Africa, Central Africa and western East Africa. There is speculation that she contracted the disease by contacting the outside surfaces of her own protective gear, which is exactly what I’ve speculated to be a likely cause of infection in health care workers. This is not certain, however.

Members of her family and others, including additional health care workers, are in quarantine. There is evidence that the hospital procedures were inadequate to keep a lid on Ebola in this context, and nurse’s unions and others are protesting and demanding change.

Meanwhile, the Spanish government has claimed that there is “scientific evidence” that dogs can transmit Ebola, so Excalibur, the nurse’s family dog, will be euthanized and incinerated. People have gone to the streets to safe the dog.

So, can dogs get, or transmit if they get it, Ebola? Short answer: Yes, and probably not. Here’s my thinking on this, and some information.

1) Pick a random species, or to make it easier, pick a random mammal, and test to see if it can transmit a disease known in humans. It is unlikely to be the case because diseases are to some degree adapted to exist in certain hosts, and host vary, well, by species. So it seems unlikely.

2) On the other hand, Ebola seems to be able to infect a very wide range of mammals. Ebola resides in multiple species of fruit bats (though maybe not uniformly or equally well). A range of mammals seen to be suitable intermediates between fruit bats and humans. The mammals known to be able to harbor Ebola are diverse. It isn’t like only primates can be infected. So, it seems quite possible.

3) On the third hand, I’ve never heard of dogs being addressed as an issue in the current crisis in West Africa or during prior outbreaks. One would think that if dogs were a concern this would have been mentioned by someone some time.

4) On the fourth hand, dogs in Central Africa are less likely to be house dogs, hanging around with the family on the couch, and more likely to be working dogs that spend all their time outdoors. A Spanish family pet may have hung around on the sick bed with an ill individual. I don’t know about dogs in West African cities. By the way, you have to go look to see what the story with dogs there is, and it may within that context. I’ve noticed that westerners tend to have a rather monolithic view of how humans “elsewhere” (especially the “third world”) relate to their dogs, based on a concept we hold of them, not based on actual knowledge. How dogs fit in with humans from place to place and time to time varies.

5) I’ve read a good amount of the peer reviewed literature on Ebola and I can not recall anything about dogs.

5) But … A quick check of Google Scholar did come up with one study. From the abstract:

During the 2001–2002 outbreak in Gabon, we observed that several dogs were highly exposed to Ebola virus by eating infected dead animals. To examine whether these animals became infected with Ebola virus, we sampled 439 dogs and screened them by Ebola virus–specific immunoglobulin (Ig) G assay, antigen detection, and viral polymerase chain reaction amplification. Seven (8.9%) of 79 samples from the 2 main towns, 15 (15.2%) of 14 the 99 samples from Mekambo, and 40 (25.2%) of 159 samples from villages in the Ebola virus–epidemic area had detectable Ebola virus–IgG, compared to only 2 (2%) of 102 samples from France. Among dogs from villages with both infected animal carcasses and human cases, seroprevalence was 31.8%. A significant positive direct association existed between seroprevalence and the distances to the Ebola virus–epidemic area. This study suggests that dogs can be infected by Ebola virus and that the putative infection is asymptomatic.

I’ve not looked further at the literature. This study suggests, unsurprisingly (see point 2 above) that dogs can harbor the virus. However, they don’t seem to be symptomatic. Therefore, spread from a dog seems unlikely. I would think the dog could be kenneled for a few weeks, rather than being put down.

A Field Guide to ALL of the Carnivores! (Almost)

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!

How geology affects your dog’s demeanor and the view from your back yard

Does your back yard slope up, away from your house, or does it slope down?

The likelihood that your yard slopes one way or the other … statistically … depends in large part on what region you live in. (Here I’ll be speaking mainly of the US, but the principle applies broadly.) If you live in New England, your yard is more likely to slope up. If you live in the Midwest/Plains, your yard is more likely to slope down
Continue reading How geology affects your dog’s demeanor and the view from your back yard

Physics, To A Dog (A poem)

To a dog, a balloon is a rock that floats.
To a dog, a lever is a perch for stoats.

To a dog, particle decay1 is not about nooks
To a dog, gravity is just another way to puke.

To a dog, a quantum is a kibble
To a dog, a quark is to nibble.

To a dog, where the yard ends begins the cosmos
To a dog, periodic tables2 iz a no-nos.

To a dog, dark matter is what cats must do
To a dog, string theory is for cats too.

To a dog, it is better to sleep
To a dog, don’t tickle the heap.3


Notes
1Bone munching
2Do not take food off the table. Periodically.
3A veiled reference to “tickling the dragon’s tail” during early A-bomb research. Dogs prefer if you tickle their stomach instead.

Why this poem?