On Mann, or one of those other remote British islands, bird conservationists noticed (some years back, before the internet, so I don’t have a link) that there were a lot of gulls or terns or whatever with one wing or a shortened wing. On further inspection they also found a lot of chicks with zero heads (they did not survive this). The enigma was studied, and it turns out that the grazing sheep there were regularly grazing of bits of nest-bound pre fledglings probably because of a lack of calcium and/or other minerals in the local soil, and thus, generally, food chain (and dirt … grazers also eat dust every time they eat anything, which includes minerals).
Because the sheep were good at snipping, the amputations were often clean enough that the chicks would grow to one-limbed adults.
or:
About Indian cows: Europeans are unaware that lots of city cows in India rarely have a chance to nibble at any grass or leaves. They feed on paper, torn cloth, household scraps and small quantities of food stolen from market stalls. It was amazing that if you drop a bit of paper in India, the nearest cow turns with interest, comes and eats it.
Re: Well, I’m one European who is certainly aware of this :) Some of my friends watched an Indian cow consume paper and other material from a burning fire… you have to feel sorry for these animals if they are really this desperate.
I learned this a few years ago from a colleague in biology. He and his students routinely collect birds in nets for tagging and measurement, and he mentioned that it's important for them to check the nets every few hours when they're set up. If they leave the birds trapped in ground-height nets too long, the local deer will find them and eat them. (This behavior was alluded to in the article.) I got the feeling that a lot of herbivores out there would happily be omnivores if they were able to catch appropriately-sized prey.
True, mostly happens with domesticated animals that has a diet lacking in minerals. But then it's usually a cadaver or the bony remains and as such not 'film worthy' I guess.
Someone posted a video on Reddit of a baboon eating a baby deer, alive. It was like 2-3 mins, couldn't watch more than a few seconds. It was horrible. I remember thinking, why can't the stupid baboon kill the deer and then eat it, instead of eating it alive?
I had a veterinarian teach me that carnivore has nothing to do with diet, and means that the animal is in the order Carnivora, which are mostly distinguished by having canine teeth.
The kinkajou (http://en.wikipedia.org/wiki/Kinkajou) is a carnivore by this definition, but does not eat meat. I am sure that there are herbivores in a similar situation.
While carnivore does mean of the order Carnivora (which includes animals like the Giant Panda), the term carnivorous does simply mean that the animal mostly eats meat.
One of the main differences between herbivores and carnivores (and the various omnivores that rank in between) is what their digestive system is optimized for.
Herbivores tend to have longer (relative to body length), more complex and less acidic digestive tracts than Carnivores. Their systems tend to make more use of grinding and physically breaking down plant fibers to get at the sugars in the material. Even then, herbivores get surprisingly little nutrition from plants and almost always have to by grazing or eating. About 50% of the food herbivores eat is excreted as waste.
Modern farming techniques solves some of this by providing easier to digest feed to the animals, usually high in protein. The feed is often made up of other animals (one of the sources of issues during the mad cow disease problem a few years ago). Herbivores generally lack the mechanical mouth parts to be effective meat eaters, but will eat animal products more or less just fine if presented in a digestible format (they don't produce all the right enzymes all the time and their stomachs aren't quite as acidic, but in some small amounts it can actually be healthy for the animal). If you've ever worked near or on a farm, you'll know about various herbivorous animals eating non-plant items pretty frequently. This article is a no duh that's common knowledge to any farmer.
Herbivores come in a few types as well, ruminants have complex multi-compartmented stomachs. As with anything complex, they tend to have a wide variety of failure modes when eating as well. The complex flora in their digestive systems often creates gaseous environments that don't often have a good way to escape. A surprisingly common vet procedure is to basically just punch a hole in the side of a ruminant to provide a vent for outgassing.
Carnivores tend to have shorter (relative to body length), less complex and more acidic digestive tracts. Protein simply processes faster than cellulose and can be broken down by acids and a few enzymes. Anybody who's owned a dog or cat can tell you that carnivores eat plants all the time. It doesn't digest well though as they simply lack the mechanisms to digest cellulose and usually it comes out more or less like it went in. True carnivores also tend to not have as much or any gut flora, which aids in breaking down and digesting plant matter.
As with many things in nature, life is a spectrum. Most things fit somewhere on that spectrum, cows are more herbivore, while goats (as goat owners can tell you) are slightly less, while lions are on the other end as pretty much carnivores. Bears, apes, humans, dogs, pigs etc. all fit in various places on this spectrum.
Humans have digestive systems that are basically somewhere between a simple herbivore and a carnivore (a horse and a dog). Humans, like brown and black bears have digestive systems that aren't particularly optimized to process plant or animal products, but are optimized to switch "modes" over a short period of time. A diet of largely plants will turn out systems to become more acidic and we'll start cultivating gut bacteria to aid in digestion. A diet of largely meats and we'll start to switch to a more alkaline intestinal environment. One problem is that our systems never really complete either transition, so we're not particularly efficient or complete either way.
Our mouth parts are more like a carnivore than an herbivore, but evolution has reduced some of the more useful hunter parts, our canines are pretty small at this point. However, our molars are still meant for ripping and not flat for grinding like a herbivore's. Our jaws provide vertical movement like a carnivore, not rotary grinding motions like a herbivore. Our stomach capacity relative to our body size is almost exactly within carnivore parameters and we pass food out of our stomach and into our intestinal tract about as quickly. We have strong stomach acid compared to herbivores and our stomachs provide almost no digestive activity (a tremendous amount of digestion occurs in an herbivore's stomach).
Our intestines are closer to a carnivore's, and our feces are produced and have consistency like a carnivore's. We have developed gallbladders (helpful for breaking down animal proteins) and our pancreas is a major contributor of enzymes needed for digestion (unlike herbivores).
In cases where humans need surgical intervention, a surprising amount of our digestive tract can be removed and we'll survive. Herbivores need much more of their tract relatively to survive. Humans for example can live without a stomach, colon and cecum. Herbivores cannot.
What's actually surprising about humans is how well we can live on diets made up mostly or solely of plant or animal material. There's some nutrients we don't get as well out of one kind of material, and our bodies don't produce some of the nutrients that animals on the extremes of the spectrum make naturally. It's likely we were scavengers and opportunists, eating pretty much whatever we could get our hands on. We've had weapons and meat processing tools in our inventory since before we were homo sapiens a quarter of a million years ago. The oldest unambiguous weapons are throwing spears from the Palaeolithic 300,000 years ago in a cache full of thousands of animal bones. Meat processing tools have been found much older than Homo erectus (up to 2 million years ago). We've been hunting and eating animals as part of our diet long enough for evolutionary forces to have an affect. If our ancestors were ever herbivores, it was long long before then (millions upon millions of years), and indications are that we've moved rapidly towards the carnivorous end of the spectrum (i.e. our mouth parts aren't anything like an herbivores and neither are any of our known ancestors). In fact it's known that meat was a major part of Homo erectus diets, but cooking was unknown to them. This diet was so effective that Homo Erectus lasted for well over a million years.
An omnivore eating less meat is good for all the reasons being vegetarian is good - it's not all-or-nothing.
That more-vegetarian-than-previously omnivore calling themselves vegetarian is helpful to other vegetarians in that it raises the profile of those issues and normalises pro-social dietary choices.
It's obvious that people making huge lifestyle changes struggle - I'd say support is more personally and societally useful than sneering disparagement about them not "actually" being vegetarian. Technically correct: the worst kind of correct.
On Mann, or one of those other remote British islands, bird conservationists noticed (some years back, before the internet, so I don’t have a link) that there were a lot of gulls or terns or whatever with one wing or a shortened wing. On further inspection they also found a lot of chicks with zero heads (they did not survive this). The enigma was studied, and it turns out that the grazing sheep there were regularly grazing of bits of nest-bound pre fledglings probably because of a lack of calcium and/or other minerals in the local soil, and thus, generally, food chain (and dirt … grazers also eat dust every time they eat anything, which includes minerals).
Because the sheep were good at snipping, the amputations were often clean enough that the chicks would grow to one-limbed adults.
or:
About Indian cows: Europeans are unaware that lots of city cows in India rarely have a chance to nibble at any grass or leaves. They feed on paper, torn cloth, household scraps and small quantities of food stolen from market stalls. It was amazing that if you drop a bit of paper in India, the nearest cow turns with interest, comes and eats it.
Re: Well, I’m one European who is certainly aware of this :) Some of my friends watched an Indian cow consume paper and other material from a burning fire… you have to feel sorry for these animals if they are really this desperate.