Cannibal chickens (and more) considered

In an article about whether free range chickens are as cheery as we might imagine them to be, there's this:

Feather pecking is when chickens peck and pull out other hens' feathers.

This can lead to cannibalism, where chickens eat the wounded flesh of the injured hen.

These three factors kill a lot of free-range hens. One Australian study found cannibalism was a major cause of death in free-range hens, second-only to being eaten by predators.

Dr Hartcher, who researched feather pecking for her PhD, says death by cannibalism is an "awful way to go".

"We understand more about it than we did a few decades ago but we still don't fully understand how to control the problem," she says.

I would have guessed that keeping too many chickens in too small a space may be a reason behind it, and  I see from another website that is one trigger, but there are many others:

These stressors include crowding, bright light intensity, high room temperature, poor ventilation, high humidity, low salt, trace nutrient deficiency, insufficient feeding or drinking space, nervous and excitable birds (hereditary), external parasites, access to sick or injured birds, stress from moving, boredom and idleness, housing birds of different appearance together and birds prolapsing during egg-laying.

 How do you cure "boredom and idleness" in a chicken, I wonder.   I would have thought letting them scratch around free range on grass would go a long way to curing that, but maybe it's more the lack of good quality chicken cinema and poetry readings?   

They're an odd animal. 

Update:  OK, let's just have a whole gross out afternoon, by reading this list of 10 cute animals you didn't know were cannibalistic.   I did know of hamsters, and had heard of pigs too.  But rabbits and red squirrels?   It's a particularly cute bunny they have chosen to picture, too.   Most of the examples are of babies being the victim of mothers, though, and I guess we tend to feel that crazy hormonal stuff maybe gives those individual Mums some sort of excuse.  Males (or females) who go killing other mother's offspring, though - harder to like them!   

As for primates and cannibalism - chimps seem to be the nastiest of all. 

I'm almost starting to wonder why we don't have cases of modern humans feeling evolutionarily compelled to do something similar.