Wild horse behavior question

A few months ago, I watched an excellent documentary. An animal behaviorist was watching and recording the actions of groups of wild horses in the hills of Colorado. It was fascinating to see natural horse behavior, but one incident puzzled and troubled me.

A mare had given birth to a new foal, but the foal seemed to have something wrong with it. It was taking a long time to stand up. Adult horses came near to sniff at it. A stallion (and I can’t remember now if it was the foal’s sire or another stallion) came near to sniff at it, and then suddenly seized it by the neck and shook the holy bejeezus out of the poor little thing. It took several wild shakings, but eventually the stallion killed the new foal.

Is this typical stallion behavior? Perhaps the fact that the foal may have been born sickly prompted this, or maybe it was another stallion’s offspring and the aggressive stallion could tell. The researcher did not speculate. I would not in a million years think that horses killed new infants like that. It was quite shocking.

Well, they are supposed to stand up right away. In a stable, there are things you can do for a foal that doesn’t, including bottle-feeding, but not so in the wild.

However, I’m surprised the mare let other members of the herd close to the foal. The mares I’ve known in captivity have been fairly protective, and the stallions have paid no attention to the foals at all.

I saw a book about wild horses once at the local feed and tack store, and was shocked to see pictures of foals that had been killed by stallions. Evidently it’s not at all uncommon. But I forget whether the stallions killed their own progeny, or only those of other stallions (like lions do). I could swing by and look for the book, but it’s been years now. Not probably there anymore.

You didn’t tell the gender of the foal, but the alpha male in some wild animals will kill male offspring. He’s cutting down the competition, so he won’t have to fight the youngster as an adult.

I worked out some better combination of search terms today while Googling, and I see that stallions do indeed kill foals. They do it both to eliminate male competition, and for the same reason that lions and baboons kill infants: so that the female will come into estrus sooner and thus be able to bear his offspring. Some websites also described this behavior in zebras and donkeys. There was some argument as to whether only domesticated horses, stressed by captivity, do this. However, the horses in the documentary I saw were wild, so I’m guessing it’s just a natural behavior, seeing as how zebras and donkeys do it, too.

Not a pleasant thing to see!