While on a cow elk hunt I could of harvested a cow who had this year's calf with her. But since they were by themselves and not with a herd I did not shoot the cow as I thought the calf would not survive the winter without it's mother. What would of been the calf's chance of survival to spring without it's mother had I harvested the cow?
The chances are pretty high of a calf surviving for several reasons. First, the cow is probably not lactating, so the calf is no longer directly reliant on its mother for nutrition. The mother has already taught the calf behavior that would help it survive, and although they appeared to be alone, there were likely other elk in the general area. Elk are pretty good at locating each other, so there’s a strong chance the calf would have rejoined a herd.
However, you clearly erred on the side of caution, and that’s rarely a bad choice.
To go deeper, elk calf survival depends on a number of factors, including disease, predators, nutrition, maternal care, weather and accidents. Generally, highest mortality in elk calves occurs during the first month of life, where predators can take a high percentage of calves. During the mid-summer through fall period, elk calves generally have higher survival rates.
Survival during winter varies considerably depending on how harsh winter conditions are, and what predators exist in the area. Elk calves are generally reliant on milk for the first month, but will continue to suckle for several months if allowed by the mother. Within a couple of weeks of birth, elk calves begin to eat natural vegetation, and by a couple of months old, they are capable of surviving without milk.
A significant factor when considering whether orphaning of elk calves results in higher mortality is whether the calf joins other elk. Generally, by July, elk cows and calves begin to form small groups. Orphaned elk calves that remain in an elk group, or find another group, are expected to have higher survival rates.