After incubating her eggs for about 32 days, a female Snowy Owl’s first chick is finally ready to hatch. But just one. You’ll remember that eggs are laid – and hatched – asynchronously. As a result, it will be 1-3 days before the second nestling hatches. Nestlings are tiny – about the size of a tangerine – and covered with soft, white feathers called down. Over the next couple weeks, the white down will be replaced with gray, eyes will open, and growth will be rapid. Because chicks do not hatch at the same time, a Snowy Owl nest may hold all stages of young - from strong, gray-feathered chicks; to tiny, white nestlings; to eggs that still haven’t hatched.
For the first couple weeks of life, Snowy Owl nestlings are helpless: they are unable to see, fly, or thermoregulate (maintain their own body temperature). Their mother broods them with her large body, keeping them warm amid cold and wet arctic conditions.
During this time, the male still does all of the hunting and regularly delivers food to the nest for his mate and growing chicks. The mother owl tears apart the meat, giving some to each nestling. When lemmings are abundant, chicks are well fed, and the nest can thrive. During low lemming years, or years when lemming populations crash, the demands of a growing nest can outpace a male’s ability to hunt with success, and an entire nest may fail. When prey is scare, it is often the older and larger nestlings who will receive more food, and the younger chicks may not survive. This increases the chances of a nest fledging young.
We've never documented siblicide (chicks killing each other) at a nest. In 27 years of research we have documented only one case of a female feeding one of her chicks to the other young. The chick had already died of starvation and the entire nest was struggling.