Nesting on the tundra
The Arctic tundra is an expansive and treeless landscape. As such, Snowy Owls have no choice but to make their nests on the ground, often digging a bowl out of ice and snow.
Females situate their nests on top of mounds, called high-centered polygons. The mounds can vary in height – from about 8 – 36 inches high – but the nest is usually located on one of the highest mounds in the immediate area. The mound formations are the result of the repeated freeze and thaw of the Arctic tundra and can take centuries to form. The result is a unique landscape of mounds and valleys across the Arctic coast.
What’s fascinating is that when Snowy Owls choose their nest-site, the mounds are often not distinguishable. Snow pack and ice have filled the low spots, making the ground appear level. Somehow the owls know how to find them. We might not understand how, but we have a pretty good idea why.
These high spots are the first places to melt in the Spring and are relatively dry. The lower areas often remain wet and marshy – sometimes with deep standing water. Additionally, the wind is stronger atop these mounds, and helps provide relief from the relentless mosquitoes and other biting insects. And lastly, since hiding is not an option, parents must be ever-vigilant to danger. When perched atop a mound, they have an improved vantage point and increased ability to defend their nestlings.