Friday, April 4, 2014

Birdy, It's Cold Outside

Recently I went to get my eyes checked and had a very enjoyable chat with my optometrist. She had recently visited World Bird Sanctuary, loved it and was curious as to how the birds were handling the cold weather. I realized that others might have the same question, so I decided to write my blog about our birds and the cold.
Peabody, the Tawny Owl, is native to Europe, where members of his species thrive in cold conditions.
Most of the birds that are on our display line in the winter are adapted for cold weather. They are either native to Missouri or even more extreme climates. Some species that are not native to Missouri can remain on our display line throughout the winter with additional wind protection or building shelters and providing them with heat lamps. Other species that are from warmer climates, such as the Brown Pelicans, move indoors for the winter and move back out once it warms up. Every now and then we need to bring birds indoors for the very cold spells, such as that week when we hit negative temperatures, but in general if a bird is out on our display line it is because it is adapted for the cold.

Ookpik the Snowy Owl - well-adpated to the cold.
How exactly are the birds adapted for the cold, you might ask. The short answer is feathers! Yes, those wonderful things that allow birds to fly also allow birds to live pretty much anywhere. Feathers have the highest insulation quality of any substance known to humans. You are probably familiar with this if you own a down comforter or jacket. You know that warm toasty feeling you have when bundled up? The temperature difference between the outside and the inside of the feather coat of a song bird can be one hundred degrees. Due to this amazing insulation birds from warmer climates tend to have more skin exposed to aid in heat exchange. Unfortunately that extra exposure means that in Missouri those particular birds are at risk of frostbite, hence why we need to move them indoors. The birds native to colder environments tend to have more feathers. For example Golden Eagles, which are found in the Northern Hemisphere have feathers all the way to the tops of their feet. These extra feathers keep their legs warm, as well as protecting them from the bites of their prey. Golden Eagles are members of the group of eagles called booted eagles, which also include Tawny Eagles. Snowy owls, native to the tundra not only have feathers on their feet, but also on the bottoms of their feet. Since Snowy owls are ground nesters, this helps to protect their feet from the snow and frozen ground. Even when it snows birds are not as affected as we are due to the feather’s structure. Feathers are made up of barbs and empty spaces between them called touch points. These suspend water away from the feather preventing it from soaking into the feather and the bird’s skin. Feathers are not the only “winterizing” on a bird of prey.

Golden Eagles are 'booted eagles' - an important factor in helping them to keep warm.
The scales on a bird’s feet also play an incredibly important role. These scales form in layers and depending on the species can be incredibly thick and act as built in snow boots causing ice to flake off rather than sticking to the bird and leading to frostbite. Bald eagles have these thick scales as well as feathers that stop before the tops of the feet, preventing feathers from freezing when they fish in icy water.

Bald Eagle feet have thick scales to help deal with the cold.
Birds, especially birds of prey, have a number of adaptations to help them keep warm. We make sure all of our birds are comfortable during these cold spells, whether that means keeping them indoors, or letting their natural adaptations take care of it. In fact during these cold spells, our birds probably feel even warmer than we feel!

Submitted by: Leah Tyndall, Trainer

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