Thursday, November 19, 2015
Hibernation, its not just for bears.
The definition of hibernation is “…to be in a dormant or torpid state during a cold period, typically winter”. When most people think of hibernation, animals like snakes, bats, and bears come to mind. But would you be shocked to find out that there is a bird that hibernates too?! I know I certainly was!
Common Poorwill watercolor (photo: wikipedia)
The Hopi Indians have known about this for a long time, calling a certain bird species Holchko, or “sleeping one”. We call this bird the Common Poorwill (Phalaenoptilus nuttallii). Living in the dry hills of the western United States and Mexico, you can find this medium-sized bird nesting on the ground or making short vertical flights into the night air to grab insects. As the smallest bird in the Nightjar family, it needs to be well camouflaged. With dark browns, greys, and black, it has no problems hiding.
The Common Poorwill has an almost owl-like look to it, with short rounded wings and a round tail. It does, however, have a large head with a tiny beak. During periods of cold weather and scarce food sources, this bird needs to conserve energy. So they will go into a state of torpor, or hibernation, for days and even up to a few weeks! During this time they can slow down their metabolic rate, slowing down their breathing, heartbeat, and lowering their body temperature. Once the weather warms up and all the insects start to come out for food, so does the common poorwill, eager to eat.
These incredibly adaptive birds will lay 2 pinkish white eggs on the ground and do not build a nest. However, if the area gets disturbed, they will move the eggs to a safer location. The young start flying at around 20 days old, and before that they have been observed moving around by somersaulting across the ground.
There are no current extra protections for these birds because they are so plentiful from Washington to North Dakota all the way into Mexico.
Submitted by Mike Cerutti, World Bird Sanctuary Naturalist/Trainer