Sunday, February 28, 2021

5 Minutes in Nature: The selectively forgetful bird

Chestnut-Backed Chickadee in Snow, Washington

When I launched the 5 Minutes in Nature project, I purposely avoided talking about specific plants or animals. This project is about finding your own connections to the natural world. I also didn’t want to suggest something that you would never see in your own area.

But today, I’m going to introduce you to the chickadee. It’s a fascinating bird. And you can find it almost everywhere. You can likely even find it now before other birds arrive for the spring.

(The 5 Minutes in Nature project is about getting away from our screens and out into nature — a few minutes at a time. It’s actually good for your health. You can learn more about the project here, and see some of the past activities here.)

Adult chickadees do not migrate. I see two types of chickadees — the black-capped and the chestnut-backed — year-round in my yard near Seattle, Washington. And that means they have to equipped to survive whatever weather conditions nature throws at them.

There have two traits that are very useful in winter.

The first is that they can lower their body temperature at night. During this period of regulated hypothermia their core temperature drops 12-14 degrees Fahrenheit (7 or 8 degrees Celsius) helping them to conserve about one-third of their energy.

The second is that they can find food — because they remember where they hid it. When insects are available in the spring and summer they make up a large portion of the chickadee’s diet. In the fall and winter, the birds are more reliant on seeds. And in the winter, those seeds are ones that the bird hid. It can remember thousands of hiding places.

A study conducted at Rochester University found that as the chickadee is scurrying around and hiding seeds, part of the bird’s hippocampus is simultaneously scrambling to grow new neurons. A bird brain isn’t very big and there is no room for it to grow, so it seems that as the new neurons are generated, the neurons holding last year’s seed locations are purged. The physical size of the hippocampus was unchanged.

The ability to manage memories like this is an especially useful capability given that chickadees can live up to a decade in the wild, although the average lifespan is significantly shorter than that.

There is a lot about brains that we don’t understand, so the results of the study aren’t absolutely conclusive. However, chickadees that were kept inside the lab and could eat whenever they wanted showed much less brain activity.

So for this 5 Minutes in Nature activity, try to find a chickadee and watch it at work. It’s one of the most common birds that you’ll find on feeders. They’re also fairly easy to see in trees.

There are several types of chickadees in North America. The black-capped chickadee is most common, and is found throughout Canada and the upper half of the continental U.S. The Carolina chickadee is found in the southeastern U.S. The mountain chickadee has a range that centers on the Rocky Mountains. The chestnut-backed chickadee is found mainly in forests along the Pacific coast. The boreal chickadee is found in Alaska and much of Canada.

I enjoy watching the chickadees that make use of my yard. As a nature photographer, it can be easy to get caught up with more glamorous, like eagles and owls, but chickadees are impressive birds, too.

Feel free to share your own experiences in the comments. And if you would like to get a notice when there’s a new 5 Minutes in Nature activity, subscribe to the mailing list.

(Follow Kevin Ebi's photography on Facebook or Instagram. Prints of his images are available through LivingWilderness.com.)

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