Sure, you could leave, take the easy way out. Head south the moment you start taking your down coats out of the closet, the moment the temperature drops to 28 degrees, the moment you start dreaming of sand and surf and blended drinks with tiny paper umbrellas. You could leave the dark, cold winter behind and take flight. Or … you could stay. Just like the little white, black, and gray guy with the black Zorro mask who’s often seen hanging upside down on a tree branch. The little bird that’s been singing to you all spring, summer, and fall, the overly-loud-for-such-a-small-bird song: dee-dee-dee, cheeeeese-burger, cheeeeese-burger.
Unlike the western tanager, Wilson’s warbler, calliope hummingbird, house wren, and many other local birds that migrate south for the winter, the mountain chickadee remains. And much like us stockpiling a pantry for the long winter ahead, the chickadee fills its cupboards too. It gathers Jeffrey and lodgepole pine seeds (and western white pine and mountain hemlock at higher elevations) from September through November, stores the seeds in hiding places called caches, and then all winter long retrieves its hidden meals, by sheer memory.
To glean the seed, the chickadee tries to reach between the pinecone scales, to grab the wing attached to the seed that helps them disperse with the wind — and pulls it out. They also collect seeds that have fallen on branches from already opened cones. They then cache them in cracks or holes or the underside of bark, relatively close to where they find the seeds as they move from tree to tree. It’s been said that the little acrobat can cache up to 1,000 seeds in one day with a potential range of 60,000 to 90,000 seeds in one fall season.
The most remarkable part of the mountain chickadee’s caching process is its memory, researched by a team of scientists at the University of Nevada, Reno. Professor Vladimir Pravosudov along with his Ph.D. candidates Carrie Branch and Dovid Kozlovsky and Ph.D. student Angela Pitera at the Cognitive and Behavioral Ecology Lab at UNR spend their days (months and years) monitoring chickadees both in the field and in their lab.
“Spatial location” is the team’s specialty, determining the differences in memory between low elevation and high elevation chickadees, and how these differences are related to survival and reproduction. To do this, Pravosudov and his grad students monitor more than 300 nest boxes at the Sagehen Field Station located 8.4 miles north of Truckee. There, they test memory in hundreds of birds and track their survival. Some boxes are set near the station itself, at 6,200 feet; others are placed above Sagehen on Carpenter Ridge, at 8,000 feet. Their research has found that the higher elevation chickadee’s hippocampus (the part of the brain involved in spatial memory) is larger than the lower elevation chickadee’s. Meaning, the higher elevation bird remembers its cache locations better than the lower elevation chickadee, due to it being more reliant on food in a higher, harsher climate.
Part of the study at UNR is in determining how the chickadees locate their caches. Branch says, “They have ‘mental maps.’ They remember things in the landscape in relation to other things in the landscape. While flying over an area, they’ll observe and remember certain markers, such as a specific group of trees.” After finding the cache, the chickadee takes the conifer seed to a safe location, away from its competitors — other chickadees, nuthatches, or Steller’s jays — and eats the seed in private.
“Based on caloric estimates, they need less than they cache to survive the winter,” Pravosudov explains, “I’m not sure whether they need just half or more than half of what they cache, but they certainly over-cache relative to their needs.”
I find much solace in knowing the Poecile gambeli stays here in the winter with us. There’s a tradition in it, a reliability. Its intelligence (and memory!) and fortitude speak to ingenuity. There’s much we can learn from this little four-seasons bird. Yep, it’s time all right, time to get ready for the snow.
For more information, check out the UNR website that follows Pravosudov’s research: chickadeecognition.com.
Do you have a question about our region’s environment? Email editors@moonshineink.com.
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