Chickadee Brains Are Bigger in the Cold

As the colder months arrive, birds that remain in northern climates face the harsh realities of staying warm and finding food. Some birds approach the food problem by storing it in advance — a behavior called caching. Chickadees, nuthatches, jays, and some woodpeckers are known to cache large supplies of seeds in many places. But what enables birds such as this Black-capped Chickadee to find the seeds they’ve stored? They amplify spatial memory.

BirdNote^®

Caching, Climate, and Chickadees

Written by Bob Sundstrom

This is BirdNote.

As the colder months arrive, birds that remain in northern climates face the harsh realities of staying warm and finding food. Some birds approach the food problem by storing it in advance, in a behavior called caching. Chickadees, nuthatches, jays, and some woodpeckers are known to cache large supplies of mostly seeds — in a great many places. Scatter hoarding, it’s called, a kind of adaptive specialization that requires very good spatial memory.

So what enables the birds to find the seeds they’ve stored? Scientists have shown that Black-capped Chickadees amplify their spatial memory in early fall by actually adding brain cells to the hippocampus, the part of the brain that supports spatial memory. [Black-capped Chickadee call http://macaulaylibrary.org/audio/163368]

Taking the question a step further, another study examined how severity of climate might affect the brain power of different populations of chickadees. [Black-capped Chickadee call; ML 163368, 0.07-.08]

These researchers found that where a stash of winter food is critical — say, in harsher northern climates — Black-capped Chickadees had a substantially larger hippocampus size and more neurons in this part of the brain than those birds from more mild, southern regions. In other words, when the “livin’ is easy,” having a big brain isn’t such a big deal.

For BirdNote I’m Michael Stein.

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Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Black-capped Chickadee call recorded by Matthew D Medler.
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
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Producer: Sam Johnson
Content Director: Jonese Franklin

© 2015 Tune In to Nature.org November 2018/2020 Narrator: Michael Stein

ID# BCCH-09-2015-11-09 BCCH-09

Key reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717531/

https://pubmed.ncbi.nlm.nih.gov/2611638/