Spring’s sweet trill of an abundance of bird species is increasing! Spring brings wonderment and elation as it fills our souls and soil with sunshine. Winter has receded, and an astonishingly diverse network of newness is accelerating. It never gets old to witness the community of life renewing itself. Here come robins plucking insects from rain-soaked soil; here come the barn swallows and more of ‘the usual suspects’ that arrive annually. (Aren’t they earlier than ever?) How does bird memory work to allow them their annual sojourn, as well as other feats of bird memory?
A paper in Scientific Reports, titled ‘Long-term memory of experienced jays facilitates problem-solving by naive group members in the wild’ by K.B. McCune et al., discusses memory in jays and other Corvidae species. They explain that birds’ long-term memory affects fitness, as shown by their foraging skills, and that experienced jays can positively influence less experienced birds in their group. The remembered behaviors in complex foraging tasks suggest that natural selection can favor long-term memory in birds and facilitate these useful skills for future generations. In other words, it pays for birds to remember.
When I marvel at the acorn cache made by acorn woodpeckers, I wonder about the memories of these creatures and other birds that store food, such as nuthatches, chickadees, and crows. Cornell Lab’s All About Birds explains that the hundreds, and sometimes thousands, of seeds stashed by individual birds each year can indeed be recalled and found by enterprising avians. Some birds even re-hide acorns and other seeds as an extra precaution to save their bounty. In David Shaw’s Birds and Blooms Magazine article titled “Fascinating Bird Behavior: Caching Food,” he explains that the captivating, labor-intensive habit of caching food occurs because of the relatively short season for finding precious seeds and nuts. This practice has been learned to protect the birds’ food source for the remainder of the year.
Shaw further explained that researchers have found that some bird species, such as titmice and chickadees, have a special physiological response to this need for memory: their brains actually grow in autumn! The area of the brain responsible for memory, the hippocampus, grows larger in fall and winter, then recedes a bit in the spring and summer months.
Just ponder the mighty minuscule hummingbirds’ annual migration of thousands of miles. How do they know to come back to my bird feeder each year? These are tiny birds with tiny brains; however, these jewels of nature have been known via bird banding by ornithologists in scientific studies to arrive in the same yard and fight for their territory year after year. Their ability to remember territory and map it into their memory is because of the reliability of the food source. Hummingbirds can recall the spaces they defended as a remembered boundary. Imagine the memory capacity of the tiny bird that these return visits represent!
Cornell Lab’s Merlin birding app can tell you exactly who’s singing during spring’s emergence of morning bird calls, or the dawn chorus, as it is known, when birds are attempting to attract a mate or defending precious territory. In my heart of heart, I comprehend that this special dawn symphony has experienced a reduction in size and is fraying over the past few decades, but the richness of what is thriving here and now is what inspires me. It’s as poet Henry Wadsworth Longfellow wrote in his ‘Birds of Passage’,
“They are the throngs
Of the poet’s songs,
Murmurs of pleasures, and pains, and wrongs,
The sound of winged words.”
As the scent of spring and a string of sounds weaves itself into countless calls, what makes you smile? Memories are our heart’s home, and, apparently, a bird’s as well!
