Smarter Mountain Chickadees Live Longer, Decades-Long Study Finds

A mountain chickadee waking up in California's Sierra Nevada range on a snowy morning has no time to dawdle: it needs to find its stashed pine nuts within minutes or risk succumbing to the cold. Fortunately, these tiny songbirds are master memorizers, tracking exactly where they hid each of the roughly 100,000 seeds they stored for winter, according to ongoing research at the University of Nevada, Reno (UNR).

The work centers on Sagehen Creek Field Station, about 16 kilometers north of Truckee, California, home to one of the longest-running studies of animal cognition in the wild. Behavioral ecologist Vladimir Pravosudov founded the mountain chickadee study in 1999 and, in 2013, developed arrays of eight feeders that can test spatial memory in the wild. Each bird wears a microchip, and the feeders, which work like hotel key cards, open only for a specific banded bird, recording the timing of every visit. Researchers test how quickly each bird learns which feeder is available to it, then change the feeder to measure how quickly the bird adapts, a test of cognitive flexibility.

The team has found that genetics can explain about 80% of cognitive differences among the birds, and in 2024 reported in the journal Science that the smartest birds live the longest. About two-thirds of mountain chickadees never survive their first winter, but those that do can survive a decade or more.

Behavioral ecologist Ai Ana Richmond of UNR wondered whether gut bacteria might also influence how smart the birds are. She examined the microbes in droppings collected from 41 birds at the feeders and found that birds with the best spatial memory had more bacteria that produce short-chain fatty acids; a few studies from other labs have suggested these fatty acids may be good for brain health. She reported the findings in July at the annual meeting of the Animal Behavior Society in Cincinnati.

Richmond next hopes to track whether the birds' gut microbiomes stay stable over time, which would help confirm their contribution to memory. "If the microbiome is very critical to memory then technically it shouldn't be changing," Pravosudov said.