### The Significance of Spatial Memory in Chickadee Survival: An Innovative Study on Cognitive Abilities
It seems logical that an increase in intelligence would enhance an animal’s likelihood of thriving in nature. Nevertheless, for many years, researchers faced challenges in proving this connection as measuring intelligence in animals such as lions, crocodiles, or even smaller species like mountain chickadees proved complex. Scientists typically utilized indirect indicators, such as the dimensions of the brain, or cognitive assessments conducted in controlled settings, like reversal learning, which gauges an animal’s capacity to adapt to environmental changes. However, a recent extensive study on wild mountain chickadees, spearheaded by Joseph Welklin, an evolutionary biologist at the University of Nevada, unveiled an unexpected conclusion: neither brain size nor reversal learning capacity showed significant correlation with survival. Rather, the predominant factor for these diminutive birds was their capacity to recall the locations where they had hidden their food.
### The Research: Evaluating Chickadee Cognitive Abilities
Mountain chickadees are petite birds that conceal food items in various caches over broad regions, especially during the autumn, to endure the winter months. These caches can number in the tens of thousands, and the birds depend on their spatial memory to later recover the food. Due to their light weight—approximately 12 grams—chickadees need to consume food frequently to avoid peril of death within hours. This dependence on remembering cache locations is vital for their survival.
“Chickadees store one food item in one spot, repeating this process across a vast area. They may establish tens of thousands of caches. They perform this in the fall and, during winter, utilize a unique form of spatial memory to locate and retrieve their stored food,” explains Vladimir Pravosudov, an ornithologist at the University of Nevada and the senior co-author of the research.
The researchers selected chickadees for their investigation since the predominant cause of mortality among them is the failure to locate their food caches. This focus enabled the team to explore the influence of cognitive abilities on survival, reducing the impact of other variables such as predation or illness.
### Study Implementation
To evaluate the cognitive capabilities of a large cohort of chickadees, the team devised an inventive methodology. They positioned metal squares with intelligent feeders attached to trees within the chickadees’ natural ecosystem. Each feeder featured RFID receivers that could identify individual birds, outfitted with microchip leg bands. When a chickadee perched on a feeder, the system would deliver a single seed. Following several days of training, the researchers commenced their experiments.
The initial task assessed the chickadees’ ability to connect a specific location with food and retain that information. Every one of the 227 chickadees in the experiment was paired with a feeder that opened upon their arrival, while other feeders remained closed. The researchers tracked how many attempts it took each bird to discern which feeder belonged to them and the number of mistakes made over four days.
“If you were to locate the right feeder by chance, it should take approximately 3.5 attempts on average. All the birds learned and performed significantly better than chance,” notes Pravosudov.
The second task examined reversal learning, a trait frequently regarded as a solid indicator of survival. After the chickadees memorized the feeder location, the researchers altered the feeder’s position to determine how rapidly the birds could adapt.
### Key Insights: Spatial Memory Crucial for Survival
The findings were remarkable. Chickadees that excelled in the spatial memory assessment—those that swiftly identified and recalled their designated feeder—exhibited considerably higher survival rates. The top-performing birds made nearly no mistakes during the initial 20 trials, whereas the least successful ones made about 2.5 errors for each trial. This seemingly minor difference had a profound influence on survival: the most proficient birds survived an average of 3.1 years, while the least proficient birds only lasted about 1.2 years, with many perishing before the first winter ended.
Curiously, the outcomes of the reversal learning trial did not correlate with survival rates. Chickadees that struggled in the spatial memory evaluation were equally likely to succeed or fail in the reversal learning challenge. This implies that, for chickadees, being adaptable and flexible is less critical than possessing a robust spatial memory.
“In our previous research, we found that spatial skills and memory in chickadees are highly heritable. There exists a strong genetic influence and consistency in this aspect. We do not observe such genetic signals for reversal learning. For them, being adaptable is not as crucial as retaining those location memories for as long as possible,” asserts Pravosudov.
### Evolutionary Advantages: Increased Offspring for Top Learners
In addition to their extended lifespan, chickadees with superior spatial memory also produced a greater number of offspring. Most chickadees form lifelong mating bonds and breed annually, with typical clutch sizes comprising seven eggs. As the best-performing birds lived twice as long as the least competent ones,
