A study published on October 7, 2026, in Biology Letters found that ground squirrels retain spatial memory after nine months of hibernation. The research, conducted by the CNRS and the University of Strasbourg, involved 10 trained Columbia ground squirrels (Urocitellus columbianus) and eight naive individuals. The squirrels were tested on a maze that mimics a natural burrow network during two consecutive active seasons. The trained squirrels made half as many errors as the naive ones and had paths that were almost twice as direct. The study used nonlinear Bayesian learning curves to distinguish retained memory from relearning. The results showed that the trained squirrels outperformed the novices by 41 to 98 percent, depending on the indicators. The CNRS press release noted that the squirrels' starting level after hibernation approached the plateaus reached before winter, indicating that the nine-month hibernation did not reset their memory. The study challenges previous assumptions that hibernation erases memory, as the squirrels' brains undergo significant changes during hibernation, including alterations in dendritic spines—small structures on brain cells that help transmit signals. Previous studies on hibernation and memory had yielded mixed results, with some reporting altered spatial memory and others showing individual variations. The study suggests that spatial memory can survive prolonged hibernation, supporting a hypothesis of neuronal plasticity that reflects adaptive retention rather than memory loss. The research highlights the importance of spatial memory for survival, as the squirrels must quickly locate their burrows, neighbors, and feeding areas after hibernation. The study is based on long-term monitoring of Columbia ground squirrels in the Canadian Rockies, a program labeled SEE-Life by the CNRS. However, the study's findings are limited to a single species and one type of memory, and further research is needed to understand memory retention in other hibernating species and types of memory. The next steps involve testing the recognition of conspecifics after hibernation, a social ability crucial for the squirrels' colony life.