Citation
Long-term spatial memory in Clark's nutcracker
TL;DR
Clark's nutcrackers cache 30,000-100,000 pine seeds annually
This research demonstrates the extraordinary spatial memory capabilities of Clark's nutcrackers, achieving 90-95% cache recovery rates across thousands of cache sites. The study documents the neural investment required for this performance - an enlarged hippocampus 2-3× larger than non-caching birds.
The findings illustrate the cost of storage efficiency: superior memory requires larger brain investment and higher metabolic costs. This supports the chapter's argument that 70-80% efficiency (squirrels) may be more optimal than 90-95% (nutcrackers) depending on ecological context.
Key Findings from Balda & Kamil (1992)
- Clark's nutcrackers cache 30,000-100,000 pine seeds annually
- Recovery rates approach 90-95%
- Memory precision within 1-2 centimeters even under 30cm snow
- Enlarged hippocampus 2-3× larger than non-caching birds of similar size
- Brain consumes 20-25% of resting metabolic rate vs 15-18% in similar birds