干旱区生态环境知识资源中心

The ability of yellow pine chipmunks (Tamias amoenus) and deer mice (Peromyscus maniculatus) to detect buried antelope bitterbrush (Purshia tridentata) seed caches of differing water content was examined in an arena containing dry sand. Neither species could detect caches of air-dried seeds (6.8% water) using olfaction, but they found some caches after the seeds had been hydrated (exposed to almost-equal-to 100% relative humidity) for only 0.25 h (7.3% water). When seeds contained >8.0% water, subjects usually found most of the treatment caches available. Search times to find treatment caches were significantly greater for caches of very low water content (<7.3-7.4% water) compared to caches of higher water content. There were no significant differences in the abilities of deer mice and yellow pine chipmunks to detect treatment caches. When seeds were moistened (41.2% water) and then were allowed to dry out (6.4% water), subjects could not find the seeds in the dry arena sand. Variation in seed water content under natural conditions in the field may have important implications for rodent-seed interactions.