Harvesting and caching capacities of Thin-billed Nutcrackers in the Russian Far East | Zeitaufwand für das Ernten und Verstecken von Kiefernsamen bei Dünnschnäbligen Tannenhähern (Nucifraga caryocatactes macrorhynchos) im Fernen Osten Russlands
2001
Bergmann, Hans-Heiner | Engländer, Wiltraud | Arkhipov, Vladimir U.
At the Ochotskian sea coast Thin-billed Eurasian Nutcrackers (Nucifraga caryocatactes macrorhynchos) harvested seeds of ripe cones of the brush pinePinus pumila in late summer. The mean number of seeds carried in their sublingual pouch was 80, which respresents the harvestable contents of 2.8 cones. These were distributed in an average of 5 caches, exclusively in the soil under low tundra vegetation. Caches were organized in nearly straight lines. Series contained a mean of 82.7 seeds, single caches a mean of 19.6 seeds. Plucking one cone and harvesting its seeds took 47 seconds on average. The caching of a complete pouchful took on average 123.4 seconds. The time invested for harvesting and caching one single seed was calculated at 3.26 seconds. Within three weeks in July, an average individual bird was calculated to have cached a total of up to 100,000 seeds.
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