ADAPTATION OF GRAY SQUIRREL BEHAVIOR TO AUTUMN GERMINATION BY WHITE OAK ACORNS
ADAPTATION OF GRAY SQUIRREL BEHAVIOR TO AUTUMN GERMINATION BY WHITE OAK ACORNS
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DOI：
10.2307/2407893
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发表时间：
1982-01-01
期刊：
影响因子：
3.3
通讯作者：
FOX, JF
中科院分区：
文献类型：
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作者：
FOX, JF
某些白橡树品种的橡子不休眠，在秋天落地后不久就发芽。当埋藏至少 3 个这样的白橡树种的橡子时，灰松鼠经常会杀死种子的生长点。这可以防止（松鼠）损失高达 50% 的食物材料，否则这些食物材料会在松鼠冬季取回种子之前转移到幼苗中。未被损坏地埋藏的非休眠橡子会长出充满食物储备的幼苗主根；正因为如此，如果松鼠随后在冬天摘掉橡子，那么幼苗在第二年春天仍然能够生长。红橡树的橡子在储存之前处于休眠状态，松鼠不会杀死它们的生长点。松鼠的行为被解释为一种应对秋季发芽的橡子的反策略。秋季发芽可能是松鼠为了逃避分散后的捕食而进化而来的一种策略。松鼠的反击并没有完全消除逃跑的可能性；由于这种行为存在例外，尤其是幼年松鼠，大约 48% 的白橡橡子被完好无损地藏起来并且能够逃脱。
Acorns of some species of white oaks are nondormant, germinating in autumn soon after falling to the ground. When burying acorns of at least 3 such white oak species, gray squirrels often kill the growing point of the seed. This prevents the loss (to the squirrel) of up to 50% of the food material, which would otherwise be transferred into the seedling before the squirrel recovered the seed in winter. Nondormant acorns that are buried undamaged produce a seedling taproot engorged with food reserves; because of this, if a squirrel subsequently removes the acorn in winter, the seedling is still capable of growth the following spring. Squirrels do not kill the growing point of acorns of red oaks, which are dormant-seeded, before caching them. The squirrels'' behavior is interpreted as a countertactic evolved to deal with autumn-germinating acorns. Autumn germination may be a tactic evolved as an escape from post-dispersal predation by squirrels. Escape is not completely eliminated by the squirrels'' countertactic; because of exceptions to the behavior, especially among juvenile squirrels, some 48% of white oak acorns are cached unharmed and capable of escape.