Reduced dietary conservatism in a wild bird in the presence of intraspecific competition
Reduced dietary conservatism in a wild bird in the presence of intraspecific competition
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在存在种内竞争的情况下，野生鸟类的饮食保守性降低
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
N. Marples
中科院分区：
文献类型：
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作者：
K. McMahon;N. Marples
种内竞争者的存在会通过资源的开发增加觅食成本。最优觅食理论表明，当追求一种食物类型的成本增加时，应该接受替代资源。欣然接受新的食物可能会使竞争者在竞争中比更保守的竞争对手处于优势，以获得足够的持续性，但也会使其面临被化学保护食物中毒的危险。饮食保守主义是一种觅食行为，其特征是在克服了新恐惧症（最初对新物体的恐惧）之后很长时间内避免新食物，因此可能被视为觅食者在竞争环境中的劣势。在觅食种群中发现了两种稳定的觅食策略：（1）冒险的消费者（AC），迅速接受新的食物和（2）觅食者表现出饮食保守主义（DC）。这两种策略的表达也可能随环境条件而变化。本研究的目的是调查种内竞争对野生蓝山雀（Cyanistes caeruleus）饮食保守性水平的影响。研究人员在两种情况下向蓝山雀提供了新奇和熟悉的食物：有竞争对手和没有竞争对手。我们的研究结果表明，经历过竞争的人比那些没有经历过竞争的人更快地将新奇的物品融入他们的饮食中。这项研究表明，第一次，在实验室条件下使用野生鸟类的DC性状的表达可塑性的程度。这种可塑性代表了一个重要的适应，以减少觅食保守的成本时，新的替代资源应该被接受。
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The presence of intraspecific competitors can increase foraging costs through exploitation of resources. Optimal foraging theory suggests that when the cost of pursuing one food type increases, alternative resources should be accepted. Accepting novel foods readily might put a competitor at an advantage over its more conservative rivals in the race for sufficient sustinance, but also opens it to the danger of poisoning by chemically protected food. Dietary conservatism is foraging behaviour characterised by a prolonged avoidance of novel foods, long after neophobia (initial fear of novel objects) has been overcome, and so might be seen as a disadvantage to foragers in a competitive situation. There are two stable foraging strategies found within forager populations: (1) adventurous consumers (AC) which rapidly accept novel foods and (2) foragers showing dietary conservatism (DC). The expression of these two strategies may also vary with environmental conditions. The aim of this study was to investigate the effect of intraspecific competition on the levels of dietary conservatism displayed among wild caught blue tits (Cyanistes caeruleus). Blue tits were offered items of both novel and familiar foods under two conditions: with a competitor and without. Our results showed that individuals who experienced competition incorporated the novel items into their diet faster than those who did not experience competition. This study demonstrates, for the first time, the degree of plascticty in the expression of the DC trait using wild birds in laboratory conditions. This plasticity represents a significant adaptation to reduce the costs of foraging conservatively when novel alternative resources should be accepted.
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