The effect of nectar guides on pollinator preference: experimental studies with a montane herb
The effect of nectar guides on pollinator preference: experimental studies with a montane herb
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DOI：
10.1007/bf00378462
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发表时间：
1985-08
期刊：
影响因子：
2.7
通讯作者：
N. Waser;M. V. Price
中科院分区：
文献类型：
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作者：
N. Waser;M. V. Price
山地飞燕草的稀有“白化”变体在整体花色方面与常见的蓝花变体不同，并且花朵中心的对比色图案的强度可能会引导传粉者获取隐藏的花蜜。先前的研究表明，当熊蜂和蜂鸟遇到两种变种的混合物时，熊蜂和蜂鸟会歧视白化病，并且这些传粉者在白化病上的连续花朵之间飞行所需的时间比在蓝花花序上飞行的时间更长。为了探索这些观察结果之间的联系，我们以两种增强白化花蜜引导的替代方式测量了授粉媒介的偏好和在给花涂漆之前和之后的花到花的飞行时间（“处理时间”）。在所有 16 个实验重复中，涂漆后对白化病的歧视都减少或消除，白化病的处理时间也向蓝花花序的值下降。这一一致的结果表明，劣质的花蜜引导器增加了白化病患者觅食的能量消耗。在蜂鸟和大黄蜂对觅食经济学敏感的合理假设下，成本的增加反过来解释了歧视。
Rare “albino” morphs of the montane larkspurDelphinium nelsoniidiffer from common blue-flowered morphs in overall flower color, and in the strength of a contrasting color pattern at the center of the flower that presumably guides pollinators to concealed nectar. Previous studies showed that bumblebees and hummingbirds discriminate against albinos when presented with mixtures of the 2 morphs, and that it takes these pollinators longer to fly between successive flowers on albino than on blue-flowered inflorescences. To explore the link between these observations, we measured pollinator preferences and flower-to-flower flight times (“handling times”) before and after painting flowers in 2 alternative ways that enhanced albino nectar guides. In all of 16 experimental replicates discrimination against albinos was reduced or eliminated after painting, and albino handling times declined toward values for blue-flowered inflorescences. This consistent result indicates that an inferior nectar guide increases the energetic cost of foraging at albinos. Increased cost in turn explains discrimination, under the reasonable assumption that hummingbirds and bumblebees are sensitive to foraging economics.