Atypical flowers can be as profitable as typical hummingbird flowers

In western North America, hummingbirds can be observed systematically visiting flowers that lack the typical reddish color, tubular morphology, and dilute nectar of "hummingbird flowers". Curious about this behavior, we asked whether these atypical flowers are energetically profitable for hummingbirds. Our field measurements of nectar content and hummingbird foraging speeds, taken over four decades at multiple localities, show that atypical flowers can be as profitable as typical ones and suggest that the profit can support 24-hr metabolic requirements of the birds. Thus, atypical flowers may contribute to successful migration of hummingbirds, enhance their population densities, and allow them to occupy areas seemingly depauperate in suitable resources. These results illustrate what can be gained by attending to the unexpected.

在北美西部，科研人员观测到蜂鸟会系统性地造访那些不符合"蜂鸟花（hummingbird flowers）"典型特征的花朵——这类花朵并不具备蜂鸟花标志性的红色、管状形态与稀薄花蜜。出于对这一行为的好奇，我们探究了此类非典型花朵能否为蜂鸟带来能量收益。我们在多个研究地点开展了长达四十年的野外测量，涵盖花蜜含量与蜂鸟觅食速度两项核心指标，结果显示非典型花朵的能量收益可与典型蜂鸟花不相上下，且该收益足以满足蜂鸟全天24小时的代谢需求。据此推测，非典型花朵或可助力蜂鸟顺利完成迁徙，提升其种群密度，甚至帮助蜂鸟进驻那些看似缺乏适宜觅食资源的区域。本研究结果亦印证了关注意外现象所能带来的重要科研发现。