[爆卦] 英國研究發現蜂鳥熱愛在微醺狀態下飛行

六月完成的研究沒看到能找到的中文報導，能在嗑藥狀態中渡過一生令人羨慕。

摘要：蜂鳥會偏好取食含有酒精的低度發酵蜜源。

https://royalsocietypublishing.org/doi/10.1098/rsos.230306

食果動物和食蜜動物都可能接觸由代謝糖的發酵酵母產生的原生乙醇。與卡路里含量相當的對照相比，一些食蜜哺乳動物表現出對低濃度乙醇溶液的偏好，但食花蜜鳥類對乙醇的行為反應尚不清楚。我們調查了安娜蜂鳥（Calypte anna）的飲食偏好）用於乙醇增強蔗糖溶液。通過重複的二元選擇實驗，將三隻成年雄性蜂鳥暴露於含有0%、1%或2%乙醇的蔗糖溶液中；每隔 3 小時測量一次有意識的花蜜消耗率。蜂鳥不區分 0% 和 1% 乙醇溶液，但表現出 2% 乙醇溶液的消耗率顯著降低。對蜂鳥餵食器內乙醇濃度的機會測量顯示其峰值約為 0.05%。低濃度（即高達 1%）的乙醇不會令安娜蜂鳥感到厭惡，並且可能是它們賴以生存的天然和人為花蜜的特徵。鑑於蜂鳥每天消耗大量的花蜜，因此長期生理接觸乙醇可能是大量的。

Both frugivores and nectarivores are potentially exposed to dietary ethanol
produced by fermentative yeasts which metabolize sugars. Some nectarivorous
mammals exhibit a preference for low-concentration ethanol solutions comparedto controls of comparable caloric content, but behavioural responses to
ethanol by nectar-feeding birds are unknown. We investigated dietary
preference by Anna's Hummingbirds (Calypte anna) for ethanol-enhanced sucrosesolutions. Via repeated binary-choice experiments, three adult male
hummingbirds were exposed to sucrose solutions containing 0%, 1% or 2%
ethanol; rates of volitional nectar consumption were measured over a 3 h
interval. Hummingbirds did not discriminate between 0% and 1% ethanol
solutions, but exhibited significantly reduced rates of consumption of a 2%
ethanol solution. Opportunistic measurements of ethanol concentrations withinhummingbird feeders registered values peaking at about 0.05%. Ethanol at low
concentrations (i.e. up to 1%) is not aversive to Anna's Hummingbirds and maybe characteristic of both natural and anthropogenic nectars upon which they
feed. Given high daily amounts of nectar consumption by hummingbirds, chronicphysiological exposure to ethanol can thus be substantial, although naturallyoccurring concentrations within floral nectar are unknown.

餵食器內的乙醇濃度雖然看似很低，但考慮到蜂鳥花蜜消耗的高體積率，其濃度並非微不足道。安娜蜂鳥每天必須消耗約 10 克 20% 的蔗糖溶液才能滿足能量需求。即使餵食器中典型的乙醇濃度僅為 0.02%，這樣的消耗率仍相當於每日 2 毫克乙醇劑量（或約體重的 0.04%）。相比之下，假設體重為 80 公斤，人類每天飲用一份常規啤酒（含 12 克
乙醇）相當於攝入體重的約 0.015%。

Ethanol concentrations within feeders, although seemingly low, were however
non-trivial given high volumetric rates of nectar consumption by
hummingbirds. Anna's Hummingbirds must consume about 10 g of 20% sucrose
solution daily to meet energetic needs [21]. Even if typical ethanol
concentrations in feeders are only 0.02%, such a rate of consumption would
still correspond to a daily dosage of 2 mg of ethanol (or about 0.04% of bodymass). By contrast, human consumption of one standard drink daily (containing12 g of ethanol) corresponds to a exposure of about 0.015% of body mass,
assuming the latter to be 80 kg.

--