Data from: Behavioural mimicry among poison frogs diverges during close-range encounters with predators

Aposematic species signal their unpalatability to potential predators with
recognisable, and frequently conspicuous, colour patterns. These visual
signals are often also associated with bold behaviour and a reduced
propensity to escape from approaching predators. Bold behaviours may act
as an aversive signal and allow defended prey to avoid the
energetic/opportunity costs that arise from fleeing predators. For
Batesian mimics, non-defended species which replicate the colours of
defended models, behavioural mimicry may also improve mimic fidelity and
reduce energetic/opportunity costs. However, as predators may test the
honesty of aposematic signals through sampling behaviour, Batesian mimics
can be at high risk during close-range interactions with predators. This
raises the question of whether/when Batesian mimics should deviate from
behavioural mimicry and initiate more extensive escape behaviour. Here, we
exposed the chemically defended poison frog Ameerega bilinguis and its
(non-toxic) Batesian mimic Allobates zaparo to a simulated predator
encounter. We predicted Al. zaparo would escape to a greater distance and
in a more erratic manner than Am. bilinguis. Yet, contrary to our
predictions, Al. zaparo did not flee far from predators. It was, however,
more likely to initiate escape prior to physical contact from the
predator. We suggest that bold behaviour coupled with pre-emptive movement
allows Al. zaparo to retain the benefits of behavioural mimicry while
reducing the likelihood that predators will test signal honesty. Our data
highlight, that when examining the evolution of mimicry, we must consider
both morphological and behavioural traits, as well as how risk to the prey
may change how they behave throughout the predation sequence.

警戒性物种（aposematic species）通过辨识度极高且通常极为醒目的体色图案，向潜在捕食者传递自身不适口的信号。这类视觉信号往往还与大胆行为及降低的逃逸倾向相关——当捕食者逼近时，被捕食者更少主动逃离。大胆行为可作为一种拒斥性信号，帮助已具备防御能力的猎物规避因逃逸产生的能量与机会成本。对于贝茨拟态物种（Batesian mimics），即复制具有防御能力的原型种的体色的无防御物种，行为拟态同样可提升拟态保真度并降低能量与机会成本。然而，由于捕食者可能通过取样行为检验警戒信号的真实性，贝茨拟态物种在与捕食者近距离互动时往往面临极高风险。这引出了一个核心问题：贝茨拟态物种应在何种情境下偏离行为拟态，启动更充分的逃逸行为？本研究中，我们将具有化学防御能力的双纹箭毒蛙（Ameerega bilinguis）及其（无毒）贝茨拟态种萨氏箭毒蛙（Allobates zaparo）暴露于模拟的捕食者遭遇场景中。我们此前预测，萨氏箭毒蛙的逃逸距离会更远、逃逸方式更不规则。但与预期相悖的是，萨氏箭毒蛙并未远离捕食者；不过，它们更倾向于在捕食者发生物理接触前就启动逃逸行为。我们认为，结合抢先移动的大胆行为，可使萨氏箭毒蛙在保留行为拟态益处的同时，降低捕食者检验其信号真实性的概率。本研究数据表明，在探究拟态的演化机制时，我们必须同时考量形态与行为特征，以及猎物面临的风险如何随捕食序列的推进改变其行为模式。