Abstract

Fireflies use bioluminescent flashes to establish a dialogue between conspecific males and females. Through this dialogue, receptive females attract conspecific males for mating. In most firefly species, the males act as independent agents. That is, as they fly and flash in search of a responding female they do not appear to coordinate their activities with other males. In marked contrast, the males of some firefly species coordinate their flashes to coincide with those of other conspecific flashing males, resulting in synchronous flashing across local populations. We propose that the need for synchrony in these species may be driven by constraints imposed by the female visual system. Since males are flying while flashing and may appear to flash from different spatial locations, the female must attend to flashes over a wide visual field. But doing so has a drawback. She may see the flashes of multiple males within her wide visual field and their flashes could interfere with her ability to respond to any single male. We present evidence of a sensitive period during which extraneous flashes interfere with a female’s response to a conspecific male and develop a model to predict how the number of independently flashing conspecific males affects the female’s responsiveness. By coordinating their flashing, the males reduce the chance that any of them will flash during the female’s sensitive period. This minimizes interference with establishing the male–female dialogue that would otherwise result by the presence of many patrolling males being in the female visual field. We conclude that the constraints imposed by the female visual system could be a factor driving the need for males to synchronize their flashing if they tend to fly and flash at high population density.

摘要

萤火虫使用生物发光闪光在雌雄同种之间建立对话。通过这种对话，雌性雌性吸引具特异性的雄性交配。在大多数萤火虫种类中，雄性起独立作用。就是说，当他们飞翔和眨眼寻找雌性时，它们似乎并没有与其他雄性协调活动。与之形成鲜明对比的是，某些萤火虫物种的雄性使它们的闪光协调一致，从而与其他同种闪光的雄性相吻合，从而导致各地种群同步闪光。我们建议这些视觉同步的需求可能是由女性视觉系统施加的限制所驱动的。由于雄性在闪烁的同时飞行并且可能看起来是从不同的空间位置闪烁的，因此雌性必须在广阔的视野内进行闪烁。但是这样做有一个缺点。她可能会在广阔的视野中看到多只雄性的闪光，它们的闪光可能会干扰她对任何一只雄性作出反应的能力。我们提供了一个敏感时期的证据，在此期间外来的闪光会干扰女性对同种雄性的反应，并建立一个模型来预测独立闪烁的同种雄性的数量如何影响女性的反应能力。通过协调它们的闪烁，雄性减少了在雌性敏感时期任何人闪烁的机会。这样可以最大程度地减少对建立男女对话的干扰，否则这种干扰是由于女性视野中有许多巡逻男性造成的。