Obara Yoshiaki, Koshitaka Hisaharu, Arikawa Kentaro
Behavioural Biology, Department of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
J Exp Biol. 2008 Dec;211(Pt 23):3698-702. doi: 10.1242/jeb.021980.
Ultraviolet (UV) vision is widespread in a variety of animals, playing important roles in behaviours such as foraging and reproduction. Despite accumulated information about UV vision and UV-dependent behaviours of animals, little is known about the effect of temporal changes and local variations in UV light on UV-dependent behaviour. Here we report the mating behaviour of male cabbage butterfly, Pieris rapae crucivora, in environments with varying content of UV light. We first confirmed that the relative UV content is higher in shaded places than in sunny places. We furthermore arranged experimental areas with varying UV contents in the field, where we compared three aspects of male mating behaviour: visual localization of females, female-searching flight and copulation success rate. In all aspects males performed more actively in UV-rich environments: males searched females for longer, approached females preferentially in the shade and copulated there more frequently. Apparently, female-searching males detect females more easily in a UV-rich environment. The present findings should be taken into consideration when UV-dependent behaviours, visual mate choice in particular, are studied.
紫外线（UV）视觉在多种动物中广泛存在，在觅食和繁殖等行为中发挥着重要作用。尽管已经积累了关于动物紫外线视觉和依赖紫外线的行为的信息，但对于紫外线的时间变化和局部变化对依赖紫外线的行为的影响却知之甚少。在这里，我们报告了雄性菜粉蝶（Pieris rapae crucivora）在紫外线含量不同的环境中的交配行为。我们首先证实，阴凉处的相对紫外线含量高于阳光充足的地方。此外，我们在野外设置了紫外线含量不同的实验区域，比较了雄性交配行为的三个方面：对雌性的视觉定位、寻找雌性的飞行以及交配成功率。在所有方面，雄性在紫外线丰富的环境中表现得更加活跃：雄性寻找雌性的时间更长，在阴凉处优先接近雌性并在那里更频繁地交配。显然，寻找雌性的雄性在紫外线丰富的环境中更容易检测到雌性。在研究依赖紫外线的行为，特别是视觉配偶选择时，应考虑本研究结果。
