動物的體色與其對視覺訊號的感知能力在捕食者與獵物間的行為互動中扮演著重要角色。當我們論及動物的顏色訊號時總是將焦點著重於日間視覺系統；日行性動物對於形狀的辨別能力對其生存及生殖而言已被大量研究證實扮演著重要角色。然而在微光環境下，夜行性動物間之視覺互動尚未受到研究人員太多的關注。由於對此領域研究投入之不足，大大限制了我們夜間之視覺互動模式之認識及適當的研究方法之發展。以致於到目前，我們對顏色訊號在夜間之陸域生態系所扮演的角色所知仍然相當有限。我們推測，在夜間的陸域生態系中應具有更多種基於顏色視覺之生物作用，包括發生於種內或種間之捕食、溝通、求偶或個體辨識等各層面。為了全面拓展視覺生態學在夜間微光環境的知識，我們在本計畫中將針對數種類型之夜行性蜘蛛其體色或誘引獵物之視覺訊號之功能及設計進行探討。計畫以紅外線攝影機監測夜行性蜘蛛的各種覓食及求偶行為，同時操作蜘蛛之體色，亦採用人工製作的假蜘蛛，配合最新的夜間昆蟲視覺模型，來探討視覺訊號在蜘蛛與夜行性昆蟲之視覺互動中扮演何種角色。此外，雖然視覺在白天是一種很重要的溝通方式，但在夜間的光強度如此低，背景雜訊如此高的狀況下，是否動物也會利用視覺做為交配間的溝通訊號呢？我們想要藉由體色鮮艷具性別二型性之夜行性溪狡蛛，來探討夜行性動物是否也會利用視覺顏色訊號當做物種辨識以及判斷交配對象品質的依據。最後，至目前為止仍沒有關於蜘蛛體色演化之系統性研究，因此本研究計畫亦將針對夜行性結圓網蜘蛛的視覺訊號演化模式進行探討。我們將採集金蛛科內各種夜行性分類群，建立其分子親緣關係樹，並將量化不同種類蜘蛛腹面亮點之反射訊號、形狀與排列，藉重建夜行性蜘蛛誘引訊號之反射光譜特性(色相與黃色色度)與色斑形狀之演化歷史來嘗試了解是那些因素影響夜行性動物視覺誘引訊號之性質與設計。 Body coloration and visual perception ability play important roles in the interactions between prey and predators.When discussing about animal color signals researchers usually focus on diurnal systems. Results from numerous studies have demonstrated that visual perception ability is vital for diurnal animals’ survival and reproduction. However, the visual interactions of nocturnal animal under dim light condition has received little attention. Insufficient effort in this research area severally limits our understanding of nocturnal visual interactions and development of appropriate research methods.We hypothesize that in the terrestrial ecosystem in the nocturnal condition, color vision should be comprehensively involved in intra- as well as inter-specific interactions in aspects such as foraging, communication, courtship and species recognition. To advance our knowledge about visual ecology in the dim light condition, we plan to investigate the functions of body coloration or visual luring signals of several types of nocturnal spiders. In this proposed study, infrared video monitoring, field manipulative experiments as well as modern neuroethological modeling will be applied to investigate the roles visual signals play in the interactions between spiders and nocturnal insects. Another topic investigated in this proposed study is whether nocturnal animals will use visual signal as a major way of communication under the dim light condition. A local species of fishing spider exhibiting sexual color dimorphism will be used to investigate whether visual signals will be used by nocturnal animals to recognize species status and assess mate quality. Finally, so far there is no study systematically investigating the evolution of color signal in orb web spiders.We will collect various taxa of nocturnal orb web spiders to construct a molecular phylogeny and to measure the chromatic and arrangement patterns of their color signals. By reconstructing the evolutionary history of reflectance pattern and signal forms, hopefully factors affecting the design and properties of nocturnal orb spider visual lure signals can be realized.
