文獻來源:McClure M, Ralph M & Despland E (2011) Group leadership depends on energetic state in a nomadic collective foraging caterpillar. Behavioral Ecology and Sociobiology 65:1573-1579.
簡介
社會性動物之集體行動可以為多數個體帶來利益，但誰要冒著較大的風險領隊出發？誰要決定對的出發時機和移動方向？在某些動物中這些決策是由團隊共同決定，有些則是由部分或單一個體來決定的。此篇研究探討在Malacosoma disstria枯葉蛾幼蟲的集體掠食行為中，是由哪隻幼蟲佔據領導位置率先出發。研究分成兩個實驗，一是探討是否有些幼蟲特別容易產生這種領導掠食行為，另一則是控制幼蟲的能量攝取，看幼蟲的飢餓程度是否與領導掠食行為有關。實驗結果顯示，在相同的食物控制下，幼蟲的齡期、重量及性別皆與領導掠食行為無顯著關係，顯示此實驗中所有幼蟲之領導傾向沒有顯著差異；另一方面，在有能量(食草)控制的情況下，能量儲存量較低(較飢餓)的幼蟲有較高的傾向領導團隊展開掠食活動，且具有飢餓幼蟲之團隊會越快決定出發，但實豪儦F食物的時間則會視團隊中所有個體之飢餓程度而定，一團隊中若具有較多飢餓之個體，其集體行動之凝結力會降低，反而減緩到達目的地之速度。
Abstract
Group living is a common strategy among animals and has arisen independently in over 300 species of Lepidoptera. Yet, activity synchrony between individuals is necessary to derive the benefits that ensue from an aggregated lifestyle. Which individuals decide which activities to perform and when to perform them is, therefore, a fundamental question. In some species of social caterpillars and sawflies, the role of a potential behavioral polyethism between individuals has been suggested, whereby certain individuals are consistently more likely to initiate and lead a foraging event. However, in these cases, evidence in support of division of labor is lacking. This study was undertaken to determine if certain individuals of Malacosoma disstria are more likely to be consistent group leaders or if transient leaders could be predicted by the differences in energetic states between individuals. The results of this study indicate that unfed caterpillars initiate foraging bouts and are more likely to lead locomotion. There was no size or sex-based bias in those individuals that acted as temporary leaders. Consistent behavioral differences between individuals, if they exist, are therefore not necessary to explain task allocation and synchronization during foraging in this species.
