2014 年,一個位於美國 Virgina 州的研究單位 (Howard Hughes Medical Institute in Ashburn, Virginia),發表了對蜻蜓如何追逐獵物的研究成果,該研究顯示:蜻蜓會嘗試去預測獵物的可能行進路徑,當獵物的實際行進路線與其預測相符時,表示其預測模式準確,此時蜻蜓的眼睛、翅膀、以及身體等就會遵循這套預測模式去做獵捕;如果獵物突然改變行進路線,導致原本的預測模式失靈時,蜻蜓會建立另一個預測模式,來調整獵殺的路徑,而在這不同預測模式的轉換過程中,蜻蜓的翅膀與身體會彼此協調運作來讓其眼睛可以一直持續地緊盯著獵物的狀態。
該研究的幾則節錄:
“The dragonfly lines up its body axis in the flight direction of the prey, but keeps the eyes in its head firmly fixed on the prey,” says Anthony Leonardo of the Howard Hughes Medical Institute in Ashburn, Virginia.
Dragonfly adjusts its flight and can predict how its prey will move before catching it.
對了,那個位於蜻蜓翅膀前緣近末端的較厚重小區域,叫做 pterostigma,中文翻譯成「翅痣」。在此簡單節錄 wikipedia 對於 pterostigma 的一段解釋:
The purpose of the pterostigma, being a heavier section of the wing in comparison to nearby sections, is to assist in gliding. Without the pterostigma, self-exciting vibrations would set in on the wing after a certain critical speed, making gliding impossible. Tests show that with the pterostigma, the critical gliding speed is increased 10–25% on one species of dragonfly.