Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, 1117, Budapest, Hungary.
Deutsches Meeresmuseum, Katharinenberg 14-20, 18437, Stralsund, Germany.
Sci Rep. 2021 Aug 4;11(1):15797. doi: 10.1038/s41598-021-95105-4.
There is a long-lasting debate about the possible functions of zebra stripes. According to one hypothesis, periodical convective air eddies form over sunlit zebra stripes which cool the body. However, the formation of such eddies has not been experimentally studied. Using schlieren imaging in the laboratory, we found: downwelling air streams do not form above the white stripes of light-heated smooth or hairy striped surfaces. The influence of stripes on the air stream formation (facilitating upwelling streams and hindering horizontal stream drift) is negligible higher than 1-2 cm above the surface. In calm weather, upwelling air streams might form above sunlit zebra stripes, however they are blown off by the weakest wind, or even by the slowest movement of the zebra. These results forcefully contradict the thermoregulation hypothesis involving air eddies.
关于斑马条纹可能具有的功能，存在着长期的争论。有一种假说认为，周期性的对流空气漩涡会在阳光照射的斑马条纹上形成，从而使身体降温。然而，这种漩涡的形成尚未经过实验研究。我们利用实验室中的纹影成像技术发现：在被阳光加热的光滑或有毛的条纹表面，白色条纹上方不会形成下沉的气流。条纹对气流形成的影响（促进上升气流和阻碍水平气流漂移）在表面上方 1-2 厘米以上时可以忽略不计。在平静的天气下，上升气流可能会在阳光照射的斑马条纹上方形成，但它们会被最微弱的风甚至斑马最慢的移动吹走。这些结果有力地反驳了涉及空气漩涡的热调节假说。
