Recent political issues and politicians.This includes (but is not limited to) submissions related to: No politics, soapboxing, or agenda based submissions. Any sources (blog, article, press release, video, etc.) with a publication date more recent than two months are not allowed. No personal opinions, anecdotes or subjective statements (e.g "TIL xyz is a great movie"). Videos are fine so long as they come from reputable sources (e.g. Images alone do not count as valid references. Please link directly to a reliable source that supports every claim in your post title. Submit interesting and specific facts that you just found out (not broad information you looked up, TodayILearned is not /r/wikipedia). Now we need to consider whether colour, stripe width and spatial patterning, and a predator’s visual system could be important factors for animals to avoid capture.”Īnna Hughes has written a blog post on this research for the journal publisher BioMed Central. Above story adapted from a BioMed Central press release.You learn something new every day what did you learn today? “More work is needed to establish the value and ecological relevance of ‘motion dazzle’. The evolution of pattern types is complex, for which there isn’t one over-ruling factor, but a multitude of possibilities,” said Hughes.
Different orientations of stripe patterning may have evolved for different purposes. “Motion may just be one aspect in a larger picture. However, when multiple targets were present, all striped targets, irrespective of the orientation, were captured more easily than uniform grey targets. When single targets were present, horizontal striped targets were easier to capture than any other target, including uniform colour, or vertical or diagonal stripes. They performed a touch screen task in which they attempted to ‘catch’ moving targets - both when only one target was present on screen and when there were several targets present at once. HMS Argus (1917) wearing dazzle camouflage.Ī total of 60 human participants played a game to test whether stripes influenced their perception of moving targets. Rather than concealing ships, this dazzle camouflage was believed to make it difficult to estimate a target's range, speed and heading. ‘Motion dazzle’ is a reference to a type of camouflage used on ships in World Wars One and Two, where ships were patterned in geometric shapes in contrasting colours. It was suggested that motion dazzle might be strongest in groups, such as a herd of zebra. In a concept termed ‘motion dazzle’, where high contrast patterns cause predators to misperceive the speed and direction of the moving animal. Striking patterns may confuse predators and reduce the chance of attack or capture. Researchers have wondered if movement is important in explaining why these patterns have evolved. Stripes, zigzags and high contrast markings make animals highly conspicuous, which you might think would make them more visible to a predator. “This could be due to how different stripe orientations interact with motion perception, where an incorrect reading of a target’s speed helps the predator to catch its prey.” Surprisingly, we also found no benefit of stripes when multiple targets were presented at once, despite the prediction that stripes should be particularly effective in a group scenario,” said Anna Hughes, a researcher in the Sensory Evolution and Ecology group and the Department of Physiology, Development and Neuroscience.
“We found that when targets are presented individually, horizontally striped targets are more easily captured than targets with vertical or diagonal stripes. The finding runs counter to assumptions that stripes evolved to make it difficult to capture animals moving in a group. Humans playing a computer game captured striped targets more easily than uniform grey targets when multiple targets were present. Stripes might not offer protection for animals living in groups, such as zebra, as previously thought, according to research published today in the journal Frontiers in Zoology.
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