It's not exactly "an innate ideal" of nature. It's competition for survival. According to an article about this video on the Huffington Post:This mesmerizing act is typically seen at the beginning of winter, right before dusk, as the birds look for a place to roost for the night. "Numbers build up slowly near the roost over the afternoon as small groups of birds return from foraging in the area,” explains Paul Stancliffe of the British Trust for Ornithology. “By late afternoon there is a huge swirling cloud. It’s all about safety in numbers – none wants to be on the outside, none wants to be first to land.” Essentially it's an epic battle to determine who in the flock survives, and who's a target for predators. According to the Telegraph, each bird tries to copy the bird next to it exactly, which results in a stunning rippling effect.
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