Ducks usually migrate at an altitude of 200 to 4,000 feet but are capable of reaching much greater heights. A jet plane over Nevada struck a mallard at an altitude of 21,000 feet—the highest documented flight by North American waterfowl. And a 1954 climbing expedition to Mount Everest found a pintail skeleton at an elevation of 16,400 feet. (https://www.ducks.org/conservation/waterfowl-research-science/amazing-waterfowl-facts)
네바다 주 상공을 날던 제트기가 21000 피트, 약 6400 미터 상공에서 청둥오리를 발견했다고...
네바다 주 상공을 날던 제트기가 21000 피트, 약 6400 미터 상공에서 청둥오리를 발견했다고...
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