One winter after a heavy snow, night keepers reported for several nights in a row that they had caught glimpses of what appeared to be an arctic fox near the small, moated grotto that housed that species. Each morning, however, keepers found all of the animals present and accounted for. It was assumed that the animal the night keepers were seeing was a native fox.
Finally one night, however, the night keeper turned a corner and managed to get a good look at the elusive animal in the headlight beam. It was definitely an arctic fox. As the keeper watched, the fox darted back to the grotto and jumped easily back in, where it was calmly waiting the next day to be counted.