The night-flying bat has evolved a species which exploits this abundant, highly nutritious food source National Geographic Video (wait for the adverts to finish). So why haven't the birds moved into this ecological niche? Owls are excellent stealth hunters of mice, using there advanced hearing, so why not fish? There should be night-owls who have evolved to hunt fish throughout the night, surely? Why has this opportunity been missed? Is this an anomaly of evolution?