I spend summers in a seagull rookery on a small island, about 2000 adult birds. Each pair averages about two young. A few years ago when the young were hatched but still tiny, puffy balls with legs there was a strong wind for two days. One by one the chicks lost their balance, tumbled away across the island and blew into the cold water. It was nearly a 100% wipe of the young. But the birds live many years, and 1 young per adult per year is unsustainable, so they have to get eaten or die somehow. It just feels horrible to see all of a year’s young go at once.