By the end, exhausted adult birds with inadequate nutrition can only use natural hollows in the cliff to make up haphazard nooks, and the eggs or the chicks often fall down the cliff and are smashed to bits.
營養不足的成鳥，只好利用斷崖上的天然凹洞，造出缺乏具體巢形的燕窩。如此一來，卵或幼雛常因此由岩壁摔下，粉身碎骨。