In ready to the Northwest of the province of Zamora, in the zone of influence of the astur-leones, when I was a kid and even then, the nests of the birds called them late. This word is still used among the elderly, but it is falling into disuse. I think that the word nal is a phonetic abbreviation of nidal: disappearance of the " (d) " and transformation of " or " " 34 n;. NAL is an old synonym for nest which is deprecated.