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“Very few species use the same material uniformly. I have seen the nest of the robin quite destitute of mud. In one instance, it was composed mainly of black horse-hairs, arranged in a circular manner, with a lining of fine yellow grass; the whole presenting quite a novel appearance. In another case, the next was chiefly constructed of a species of rock moss.”
Birds’-Nests, In The Catskills by John Burroughs