Midrash for Chullin 278:18

מכאן אמרו

so everywhere the nest must not be ready at your hand; hence they said, [Wild] doves of the dove-cote, and doves of the loft, and birds which made their nests in the cornices<span class="x" onmousemove="('comment',' pitcher-shaped vessels put up in walls and corners as resting places for birds (Jast) . Cf. Bez., Sonc. ed., p. 124, nn. 3-4.');">⁸</span>

Sifrei Devarim