Laudator Temporis Acti

A fable by John of Schepey, in Ben Edwin Perry, Babrius and Phaedrus (Cambridge: Harvard University Press, 1965), pp. 562-563 (Appendix, number 644):

A buzzard put one of her eggs in a hawk's nest, and the hawk hatched it and nursed the buzzard chick along with her own brood. The hawk's nestlings cast their excrements outside the nest, but the buzzard's chick befouled it. On seeing this, the hawk asked, "Which one of you is it that befouls the nest like this?" And they all answered, "Not I." Finally, after further investigation, the hawk's young ones found it necessary, in self defence, to reveal the truth, and they said, pointing to the young buzzard, "It's that one with the big head." On learning this, the hawk in great indignation seized the young buzzard by the head and threw him out of the nest, saying, " I managed to bring you up from the egg, but I couldn't get you beyond your nature." For, as Horace says, Naturam expellas furca, tamen usque recurret.—TMI Q432.1.

TMI = Stith Thompson, Motif-Index of Folk-Literature.

I don't have access to Perry's Aesopica, but I found the original in Léopold Hervieux, Les fabulistes latins, IV: Études de Cheriton et ses dérivés (Paris: Didot, 1896), pp. 437-438:

Busardus proiecit in nidum Accipitris ouum suum. Accipiter autem, credens ouum suum esse, cubauit super illud una cum ouis suis, et creatus (est) inde pullus quem nutriuit Accipiter tanquam suum. Pulli vero Accipitris proiecerunt fimum suum extra nidum; pullus maculauit nidum. Quod aduertens, Accipiter ait: Quis vestrum est qui sic maculat nidum suum? Et omnes dixerunt: Non ego, domine. Tandem facta pleniori inquisicione, oportebat eos pro sui liberacione prodere veritatem, et dixerunt: Domine, iste est cum magno capite, ostenso filio Busardi. Quem Accipiter, cum magna indignacione, per capud arripiens, proiecit extra nidum, dicens: De ouo te produxi; extra naturam non potui.

Quia, vt dicit Oratius (1):

Naturam expellas furta (sic); tamen vsque recurret.

(1) Ép., I, x, 24.

De nobis fabula.