Passage 8.22.6
εἰ μὲν δὴ καὶ αἱ κατʼ ἐμὲ ὄρνιθες αἱ Ἀράβιοι τῶν ἐν Ἀρκαδίᾳ ποτὲ ὀρνίθων τὸ ὄνομα, εἶδος δὲ οὐ τὸ αὐτὸ ἐκείναις ἔχουσιν, οὐκ οἶδα· εἰ δὲ τὸν πάντα αἰῶνα κατὰ τὰ αὐτὰ ἱέραξι καὶ ἀετοῖς καὶ Στυμφαλίδες εἰσὶν ὄρνιθες, Ἀράβιόν τε εἶναί μοι θρέμμα αἱ ὄρνιθες αὗται φαίνονται, καὶ δύναιτο ἂν πετομένη ποτὲ ἀπόμοιρα ἐξ αὐτῶν ἐς Ἀρκαδίαν ἀφικέσθαι ἐπὶ Στύμφαλον. ὑπὸ μὲν δὴ τῶν Ἀράβων ἄλλο τί που ἐξ ἀρχῆς καλοῖντο ἂν καὶ οὐ Στυμφαλίδες· τοῦ Ἡρακλέους δὲ ἡ δόξα καὶ τὸ Ἑλληνικὸν πρὸ τοῦ βαρβαρικοῦ τετιμημένον ἐξενίκησεν ὡς καὶ τὰς ἐν τῇ ἐρήμῳ τῇ Ἀράβων Στυμφαλίδας καὶ ἐπὶ ἡμῶν ὀνομάζεσθαι.
Whether the Arabian birds of my own day bear the name of those once in Arcadia, but differ in appearance from them, I cannot say; but if throughout all time the Stymphalian birds have been similar to hawks and eagles, these present-day birds seem to me indeed to be Arabian in origin, and it would have been possible for some of them, flying astray, to reach Arcadia at Stymphalos. Originally, however, they must have been called by some other name among the Arabs and certainly not Stymphalian; but the fame of Herakles, along with the honored status of things Greek compared to the barbarian, has prevailed to the extent that even the birds in the Arabian desert are called Stymphalian up to our own times.