From the Suda, s.v. Seirênas
“The Sirens were some Greek women with beautiful voices in ancient Greek myth who sat on some island and so delighted passers-by with their euphony that they stayed there until death. From the chest up they had the shape of sparrows but their lower halves were woman.
The mythographers claim that they were small birds with female faces who deceived passers-by, beguiling the ears of those who heard them with pornographic songs. And the song of pleasure has no end that is good, only death.
But the true story is this: there are certain places in the sea, narrowed between hills, which release a high song when the water is compressed into them. When people who sail by hear them they entrust their souls to the water’s swell and they die along with their ships.
The creatures who are called Sirens and Donkey-centaurs in Isaiah are some kind of demons who are foretold for abandoned cities which fall under divine wrath. The Syrians say they are swans. For after swans bathe, they fly from the water and sing a sweet melody in the air. This is why Job says, “I have become the Sirens’ brother, the companion of ostriches. This means that I sing my sufferings just like the ostriches.”
He calls the Sirens strouthoi, but he means what we call ostriches [strouthokamêmlos: “sparrow-camel”]. This is a bird which has the feet and neck of a donkey. There is a saying in the Epigrams “that chatter is sweeter than the Sirens’”. The Sirens were named Thelksiepeia, Peisinoê, and Ligeia. The Island they inhabited was called Anthemousa.”
Σειρῆνας: γυναῖκάς τινας εὐφώνους γεγενῆσθαι μῦθος πρὶν ῾Ελληνικός, αἵ τινες ἐν νησίῳ καθεζόμεναι οὕτως ἔτερπον τοὺς παραπλέοντας διὰ τῆς εὐφωνίας, ὥστε κατέχειν ἐκεῖ μέχρι θανάτου. εἶχον δὲ ἀπὸ μὲν τοῦ θώρακος καὶ ἄνω εἶδος στρουθῶν, τὰ δὲ κάτω γυναικῶν.
οἱ μυθολόγοι Σειρῆνας φασὶ θηλυπρόσωπά τινα ὀρνίθια εἶναι, ἀπατῶντα τοὺς παραπλέοντας, ᾄσμασί τισι πορνικοῖς κηλοῦντα τὰς ἀκοὰς τῶν ἀκροωμένων. καὶ τέλος ἔχει τῆς ἡδονῆς ἡ ᾠδὴ ἕτερον μὲν οὐδὲν χρηστόν, θάνατον δὲ μόνον. ὁ δὲ ἀληθὴς λόγος τοῦτο βούλεται, εἶναι τόπους τινὰς θαλαττίους, ὄρεσί τισιν ἐστενω-μένους, ἐν οἷς θλιβόμενον τὸ ῥεῖθρον λιγυράν τινα φωνὴν ἀποδίδωσιν· ἧς ἐπακούοντες οἱ παραπλέοντες ἐμπιστεύουσι τὰς ἑαυτῶν ψυχὰς τῷ ῥεύματι καὶ αὔτανδροι σὺν ταῖς ναυσὶν ἀπόλλυνται.
αἱ δὲ παρὰ τῷ ᾿Ησαΐᾳ εἰρημέναι Σειρῆνες καὶ ᾿Ονοκένταυροι δαίμονές τινές εἰσιν, οὕτω χρηματιζόμενοι ἐπ’ ἐρημίᾳ πόλεως, ἥτις χόλῳ θεοῦ γίνεται. οἱ δὲ Σύροι τοὺς κύκνους φασὶν εἶναι. καὶ γὰρ οὗτοι λουσάμενοι καὶ ἀναπτάντες ἐκ τοῦ ὕδατος καὶ τοῦ ἀέρος ἡδύ τι μέλος ᾄδουσιν. ὁ οὖν ᾿Ιὼβ λέγει, ἀδελφὸς γέγονα Σειρήνων, ἑταῖρος δὲ στρουθῶν. τουτέστιν ᾄδω τὰς ἐμαυτοῦ συμφοράς, ὥσπερ Σειρῆνες.
στρουθοὺς δὲ λέγει, ὃν ἡμεῖς στρουθοκάμηλον λέγομεν, ὄρνεον μὲν ὄντα, πόδας δὲ καὶ τράχηλον ὄνου κεκτημένον. καὶ ἐν ᾿Επιγράμμασι· καὶ τὸ λάλημα κεῖνο τὸ Σειρήνων γλυκύτερον. ὀνόματα Σειρήνων· Θελξιέπεια, Πεισινόη, Λιγεία· ἡ δὲ νῆσος ἣν κατῴκουν ᾿Ανθεμοῦσα.