The swan - More probably the ibis, the sacred bird of the Egyptians. "The gier eagle" is most likely the Egyptian vulture, a bird of unprepossessing appearance and disgusting habits, but fostered by the Egyptians as a useful scavenger.

The swan - תנשמת tinshemeth. The Septuagint translate the word by πορφυριωνα, the porphyrion, purple or scarlet bird. Could we depend on this translation, we might suppose the flamingo or some such bird to be intended. Some suppose the goose to be meant, but this is by no means likely, as it cannot be classed either among ravenous or unclean fowls. Bochart thinks the owl is meant.
The pelican - קאת kaath. As קאת kaah signifies to vomit up, the name is supposed to be descriptive of the pelican, who receives its food into the pouch under its lower jaw, and, by pressing it on its breast with its bill, throws it up for the nourishment of its young. Hence the fable which represents the pelican wounding her breast with her bill, that she might feed her young with her own blood; a fiction which has no foundation but in the above circumstance. Bochart thinks the bittern is meant, vol. iii., col. 292.
The gier eagle - רחם racham. As the root of this word signifies tenderness and affection, it is supposed to refer to some bird remarkable for its attachment to its young; hence some have thought that the pelican is to be understood. Bochart endeavors to prove that it means the vulture, probably that species called the golden vulture - Bochart, vol. iii., col. 303.

And the swan,.... This is a bird well known to us, but it is a question whether it is intended by the word here used; for though it is so rendered in the Vulgate Latin, it is differently rendered by many others: the Targums of Jonathan and Jerusalem call it "otia", which seems to be the same with the "otus" of Aristotle (n), who says it is like an owl, having a tuft of feathers about its ears (from whence it has its name); and some call it "nycticorax", or the owl; and here, by Bochart (o), and others, the owl called "noctua" is thought to be meant; and with which agrees the account some Jewish writers give of it, as Aben Ezra and Baal Hatturim, who say it is a bird, which every one that sees is astonished at it, as other birds are at the owl, are frightened at the sight of it, and stupefied. But as the same word is used Leviticus 11:30 among the creeping things, for a mole, what Jarchi observes is worthy of consideration, that this is "calve (chauve) souris" (the French word for a bat), and is like unto a mouse, and flies in the night; and that which is spoken of among the creeping things is like unto it, which hath no eyes, and they call it "talpa", a mole. The Septuagint version renders it by "porphyrion", the redshank; and so Ainsworth; and is thought to be called by the Hebrew name in the text, from the blowing of its breath in drinking; for it drinks biting, as Aristotle says (p):
and the pelican; which has its name in Hebrew from vomiting; being said by Aben Ezra and Baal Hatturim to be a bird that vomits its food; and it is observed by several naturalists (q), of the pelican, that it swallows down shellfish, and after they have lain some time in its stomach, it vomits them up again; where having been heated, the shells open, and it picks out the meat:
and the gier eagle; or vulture eagle, the "gypoeetos" of Aristotle (r), and who says it is called also "oripelargos", or the mountain stork; and which Pliny (s) also makes to be an eagle of the vulture kind. Dr. Shaw says (t), that near Cairo there are several flocks of the "ach bobba" (white father, differing little from the stork but in its colour), the "percnopterus" or "oripelargos", which like the ravens about London feed upon carrion, and nastiness that is thrown without the city; this the Arabs call "rachama", the same with Leviticus 11:18 and in Deuteronomy 14:17 and whatever bird is here meant, it must be one that is tender toward its young, as its name signifies, as Aben Ezra and Baal Hatturim observe; and though both the eagle and the vulture are rapacious birds, yet have a great regard to their young; of the eagle see Deuteronomy 32:11 and the vulture, with the Egyptians, was an "hieroglyphic" of a tender mother, or any merciful person; it being reported of it, that during the one hundred twenty days its young are under its care, it very rarely flies from them, being so solicitous of nourishing them; and that by making incisions in its thigh, it lets out a bloody flow of milk, when it has nothing else to support them (u). The Talmudists (w) say, that the bird "racham", as it is here called, is the same with "serakrak", and is by the Targum of Jonathan, and in the Syriac version, here rendered "serakraka", so called from which signifies to "squall"; and, according to Munster (x), is thought by some to be the "pica", magpie, or rather the jay; and Dr. Shaw (y) observes, that by a small transmutation of letters, that and the "shagarag" of the Arabs are the same; which he says is of the size and shape of a jay, though with a smaller bill, and shorter legs; the back is brownish; the head, neck, and belly, of a light green; and upon the wings and tail there are several spots or ringlets of a deep blue; it makes a "squalling" noise; and, he adds, it has no small affinity both in voice and plumage with the jay. The Septuagint version renders the word by the "swan"; which if not intended by the first word in this text, may by this, being kind to its young, though otherwise reckoned a cruel and unmerciful bird, as Bochart (z) observes; some think the woodpecker is meant, so called from its love to its parents (a).
(n) Hist. Animal. l. 8. c. 12. Vid. Plin. l. 10. c. 23. (o) Ut supra, (Apud Bochard Hierozoic. par. 2. l. 2.) c. 23. (p) Ut supra, (Hist. Animal. l. 8.) c. 6. so Plin. l. 10. c. 46. (q) Aristot. Hist. Animal. l. 9. c. 10. Aelian. de Animal. l. 3. c. 20, Plin. Nat. Hist. l. 10. c. 40. (r) Hist. Animal. l. 9. c. 32. (s) Nat. Hist. l. 10. c. 3. (t) Travels, p. 449. Ed. 2. (u) Horns Apollo & Pisidas apud Bochart. ut supra, (o)) c. 27. col. 388. (w) T. Bab. Cholin, fol. 63. 1. (x) Dictionar. Chald. p. 4. 18. (y) Travels, p. 183. (z) Ut supra (o)), c. 25. col. 300. (a) Plin. l. 10. c. 33.

the swan--found in great numbers in all the countries of the Levant. It frequents marshy places--the vicinity of rivers and lakes. It was held sacred by the Egyptians, and kept tame within the precincts of heathen temples. It was probably on this account chiefly that its use as food was prohibited. MICHAELIS considers it the goose.
the pelican--remarkable for the bag or pouch under its lower jaw which serves not only as a net to catch, but also as a receptacle of food. It is solitary in its habits and, like other large aquatic birds, often flies to a great distance from its favorite haunts.
the gier eagle--Being here associated with waterfowl, it has been questioned whether any species of eagle is referred to. Some think, as the original name racham denotes "tenderness," "affection," the halcyon or kingfisher is intended [CALMET]. Others think that it is the bird now called the rachami, a kind of Egyptian vulture, abundant in the streets of Cairo and popularly called "Pharaoh's fowl." It is white in color, in size like a raven, and feeds on carrion; it is one of the foulest and filthiest birds in the world. [See on Deuteronomy 14:17.]