The African sacred ibis writes Thoth's name. It is the standard hieroglyphic form for the god of writing, reckoning, the moon and the adjudication of disputes, and the choice is not arbitrary: the long curved bill was read as the crescent moon and as the stroke of a reed pen, and the bird's deliberate wading gait reads as method.
Thoth's functions cluster around the same idea. He records the verdict at the weighing of the heart, standing with a palette while the scales are read. He is credited with the invention of writing, with the division of time, and with the words of power that make ritual work. Where an Egyptian text needs someone to have written something down, Thoth wrote it.
The Greeks identified him with Hermes and produced Hermes Trismegistus, thrice-greatest, from an Egyptian epithet, and the entire Hermetic literature descends from that identification. A body of Greek philosophical and magical text that shaped the whole Western esoteric tradition begins with an Egyptian bird god of accountancy.
The bird itself is now extinct in Egypt. It disappeared from the country in the nineteenth century, probably through habitat loss along the Nile, and survives elsewhere in Africa and as an introduced nuisance in southern Europe.