The gens Fabia was a prominent patrician family, who claimed descent from both Hercules and Evander. One branch of the gens Fabia, the Fabii Buteones, took their name from a bird, buteo, which during the Punic War siege of Drepanum settled on the prow of a ship commanded by consul Fabius and was a good omen. Pliny identified the buteo as a type of hawk, but the type of bird is questioned by Crawford in Roman Republican Coinage.
Auspicious and Auspices both have roots in “avis” bird and “specere” to look. In ancient Rome an Augur would be consulted before any major undertaking. Augurs would look for omens in the flight and feeding of birds. The story of the founding of Rome by Romulus and Remus told by Plutarch and others, relates that the two tried to settle their question of where to build the city “by the flight of birds of omen”. There is, of course, more to the story and interpreting the omen leads to a fight in which Remus ends up dead. Still the Romans put a lot of faith in augury:
"Auspiciis hanc urbem conditam esse, auspiciis bello ac pace, domo militiaeque omnia geri, quis est, qui ignoret?" “Who is it that does not know that this city was only founded after taking auspices and that nothing is done in war and peace, at home or abroad, without taking auspices?”
-Livy (Ab Vrbe Condita VI.41)
In addition to birds they would consult the entrails of a dead animal for signs as well. Haruspex from haru, entrails, intestines, specere, to look or observe. For me this puts a new twist on having the guts to go into battle, but that takes us away from the birds.
Here is an AR denarius of C. Fabius C.f. Hadrianus featuring a bird on the reverse that may be a buteo or marsh bird (sumpfvogel) and making a questionable connection between the moneyer and the gens Fabii.
Date: 102 BC
Obv: EX A PV, Turreted and veiled bust of Cybele right
Rev: Victory driving galloping biga right, E below horses, bird before, C FABI C F in exergue
Size: 19.6mm, 3.96 grams
Ref: Crawford 322/1b; Fabia 14; Sydenham 590
Note: EX A PV translates to EX Argento PVblico, indicating a special issue struck from the reserve bullion in the public treasury.
Crawford also connects C. Fabius Hadrianus to Fabius Hadrianus who was praetor in 84 BC in the Roman province Africa. Fabius Hadrianus was burned alive in an uprising in Utica. There is reason to suspect that this was because he got on the wrong side of Sulla - his successor was Pompey the Great a Sulla supporter.
Cicero had no kind words for C. Fabius Hadrianus: “He, because Roman citizens could not tolerate his avarice, was burnt alive at Utica in his own house; and that was thought to have happened to him so deservedly, that all men rejoiced, and no punishment was inflicted for the deed.”
Apparently, the bird on this denarius did not augur well for C. Fabius Hadrianus.