Those would be the sacred geese of Juno. According to legend, their squawking warned Marcus Manlius Capitolinus of a Gallic attack in 390 BC, so he was able to prevent the Gauls from taking the Capitoline Hill (although they did sack the rest of the city, and left only after receiving a huge sum in tribute). I have never seen any references suggesting that the wings depicted on legionary shields were meant to represent Juno's sacred geese, although if you have some I would love to read them.lreissin wrote:The eagle wings mention early in the post are really the wings of geese.
From what I read, an enemy was trying to breach the walls of Rome and the alarm was giving by a bunch of geese.
After that the Romans for centuries had a group of sacred geese that they took care of.
Everything I have ever read about the depictions of wings and lightning on Roman legionary shields of the Late Republic and Principate indicates that both were meant to represent aspects of Jupiter Optimus Maximus - the lighting as his primary weapon and the eagle as his messenger. A few online examples here:
http://www.redrampant.com/roma/religio.html
http://www.crystalinks.com/jupiterrome.html
Likewise for the legionary eagle standard: http://www.legiiavg.org.uk/military/aquila.html
Cheers,
Scott