He  fathered Remus and Romulus after seducing Rhea Silvia.
The Equirria was a festival celebrating this deity, and this deity's sacred bird is the  woodpecker. One sacrifice made to this god is called the suovetaurilia. This god's mother gave  birth to him alone, with a flower from Flora, and one of his festivals is in October, which marks  the end of farming. This god's shield, the Ancile, fell from the heaven upon Numa Pompilius. He  fathered Remus and Romulus after seducing Rhea Silvia. For 10 points, identify this Roman deity,  the guardian of agriculture and god of war.
The Equirria was a festival celebrating this deity, and this deity's sacred bird is the  woodpecker.
{Mars} [do not prompt on or accept “Ares”]