Auspices are a form of divination done through the observation of birds, lightning and other aerial phenomena.
Divination done through auspices isn’t a prediction of future events; but rather serve as a sign from the Gods indicating approval or disapproval of a proposed action.
Dervenis, Kostas. Oracle bones divination: the Greek I Ching. Rochester, VT: Destiny Books, 2014.
Dunn, Patrick. The practical art of divine magic: contemporary & ancient techniques of Theurgy. Woodbury, MN: Llewellyn Worldwide, Ltd, 2015.
Nova Roma. “Auspicium.” NOVA ROMA Dedicated to the restoration of classical Roman religion, culture and virtues. Accessed August 31, 2017. http://www.novaroma.org/nr/Auspicium.
Opsopaus, John. The oracles of Apollo: practical ancient Greek divination for today. Woodbury: Llewellyn Worldwide, Ltd, 2017.