Augury was a Greco-Roman religious practice of observing the behavior of birds, to receive omens. When the individual, known as the augur, read these signs, it was referred to as "taking the auspices". "Auspices" (Latin: auspicium) means "looking at birds". Auspex, another word for augur, can be translated to "one who looks at birds". Depending upon the birds, the auspices from the gods could be favorable or unfavorable (auspicious or inauspicious). Sometimes politically motivated augurs would fabricate unfavorable auspices in order to delay certain state functions, such as elections. Pliny the Elder attributes the invention of auspicy to Tiresias the seer of Thebes.
Over the development of the Roman empire, the definition of augury broadened to include other forms of divination. Haruspicy—the examination of animal entrails—was learned from the Etruscans. The Etruscan practice of observing thunder and lightning was also adapted. In Cicero's time, the augurs had mostly switched from using the flight of birds to haruspicy for public divination.