This species eats any small dryland and marsh animals it can catch, or even pirate (as from an aplomado falcon in one reported incident). It often holds still but also walks very slowly and may use more active techniques, even running after prey or catching flying insects (notably dragonflies) from a standing position.
It may allow humans to approach fairly closely rather than leave a good feeding spot. It typically feeds alone or in pairs, but is sometimes seen in groups up to 100, especially before roosting for the night.