 The American white ibis is a tactile , <unk> forager , which limits its ability to choose from a wide variety of prey . For the most part , the American white ibis forages for food by tactile probing . It wades slowly through shallow water and sticks its long , downcurved bill into the substrate of the water body with its bill held at around 1 to 2 cm ( 0 @.@ 39 to 0 @.@ 79 in ) agape at the tip , and sweeps its long bill back and forth across the bottom to pick out suitable food items . Birds may also probe when standing still . <unk> with a wide open bill is a technique used by ibis in deeper water when alone , as is head swinging , in which the ibis swings its wide open bill widely in open water . Others copy this type of foraging if they see one ibis doing it . On land , the American white ibis locates prey by sight and pecks , and does not have to insert its bill into the substrate . The American white ibis seeks small prey when other birds are around , as it needs time to break up larger food items into smaller pieces to eat , and other predators such as herons and egrets often take the opportunity to rob the ibis of its catch . Along with the scarlet ibis , the species coexists with another five species of ibis in the Llanos in Venezuela . American white ibis males are aggressive to and take prey items from smaller ibises , but the smaller females are more often the victims of this behavior . 
