Rare prey items include ticks, earthworms, crayfish, fish, and small birds. Frogs and toads are apparently important food items for chicks. After the breeding season, cattle egrets often feed in cotton and grain fields and follow farm equipment. Lack of food may limit their winter distribution in Texas. Consumption of grasshoppers and cattle-associated flies may be of great economic benefit to cattlemen.
Cattle egrets reduce the number of tabanids and, thereby, the incidence of bovine anaplasmosis.
Laboratory tests have shown that cattle egrets are not carriers of brucellosis, as was once suspected. Heronries near human habitation cause noise, odor, and fear of diseases such as ornithosis and histoplasmosis. There is no evidence, however, that cattle egrets have introduced diseases or parasites detrimental to humans or native herons and egrets. The Texas State Historical Association, 1997,1998,1999.