The Cattle Egret: The Opportunist
Southern folklore depicts Brer Rabbit as the quintessential easy-going trickster, who uses his wits rather than brawn to win the day. In other cultures, foxes, coyotes, and crows play much the same role. Yet these ancient authors would have done just as well with a Cattle Egret as their protagonist. Though far less graceful than most other wading birds, this stocky species puts them—and nearly every creature on the planet—to shame with its adaptability and resourcefulness.
Take world domination, for instance. Few, if any birds have expanded their range more than the Cattle Egret in the last century. Even more remarkable, the species did so on its own, with little direct help from humans—unlike House Sparrows and starlings.
Originally native to open, dry pastures in Africa and parts of Asia (as well as southern Portugal and Spain), the first Cattle Egrets flew to the New World by 1877, most likely following the northeast trade winds. As rangeland and livestock spread, so did the birds. The population took off in the ‘30s, reaching most of South America, Central America, the Caribbean, Mexico, the United States, and the Galapagos in the span of just a few decades. In 1973, just 20 years after the discovery of the first U.S. nest in Florida, two scientists wrote in The Auk that the “species has probably become the most plentiful egret in North America.” It even appeared at altitudes of up to 14,000 feet in the Andes and on islands near Antarctica. Meanwhile, Cattle Egrets from Asia expanded into Australia and New Zealand, and the African population spread deep into Europe, breeding in the United Kingdom for the first time in 2008. This torrid rate of expansion has since slowed, and Cattle Egrets have even disappeared from some U.S. areas they previously occupied. Nonetheless, they’re as common as ever in the Southeast and southern California, and have been seen nearly nationwide (even Alaska) during migration and post-breeding dispersal.
This conquistador-like colonization was greatly aided by the spread of modern farming. Despite being perfectly capable of gleaning food on their own, Cattle Egrets have always freeloaded off large mammals in order to conserve energy (hence the name). Occasionally, they will land on a bovine’s back to pick off a delicious tick or fly, but they mostly stay on the ground near its front legs, waiting for its movement to flush out insects like crickets and grasshoppers. When mechanical farm equipment appeared on the scene, Cattle Egrets quickly realized that tractors and lawnmowers are perfectly good insect-flushers in their own right, and began to follow them around, too. They’ve even been known to fly toward smoke to nab fire evacuees, and to stand on airport runways, waiting for planes to jolt invertebrates out of the grass.
Though insects make up most of its diet, the Cattle Egret isn’t picky: If there are no bugs around it has no problem making due with rodents, fish, frogs, worms, lizards, crayfish, and snakes, or maybe some garbage. In the Dry Tortugas, 70 miles from Key West, Florida, where insects are scarce, they’ve even been observed hunting warblers during migration. Given the opportunity, they also won’t hesitate to steal a snack from another Cattle Egret or a different species.
By now, readers may have guessed that Cattle Egrets are equally opportunistic when it comes to sex. Studies in Japan and Australia found that more than half of all mating attempts within a colony occurred outside of “marriage.”
Moreover, they tend to nest in colonies already established by birds rather than staking out their own. They will also dump their eggs into the nests of rival Cattle Egrets, and their eggs have even been found in the nests of Little Blue Herons, Snowy Egrets, and others—the same parasitic strategy employed by Brown-headed Cowbirds to have their young raised for them.
For those inclined to consider them lazy, Cattle Egrets are too busy living the good life to care.