This week for Flora and Fauna Friday we have the companion of cows, the Cattle Egret (Bubulcus ibis).
Cattle Egrets are a small, stocky egret with snow-white plumage, greenish-black legs, and a sunflower-yellow bill. In their summer breeding season they don a blonde mullet with matching bib and back. They are rarely seen alone and typically travel in flocks of one to two dozen birds. Cattle Egrets are common in flooded lawns and fields, near ephemeral wetlands, and roosting over ponds but they’re most often spotted between the knees of Cows and Horses in our sea island pastures. Wiggling their neck as they stalk through the grass and spearing the spiders, grasshoppers, and frogs scared up by the hooves of their neighbors. This is an example of a symbiotic relationship. The Egrets are protected from predators like Foxes and Bobcats by sticking close to their beefy buddies. The Cattle worry less about predators themselves as the keen eyes of the Egrets more surely alert them to threats. The trouble is, there weren’t cattle in the Americas until the 1600s. Neither were there Cattle Egrets.
Cattle Egrets are a curious case of a species’ self-made transoceanic range expansion. One that happened in modern history at that. Cattle Egrets are native to Africa. There they live in the savannas and marshlands amongst the Wildebeest, Zebra, Buffalo, and Antelope. Feeding between their feet and alerting them to the toothier mammals. In the 1870s, by chance, a few flocks of Cattle Egrets flew their way to Suriname in South America. Maybe they were swept there by a hurricane or maybe they hitched a ride on the trade winds. No one knows. By the 1940s they began showing up in the United States. Now they’re the most common Egret in North America. Surely a bird as numerous as the Cattle Egret would have found its way across the Atlantic before, no? Likely they did. Likely not once but dozens of times in the past. But before, there was nowhere for them to live. Colonization changed that and when the Cattle Egrets immigrated to South America in the Victorian era, they found Cows. Lots of Cows all over the place. From there it was just a hop, skip, and a jump to the pastures of the United States. Now the Cattle Egret is ubiquitous across the hemisphere. Here they fill the same niche they did back home. A new niche recreated by man a long way from home.
