National Geographic : 1954 Aug
292 Samuel A. Irlmes Cattle Egrets, Resplendent in Nuptial Plumage, Court in a Florida Bush Like all herons, cattle egrets carry out an age-old mating ritual that varies little. Loud chatter, strutting, billing, preening of feathers, and crossing of necks mark the courtship performance. These immigrant birds now nest in the United States (page 288); they have been seen in at least half a dozen eastern States. States National Museum in Washington, D. C., told me that when he visited South Africa in 1924 he saw only one bird. In 1950, a quarter century later, he observed thousands, often hundreds at a time. In a city park in Natal he found them as tame as chickens. The spread has been well documented in Natal and east ern Cape Province. Population "Explosion" Puzzles Scientists Biologists are abuzz with conjecture about this world-wide "population explosion." The cattle egret has now established beachheads on every continent save Antarctica, where there are no cows. It was a new bird for Australia in 1948 when Herbert G. Deignan of the National Geographic Society-Smithsonian Institution expedition spotted hundreds from the air in northern Australia's Arnhem Land. He cor roborated his discovery by collecting several specimens for the U. S. National Museum. Some people contend that these are de scendants of 18 birds liberated in 1933 in the Kimberley area of western Australia in the hope that they would control cattle ticks. But those birds (of unknown sex) quickly dis appeared. Deignan believes that the birds in northern Australia more likely are immigrants from across the water. He points out that they have recently been reported by farmers in southern New Guinea. Since Deignan's dis covery similar reports have circulated else where in Australia, one from as far south as Melbourne. What will be the effect of the cattle egret on America's native herons? Will it compete? Is it a good or bad acquisition? After experiences with such introduced species as the house sparrow and starling, we naturally view exotic birds with a jaundiced eye. But the environment for the cattle egret-pastures and cattle-is man-created, introduced from the Old World into the New. The bird is merely completing the picture. The cattle egret's food habits, with accent on insects, are mostly different from those of other herons. Although it shares heronries with snowies and ibises, there is no basic con flict. All seem to benefit. And the larger the colony the less it apparently suffers from predators. The cattle egret, beautiful and beneficial, is a fine addition to American avifauna. Con ceivably the day may come when it will be as familiar to many Americans as the starling or the ring-necked pheasant.