The Great Egret Ardea modesta, as its name suggests, is the tallest of the Australian egrets. It is also called the Large Egret, the White Egret (they all are), the Eastern Great Egret (there is no western one, at least in Australia, but the very closely related Eurasian species is also known as the Great Egret) and the White Crane (see notes under the white-faced heron about this).
As has been mentioned in the page about the white-necked heron, the great egret, like other herons and egrets, has a sprung, s-shaped neck to help it stab prey in shallow waters at lightning speed. Given that this species also has the longest neck of any Australian bird for its size — its neck is about one and a half times its body length — it really is important to be able to tuck it away neatly, particularly when in flight.
This outstandingly long neck is also very useful when wading through water full of tall water plants and seeing prey or enemies over the top. It is not uncommon to see these large, graceful birds standing very still, peering across the wetlands then very slowly stalking prey they have spotted from much further distances than their shorter necked relatives.
So what, after all, is the difference between an egret and a heron? After all, they have much the same features, including the trigger neck, lifestyles and other appearances. The secret lies in one of the many very bad things humans do when we are utterly selfish and capricious. The word egret comes from the French word aigrette, the word both for the bird and the feathers that come from it when it is in breeding condition. When egrets breed they produce long lacy plumes that cascade down their backs. These plumes became almost fanatically sought after as a symbol of high fashion. Women stuck them singly or in masses in their hats. It became … normal. Thousands and thousands were killed and across several countries the species became endangered. Many important populations were exterminated. When the fashion (during the late 19th and early 20th centuries) disappeared (along with the birds), the word became anglicised to egret and referred only to the bird again. Luckily for this elegant bird, it is no longer in danger, because it is no longer fashionable to have it killed. But who knows what species may come into fashion next? From this perspective alone, many many humans can only be viewed as deliberately killing harmless and attractive creatures at a silly whim, without the least pang of guilt. It is unlikely that, at least as a species, we have changed very much.
So the answer is superficial. Egrets are herons that look different. They have lacy breeding feathers and are snowy white. Modern research into their DNA has shown that this difference has little to do with any real relationship between them. For example, two Australian egrets belong to the genus Egretta, along with two herons, including the white-faced heron, which has the plumes, but is not white. The other three Australian egrets belong to the genus Ardea, along with two other herons, including the white-necked heron, which does not have breeding plumes.
In other words, the word egret is an arbitrary division within a group that only serves to reflect a couple of visual clues and a long history of callous, unnecessary killing for vanity, cash and a short-lived fad.
Egrets, like other herons, prefer their own company and will defend feeding territories with violence if necessary. They don’t mind the presence of other species that don’t offer competition for valuable resources. If there is plenty of food they are inclined to accept the company of others of their own kind.
Great egrets first appeared in the wetlands as water levels declined following flooding and water plants thrived in the warmer weather. Their numbers greatly increased as water levels shrank and the shrinking pools teemed with concentrated life. In the last few weeks of this situation the shallows thronged with wading birds including two species of spoonbill, two species of ibis, two species of herons and several great egrets, not to mention many other species of water birds. At one point several pairs of egrets brought their fledged young with them and fed them on their catches in the wetlands. When the shallows had been picked clean by May, the egrets left.