Wednesday, September 17, 2008

Bad Year for Great Egrets

It has been three months since my last message and a summer unusually filled with travel. How the time goes!

Normally some egrets would still be scouring the grass for grasshoppers, and from past experience, we would have expected this to continue till mid-October. Not so this year, but the news are good.

Despite the impossibly hot summer and a much greater number of birds in the rookery, which included, in order of abundance, the cattle egrets, great egrets, little-blue herons, ibises, snowy egrets, and night herons, we rescued only about 60 distressed fledglings, compared to several hundreds in previous years. The large majority of the birds who needed our help this year were the great egrets, whereas in previous years these were the cattle egrets. Though there were about 10 times as many cattle egrets in the rookery as there were great egrets, we found only one cattle egret who needed rescuing. We did also rescue a couple of little-blue herons and one night heron. The rest were all great egrets.

Why this change? Normally, the great egrets arrive here first, around Valentine's Day. They were about a week early this year. In addition, they abbreviated their courtship and immediately set about mending their nests and laying their eggs. The cattle egrets and others would normally have come in April, when the great-egret chicks were about to hatch. Usually it is a quite festive atmosphere, almost as if the new arrivals come to celebrate the hatchlings. This year, though, the second crew of birds arrived about a month earlier than usual and just as urgently went about the business of nesting. By mid-August, i.e. about two months earlier than in previous years, all the birds and their juveniles were gone -- mostly south, some flying as far as Brazil and Argentina. We did suspect from their behavior that trouble might be coming to the Gulf.

While attending a wedding this weekend, we could not help but marvel at how much a bride's veil and train resemble a snowy egret's courtship plumage. True: being hopeless birders, we are unusually well disposed to notice how much our culture is influenced by the customs of other animals, and our language too, but this is rather fun.

Did you know, for example, that the word "congruence", i.e. to come together, to agree, has its root in "Grus", the genus name for many cranes, including the Sandhills (Grus canadensis). What is more congruent than a flight of cranes?