Wednesday 30 August 2023

Intermediate Egret

Intermediate egret (Ardea intermedia, 中白鹭).

The summer is a great time for herons in Hunan, including great, intermediate, little and cattle egrets. These names suggest that the birds differ in stature: but in the field it can be hard to measure individual birds; and in reality the little, cattle and intermediate egrets are often about the same size. But the intermediate egret can be quickly distinguished from the little egret by its black (not yellow) feet and from the great egret by its shorter bill. During the nonbreeding season, cattle egrets can be similar in plumage to intermediate egrets but they are always more squat with their shorter legs and shorter necks; they are also less fond of wading into the water.

The colour of their bills is another clue. Cattle egrets always have yellow bills. Little egrets always have black bills. Curiously, in Asia the bills of intermediate and great egrets are yellow but become black during breeding season, while the bills of their European, American and African cousins are yellow all year round.

There are always many little egrets in the wetlands around Yuelu Mountain (嶽麓山) but only during the dog days do intermediate egrets frequent the waters: most likely because of the superfluity of fish. Last week, this egret was devouring plenty of sharpbelly in Xianjia Lake (咸嘉湖), though it was driven from fishing ground to fishing ground by small but territorial moorhens.

Intermediate Egret at Xianjia Lake