This joint issue of Azerbaijan and Kazakhstan is dedicated to the fauna of Caspian Sea. The stamps depicting a squacco heron and a flamingo were designed by the Kazakh painter Danijar Mukhamedjanov and the Azerbaijani painter Khasay Mirzoyev.
The Squacco Heron is a small heron, 44–47 centimeters (17–19 in) long. It is of Old World origins, breeding in southern Europe and the Greater Middle East. This is a stocky species with a short neck, short thick bill and buff-brown back. In summer, adults have long neck feathers. Its appearance is transformed in flight, when it looks very white due to the color of the wings.
Flamingos often stand on one leg, the other tucked beneath the body. The reason for this behavior is not fully understood. Some suggest that the flamingo has the ability to have half of its body go into a state of sleep, but this has not been proven. Recent research has indicated that standing on one leg may allow the birds to conserve more body heat, given that they spend a significant amount of time wading in cold water.