SCG5984 - USSR 1976 – Black-throated Diver (Gavia arctica)Issued by the Soviet Union in 1976, this 3 kopeck postage stamp showcases the Black throated Diver (Gavia arctica), depicted elegantly underwater in pursuit of prey. Part of a series celebrating the USSRs protected nature reserves (Zapovedniks), it highlights the Matsalu Nature Reserve in Estonia. The stamps rich green tones evoke the aquatic habitat of this graceful bird, symbolizing Soviet dedication to wildlife conservation during the 1970s.