There were three separate bird stamps issues in 1980. This stamp was issued last on 17 NOV 1980. Can be tough to find.
18c The Spotted Catbird
The stamps & cover artwork were both designed by Kay Breeden-Williams. Here is some information from the Unicover website:
Australian 1939 –
Born Kay Carter in 1939 in the rural hamlet of Palmwoods, located in the hinterland of Queensland, Australia, Kay Breeden Williams is regarded as one of Australia’s premier wildlife artists. During her long and distinguished career, she has created an extensive collection of celebrated artwork for numerous books and magazines, as well as several series of commemorative stamps for the Australia Post.
When one of Australia’s largest companies, Broken Hill Proprietory, commissioned a series of Australian wildlife paintings from Williams for its international public relations program, the response was unprecedented: over 100,000 letters from 30 countries, resulting in the distribution of well over one million prints! Known for her meticulous attention to detail and the surprisingly life-like quality of her renderings, Williams continues to use her formidable talents to champion the important cause of natural conservation in Australia and worldwide.