John Olsen was an Internationally known Australian artist that died in 2017. He made this set in 1970 and signed them in metal on the top of the bases as well as in paint on the bottom. The earlier works are more valuable than his later works. He actually made these from rebar, crane hooks, springs, machine parts, etc. The largest bird is 70" tall on a 17" square base. They are quite heavy and can be used both inside and outside.