Carving Tropical Birds
by Anthony Hillman
Dover Books
ISBN#0-486-28579-0
copyright©1995
US site
http://store.doverpublications.com/UK site
http://www.doverbooks.co.uk/

I guess you could carve them out of steel. Made from assorted non ferrous materials or steel sheet and painted like the cover shot. Or even again just the silhouette for vanes or whirly-gig's.
Dover is a great source for reprints and old tech and other interesting books along with an amazing assortment of pattern and art work books from lettering, to some very obscure decorating books.