Ernst Haeckel (German, 1834–1919) Trochilidae – Kolibris, From Kunstformen der Natur, 1904 Hummingbirds dart energetically around this artful, scientific illustration by German biologist Ernst Haeckel. His elaborate forms have been called a precursor to Art Nouveau, and you might well imagine these winged beauties as decorative ornaments. There are plenty of colors, lines, and shapes to keep you occupied while completing this 300-piece jigsaw puzzle.