Figure 1.
Optical photographs of wing, breast and belly feathers for the six bird species. (a) Reed cormorant, (b) Great cormorant, (c) European shag, (d) African darter, (e) Common shelduck and (f) Mallard are shown. Feathers are typically 2–3 cm in length and wing feathers (leftmost among the three feathers) are typically more regular than breast and belly feathers (middle and right feather respectively). (g) A wing feather of a common shelduck after dip-coating in 50–50 fluorodecyl POSS/Tecnoflon solution is not wetted by water (γlv = 72.1 mN m−1, blue), or rapeseed oil (γlv = 35.5 mN m−1, red). The scale bar in the figure corresponds to 1 cm. (Online version in colour.)