Grass nesters such as this American Wigeon Mareca americana depend on camouflage and subtlety.
Never look them in the eye!
Any brown dimorphic female can abandon the nest if she feels her cover is blown... they are best checked from 10 days, so if they need to be lifted to an incubator, they have a greater chance of survival.
The wigeon and shoveler will also adopt the faecal explosion method, whereby if they are found, they will defecate all over their eggs. Whether a tactical move to make the eggs unpalatable or a last effort to escape; this can ruin a clutch through yolk sac infection.
Photo from Phoebe Vaughan
