I may come back to this to add in the ducks reflection as well, but for the time being, here's my entry for the Birch challenge
It's gorgeous....definitely worth revisiting! The birches and reeds/grasses and the palet are all simply brilliant. I'd love to see an updated version. I'd suggest some added depth to the duck's shading and a slight ripple in its wake maybe... Some breaks/variance in the bg tree trunks for a more natural look.
As for non-strictly-technical points, I'd also advise to remove the bottom row off the duck, its draught is a bit styrofoamy--and since this is animated, it looks off that the redlection is distorted but there's no movement to the water.