There are only four ducks in whole Krupajsko vrelo, at least I saw just for of them. They got used to people there and they won't run away from them. I took few photos of them close up. They blended pretty well as you can see, their color matched with rest of the water and grass. :D
What camera did you use?
I used Canon 6D with 85mm 1.8 lens. :)