>>4468028You need to find a branch right above the water on which they like to stay, observe where they stop. These branches often have birb poop on them.
Then get under the cover of a nearby patch of trees/bushes, or in a special tent if you've got the gear. Stay quiet and hidden for a while and you'll get your shot, that's how I took this one. If they spot you they might stop for a split second and fly away directly, in which case you'll need a better concealment.