tough retrieve
one, if it be something like a pheasant that comes down really dead, you have the "air wash" theory to consider and sometimes dogs have a terrible time finding those. again like on a rooster that can still run, they can do so about 16 or so miles per hour, some dogs have a hard time at that speed, so the bird gets away or at least puts lots of distance between it and the dog, tough deal to make a find. on the other hand ducks do dive, some come right back up, some swim quite a ways, no dog can swim faster than a slightly wounded duck, some ducks like blacks are known to dive and never come up, they commit suicide by entangling themselves in the weeds, again on fairly calm water a good dog can actually follow a scent trail left in the water and therefore find the duck. didn't answer much but depending on the situation but it can be a tough deal or an easy one. you do need a dog to go for it and not quite on ya
cheers