Ducks not spawning while in blind?

[opaque jetty]

So I just spent multiple real world hours in a waterfowl blind on Layton trying to make use of the retriever and not once did mallards appear in the sky while I was physically in the blind. But after walking a little bit away with the dog after a minute or two every time mallards would appear. At first I thought it had to be a coincidence but it always happened, 6 or more times, and with different intervals of waiting in the blind before leaving. The dog stayed with me so maybe it's him being near the lake rather than the player being in the blind, but something was definitely off.