Nicely captured through the marsh Yves. It really show how he is looking for food while trying to stay hidden. Great opportunity to find birds like this. Wonderful shots.
You are right. The poor little guy was beside a crowded trail and he did not bother with people (the time I was there though). Since he is a nocturnal bird may be he doesn't see very well in the full sun.
What I really like about this image is that he seems oblivious to your presence and you've captured him in his element. Very nice see through shot, too.