Another photo with the same camera I used for the Mute Swan photo is a newly fledged Great Horned Owl. It was not pleased that I had approached within 15-20 feet. It was clicking its beak to show its displeasure. I looked around and above to see an adult Owl that was a bit nervous so I exercised some good judgement and backed off. Adult Owls can be very aggressive and may strafe and even attack a human if too close to its offspring.