PHOTOS OF RIPPLES/BUBBLES WHILE HERON WAS FEEDING ON AMMOCOETES
TAKEN JULY 2, 2019

I did not notice these ripples and/or bubbles on July 2 when I took photos of the Green Heron eating the ammocoetes, but upon seeing a short stream of bubbles coming up from the silt on my return visit on July 12, I (eventually) went back and looked through the July 2nd photos and discovered there were two photos from that set which also show ripples on the water surface a short distance from the Heron. I want to stress that on July 2, the photos were taken near 9am on a windless lightly overcast morning. There were no leaves falling from the trees. These ripples were either from something moving in the water or from bubbles rising up out of the silt. (The July 12 photo set further down this page includes one which shows definite bubbles coming up). It is possible that small fish were making some of these ripples, though they couldn't make the sreams of bubbles seen in some of the photos seen further down this page. Also if the ripples were made by small fish, that leaves the question of how the Green Heron was finding the ammocoetes from two or three feet away, because he ran a few feet each time to pick up another ammoecoete.

Green Heron eating ammocoete with ripples further away from camera (higher up in photo) near the shoreline.

Closer view of Ripples/Bubbles from previous photo

Ripples/bubbles near Heron while it feeds on an ammocoete
Notice ripples near Herons legs are smaller than those in the water in front of the Heron

RETURN VISIT JULY 12, 2019 Ripples on surface (possibly from Bubbles rising up from silt) at site where Heron had been feeding on ammocoetes

Feeding area and two ripple/bubble locations
Once photo opens click on it go get a much larger view

The most conspicuous bubbles
This set of bubbles was the first one I actually saw while it was taking place. Until this time, on July 12, (nor on July 2) I'd had no thought of bubbles and had not noticed any. I was re-visiting the site to see if any Herons or other birds were feeding on ammocoetes or at least to get photos which gave more detail of the silt from which the ammocoetes were being pulled by the Green Heron on July 2.
Even after seeing these bubbles I didn't think too much about them. In fact it was days later that I looked through my photos and noticed bubbles in another photo also taken July 12. Did I then go back to the July 2 photos to see if there were any bubbles to be seen? No, I'm sad to say, it didn't even occur to me to do that. I guess I assumed if there had been any bubbles the morning of July 2, when I photographed the Green Heron eating ammocoetes, I guess I thought (without really thinking) that I would have seen them. Well I was wrong about that, as the photos in the section above demonstrate- there WERE bubbles coming up in one of the photos of the Green Heron eating an ammocoete! When I told retired UofO Professor of Ornithology Dan Gleason this story his first question was to ask how the Heron was finding the ammocoetes. When I told him there were some streams of bubbles and ripples on the water surfce, he nodded and said that must be what the Heron was cueing in on. He seemed confidant about it.

Ripples on water surface in another spot where the Heron had been consuming ammocoetes on July 2. This photo was taken around 10am, July 12.

More ripples on water surface a few feet away

Enlargement of above photo