This swamp at The Phoenix Zoo is very large, and it used to be the old alligator habitat. In the words of my Aunt Margaret in a recent message: "Uncle Bill and Bill Mangino designed the old alligator enclosure as one of many architects who donated their time and design to the zoo for different animal enclosures. There were bronze plaques with names at each place and Uncle Bill's and Bill Mangino's names were at the old alligator pit." I became aware of the duckweed in Fall 2003. Since that time, the zoo has made several attempts to remove it from the swamp. It eventually reached the water in the Ant-eater exhibit nearby, also Monkey Village a good distance away. Each time a group of flying fowl has made the swamp their home, they have been relocated. The ducks were relocated because one duck turned up without a foot, causing concern that there was a snapping turtle in the pond. The swans were relocated to a different zoo. Over time, the duckweed invasions and control have become a saga that is still going on as of March 2007.

The timetime for the initial sets of pictures (the row above and seven below) is between November 2003 and January 2004, before the first big campaign to rid the swamp of the duckweed. The image on the far right reveals a clear spot behind the palms where there was more circulation in the water (duckweed cannot thrive where water is circulating) at a location about halfway up the bridge and to the right.

In the pictures above, a horticulturist from the Phoenix Zoo reached into the swamp to gather some Duckweed on his hands for up-close pictures. It looks like a small clover. It sits on top of the water. There is very little branching off the root, since there is no need to hunt for water

Some of the pictures show the quiet of the area nicely. It is overall very peaceful, with moments of unrest. The middle image shows what appears to be two ducks facing off after a flurry of preceding activity. Only a small group of ducks has chosen this area of the zoo to live in.

This is the only page on my site with no mathematical models in the pictures. I have included it because of the fractal boundary patterns the duckweed makes in the water: duckweed fractal coastlines, if you will. Fractal properties are visible in almost all nature photographs. It is a only matter of being able to identify them, a relatively simple task once one knows what to look for.

These images show a nearly complete invasion of the water and banks of the swamp by the Duckweed. I like the way it is a tattletale. Even after it closes back in on itself, it leaves a visible seam where it was breached.

Although an extraordinarily clean plant with no toxic by-products, during the night when no photosynthesis is taking place, it depletes the water of needed oxygen, causing some water life including fish to suffocate. Notice the clumping of the Duckweed on broken tree branches sticking out of the water. This is what initially attracted me to it. I can't say for sure, but this is likely an instance of a fractal property called diffusion limited aggregation, or DLA.

The middle and right images were taken at the same spot shown in the first row, far-right image, where the swamp has good water circulation.

This ends the images taken between November 2003 and January 2004. What follows are images all taken the same day in April 2005 after the duckweed was again in full swing. A group of swans had taken up residence, pictures of them follow, along with many turtles. I had unfortunately stopped visiting the exhibit and was very lucky to revisit the area in time to take pictures of these swans. About a week later they were relocated to a different zoo during the second major attempt (that I know of) to rid the swamp of the duckweed.

Notice in the pictures shown above, that the duckweed is plentiful but there are also areas where it is barely present. It was heavy before the impending removal, but not as heavy as it might have been. The pictures below were taken on September 29, 2006, and as you can see, the duckweed has absolutely taken over! There is not a breath of water visible in the swamp. There is a new group of birds in residence, athough, they don't appear to land on the duckweed. They stick their narrow beaks into it, but this may be to get to the water below. There are a few turtles that I observed living in the swamp. The turtles in these pictures are located in the same spot as the turtles in the previous set of pictures. They are sitting on the same log. The enclosure surrounding the swamp is the Capybaras and Pelican exhibit, although I have yet to see either of them in the swamp or near its edges.

This ends the representative images I have to date of the changing states of the duckweed in the swamp at the Phoenix Zoo. The conversation is not over, I wonder if the zoo isn't stuck with it for the duration, with the best they can do being to (try to) control it.

Here is to the ducks and swans of recent years past, to the alligators way back when, and finally, to my late Uncle Bill Scarbro and his partner, Bill Mangino, for designing the 'alligator' exhibit. The bridge approaching the overlook is shown in the first row of pictures. The circular overlook that actually sits in the swamp is shown in the picture above-right, taken in February 2004 after the first major removal of the duckweed.

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