🚀 go-pugleaf

For six years I have been experimenting with floating nest boxes 
and artificial floating "islands" for waterfowl in urban lakes.  
They are designed to provide waterfowl with a nesting, roosting 
or feeding site that is safe from land-based predators and 
flooding.  The floating nest boxes provide a single nest site, 
while the larger islands can support up to four nest sites.  In 
addition, the islands can be modified to support potted plants 
so they can provide a save roosting or feeding site.
 
Mottled Ducks (Anus fulvigula), Common Moorhens (Gallinula chloropus) 
and Mallard Ducks (Anas platyrhynchos) have used the nest boxes and 
nesting islands.  To encourage waterfowl to explore and use the 
nest boxes, I have used a food trail to train them to approach and 
explore the floats.
 
construction
 
The floating nest sites consist of a nest cavity, a plywood platform, 
a floatation system and an anchor.
 
The Smaller Nest Box
 
Each nest box consists of a small nesting cavity on a 2'x 2' 
(60 cm x 60 cm) floating plywood platform.  The nest cavity may 
be of any design.  In the past I have tried several designs, but 
the vegetation covered nest cavities have been the most 
successful.  A vegetation covered table or an inverted wire 
basket makes a good simple nest cavity.  
 
Any nest cavity should include an opening that is at least 8" 
(20 cm) high.  For ventilation the opening should face the 
anchor line when the nest cavity is secured to the platform.  
 
The Platform
 
To minimize the weight I use plywood that is between 5/16" to 3/8" 
(7-8mm) thick.  All the platforms have a 3" (7-8 cm) wood hang-down 
skirt to prevent the plywood from warping and to protect the 
floatation from ultraviolet sunlight.  
 
Floatation
  
For floatation for the smaller (2'x2') platforms, I use four 
2.5 gal (.946 l) plastic rectangular bottled-water containers.  
The four containers fit nicely inside the hang-down skirt.  
Unfortunately, rectangular containers will occasionally leak, 
so I keep a replacement handy in case one of the containers 
fills with water.  
 
(I recommend that you DO NOT USE foam floatation because it enters 
the food chain when fish nibble at the algae that grow on it).
 
Anchoring
 
The nest boxes are anchored with a (8"x8"x16") concrete block 
and a 1/4" nylon line.  To prevent the concrete from chafing the 
line, I pass the line through a piece of garden hose before 
looping it through the block.
 
I anchor the nest boxes in waist-deep water near shoreline 
vegetation.  If the water rises, the nest boxes will sink and 
the nest will be lost.  To prevent this, leave an extra 
length in the line to accommodate major changes in water depth.  
 
The Larger Islands
 
The islands can be designed for nesting, roosting or feeding.
 
All the islands are 4' by 4' (122 cm x 122 cm).  They also have a 
3" (7-8 cm) hang down skirt to protect the floatation from sunlight.  
The islands are used for either nesting, roosting or feeding.
 
Nesting Islands
 
Nesting islands provide vegetation covered nesting shelter for up 
to four waterfowl.
 
If the waterfowl are colony nesters, you might put several nesting 
cavities on the island by separating them with partitions.  I am 
currently using crossed vertical 12" partitions covered with a 
plywood roof to provide for four nest cavities on one platform.  
I then cover the roof with vegetation to give it a natural 
appearance.
 
Roosting Islands
 
Roosting islands have up to five wet wells for potted plants that 
can tolerate wet roots and direct sunlight.  To support the potted 
plant, I cut a circular hole in the plywood to hold the pot so 
it's base is only slightly below the water level.   You might put 
some screening over the holes in the inside of the pot so the soil 
doesn't run out.
 
Feeder Islands
 
Feeder islands have a covered 5 gal paint container filled with 
chopped corn.  The feed container has a hole at its base so the 
chopped corn can drain out onto the platform slowly.   I have 
placed these islands close to or on the shore so that they are 
easy to load
 
Floatation
 
For floatation I use four 5 gal (19l) HDPE paint containers.  
They are inverted (opening down) and placed at the corners of 
the island.  Small wooden blocks are positioned on the bottom 
of the plywood so the containers are held loosely in the 
corners.  When the island is in the lake, I can control the 
elevation  of the platform above the water by using a hose to 
add or withdraw air from the inverted containers.  The islands 
are anchored about 30' (10m) from shore.
 
 
If you are interested in building your own island, feel free to 
take advantage of these ideas.  Feel free to cross-post this notice
to other news groups.  If you have any questions or comments, feel 
free to contact me.
 
Good luck,
 
Ted Andresen
1873 60th Ter NE  
St. Petersburg, FL 33703-1721
Ph: 813-526-6440
email: sfk8suz@scfn.thpl.lib.fl.us