Wood Duck Nest Box Inspections, 1/6/2012

Wood Duck male photo by Paul Fusco
Wood Duck Successful Nest, showing egg shells,
membranes that surrounded the chicks when they
hatched, and down from the mother; all on a bed of
wood shavings which we provided.
Photo by Dave Rosgen
This past Friday, 1/6/2012, Nick Miofsky and I (Dave Rosgen) checked 6 of our duck nest boxes for usage in 2011. We visited all 3 boxes at Duck Pond, the one in Pine Island Marsh, and both of the boxes in Mallard Marsh. All of these boxes had been moved from dangerous deepwater locations to safe shoreline locations by Scott Dayton and me last winter. Still, 80" of rain in 2011 put these formerly shoreline spots under as much as 2' of water. Because of all the mild weather that our area has experienced in the past month, much of this water was coated with less than 1" of ice. We were able to break through this ice with a potato hook as we walked to every box except the one on the south side of Duck Pond. The ice there was over 2" thick and held us as we walked on it. If we had fallen through it wouldn't have been a big deal since the water was only about 6" deep. Another major reason to move these boxes to shoreline locations (which was discussed in a few blog postings last winter) was to eliminate flooding of the boxes as a cause of nest failures. It worked! None of these boxes came anywhere close to being flooded, despite massive amounts of rain last year. Coupled with relatively mild weather last spring and our PVC pipe predator guards effectively stopping Raccoons and other predators from raiding the boxes, all 6 of these boxes were successful in fledging young. They were all occupied by Wood Ducks, and leftover eggshell membranes indicated that a total of 46 young hatched from them. Subtracting the one dead baby that we found among the nest material, that means that 45 young successfully fledged from these boxes. That's excellent! We also found a total of 14 unhatched eggs in these boxes. They were probably the first ones laid by the hens last April, and they probably froze on a few cold nights before she commenced incubation of the full clutch. Unfortunately, that's common, but it is offset by the large clutch sizes. More often than not, at least half the eggs in any given clutch hatch. In these boxes it was 77%. Last summer, Marcus Johannson and I checked the 5 shoreline boxes at Ongley Pond, and N. Shore, Pike, and Icehouse Marshes. All of them had Wood Duck nests, with 4 successfully fledging a total of 38 young. The fifth, at Icehouse Marsh, failed due to freezing of the entire clutch of 18 eggs. This probably was a dump nest where more than one female lays her eggs in a box, but none of them settle down to incubate the clutch. It might indicate a need for another box in that area. Despite this one failure we are very pleased that 10 out of the 11 boxes checked so far have been successful. That makes for an excellent success rate of 91% so far. Nicole Morin and I plan to check the last 4 boxes in safe locations this afternoon. Then it will be a matter of waiting until prolonged cold temperatures make ice around the rest of the 19 boxes less dangerous for us to walk on so that we can go out and check them. If that doesn't happen, we will have to use a canoe to get to them when the ice is gone. Somehow, we will make sure that they are checked before the 2012 nesting season begins in April. Stay tuned.

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