My final report for the ducks and mergs team this season:
Well, our box score for the season shows a lot of at-bats but not too many runs across the plate. The mergansers started 10 clutches but only hatched 4; the Wood Ducks started 5 but only completed 1. We had evidence of predation in only 1 box (raccoon, #60). A possible hypothesis to explain the high rate of nest abandonment by the mergansers is simply that there were too many birds chasing scarce resources.
The egg and hatchling counts are similarly depressed: 139 eggs laid by the Hooded Mergansers, with 52 hatched (37%); 34 eggs laid by the Wood Ducks, with 7 hatched (21%). Summary worksheet from our monitoring.
A recap of the boxes: I applied some insulating foam to patch gaps in boxes #1 and #3. Boxes #4 and #7 should be replaced. A map of nest box locations.
Monitors, thank you for all your help!