By Bruce Urben, President
This article originally appeared in Wisconsin Waterfowl Association’s May 2020 Newsletter edition.
Many of you have spent countless hours cleaning out, repairing and restocking wood chips in wood duck boxes all over Wisconsin. Not to mention the new boxes that you installed this spring to entice hen wood ducks to utilize.
Wood duck pair on one of WWA’s Adopted Wildlife Areas April 2020. Photo by Mike Alaimo
It is coming to the time of the year when we can see if the boxes we put up and maintained are actually being used. In early April, paired hen and drake wood ducks begin to search for a nesting area. This may be in a natural tree cavity or in a wood duck box prepared for them. Nesting typically begins in mid April. Ducks are unlike geese or swans, they do not mate for life! The drake stays with the hen until incubation actually begins, after which he fades into wetlands and his annual molting period begins.
A hen wood duck nesting in a box placed by WWA volunteers
The hen usually lays one egg per day, routinely in the morning hours. She may spend less than half an hour in the box while doing so, then returns to a safe wetland/pond area sometimes accompanied by the drake. The hen has already prepared the nest by pulling down from her breast feathers and surrounds the laid eggs with a soft insulation. Once she has laid a full clutch of of glossy, creamy white to tan eggs (usually 12-14 eggs), she begins incubation. Her body heat starts the incubation process while she turns and adjusts the nest of eggs to evenly heat them. This helps to ensure that all of the eggs have a good chance to hatch together on the same day. During incubation, the hen will only leave the box twice daily to feed, usually once in the morning and once in the afternoon for about a half hour or less. Before she leaves, she will cover the eggs with down to maintain incubation temperature.
Incubation for wood ducks is usually 28-32 days. The entire clutch usually hatches within 24 hours of each other. The hen will stay in the box with the hatched chicks for 24 hours, then leave the box, fly to the base of the box and call to her brood to join her on the ground. The young are eager to join the hen and will respond to her calls and “jump” to the ground, one by one! Being able to actually watch the chick “jump” is a once in a lifetime opportunity. My wife and I were fortunate to be in the right place at the right time to see the “jump” take place on our property – awesome experience. Watch the full video to see what we got to see!
Once all of the chicks are on the ground and have joined the hen, she brings her new brood to the safety of the nearest pond for food and cover.
Studies have shown that only 30-40% of the brood will survive predators during their first 90 days of life. The surviving ducklings will feather out in about six weeks and be able to fly in about nine weeks!
There are several methods for predicting “jump” day. All are just an estimate. A method I have used is to monitor the hen, and when she begins to stay in the box most of the day, you can add about 30 days and come up with an estimated “jump” date. Then closely watch for the next day or two.
Have fun monitoring your boxes and I hope you have the opportunity to see “jump” day in one or more of your boxes this month – it is awesome!