by Lisa Benetti - January 2003 - Information copied from the Ottawa Duck Club
Starting up a duck box program is a great way to give a little bit back to mother nature. However, when started, it is very important to be committed to maintaining it. This is because once you have breeding success, wood duck and their offspring tend to return to the same location year after year for nesting.
In order to increase your chances of having a successful duck box program, you should plan on having an annual maintenance routine.
Luckily, unless you have about 200 boxes like us, it is not too much work. Also, its fun and it's a good excuse to go outdoors.
The nest box that we use is a product of many years of trial and error. Over the last thirty years, we have seen success ratios of 60% to over 80%, with minimal predator loss, reduced starling activity and occasional second occupancy in the same season. One of the main reasons for our success is that we actively practice good management of our artificial nest sites.
It is generally agreed that the best time to give your duck box a "tune-up" is over the winter or just before the nesting season. We service our duck boxes over the winter because the ice and snow usually provides us with easier access.
Begin your Duck Box maintenance routine with home inspection and repair.
Inspection and Repair
A standard duck box is sturdy, however, they are normally placed in very exposed areas. Over time, a box will see weather damage and may need to be repaired.
Things to look for during an annual pre-season nest box check are that:
- the main support is secure
- the box is securely attached and cannot be moved
- the box is vertical with a slight lean forward (ducklings may not be able to climb up and out of boxes that are tilted back away from the opening)
- the box is at the optimal height of 6-12 feet
- all screws and bolts are tight
- the predator guard is in good condition and firmly attached
- damaged and rotten pieces are replaced
- the entrance diameter is 3x4 inches - this size is critical for stopping predators like raccoons; if damaged or worn, firmly attach a face plate with a proper sized hole onto the front of the nest box so that it aligns with the original entrance hole
- the removable door opens and closes easily
- the ladder for newly hatched young is intact (Note: some suggest that engraving horizontal lines along the interior with a screwdriver and/or chisel is preferable to wire mesh so that there is no chance that your houseguest(s) will get caught up in the mesh
- the entrance hole is oriented toward water and is not obstructed by any brush or overhanging tree limbs; this is to ensure that the female has an unobstructed flight path and that there is a clear way for baby ducks who are exiting the box
* Sometimes, repairing may not be worth it and you may decide to replace the duck box altogether.
Once you have made the necessary repairs, you can then start the house cleaning.
This means that:
Why is it important to clean a nest box on an annual basis?
- all soiled material like old shavings, membranes, or eggshells should be removed and scraped away
- that the drainage holes should not be plugged with any debris (should be ¼ inch in diameter)
- a layer of clean loose wood shavings of about 4 inches needs to be added (Wood Ducks do not carry nesting material into nest boxes). The hen will use the shavings to cover her eggs as she lays them. The shavings also provide insulation and protection for unhatched eggs. Fine sawdust should not be used because it can suffocate young ducklings. It is important to add the appropriate height because if the shavings are too high, a roosting hen might be within grasp of potential predators.
- there is evidence that duck boxes that are not cleaned annually are not as productive as those that are
- to reduce the chance of a disease or parasite being transmitted from one breeding season to the next
- it prepares the house for the new occupant in the spring
- ducks migrating south in the fall might be scoping them out as nesting sites for the following spring so you want to ensure that all is in good order
Uninvited house guests?
When opening up a duck box for maintenance it is important to tread with caution at all times of the year. Experience has taught us that ducks are not the only creatures that frequent nest boxes. Just like natural situations, there will always be competition from other species for natural or man-made cavities.
Non-target inhabitants include other bird species like European starlings, eastern screech owls, great crested flycatchers, and American kestrels. Also, squirrels, bees and wasps have also been known to set up home in nest boxes.
So, before opening a box, tap it a few times and watch it for any signs of activity.
The most common unexpected duck box user will usually be the European Starling. Starlings can be a problem during the nesting season because female Wood Ducks will avoid boxes that are filled with starling nesting material. These are usually quite obvious because starling nests consist of a large amount of grass and small twigs that often fill half of the nesting box. Starlings can be very aggressive and may harass Wood Ducks away from the nest box that they are using. Also, if a starling has a successful hatch in your duck box, the young will be imprinted to use duck boxes as nesting sites in future years. So it is very important to try to limit starling use.
At the Duck Club we try to control starlings in the duck boxes that we monitor by removing their nesting material before they lay eggs. But they can be persistent and it is a constant battle. Luckily, these birds affect only small numbers of our boxes.
Duck boxes are probably like red flags to potential predators. Unlike naturally occurring nesting cavities, all duck boxes look very similar. Once successful predation occurs, a predator will learn that duck boxes are possible food sources. Since we are providing breeding females with these luxurious homes, we are obligated to make them as predator proof as possible! And always remember, predators are resourceful and cunning creatures, and probably have babies of their own to feed. So it would be hard to resist a box full of tasty eggs.
Regular monitoring of your nest box during the breeding season is a good way to discover whether predation pressure must be addressed.
Some obvious signs that you are having predator troubles are:
- eggshells on the ground
- complete or partial disappearance of eggs
- carcass of a dead female
This is the time to question whether or not your duck box set-up is predator proof. Good questions you can ask yourself are:
- Is your predator guard effective?
- Is there a tree or overhanging limb nearby that a predator could use to access the box?
- Is it high enough off the ground so that a predator cannot jump on the box?
Time for Relocation?
The best proof of a successful hatch is the remains of some egg shell fragments and membranes in your nesting box. You may want to consider moving your duck box for various reasons.
- If there is no evidence of nesting activity after 2-3 years.
- Predation is still a problem despite deterrent attempts.
- If there is excessive dump nesting - This occurs when more than one wood duck lays eggs in a single box. It is common to find more than a dozen eggs, but if you consistently have over 30 eggs, then dump nesting is a problem. This can happen if you place your boxes too close together. We don't have too many problems with this at the Duck Club. One of our members thinks that this is because we keep the boxes apart at a minimum distance of 50ft.
- Is it too far from water? - It is true that in natural situations hens will use cavities up to ½ a mile away, but it is also true as the distance increases the survival rate of ducklings decreases. We believe that our boxes at Shirley's Bay which are exposed and surround the man-made ponds are successful because there is a lot of vegetation close by where ducklings can hide from potential predators.
Make Regular Inspections During the Nesting Season Part of your Maintenance Routine
If possible, the best way to address predation problems and uninvited house guests is to monitor your nest box during the breeding season. Monitoring once every two weeks is ideal, but if this is not possible, checking your box at least twice during the nesting season can increase your success rate. Hopefully, the location you chose for your duck box won't make it difficult for monitoring.
Monitoring our duck boxes improves our hatching success because we can:
- remove debris brought in by other animals
- remove undesirable species (i.e. bees, wasps, starlings)
- make repairs as needed
- replace nest materials as needed (invaders may remove it)
- clean out the nest box after early nest attempts for possible second nests
- to keep the boxes available for Wood Ducks nesting throughout the nesting season
- gives us a better chance to document and collect information on nest box use; keep track of who is using your duck box, and how successful it is. This will also help you decide whether an unsuccessful box should be moved or modified.
IT IMPROVES YOUR HATCHING SUCCESS!