While chickadees are more skittish compared to bluebirds, most chickadees will accept a wren guard. However, every chickadee is different, and not all will tolerate wren guards. Observation is key when testing a new wren guard, and there are important steps to help chickadees tolerate them better.
Chickadees are native cavity nesting birds in North America, and they only have one set of babies (brood) per year. Protecting them from predators and nest invasions is very important.
House wrens are common nest box invaders, acting on instinct. But their invasion comes with a cost. House wrens are known for entering a box with eggs or young nestlings, poking the eggs and tossing them out of the box, or tossing younger nestlings out of the box.
A house wren will act in this way until eggs or nestlings are clear and then they begin building a nest overtop the existing one.
One of the best ways to minimize the risk of a house wren invasion is to add a wren guard to the nest box, which is like a little hood that disguises the entry hole.
But if you’re new to hosting chickadees, you might be wondering if they are nearly as tolerant of a wren guard as bluebirds are.
For the most part, chickadees will accept a wren guard added to the nest box. But you will want to observe the nest box to make sure the chickadee has gotten into the nest box and is not struggling.
Usually, all you need to see is that both chickadee parents are able to get into the nest box at least once. If they got in once, they’ll be able to get in again.
If you find they are struggling after an hour or two, there are a few steps you can take to try to make the wren guard work for them.
Adapting a wren guard for better chickadee tolerance
It can be a struggle for a chickadee to get into a nest box right after the wren guard is added. If you’ve observed for an hour or two, and you have not seen both chickadees successfully enter the nest box, you’ll need to make some adjustments. And if these adjustments don’t work – the wren guard will need to come down for the sake of the birds and their eggs.
Ensure you have good clearance between the wren guard and entry hole
One of the reasons your chickadee could struggle with entry is not having enough clearance between the entry hole, or really – the wall of the nest box and the hood of the wren guard.
For this, you may need to slide the roof of the wren guard forward (further away from the entry hole) to see if you can grant more clearance. See the photo above.
You want to aim for having about 3-4 inches between the hood of the wren guard and your nest box for chickadees. But since every bird is different, a little more room may be necessary.
If you’re working with a wooden wren guard that doesn’t allow this, you can make one out of cardboard instead. In fact, we really recommend this route because it’s easier to adapt. It also tends to hold up long enough for the nesting cycle. Though occasionally you may have to replace it.
Raising your wren guard may grant even more clearance
If you have reasonable space between your wren guard and the nest box entry hole, but find your chickadees are still struggling, the next thing to try is raising the wren guard.
Sometimes the issue is due to how much headroom is available for your chickadees, or any bird for that matter.
To raise the wren guard, simply sandwich a wooden block between the roof of the wren guard and the roof of the nest box. Even an inch can make quite a difference.
Keep in mind, when raising the wren guard, you may need to find a way to extend the front panel guard. This is another reason why making a wren guard out of cardboard is a great option.
Train your chickadees with different wren guard hood heights
Think of a wren guard like an awning, where a small little panel hangs a little lower than the roof (sort of like a lip).
On a wren guard, this panel, or lip, is meant to block the view of the entry hole as well as make it difficult for birds to access. And birds who don’t have an egg in the nest box are more likely to give up.
If your chickadee is struggling to accept the wren guard, you might want to play with the size of that panel, starting with a shorter size and slowly making it taller.
You’re probably wondering how to do this. And that’s where cardboard comes in handy again. Just cut a strip wide enough for the guard and nest box but short enough to where it doesn’t fully block the view of the entry hole. Tape it to the roof of the wren guard and then observe.
Your chickadees should have no trouble accepting the wren guard at this stage. Once you see them go in and out a few times, cut another strip of cardboard the same width, but this time make it a little taller so that it starts to hide the entry hole.
Repeat these steps until the entry hole is visually blocked. Keep an eye out and make sure your chickadees are no longer struggling.
What to do if nothing is working
If nothing is working, you’re going to have to take on the risk of going without a wren guard. But only do this after you have exhausted these options and it still isn’t working.
Also, be careful as you try to optimize your wren guard setup. You don’t want to stress or tire your chickadees out. Be extremely compassionate, observant and sensitive. Take it slow and easy.
Once everything has been tried and still doesn’t work, we recommend adding a second nest box further away from your chickadee nest. Put it close to a tree line or a bush. If you don’t have many options, you can try to put it close to your house under an eave.
Wrens will hopefully prefer that nest box over the chickadee box. For more tips on how to optimize the placement of a second nest box and balance the relationship of house wrens and other birds in your yard, you may want to take a look at this video.
While the video discusses the challenges between bluebirds and house wrens, a lot of the same principles apply to chickadees.
When to add a wren guard to your chickadee nest box
A wren guard should be added to a chickadee nest box after the first egg is laid. It is risky to try to put a wren guard up any sooner.
The reason it is best to wait until there is at least one egg is because birds are generally more committed to their nest once there is at least one egg in there, and they will be less likely to abandon.
The challenge with waiting until the first egg for chickadees, is that while a mother chickadee is going through the egg-laying process, she will usually cover everything with a tuft of fur, and it is risky to move the tuft out of the way to see if there is indeed an egg in the nest cup.
A lot of times, you won’t even know there are eggs in the nest box until every single egg has been laid.
We don’t advise you to rummage around in the nest box in order to search for any eggs for two reasons. First, it could break the eggs on accident. Second, it’s not really legal. Monitoring a nest box is one thing, prodding around in one gets into some gray areas when it comes to wildlife laws.
A nest box camera is a helpful way to discover the presence of the first egg in the nest. Motion activated cameras will notify you when the mother bird has returned to her nest, and from there you can try to look for evidence of an egg.
Otherwise, wait until you know for sure and then add the wren guard.
When to remove a wren guard from a chickadee nest
The general advice about when to remove a wren guard from a chickadee nest is when nestlings are 12-14 days old. During this time, they are larger and wrens shouldn’t be able to get them out of the nest box.
The other reason for this advice is that the demands of feeding increase as nestlings get older, and the wren guard makes the feeding process a little difficult.
However, wren guards can reduce the risk of other invading birds, especially Eurasian tree sparrows if you have them in your area. If you’ve taken the wren guard down only to discover the nest box is being harassed, put it back up until they are old enough to fledge (16-19 days old with hatch day being day 0).
Making a wren guard
You can make a wren guard out of wood or you can make them out of sturdy cardboard. We recommend cardboard wren guards because they’re very easy to manipulate and very easy to make. If you double up on the cardboard strips, your wren guard will last a lot longer.
In our experience, we’ve had cardboard wren guards last a whole nesting season when using good cardboard and doubling up.
