Noel guards are wire mesh predator guards that fit around a nest box entrance. They protect bluebirds, tree swallows and other cavity birds from raccoons, squirrels, and predatory mammals. Noel guards also prevent birds of prey and crows, but they don’t stop snakes or chipmunks.
The Noel guard is designed to increase the distance between a potential predator and the nest box entry, as well as having a sharp metal perimeter making it very uncomfortable for predators to reach into the nest box.
While Noel guards are very effective against many types of predators, they are more limited compared to a good stovepipe baffle.
Article Contents
What predators are Noel guards effective against?
How effective are Noel guards against predators?
When are Noel guards best to use?
Noel guards may impede nest box access
Noel guards can conflict with wren guards
Cavity birds may not accept Noel guards
Predators can sometimes tear Noel guards off the nest box
Noel guard plans – make one yourself
Watch the video: All about Noel guards – metal mesh birdhouse predator guards
What predators are Noel guards effective against?
Noel guards protect nest boxes from raccoons, opossums, cats and birds of prey. They may be moderately effective against squirrels. And they are not at all effective against snakes, chipmunks or competing birds.
Below is a quick glance of different types of predators or nest box invaders and whether a Noel guard will work against them.
Table 1. List of songbird predators Noel guards are effective against and are not effective against.
| Nest box predator / Invader | Noel Guard Effectiveness |
| Birds of prey (owls, hawks, falcons) | Yes |
| Cats | Yes |
| Chipmunks | No |
| Crows | Yes |
| Opossums | Yes |
| Raccoons | Yes |
| Snakes | No |
| Squirrels | Maybe |
| House wrens (competing birds – native) | No |
| House sparrows (competing birds – invasive) | No |
| European starlings (competing birds – invasive) | No |
Unfortunately, Noel guards are not effective against snakes, a very prominent nest box predator. Snakes can maneuver around the spikes and traverse through the opening in the wire mesh, infiltrating nest boxes.
Rat snakes are very common predators of bluebirds, tree swallows, chickadees, titmice and other cavity nesting birds.
The best way to protect against snakes is to use a stovepipe baffle.
How effective are Noel guards against predators?
Noel guards are not as effective against predators compared to an 8-inch diameter stovepipe baffle. This is partly because Noel guards only prevent a limited variety of nest box predators. However, when a Noel guard is paired with a stovepipe baffle, the probability of nest success increases.
In 2017, NestWatch Project Leader Robyn Bailey published a large-scale study about nest box predator guards and their effectiveness.
When it came to the effectiveness of a Noel guard, Bailey found, “Nest survival estimates were relatively high across all nest attempts in boxes with a predator guard, although survival estimates were lower for the Noel guard than for other guard types.”
Bailey’s study also found combining multiple predator guard types – a stovepipe baffle with a hole extender, or a stovepipe baffle with a Noel guard, for example, increased daily nest survival rates.
Table 2. Comparing two predator guards and their effectiveness at preventing listed predators
| Nest box predator / Invader | Noel Guard Prevention | Stovepipe Prevention |
| Birds of prey (owls, hawks, falcons) | Yes | No |
| Cats | Yes | Yes |
| Chipmunks | No | Yes |
| Crows | Yes | No |
| Opossums | Yes | Yes |
| Raccoons | Yes | Yes |
| Snakes | No | Yes |
| Squirrels | Maybe | Yes |
| House wrens (competing birds – native) | No | No |
| House sparrows (competing birds – invasive) | No | No |
| European starlings (competing birds – invasive) | No | No |
Learn more about nest box predators in our detailed guide
When are Noel guards best to use?
Noel guards are most appropriate to use if you do not have your nest box mounted on a pole with a baffle, if you have birds of prey frequenting your yard or nesting in your area, if you have multiple nest boxes across a long span of land, or they may be helpful if you manage a bluebird trail.
A tall stovepipe baffle is one of the best protective devices against nest box predators; however, they are not going to protect nesting bluebirds, chickadees and tree swallows from birds of prey (hawks, owls, falcons).
In addition to birds of prey, Noel guards and metal hole guards have been a good line of defense against larger invading birds such as crows.
Hawks, owls and falcons have all been reported to land on nest boxes, reach in and take adult birds and nestlings.
Though, if you’re using a well-constructed nest box, the chances of this are low. Many times, bluebird landlords have seen them land on nest boxes, but never try to grab something from inside.
Noel guards not only provide distance between the predator and entry hole, but they also have sharp prongs along the perimeter. These prongs cause a lot of discomfort and help deter predators from persisting with their hunt.
Another time Noel guards are useful is if your bluebird or tree swallow nest box is not mounted to a pole but instead is mounted to a wooden post, fence post or a tree.
We cannot stress enough how important properly mounting a nest box is. Bluebird, tree swallow and chickadee nest boxes should be mounted to metal poles and protected with a stovepipe baffle.
Wooden posts and trees can quickly turn nest boxes into lunch boxes.
However, if you’re in a situation where your nest box is not mounted to a pole, but you are in the middle of a nesting period, adding a Noel guard might just save your nest box.
You do have to be extremely careful. If there are eggs or nestlings, adding a Noel guard is risky.
When your bluebirds or tree swallows or chickadees have only begun construction on their nest, rather than trying to add a Noel guard, we recommend purchasing a pole and baffle, and then mounting your nest box there instead.
Noel guards can be appealing to some people who manage multiple nest boxes on a large area of land. This is especially helpful if nest checks can only be done once a week, or when there is more chance of aerial attack.
The same can be said about bluebird trails, where Noel guards offer added protection on top of a stovepipe baffle.
Most trail managers prefer to use an 8-inch diameter by 24-60-inch-long stovepipe baffle over a Noel guard. Though studies do suggest that pairing predator protection increases nest box success, especially on trails.
According to Bailey and Bonter’s 2017’s study about predator guards and nest boxes, Noel guards were the least observed type of predator guard used.
When to install a Noel guard
Since there is ongoing debate about when to install a Noel guard, we recommend installing one when you feel it is necessary and then observe the box closely to make sure bluebirds and tree swallows accept it. If they do not, uninstall it and wait until the first egg is laid.
Many trail managers in community forums stated Noel guards can be added at any time, whether there is an egg in the box, or the box is completely empty.
However, other trail managers and even some publications recommend waiting until there is at least one egg in the nest box. By waiting to install a Noel guard until an egg is laid, a cavity bird becomes more invested in the nest and there is less chance it will abandon it.
Because the information is conflicting, it’s better to make sure your resident birds are accepting the guard and to take it down immediately if not.
Once your Noel guard is installed, you can try to leave it up year-round. But when the new nesting season approaches, keep an eye out again for acceptance.
You may even find that only one parent accepts the Noel guard, while the other one does not. In this case, we recommend taking the Noel guard down and running with a stovepipe baffle alone. Or experiment with a wren guard instead.
Installing a Noel guard is very easy. If you buy a commercially available Noel guard*, they should come with the screws and washers needed to secure the guard to the nest box. From there, all you do is place your Noel guard, mark your holes, and drive the screws in with washers pressing against the mesh.
If you plan to make your own Noel guard, installation works the same way. You will just want to make sure your screws and washers are larger than the ½ inch mesh of the wire guard.
Noel guard cautions
There are four major areas of caution when considering a Noel guard:
- Noel guards can block nest box access on certain nest box models.
- Noel guards make it very difficult to install a traditional style wren guard.
- Bluebirds, tree swallows, chickadees and other cavity birds may not easily accept a Noel guard.
- Predators have occasionally torn Noel guards off the nest box.
Noel guards may impede nest box access
If your nest box’s access panel is front facing and pivots at the top, opening from the bottom), a Noel guard will prevent you from opening the nest box.
Video. Shows access for a front opening nest box that opens upward is impeded by Noel guard. There are ways of fixing this situation.
There are a few remedies for this:
- Swap out your nest box for one that opens downward or at the side.
- Remove the pivot screws at the top with a screwdriver and place them nearer to the bottom so that your nest box’s access panel swings downward.
The second option is not very difficult and would probably only take 15 – 30 minutes to modify the box. It’s also a light form of box modification and doesn’t require much hardware.
Noel guards can conflict with wren guards
Because Noel guards create distance from the nest box entry hole, they can make it very difficult to install a wren guard on a nest box or make an installed wren guard acceptable for birds. You may have to choose between one (we recommend a wren guard) or experiment with different wren guard designs.
Video. Wren guards may be able to fit on a nest box with a Noel guard, but the wren guard combined with the Noel guard begins to obstruct the entrance.
House wrens are native cavity nesting birds in North America, but they are famous for invading occupied bluebird, chickadee, tree swallow and other cavity bird boxes and tossing out the eggs or nestlings inside.
Once they’ve tossed out the tenants of that nest box, they get to work building their own nest, and quite often, it’s only a dummy nest.
A way to discourage house wren takeover is to install a wren guard. This is a hood or awning that is placed over the nest box and hides the entry hole. It also creates a heavy obstacle for house wrens trying to bring nesting material into the box since they build their nest with sticks (too hard to maneuver).
The problem is that both a wren guard, and a Noel guard stick out away from the nest box, and because the wren guard is a hood, if it were placed overtop a Noel guard, it will make access into the nest box an even greater challenge.
If you look at figure 6, you can see that the wren guard combined with the Noel guard closes the gap and makes entrance harder. Cavity birds can certainly figure this out; however, they may end up spending more energy than they have available, or they might fall behind in feeding.
Another concern is if you have already lost one parent bird. This happens from time to time. A single bird can usually keep up with feeding young, but when there is an obstruction like this, it can make it harder for a single bird to maintain.
So what do you choose, a wren guard or a Noel guard?
Given that Noel guards are less effective compared to stovepipe baffles, and because house wrens are a very common invader of nest boxes, we recommend choosing a wren guard and making sure you have a stovepipe baffle installed on your nest box pole.
We have found wren guards not only help minimize the potential of evictions by house wrens, they also can sometimes minimize other invading birds.
Cavity birds may not accept Noel guards
Bluebirds, chickadees, tree swallows and other cavity birds tolerate Noel guards, but there have been several instances when these birds do not accept the Noel guard and either temporarily or permanently abandon the nest box.
If you are worried about whether your resident cavity bird will accept a Noel guard, the first question to ask yourself is if a Noel guard is even necessary?
In most cases, a stovepipe baffle will suffice.
But if you are leaning toward using a Noel guard, you will want to watch your nest box after installing one.
Make sure both the male and female bird are going in and out of the nest box. If they are, then they have accepted the Noel guard.
If they flutter and hover but do not go in, especially after an hour or two, they likely are struggling with the Noel guard too much and might possibly abandon. Take it down in this case.
TIP: We really do not recommend generic hole extenders or tubes as an alternative because we have found more birds really struggle to accept those.
Predators can sometimes tear Noel guards off the nest box
Raccoons have been reported to tear off Noel guards and infiltrate a nest box. Ensure your Noel guard is secure to your nest box to minimize the possibility of this happening.
Aside from tearing off the Noel guard, predators, more likely raccoons will also bend or break the mesh guard. Guards can sometimes get bent in a way that prevents birds from accessing the nest box or leaving the nest box.
It is very important you monitor your nest boxes regularly. If your Noel guard has been bent or broken, take it down and replace it.
Where to get a Noel guard
You make a Noel guard using ½ inch hardware cloth, screws and washers. But they are also commercially available, highly affordable and more convenient to use than making one yourself.
Noel guards can be found on Amazon and some bird supply stores carry them from time to time. You can find one here*.
Find Predator Guards on Amazon*
Stovepipe Baffle (8-inch diameter x 24-inch length on Amazon
If you are interested in using a Noel guard and are debating whether to make one or buy one, we recommend buying one.
Making a Noel guard is not hard to do. The challenge is working with hardware cloth (metal wire mesh similar to chicken wire).
Hardware cloth is purchased in rolls of different lengths, 5 feet being the smallest amount we’ve found.
Once you cut into the wire to cut out your Noel guard template, you’ll deal with the spiked edges that can scratch and cut skin or snag clothing. And because the hardware cloth came in a roll, it will want to roll back up on itself.
The other important reason behind our recommendation is that the cost of hardware cloth is only a little less than buying a commercially available, that it is worth the slight premium to save you time.
When making a Noel guard, it is important to wear old clothes that you’re not afraid of getting ruined. Gloves are also essential.
Noel guard plans – make one yourself
We’ve created a printable template to place over your hardware cloth and guide you as you cut around it.
Just click the image for the PDF printable plan. Make sure when printing this template that you print its actual size.
When using this template on hardware cloth is that the template will probably not perfectly align with the hardware cloth mesh. This is because the hardware cloth has been rolled and therefore the mesh is a little bent and skewed.
Fortunately, making a Noel guard is a very forgiving process. If the dimensions are off a little bit, it will not hurt the overall design.
References
Bailey, R. L., & Bonter, D. N. (2017). Predator guards on nest boxes improve nesting success of birds. Wildlife Society Bulletin, 41(3), 434-441.
Rodriguez, L., Jordan, J., Hostetler, M. E., Packard, C., & Kochert, J. (2010). Bluebirds and Other Cavity-Nesting Birds: Leader’s Guide. EDIS, 2010(2).
*Amazon links are affiliate links. We test most of these products, including the ones mentioned in this article. Affiliate links help pay for maintenance on this site, which is a costly endeavor. We thank you for your support.
