Unfortunately, the purple martin is extremely vulnerable towards predators. If you have a purple martin colony without any protection from predators, it’s very likely you won’t have it for much longer. It’s not a matter of if you will receive predators coming after your colony, but a matter of when.
Luckily for you, there are many other landlords that have battled this problem and there are quite a few unique solutions you may consider when putting together your purple martin house. Here are a few steps I would definitely take, and then I have followed that up with an optional tactic as well.
Necessary Protection You Should Consider for Purple Martins
1. Regular Nest Checks
Your first line of defense against predators is to do regular nest checks. The ultimate goal is to do them daily. This is a time for you to check for any predators that may be lurking within your compartments. Many landlords have been able to rid their purple martin houses of snakes before getting too many eggs or young.
I believe that part of nest checking is documenting your findings so you can determine if there may be a problem. I am aware of other landlords that have found issues with their colony such as missing eggs and were able to help them determine whether they have a predator problem or not.
2. Predator Guards
The most common resource for defending your colony is a predator guard. There are numerous available commercially. These are devices that typically snap onto your pole. Your most common predators are likely going to be snakes and raccoons. These guards are a pretty good first line of defense. It prevents smaller snakes from being able to go up the pole as they get stuck in a shape similar to an upside down cup and can’t go up any further. The device also will slant with weight being added to it so raccoons find it difficult to climb.
There are also quite a few homemade style guards that you can find online. This is considered the best option, but may be a bit of a challenge to setup for a lot of landlords. Below is a video that provides some instructions on how you can set one up.
3. Bird Netting
If you are performing regular nest checks and have a predator guard up, this is really a great first step to defending your colony from predators. However, there have been many that have found large snakes to be able to go over the top of many of the commercial predator guards available. If they are large enough, they can twist their bodies around the pole, and lift their heads up haver the top of the sides of the predator guards. If they can reach the top edge, there is nothing else preventing them from reaching your purple martin nests.
For this reason, many people prefer to use bird netting to create additional protection against larger snakes. You do not need a lot of it. Generally I have seen people create a “bed” of it that extends out using some type of metal rods. you want it to extend at least 12 inches on each side of your guard. It should also be the second line of defense, meaning that you will place this above your guard on the pole.
The reason for placing this above the guard is because this netting does not prevent raccoons at all. Consider it a small ladder for your raccoon if nothing else. However, it is a great defense against snakes and many purple martin landlords swear by this system.
Optional Protection for Your Purple Martin Colony
Below are a few optional choices for you. Some may help more than others, but they may be a bit more rare to use in many instances.
If you have issues with owls, there are very few options to help you keep them out of your purple martin house, killing off and eating the young. For many people, the option is to add a cage, much like you may see dog kennels made of. They are also often homemade. Keep in mind these are meant to keep owls and other flying animals from your purple martin nests, so you want to ensure that you install it at least 12 – 16 inches away from the entrances on the house or gourds.
Keep in mind if you add such a structure that it will add significant weight to your setup. Consider investing in a strong pole.
Radio noise or some of the commercial options online may be a good option for preventing owls. There are several devices meant to keep owls away from chickens and any of these should be sufficient for helping with your purple martins as well.
The downside to using these devices is that some landlords have stated that if you already have problems with owls attacking your colony, this will not fix the issue. It may keep them from coming initially, but if they know there is a meal there, they will return regularly with or without the noise.
I really like the use of cameras. Not only is it an awesome way to monitor to your colony, but if you are starting to notice anything odd or have any concerns about predators coming in the late night hours, this may be a good option for you. A basic game / hunting camera will work well. It has been known to see owls or raccoons attempting to get to your colony. If you know they are working at it, you may be able to prevent them from ever reaching the nests.
I found the Purple Martin Fanatics Facebook page to be extremely helpful with the information above. They had a Zoom meeting about some of the options available out there for guards that I found to be quite interesting. It is worth the watch if you are having issues!