Strategies so that bird feeders feed only birds

Bird feeders were the best things ever invented for animal damage control operators. By increasing the food supply, bird feeders encourage the rapid growth of animal populations. The technical term for this is increasing the carrying capacity of the land. As populations increase due to the increased food supply, animals may eventually try to enter your home for shelter.

Bird feeders directly benefit the following animal species, some of which can cause extensive property damage:

• Rodents, such as flying squirrels, gray squirrels (Sciurus carolinensis), fox squirrels (S. niger), western gray squirrels (S. griseus), tassel-eared squirrels (S. aberti), red squirrels (Tamiasciurus hudsonicus), mice, chipmunks, voles, and rats
• Carnivores, including coyotes, opossums, skunks, bears, and raccoons
• Birds such as geese and ducks

Bird feeders nourish wildlife in one of two ways:

1. Foraging – Food falls to the ground below the feeder, allowing a wide variety of animals to eat.
2. Direct access – This method is common; think of squirrels that always seem to find a way into the feeder.

Reducing Foraging

Don’t buy mixed bird seed.

Birds like blue jays prefer sunflower seeds. They will dump seed onto the ground seed until they find the next sunflower kernel. It is better to buy more bird feeders and put a single kind of seed into each one. This way, birds will fly to the feed they prefer.

Thistle Seed (Nyger)

Generally speaking, squirrels don’t eat thistle seed. (We have received e-mails from people who claimed that squirrels were eating thistle seed; perhaps those squirrels were really hungry.) However, mice do. Be sure that you don’t allow thistle seed to reach the ground. Food so easily accessible will increase your mouse population, and they will then enter your home. Our experience tells us that when mice enter a home, it is only a short time until squirrels enter. Consider attaching a bucket below the thistle feeder to catch seeds. Cut small holes in the bottom of the bucket so rain water can drain. You may also cut out the bottom and cover it with mosquito netting.

Safflower Seed

We have read and heard that squirrels do not enjoy safflower seeds. Nevertheless, we do understand that some squirrels will still eat the seed, so this technique is not fool-proof. We have been told that the seed is taken regularly by chickadee, titmouse, house finch, and cardinal (even from the perch). Info from J.W. of Billerica, MA.

Recapture the Seed

Modify your feeders so that spilled food is caught by a basin or tray before reaching the ground. This also requires you to empty these trays frequently so they don’t overflow. Make sure that the basins allow water to drain, otherwise they will get too heavy and possibly break the feeder. One method is to cut out the bottom of a bucket and then line it with mosquito netting (window screen). The mesh is open enough to let the water flow through, but not the seed.

You may wonder, “How am I going to feed the ground feed birds, like mourning doves?” One way is to lay out a blanket and scatter the food onto it. When the feeding is done, simply take up the blanket and store it away until the next feeding.

Repellents

Cayenne Pepper in Bird Seed Doesn’t Always Work

One e-mail respondent said that this didn’t work for her; the squirrels still ate the feed. Some questions to consider before disregarding this option: how much did she mix into the seed and what was the strength of the pepper? Of course the gray squirrels may think that easy, bad-tasting food is better than starving.

People have asked us regarding the safety of mixing capsaicin with the bird seed to repel squirrels from eating the seed. Here are replies from a couple of scientists.

I asked Russ Mason, an expert on chemical repellents, whether birds are affected by capsaicin. Here’s his reply: “No – the ethmoid branch of the trigeminal nerve innervates the eyes, nose, and oral cavity. This is the nerve responsible for mediation of chemical irritation. There is no evidence that birds code capsaicin (red pepper) as an irritant at concentrations as high as 20,000 ppm (the hottest chili is about 2,000 ppm). Mammals like squirrels (rats, mice) reject capsicum concentrations as low as 1-10 ppm.” In other words, birds are insensitive to red pepper, period. They could be irritated by excessive dust, however. Robert H. Schmidt, Associate Professor, Dept. of Fisheries and Wildlife, Utah State University.

Jason Watkins says, “I am an avid bird feeder, and have used cayenne pepper to deter the squirrels from my mixes. I have observed that powdered cayenne in a mix will aggravate the birds as the powder can fly into their eyes easily as it is avoided by the squirrels. The pepper doesn’t bother the birds’ taste buds but will still cause topical aggravation/pain, as it will to the one who mixes the food, especially in the eyes. Because of this I have ceased using cayenne pepper in this way.

I do, however, still use the cayenne in my suet mix. I make my own suet and add quite a lot of cayenne to it. The squirrels will only eat a tiny bit at a time, if at all, and the birds seem to prefer the mix over my recipe without the cayenne. I think that the pepper “tied” up in the lard, peanut butter and other ingredients is “safe” for the birds, as the powder does not fly freely but is contained in the homogenous mix. In addition, I have never observed a bird that appeared to be affected by the suet mix, like I noticed with the dry seed mix. So I guess it depends on how you are going to use it to deter the squirrels on whether it will cause harm to the animals you want to feed. Hope this helps.

Jason J. Watkins, Plant Regulatory Officer
WV Dept. of Agriculture, Plant Industries Division
1900 Kanawha Blvd, East, Charleston, WV 25305-0191
Information used with permission.

Reduce Direct Access by Squirrels

A number of feeders will do a pretty good job of repelling squirrels, although this is by far the most difficult task to do. The strategies, however, are simple and straightforward.

Option 1. Pole Feeder Modifications. Attach a feeder on a post so the feeder is at least 6 feet off the ground and at least 10 feet away from any nearby branches or structures. Any squirrel can access a feeder hanging from a tree branch. Baffles help and may even prevent access, but why give the squirrels so many opportunities to try? The feeder at the right was situated on a pole that was covered with aluminum flashing. Place flashing starting from the bottom of the pole and be sure that each layer of aluminum overlaps the lower one (as you’d shingle a roof). The post is not round; it is a square, approximately 3″x 3″. This feeder proved that a squirrel-proof feeder is possible. And squirrels don’t need to reach the feeder to eat. They only have to get the food onto the ground. If squirrels can shake a feeder so that it spills its cargo, they are satisfied.

Option 2. Baffle Cones. Attach a baffle cone around the pole with the widest part facing out and down to prevent squirrels from climbing the pole. These cones should be attached at least 4 feet off the ground and extend out at least 2 feet. You don’t want a squirrel able to hang ten around the baffle. This baffle should also prevent other animals like raccoons from accessing the feeder.

Option 3. Choose Specialty Feeders. There are a variety of feeders designed to reduce squirrel access to feeders.

Feeders with Screens. This feeder, sold by Handsome Rewards (909-943-2023), may be helpful to keeping away larger, messier birds. Larger birds are more likely to spread food onto the ground, increasing food availability to various squirrels. Of course, baffles and the feeder should be positioned properly.

We do NOT recommend using mixed seed in a feeder. Each feeder should only contain one type of seed.

ICWDM would like to thank the Burgess Family for the following tip:

“Some of the more expensive type of store-bought tube bird seed feeders come supplied with a metal hood, but the cheaper ones don’t. I recycled an aluminum pie plate to make an effective alternative. Cut a slit in the center of the plate, same width as the tube, remove the wire hanger from the feeder, upturn the plate and thread it onto the hanger then put the hanger back on the tube, with the plate forming a second roof over the tube. The squirrels find it very difficult to negotiate around the pie plate and cannot climb down onto the feeder. Hang the feeder from a large branch far with enough distance from tree trunk and ground. Before I did this, squirrels were all over my feeder. Now they can never get on it.”

Feeders with Gravity Door Protection. These feeders are more costly than alternatives, but they have a good reputation and may well pay for themselves in seed savings. The feeder pictured at the left has a weight-activated bar to prevent access to the bird seed. A screw is used to create tension. Once the tension is set properly, since squirrels weigh more than birds, when the squirrel steps on the bar, it closes  access to the seed. A bird that lands on the bar doesn’t weigh enough to make it move, and can enjoy the food. Unfortunately, some squirrels learn how to hold on to one end of the feeder and hang down to get the seed, bypassing the need to step on the bar.

Additional Resources

Bird Feeding – Tips for beginners & veterans (coping with squirrels) – University of Wisconsin-Extension

Selective Bird Feeding: Deterring Nuisance Wildlife from Bird Feeders – University of Nebraska-Lincoln