How to clean a bird feeder – an ornithologist shares 5 key steps for clean feeding during avian flu

Bird feeders are one of the best ways to help native bird populations. A feeder gives birds a reliable, healthy food source to help birds and their young grow strong.

However, a poorly-maintained bird feeder can cause more harm than good. With increasing rates of avian flu - and as some local wildlife departments even advise taking down bird feeders during avian flu - an unclean bird feeder could spread disease.

Thankfully, it's easy to keep a bird feeder clean. I spoke to an expert ornithologist about how to clean a bird feeder to keep local birds safe and healthy.

What you'll need for the job

• A brush, like these heavy-duty brushes on Amazon
• Unscented dish soap like this at Walmart
• Bleach
• A bucket like this from Walmart

1. Dissasemble the bird feeder

Once all the food in the feeder has gone, it's time to clean out old seed and suet. If you have a metal, glass, or plastic bird feeder, the first step is to disassemble it. This makes it much easier to clean, and lets you remove seed oil build-up in otherwise awkward spots.

This is usually easy to do - just remove the top of the feeder and the bottom, which should give you a lid, tube, and feed tray. In some feeders, the perches are removable, too.

However, you don't need to disassemble wooden bird feeders. These feeders are usually nailed or screwed together, so it's best to leave these as they are. You may find that you need to use a crevice brush like this from Amazon to clean along the joints, however.

2. Soak the feeder in a soap or bleach solution

The next step is to make a cleaning solution for your bird feeder. You don't need anything complicated. In fact, the best solution is just bleach and water.

Expert ornithologist Maren Gimpel says: 'If your feeder is mostly clean, you can just rinse it out a few times with a very mild bleach solution (1 part bleach to 9 parts water).' If not, Maren says you need to 'soak the feeder for at least 10 minutes in a mild bleach solution, and then rinse them'. This will kill any germs on the feeder.

If your feeder is particularly dirty, Maren suggests using warm, soapy water. 'If you have some stuck-on bits or algae, warm soapy water and a bottle brush will get it cleaned up.' Once you've brushed the feeder, thoroughly rinse off the soap to ensure it doesn't irritate the birds' skin.

If you can, use an unscented dish soap, especially if cleaning a wooden bird feeder. Birds can be deterred by strong scents, so a mild, scentless dish soap is the best way to ensure they return to the feeder once it's clean.

Maren Gimpel

Maren Gimpel is Associate Director at Washington College’s Foreman’s Branch Bird Observatory where she bands birds for both migratory and breeding studies. A bander since 2002 and a birder for over 25 years, Maren is a North American Banding Council certified bird bander and trainer, and secretary of the Eastern Bird Banding Association. 

3. Brush the feeder

It's important to brush the feeder to remove any residue or moldy seeds. Seeds can easily get stuck in the nooks of crannies of a feeder, and they can turn moldy or even germinate if left outside too long. This is especially true of cheap metal feeders because seeds are often caught in the feeder mesh.

This is also the case if you feed birds with suet. Suet will leave a cast of fat on the feeder that can attract pests like raccoons to your yard, so it's vital to brush off any leftover oil or fat.

Maren Gimpel says: 'Every week or two you should scrub off any hulls or residue stuck to the feeder' in order to keep it hygienic. You don't need anything fancy for this, but if you have an awkwardly shaped feeder, you may find that you need to buy a specialist brush.

4. Dry the feeder

Once the feeder is clean, it needs to dry. Maren warns 'Don't fill and hang a feeder up again until it is fully dry.' A damp feeder will cause seeds to rot and go moldy, which can make birds sick, and it can also make seeds sprout, which prevents birds from eating them.

Drying is easiest with metal, plastic, and glass feeders. You can just wipe these down with a dish towel and they'll be ready to fill.

However, wooden bird feeders take a lot longer to dry, since wood is porous. You should leave a wooden bird feeder to air dry for a day or two, preferably in the sun, to ensure that it's dry enough for new bird seed.

5. Refill the feeder - but only by one third

With the feeder dry, you can refill it with your chosen seeds or suet. However, Maren suggests you only use a little feed the first time the feeder is back in the yard.

Maren says: 'I recommend filling feeders only about a third of the way until birds find them; you don't want to waste seed. Seeds will get stale and if they get wet will start to sprout and can get moldy.' Filling a little of the way will let birds find the feeder without wasting lots of food - once it's reestablished, you can fill it up to the top again.

It's unlikely that common garden birds around feeders will transmit avian flu. In most places, the advice is that you should only take down your bird feeder if you also keep poultry. However, if you're still worried about bird flu, there are lots of bird feeder alternatives that can help native birds while reducing the risk of infection. You can also choose a bird feeder that helps to limit infection.