Why do birds throw seeds out of the feeder?

 So, why do birds throw seeds out of the feeder?

Here are the top 3 of the 7 reasons birds throw seed from feeders:

Birds throw seeds they don't like from the feeder, searching for their favorite. Birds throw the inedible outer seed hulls from the feeder, eating the edible kernel. Birds may accidentally knock seed out of the feeder.

Below I identify 7 reasons why birds might throw seeds out of your feeder. Once we understand those reasons, we are in a better position to solve this common feeder problem. Throughout this article I link to other articles that solve some of these problems.

Only one of these reasons is accidental, though. In the other six cases, birds are throwing seed from the feeder on purpose. Why would they do this? Let's find out.

Birds throw seed hulls from the feeder

In general, birds do not eat the entire whole seed.

Birds eat the meat of the seed, the kernel. They discard the seed's fibrous outer covering, the hull. If you examine the seeds under the feeder you may see that it is mostly the two inedible halves of the hull that have been tossed on the ground. This is true even for tiny seeds--they all have an outer covering that must be discarded before they reach the edible kernel.

Doves and quail eat the entire seed. They use their gizzards to grind it all up.

[I have written an article comparing different types of no mess and waste free bird seeds. Most of these have seeds with the hulls removed.]

Finches and sparrows "chew." Their jaws move both up and down and also sideways, in a circle. Thus they are able to use their bill and tongue and split the seeds in half, extract and swallow the kernel, and spit out the hulls. They sit on the feeder and chew and spit. Okay, it's not really spitting, more just letting the inedible pieces fall from their mouths. These are the birds responsible for much of the mess.

Chickadees and nuthatches are not able to chew in this way. Thus, they take one seed at a time, such as a sunflower seed, and fly off with it to a nearby perch. They hold the seed with their toes against the tree bark to wedge it tightly. Then they pound the seed open with hammer blows of their beak. In fact, this is very action is the origin of the nuthatch's name.

This type of “one seed at a time” and eating it elsewhere makes for a very neat bird feeder. Don't we wish all birds were so non-messy?

Spotted Towhees habitually kick when they feed. Greg Gillson.

Some birds kick seeds out of the feeder by habit

Towhees, Fox Sparrows, White-crowned Sparrows and some other ground-feeding birds habitually kick over leaf litter as they feed, searching under fallen detritus for a snack. They can't help themselves when they get on the feeder. Kicking is how you eat. Off flies perfectly good seed—thrown from the feeder!

The Cornell Lab of Ornithology (source) calls this maneuver of the towhee the "double-scratch." They quickly kick and scratch the ground, hopping forward and back with both feet at once. Then they look to see if they've unearthed any goodies to eat.

Birds throw poor quality seeds from the feeder

The components of bird seed are harvested by machine. The plants are cut and the seeds separated from the stalk and leaves. By cutting all at once there will be some mature seeds and some not quite ready. Some seeds may not have anything in them.

Birds weigh and examine and test seeds to see if they have a nice meaty center, before they open them. If there's not food inside, then they are discarded. There's no sense expending energy on an empty seed. A bird who can't figure out the difference won't long survive.

Birds ate the sunflower seeds, but not the cracked corn.

Birds throw seeds they don't like from the feeder

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Wagner's Songbird Supreme bird seed is my favorite for attracting the most kind of birds to my feeder. If it isn't available, a close second is Wagner's Greatest Variety. These are Amazon affiliate links that help support this blog. Thank you.

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While you may think you're getting a great deal on bird seed, the birds may have other ideas.

Many of the cheaper mixed bird seed packages contain more than half seeds that most birds don't like. Such seed includes red milo, wheat, and cracked corn.

What do you do with food on your plate you don't like? Yep, into the trash it goes. Birds throw out the seeds from the feeder they don't want in order to get to the seeds they do want.

What does this mean? It is the equivalent of buying a whole bag of mixed bird seed, bringing it home and immediately dumping half of it out on the ground! No wonder it creates a mess!

Most birds at the feeder love black oil sunflower seeds. Many sparrows also love white proso millet. Choose bird seed with mostly these two ingredients.

[I recommend Wagner's Songbird Supreme (my review) as a mixed seed with only foods that birds love! No filler! It's what I continue to buy for my bird feeders.]

Birds throw germinating seeds from the feeder

Is wet bird seed bad for birds?

Not at first, during or immediately following a rainstorm. Wet bird seed may clump together and be hard to eat. 

If bird seed gets soaked through it may germinate and start growing. Birds will not eat germinating seeds. Birds will throw such "bad" seed out of the feeder. And it leads to the next problem if not quickly cleaned up.

Birds throw moldy bird seed from the feeder

If seed sits in the bird feeder and stays wet it will become mushy and dank-smelling. That's mold and bacteria growing.

Can birds eat moldy bird seed? They may try. And it may end up making them sick or killing them. If they don't eat it, they may throw it out of the feeder, making quite a mess.

More than likely, though, they'll abandon a feeder that has moldy bird seed, especially if it is wet.

For the same reason, birds may not eat old seed left over from last year. Start with fresh seed every fall.

Birds accidentally spill seed from the feeder

Sometimes the seed is accidentally knocked out of a hopper or tray feeder by active birds. 

Or when pulling one seed from a tube feeder, another seed or two falls to the ground.

For all these reasons, birds may throw out seed from the feeder, making quite a mess.

So, that begs the question: What do you do about it?

For that, please read my article:  End the mess of feeding wild birds!