Jeremy Shere

My kids (two boys, 7-year-old-twins) recently made a bird feeder. We painted it, hung it up in the backyard, and waited for birds to come. Now that spring is here, there are more and more birds at the feeder every morning. It’s nice to watch them, my kids learn about nature, the birds get a free treat. It’s all good, right?

Or maybe not. According to a recent paper by Gillian Robb, a postdoc researcher at Queen’s University in Belfast, bird feeders could have ecological ripple effects that harm some birds even as they benefit others.

For example, if you leave your bird feeder out during the winter, birds that stick around to brave the cold will eat seed to their heart’s content. Studies show that winter birds with access to birdseed have a higher survival rate than birds without access. They also have more offspring and breed earlier. But, in some cases, they may breed too early. When the eggs hatch, there’s not enough natural food to feed the chicks.

And here’s another potential problem … birds that plump up on bird seed during the winter have a head start on migrant birds. When the fair weather fliers return during the spring, they face stiff competition for food and breeding territory from winter birds bulked up on seed.

Then, finally, there’s the environmental cost of the more than half a million metric tons of birdseed used every year. Soil is used to grow the seed and fossil fuels are burned to transport it.

So does this mean you should shut down your backyard bird feeder? Not necessarily. First, because they study shows that bird feeders have varied effects. Some birds prosper. Some don’t. And it surely depends on where you live, what the weather’s like, how many species of birds there are competing for resources in a given area, etc.

So no, you should not take this as an admonishment or as a warning to immediately remove your bird feeder. But it is an interesting lesson on the delicate balance of habitats. It’s not always easy to see (and certainly easy to not think about), but how we behave and what we do has serious and immediate effects on the environment. The bird feeders in your neighborhood could tip the ecological balance and give one species of bird enough of an advantage over another. And that will effect which species thrives and which declines.

Food for thought.