Keeping a bird feeder in your yard is a great way to get wild birds to visit your garden. In the spring and summer, your bird feeders are a welcome source of treats for feathered creatures that happen to drop by. By winter, when the ground is hard and insects are in hiding, a steady access to full bird feeders can sometimes be the only thing that keeps many wild birds from starving, especially if the weather is especially harsh and cold. Here’s how to make bird feeders out of plastic bottles.