As summer draws to an end, change is in the air. Our summer bird residents have been leaving, but there are new birds coming through. Fall migration has begun! The immatures you helped hatch have survived their first summer and now join the adults for the long flight south.

September is the time to prepare for winter by building brush piles from fall clippings. We suggest cleaning out your nesting boxes in September. The nesting season has finished and if you clean your boxes now they will be ready for nesting next March. Continue to maintain water features for your birds. September is still hot and water will be highly attractive to migrants and residents alike.

As activity at your feeding station picks up, by the end of September you may want to make sure your feeders are full every day. We have been having a siskin invasion this month. Siskins love nyjer seed and sunflower chips. Could this be an indication of other finch species such as evening grosbeak coming to our region this fall and winter? Let's hope so, but only time will tell.

Most birds have a poor sense of smell, so they find their food by sight. No other living animal possesses the visual acuity of birds. Though they look small-hidden behind the lids and set in protective rings of overlapping bone-birds' eyes are, relatively speaking, enormous. Since most birds must locate their food while flying, the image must be big and sharply detailed. Imagine the extraordinary vision needed by a hawk cruising over a meadow in search of a mouse; a loon in pursuit of its underwater prey; a hummingbird gleaning a miniscule insect from a trumpet vine; or a chickadee searching for a source of black oil sunflower seed.

Raptors, such as owls, eagles, and hawks, have eyes located to the front of their heads and possess exceptional binocular vision. Because these birds hunt lively prey, binocular vision is vital. To see to the side or to the rear, raptors turn their heads. An owl can rotate its head about 270 degrees, but not, as myth would have it, completely around.

Most other birds have eyes set on the sides of their heads. They feed on seeds and insects and need some forward binocular vision, but they must also be able to see far to the side to avoid predators. Because your backyard birds locate their food by sight, your feeders should be placed so that they can be easily seen by the birds.