SAUVIE ISLAND - When a flock of migrating waterfowl takes flight from the Sauvie Island Wildlife Area, it's a heart-pounding moment and a scene that takes your breath away.

But you don't have to travel far to experience the same fun. In fact, backyard bird feeders can draw scores of species close to our homes each winter.

What you put out for the birds can also make a difference to your feeding success.

Portland Audubon's Karen Munday told KATU that some seed is bad for birds because some feed mixes contain non-native weed seeds.

"The last thing we want for the health of our birds is to have non-native weed seeds and weeds be out there. The weeds non only hurt habitat bio-diversity but the wild birds can fly away and spread the seeds elsewhere."

Recently, Oregon State University researchers discovered up to 14 non-native weed seed species in bags of seed that were purchased from Corvallis-area stores.

The bags included Pigweed, Russian thistle, crabgrass and witchgrass weed seeds.

Each is an invasive weed that's banned by the Oregon Department of Agriculture.

Last summer, KATU showed you how non-native weeds crowd out native plants like Willamette Daisy and Kincaid's Lupine in a constant battle on a Nature Conservancy Preserve near Eugene in Lane County.

Preserve Manager Jason Nuckle told KATU: "We've worked up from a few acres, being able to restore an acre here and an acre there."

Ed Iverson added: "The (native plants) may not hang on for a hundred years without our help but they'll hang on for a few more years, so we have some time to continue to weed out the preserve."

There's more to the problem of bad seed mixes: not only are some seed mixes environmental nuisances by promoting non-native weeds to grow, but some of the seed mixes that you buy at the store don't even do the job and are a complete waste of your money.

Sarah Pinnock is a bird expert at the Jackson Bottom Education Center in Hillsboro and told KATU: "If you see anything on a bag of birdseed that says, "Milo" - don't buy it."

Sarah added that many mixes contain a small dark brown seed, about the size of a B-B called "Milo" that's used as filler.

"It's heavy, it's bulky, it fills up the bag and a lot of the birds in this area, frankly, don't eat it."

So, it winds up on the ground as waste – and you paid for it too.

Best advice: read the label and shop for birdseed as though you're shopping for your family. Instead of buying seed mixes, buy specific environmentally friendly seeds like "Black Oil Sunflower Seeds."

Another tip: Pour enough seed into your filler for only a week (try one-third full to start) because in our wet climate, seed often goes bad before the birds can eat it.

You'll help the birds get through winter and help the Northwest outdoors too.