Why did the Goldfinches stop coming to my feeder? It's still half full!
There is no one reason you don't have finches. First make sure your Nyjer seed is fresh. One way to do this is to pinch the seed with your fingernails and see if any oil comes out. The finches use their bills to twist the seed and sip the oil and then drop the shell. On these cold days where every meal counts, if your seed has dried out your feeder will be skipped. (Wild Birds Unlimited receives a fresh load of seed each week).
Second, make sure there is no mold in the bottom of your feeder. In Michigan where it can rain several days in a row the seed may not get a chance to air out and begin to mold. This can be dangerous to the finches and they will avoid your feeder again. To prevent mold in bad weather use Feeder Fresh (a silica grit that absorbs water and humidity, is safe for birds, and made from non-toxic absorbent sand). You can also shelter your feeder from the elements by using a WBU Weather Guard.
Third, finches are notorious for leaving a tube feeder half full. I was taught it was polite to leave at least a little food on your plate so as not to appear gluttonous. So what do you do if you have polite birds that eat only to a certain level and then stop even if there is still good, fresh, seed in half of the tube? Don't just top off your feeder with fresh seed. Empty the older seed (if it's still good) into a different container, fill the bottom of your feeder with new seed and top it off with the older seed. The birds will probably eat down to that certain level again and you'll have to repeat the process.
My favorite feeder is a WBU Mesh Finch Feeder. Several birds can feed at a time, the seed airs out, it's easy to clean, easy to fill, has a lifetime guarantee, and is made in the USA. They eat from top to bottom. However if you're thinking of switching feeders be aware that finches don't like change and it may take several minutes to several months for Goldfinches to accept a new feeder.
Fourth, yellow attracts Goldfinches that are scouting for new feeding sites. Just like you know about the golden arches of McDonald's, the birds know yellow represents food whether its a sunflower or a feeder. If your feeder isn't yellow, attach a yellow ribbon to the feeder to catch a scout's eye. Once one Goldfinch finds your feeder, a flock will follow.
Is it worth the bother? Yes! I love the happy, warm, song of the Goldfinches. I love the huge flocks of finches that flutter down from the tops of trees as they take their turn at the feeder. I love that I can hang the feeder anywhere because squirrels and other animals don't bother with Nyjer Thistle. And once you understand the Goldfinches' needs, they are easy to please and very pleasing to watch.