Now that Pine Siskins are becoming widespread, here's some tips for feeding these gregarious finches.
1) Offer Niger (thistle) seed but make sure it's fresh.
Don't buy more niger seed than you'll go through in a couple months. Always buy your niger seed from a quality shop like Wild Birds Unlimited to ensure that it's fresh. You never know how long that big, cheap bag of thistle has been sitting in a warehouse or on the shelves of that big box store!
3) Spread the feeders out.
Siskins are prone to salmonellosis so spread the feeders out so the disease is less likely to spread.
4) Keep your feeders and feeding areas clean.
Clean them now while you're thinking about it and then again a couple times during the siskins' presence. Again, they are prone to salmonellosis and clean feeders and feeding areas reduce the spread of disease.
5) Watch for them on other foods.
They eat lots more than just niger seed! At my house, they've eaten Bark Butter, they often eat from seed cylinders and Stackables, and they'll also eat black oil sunflower and sunflower chips (shelled sunflower seed).
Enjoy the Pine Siskins while they're here. They may just be moving through, with another winter finch, Common Redpolls, coming later! It's gonna be a fun winter full of birds!