Niger seed (nyjer seed or thistle seed) is known to be a favourite of finches, due to the shape and structure their beaks, which are suitable for a smaller type of bird seed.
“I bought these seeds to attract our local goldfinches. They visit the teasel in our garden but struggle this time of year. Also with the fast sinking father in law in a care home this coronavirus time they can help. He spends days looking out of the window and he will be fascinated to see these feathered marvels when they appear when l place a feeder outside that window. The Niger seeds also attract green finches and l hope to see one or two bull finches.”
“I got the niger seed following a viewing of goldfinches on the bird feeders, to encourage them to stay. I had heard it was their favourite seed. However, my goldfinches are very happy with dehusked sunflower bits and have yet to sample the niger seed in large quantities. They don't know what they are missing.”