Hooligan!

The Goldfinches are increasing in numbers.  When we first got here, they were completely absent from our garden and feeders. The Blue Tits, Great Tits, Greenfinches, Chaffinches, Sparrows, Robins and the occasional rarer visitor all shared nicely.
Then, one year, they appeared.
Since then, they have increased to the extent that we have to hide other feeders elsewhere to give the others a chance of getting some seeds.
Why hooligans?  Because they appear when the feeders are full and proceed to empty them!  Not by feeding, but by dumping all the seeds on the ground below.  Indiscriminately starting at a feeder hole and chucking the seeds out. They don’t eat them, they are just looking for the “perfect” seed.  They must find some, but it IS annoying to see the other birds missing out.
Solutions on a postcard………..?