A few months ago I bought one of those bird feeders designed to supply goldfinches with nyjer seeds. Janet put me onto it, so I bought the feeder together with a bag of nyjer seed, filled the feeder right to the top and hung it in the magnolia tree in the back garden.
Nothing much happened for weeks, but eventually we saw the occasional goldfinch pecking at the feeder. As they are such pretty birds, we were delighted.
What we didn’t know was the as far as nyjer seeds are concerned, goldfinches are vacuum cleaners with feathers. Forget mental calculations about how much seed a tiny goldfinch can ingest without violating a scientific law of some kind. There is as far as I can tell, no physical limit to their capacity for nyjer seed.
Either that or the little sods are selling it back to the shop.