A Tiny Bunch Of Keys

At first I thought this goldfinch had some lichen in its beak for nest building but on closer inspection I think it is a bunch of very immature ash seeds. Ash trees can have either female or male flowers, or both on the same tree. That can change from year to year. The wind blows the pollen from the male flowers to the females and the seeds start to develop. They will eventually grow into the familiar bunches of keys.

As goldfinches are seed eaters and don't start nesting until later in the year than most other birds, I'm guessing this beakful was for sustenance not for homemaking.