The smallest bird, other than a humming bird, that I have ever seen is persistently pecking holes, and or eating, the leaves of some sunflowers.

The sunflowers are at the end of a row and get more shade than the others and are not very vigorous.

This tiny, tiny, bird with a dark blue back and a dirty cream breast just vigorously attacks the leaves, proximal I think is the word, back near the stem. Making holes up to a half inch in diameter.

I have never seen the bird anywhere else.

I have examined the leaves with a hand held magnifier and cannot find any insects.

I live in the high desert. In the Great Basin of Utah and Nevada. Hot, dry, the sage brush and tumble weed are sparse and sickly.

Anyone care to conjecture what the bird is or why it is doing this thing?