from Brewer's Dictionary of Phrase and Fable

The eggs of this bird are spotted with red. The tradition is that the bird fluttered about the Cross, and got stained with the blood in its plumage, and by way of punishment its eggs were doomed ever after to bear marks of blood. 'Tis a very lame story, but helps to show how in former times every possible thing was made to bear some allusion to the Redeemer. Because the bird was "cursed," boys who abstain from plundering the eggs of small birds, were taught that it is as right and proper to destroy the eggs of the bunting as to persecute a Jew.

Hammer is a corruption of the German ammer, a bunting.

Yel"low*ham`mer (?), n. [For yellow-ammer, where ammer is fr. AS. amore a kind of bird; akin to G. ammer a yellow-hammer, OHG. amero.] Zool. (a)

A common European finch (Emberiza citrinella). The color of the male is bright yellow on the breast, neck, and sides of the head, with the back yellow and brown, and the top of the head and the tail quills blackish. Called also yellow bunting, scribbling lark, and writing lark.

The flicker.

© Webster 1913.