Meanings of speckled breast in English

This bird was black and white, with a speckled breast and neck.

I see by his impulsive, graceful movement, and his dimly speckled breast, that it is a thrush.

I see by his impulsive, graceful movements, and his dimly speckled breast, that it is a thrush.

Next to pass down the road is an anxious ruffled hen, her speckled breast astir with maternal troubles.

Sometimes it stopped for a few seconds, spread out and resettled its wings, then swelled its speckled breast and again burst into song.

At three passed another ship and brig nearly together; after dinner a small bird resembling our sparrow though rather larger and with speckled breast.