I'm new to birding, and recently put up a bird feeder on my back porch in Chicago. It has attracted grey squirrels and cats, as well as mainly house sparrows. A squirrel baffle seems to keep the squirrels off the feeder, and I've been vigilant about chasing cats away. I've seen a pair of blue jays 3 times in the past several weeks, plus a cardinal twice. One bird identification has stumped me, however. It's about the same size, shape, and stripping as a house sparrow, but it has a dull, ruby red breast, and also some red on its head and back. It is outnumbered about 20 to one by the house sparrows. Does anyone know what it is? Thanks for reading.