Deformed Chipping Sparrow & Unusual Cardinal Behavior

Check out this photo of a chipping sparrow that was at Mr. Neil's feeder today. At a distance, it looked like it was sporting a beard, but closer inspection through a spotting scope showed some type of growth or tumor.

The bird was able to feed, but did not hang around with the other chipping sparrows. In fact, this bird preferred to use the tube feeders as opposed to feeding on the ground.

I also wondered if this was some sort of weird crop (a storage pouch on birds) infection as well.

Has anyone seen anything like this? Anyone know what this could be?

In other news, Hasty Brook sent over this question:

I've got a question for you. I've been watching a wren working hard, stuffing sticks into a birdhouse attached to our shed. While I was watching a male cardinal swooped in and snatched the twig out of its beak! I though it was a fluke but a few minutes later it did it again. In fact for several minutes the two birds continued this. At one point the wren went into the house (sans stick), the cardinal landed on top of the house and when the wren tried to exit the cardinal attacked. Is this common bird behavior? Are cardinals that territorial?

I asked my buddy Stan and he said he thinks the cardinal is stealing nesting material--birds do that. I agree, although I have watched how aggressive cardinals are at the feeder and wonder if the cardinal is trying to discourage the house wren. Has anyone out there witnessed this type of behavior from a cardinal (or any other bird)? Any experts lurking out there who knows what is going on or can point us in the right direction for more information? I tried BNA, but have not been able to log on tonight.