u/Honest-Physics920

This little fella was curled up in a ball and barely even reacted to my presence. I checked again on it 10 minutes later and it was sprawled along the path. It even let me pick it up (I was very gentle), and I couldn't see any obvious signs of injury, although it's wings and legs were caked in wet leaves and mulch. I cleaned it off and stuck it close to some water but it still barely moved and doesn't seem right to me at all.

Does anybody know why this bird would behave in such a way? Could it be illness or age related? Thanks in advance.