a sad mystery

While walking in the garden, I dislodged a stick, which in turn sent some little creature scurrying away among the dried leaves. It was so well camouflaged and so well hidden that it took me a while to actually "see" it was a little sparrow trying to hide by one of my potted plants. It obviously could not fly, but I didn't see any visible injuries, so I thought it might be de-hydrated. I put out a small dish filled with water for it and left it alone, hoping it would drink up and recover. A few hours later, however, we found its lifeless little body keeled over. It is the second dead sparrow we find in just a few days and I wonder what killed them since neither seemed injured or old or malnourished. Birds can fall prey to predators, of course, or die from old age and a host of other natural causes, just like the rest of us, but it seemed so sad to see them go for no apparent reason.