with El Pollo. Also, look on the tops of leaves for frass— catepillar poop. They'll be little pellets ranging in color from pale green to dark brown. Then start looking above them for the pooping hornworm overhead somewhere. Also, look for chewed foliage, then follow the stalks in both directions. I find that when they are very big I have some (mental) difficultly squishing them, so I drop them in a bowl of soapy water.
I will reiterate how hard at first it is to spot these guys. When you see it, you'll wonder why you were so blind at first. Here's one I discovered 6 inches from my nose.
Edited to add: well it always helps to read the original post more accurately. You say the leaves are NOT being eaten? First make sure of that—it's easy to miss so look carefully on the newer growth at the ends of the stems. But if no leaves are eaten, then it is likely something other than hornworm. Your original suspicion of a bird makes sense, or a critter like a squirrel, chipmunk, whatever might be in your area.
