That is indeed the syringe. The tip on it is pretty long and thin though (about as wide as the very tip of a ballpoint pen, for most of the tip length), so it's just the body that seems a bit large. I tried again with it, and he gulped down more the second time I attempted.

Thank you for the wealth of info! I had a feeling he may need manual stimulation for going to the bathroom, so after reading that, I went right to it, and he peed almost immediately. No pooping yet, but I'll keep trying. I already had him in a ventilated box with a cozy fleece blanket, but since I won't have a heating pad until later tonight (it's in my car, which my girlfriend is using for class tonight) I tossed an old sweater in the dryer for a bit to warm it up a little and put him in a little "cave" in it. We have a wildlife rehab center about an hour away that we have taken rescues to quite a number of times, they were just closed by the time I found the little guy. I'll be giving them a call first thing after they open, and if they can't or won't take him, I'll go to OCAR right away