Sicyos angulatus looks like a good candidate, it is the only Sicyos present in MI. The leaf shape is very similar but it is suppose to have hairy vines and the photo I have of the vines shows them smooth. I guess the most confusing thing about this vine is the fact that it never had flowers or fruit, and I checked it closely all through the year. Echinocystis lobata was observed in another location but it's leaves are much more pointed, it had profuse white flowers and was covered in spiny fruits in the late summer, which is why it was much easier to ID.

I just have to chime in. Yesterday morning as I turned onto the street of where I work Orange County, CA right in front of me was a big turkey vulture dragging a dead possum to the curb. There is not much left of that possum today. We also enjoy the occasional blue herons and the numerous snowy egrets down at the creek near our house. We also see kites and kingfishers. Ah, life is good.

There are white herons BTW. Egrets are smaller than white herons. I use a black bird net bought at Wal-mart. I pounded six 24" rebar, 3 to a side. I then put black plastic piping over the rebar to it arches over the pond. On top of that I stretched the netting and secured it with electrical zip fasteners in various places. I can lift the whole thing off or just one end if I need to access part of the pond and slip it right back on when done. I live in Great Blue Heron land and they fly over my house at any time. After a few years of no fish being eaten I thought I'd take it off and put up a double row of fencing on the edge and also strung fishing line in triple rows. It was not a day or two the heron came back and ate another fish, so I put my portable net back up. My net extends beyond the edges of the pond by about 12 to 18 inches but is open by about 12" so frogs can move in and out safely and also birds. Herons won't duck under it. From nancyd: "Use bird netting - it's virtually undetectable and cheap. I've purchased decorative four foot posts and stretch the netting over them so that it hangs 3/4 of the way down the posts. This allows birds, toads and frogs access to the pond without getting caught in it. Easy to pull off when you need to. The only thing I've sacrificed are dragonflies. They don't like flying under the net unfortunately. We have not lost a single fish since we put up the netting." I like the idea of using decorative poles so I may switch out my black tubing. The black netting is invisible from not so far away from the pond, but I can see my piping even though it looks OK I'd rather not see much at all. I'd like this to go straight across with no hanging down and take it out beyond the pond edge right up to the pondside plantings. I think I would like it to be 12" off the top of the water and pulled very tight. Thanks for the idea Nancy!

Probably a little blue heron. In real life they look very dark all over, not the reddish purple in the field guides.