I would be looking for a caterpillar, the larva of a moth, that would eat those leaves rather than a rabbit or deer.

Looks like a worm - caterpillars, tomato horn worms or loopers. That's considerable damage! Try spraying malathion and give it a good dose of a high Nitrogen fertilizer.

AS I recall, Morning glory is the host plant for fritillaries. The folks in the Butterfly Forum would know.

Here is a link that might be useful: Butterfly Forum

We found the culprit today. It was a rat.

Yesterday I pulled out the remainder of my pik-up-stix morning glory after the new leaf at the very tip top of the obelisk was removed on Friday night. Today my dh noticed a hosta leaf laying behind the acuba. This is on the way to the dry, empty, protected space under our stairs. He looked underneath and found much leaf litter, and rat feces.

When I returned home this afternoon I looked under the step, and there she was, sniffing and nibbling.

The hosta leaf was the only sign of anything amiss in our small garden. No other leaves laying around, no rat poop anywhere. We pulled out our recycling station and found a few pieces there, she ran behind it to get back to her hidey-hole. Upon inspection we see that she has now started nibbling the hosta and hydrangea leaves.

She is only active at night, we have never seen her during the day. The live trap has now been activated and baited with peanut butter. I plan on releasing her in the gulley a block from our house.

Hmmm, I got her. NOW what? The only words of advice I got from my fella 'wear gloves'. Thanks Sweetie :)

Don't flush ;) Some choices are - bury - Or how far from a woods road are you, a critter or two here has been taken for a ride. In most places its acceptable to place in a heavy plastic bag and dispose of in your garbage can, I don't know about BC though.

By all means, wear gloves!

You might consider setting the trap again, seldom is there just one rat.

I drove the bugger away, a few blocks and to the other end of the area.

I set the trap before going off to work and the fella returned home in the afternoon to find another rat in the trap, smaller than the first one we caught.

That one got the plastic bag, garbage can treatment.

The trap has been set since then, and either they were the only ones (ha!) or they are now smarter than us. We have cleaned up all the feces and will watch for signs of anyone new moving in.

I had the same thing but mine all disappeared between 7:45AM and 5PM today. My other morning glories were not touched and lower to the ground and this one was cleared to above my head. No leaf pieces on the ground or even full leaves. Next to it is a grape vine, also untouched. I watered this morning and this, this afternoon...

Salem Massachusetts, sunny hot weather and next to the AC but the AC has been running all week and this only happened in 8 hours.