The first observation I posted to iNaturalist was this Sycamore (https://www.inaturalist.org/observations/20476571). Four years later, it's still here (and this is my observation # 4184).
This is supposedly the last wild Sycamore in Prince Edward County (although I hope there are a few more away from a road somewhere). When I was first shown this tree, it wasn't alone - there were trunks accounting for five trees in this grove, and while some had died, at least one other was still alive at that time.
So when I visited the tree in 2018, and every time I've seen it since, it didn't have any seeds that I could see. I've been worried that this tree might join its former compatriots without any replacements - which would mean local extinction. This time, happily, it had a few - at least 5 seed balls. That's not much, but that's not zero either. Keep on keepin' on, Buttonwood.