For me, kind of. I keep a pair in my hatchery pond, and if I move them around, they do seem to keep GBH away. If I put them out and don't move them, the herons seem to get accustomed to them.
I'm not sure it would do much except entertain human guests.
Our 1/3,acre pond in NC usually has gators from about March/April to sometime in November. I also maintain about a 1/10th acre decorative pond with fountain. During the warmer months we usually have a few small juevenile gators in what I estimate to the 3 foot range. They still have yellow stripes on their tails. We get regular visiting gators in the 4-8 foot range. In general they don't bother anything or anybody. About a 5-footer got one of my two foot long grass carp last year, The grass carp fought pretty hard, but lost the battle.
The gators sure don't scare away birds like herons, egrets, etc. Those birds will get within about two feet of gators. The bigger gators do take occasional turtles. The smaller gators take of lot of frogs.
Works great for geese for me. I found they work best when you give them a lot of slack on the anchor line. 6' of water, 20' of line. This way the they move quite a bit on their own. But even then the GBH did get use to them over time. Once a snapper go tangled in the line and dragged it around my 2 acre pond for a couple days. That kept everything away. I'm in Central NC where there are no gators, and I even did a double take when I saw it "swimming" across the pond the first time.
