I've caught Canadian geese with fishing string tied around a leg. You need to entice it with food for sure. Lots of times they are really hungry, because standing up forging hurts. Sometimes they will sit down to eat the food you are providing, sometimes not. Then, I would just get close as I could and grab it if I was pretty certain I could. If I didn't think I could get it, I wouldn't try at that time. A failed attempt could make the goose avoid you from then on.
The goose having a bad eye would be to your advantage. Try to get on the bad eye side when you try to grab. Also, if you end up grabbing a wing, hold on, and then quickly fold the wings by putting your arms around the goose. You may get hit in the head a few times, which can make your ears ring, but hold on tight! (Don't wear glasses of any type while trying this.)
Next, since it was a wild bird, I always had cuticle scissors and a bottle of hydrogen peroxide with me. I would take the goose the short distance to where the supplies were and cut off the string, while still holding on tightly. After getting the string off, I would pour hydrogen peroxide all over the wounded area and then release the bird. Thankfully, it worked well in my cases. The goose would quickly fly off, but I would see it again later. Even if the wound was deep, the leg still healed up. Good luck if you try this. Anyone else trying to catch the goose, who the goose does not know, will have a lesser chance of succeeding, unless it is greatly weakened. Stranger can spook it.
Thanks for the update on Gooslyn. So glad to hear he is still doing well!
