I think the fence wire is 14 or 11 ga. ,The 9 gauge galvanized stuff needs bolt cutters to cut.

Beav are you talking the high tensile fence wire ? I think it’s 11 or 12 ga. either way it’s pretty stiff wire, probably a good choice for a support wire .

Black annealed wire 11 gauge has always been best for me. Although I have caught a lot of stuff with #9 black annealed and also doubled 14 gauge tie wire. I never use the wire alone to anchor any animal. Learned that mistake the hard way many years ago.

Caught many hundreds of cats,fox and beaver in lethal snares tied off with wire.Never a loss to tie off failure.
I would never tie off any trap with wire unless set to kill.
Wolves are the only exception.Those lethal snares are tied off with cable and supported with doubled 11ga and whammy.Reason is I need to be able to adjust the loop size on wolf snares and still have solid support directly at the lock.
Some guys on the wilderness forum here tie off lethal wolf snares with #9 wire with no apparent problems.

Needed wire gauge depends on length of span supported. If your support wire runs 12" from a bush or kill pole to support collar 14 gauge is sufficient. If it runs from ground to 20" or higher snare support collar I would suggest 9 gauge.

I agree to a point with this, however just because you can get away with lighter wire for shorter runs doesn't mean its the best option IMO. Even if I was using just 6" of wire off the side of a killpole for example, I'm still choosing #9 wire. I don't want the support wire to move at all until AFTER the snare has fired shut. The annealed #9 is my choice as well, as its still stiff for a rigid support yet is easier to work with than galvanized, blends in better, and doesn't get slick on the end so my support collars hold better. I never support snares higher than 8" loops, 8" off the ground, but I do use alot of kill poles for my higher set coyote snares. IMO even #9 isn't stiff enough to solidly support a coyote snare 12+" off the ground, you need to support it off something more stable like a tree, killpole, or one of the numerous support systems like the devil's hatpin.

Lol, not a good support

By Anchoring I do not mean tying off. I mean to a stake.