Doesn't mean you can't get a permit or something, might even be legal since it's private property and possibly a problem animal. Personally I would rather have a Fisher than a chicken.
FISHERS (WMUs 1B, 2C, 2D, 2E, 2F, 2G, 2H, 3A, 3B, 3C, 3D, 4D and 4E): Dec. 16-27. One fisher per license year. Licensed furtakers may obtain one permit each.
No open season on other wild birds or mammals.
Waterfowl and Migratory Game Bird seasons to be established in accordance with federal regulations following the March 10 Waterfowl Symposium.
http://www.pgc.pa.gov/HuntTrap/Law/Pages/SeasonsandBagLimits.aspx