My coop sits under a canopy of trees against the woods but its close to our house . This helps to discourage large predators.I'm sure an electric fence would help but bob cats can climb trees and jump over some fences.
The only way the OP can protect their chickens is to lock them up because killing this bob cat won't stop its offspring or others from coming. Adult predators teach their young how and where to hunt and bring them straight to our flocks. It helps to study predators and the many different breeds...
We've had Bob cats here for as long as I can remember close to 50 yrs and they avoid humans. Never had any cats or dogs go missing here but I have heard they will kill a cat over territory for food (outdoor cats).
I live in the mountains of WV so its difficult to protect chickens here from predators. You can't trap,harass or kill any Owls or Hawks under Federal law so you have to get a breed thats alert and fast on its feet so it can escape. We have better luck raising Game chickens because they...
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Standard size modern or old english game chickens are called large fowl. Cackle sells the Old English(see link) https://www.cacklehatchery.com/product/gold-duckwing-standard-old-english-chicken/