Never said anything about a "best way." Not a buddhist so no karma for me. Spaying does not account for the threat ferals pose as an invasive species to native wildlife, nor the parasites and diseases ferals carry and spread through fecal contamination and bites.
They are pests, and do not belong wandering the streets any less than packs of wild dogs do.
Blah, blah blah. When ferals are fed, they pose NO threat to birds or lizards, or any wildlife. KARMA, BABY. Don’t have to be a Buddhist to understand that what goes around, comes around.
And p.s. - they do not bite, unless they have the opportunity to do so with jackass lowlife who try to trap and drown them.