Trap-neuter-return (TNR) programs manage feral cat populations humanely. Understanding their effectiveness and limitations helps advocates implement them well.
TNR programs reduce feral cat welfare problems by preventing reproduction and providing veterinary care that reduces disease burden. Neutered cats no longer experience the welfare costs of repeated pregnancies and kitten mortality. Ear-tipping — removing the tip of one ear during surgery — allows identification of neutered cats and prevents repeat capture. The welfare-ecology tension is genuine — healthier, stable feral cat populations that live longer still cause predation pressure on wildlife. Integration of TNR with wildlife protection measures and cat colony management best addresses both concerns.