have supported TNR have also been criticised for using anecdotal data to evaluate their effectiveness. In order for TNR to reduce the cat population, sterilisation rates of at least 75% must be maintained at all times, particularly because TNR practitioners providing cats with food makes the problem worse by increasing the survival rate of feral kittens. Also, this food source causes other cats to be drawn into the colony from outside. Members of the public often begin dumping unwanted pet cats at TNR sites, increasing the rate of recruitment. And neutered cats are less territorial, allowing for higher populations. TNR programs are sometimes able to attain local reductions in the numbers of cats at specific colony locations, but it has never been demonstrated to meaningfully impact cat populations over large areas or regions, because the effort necessary to maintain sufficient sterilisation rates means that systemic TNR will never be a credible option. For example, to reduce a typical Australian city's population of 700,000 feral cats through TNR would require sterilising at least 500,000 of them initially, and then continuing to sterilise more than 75% of the kittens that the other 200,000 would continue to produce each year indefinitely, along with all the new recruits from other cat populations drawn by the food supply. TNR is backed by well-funded advocacy organizations: in 2010, Alley Cat Allies spent US$3 million advocating to legalise TNR throughout the United States, while the Best Friends Animal Society spent $11 million on a "Focus on Felines" initiative that included TNR advocacy. Promoters of TNR are often funded by big businesses with a commercial interest in selling cat food, such as pet food mills and the pet products retailer PetSmart. TNR and wildlife De-sexing cats, as in TNR programs, does nothing to prevent them from continuing to destroy wildlife. In Mandurah, Western Australia, a single, neutered, semi-feral cat raided a protected fairy tern colony on at least six nights in November 2018. It killed at least six breeding adult fairy terns; directly or indirectly killed at least 40 nestlings, and caused enough stress on the fairy tern colony that all 111 nests were abandoned; resulting in a complete breeding failure for the entire colony of threatened seabirds. The predation was documented by wildlife cameras, as well as by the presence of cat tracks, cat scat, decapitated fairy terns, and injured and missing fairy tern nestlings. Though the