Costs and Benefits of Trap-Neuter-Release and Euthanasia for Removal of Urban Cats in Oahu, Hawaii

• Published in: Conservation biology 2013-02, Vol.27 (1), p.64-73
• Main Authors: LOHR, CHERYL A., COX, LINDA J., LEPCZYK, CHRISTOPHER A.
• Format: Article
• Language: English
• Subjects: Abandono de mascotas; Animal, plant and microbial ecology; Animals; Applied ecology; Aves; Benefit cost analysis; Biological and medical sciences; bird depredation; cat colony; Cats; Cats - physiology; colonia de gatos; Conservation of Natural Resources; Conservation, protection and management of environment and wildlife; Costs and Cost Analysis; depredación de aves; dinámica de poblaciones; Euthanasia; Euthanasia, Animal; Fundamental and applied biological sciences. Psychology; Hawaii; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; pet abandonment; policy; política; Population Control - economics; Population Control - methods; Population Density; population dynamics; Puffinus pacificus; Spaying & neutering; Sterilization, Reproductive - economics; Sterilization, Reproductive - psychology; Trapping; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1111/j.1523-1739.2012.01935.x

Our goal was to determine whether it is more cost-effective to control feral cat abundance with trap-neuter-release programs or trap and euthanize programs. Using STELLA 7, systems modeling software, we modeled changes over 30 years in abundance of cats in a feral colony in response to each management method and the costs and benefits associated with each method. We included costs associated with providing food, veterinary care, and microchips to the colony cats and the cost of euthanasia, wages, and trapping equipment in the model. Due to a lack of data on predation rates and disease transmission by feral cats the only benefits incorporated into the analyses were reduced predation on Wedge-tailed Shearwaters (Puffinus pacificus). When no additional domestic cats were abandoned by owners and the trap and euthanize program removed 30,000 cats in the first year, the colony was extirpated in at least 75% of model simulations within the second year. It took 30 years for trap-neuter-release to extirpate the colony. When the cat population was supplemented with 10% of the initial population size per year, the colony returned to carrying capacity within 6 years and the trap and euthanize program had to be repeated, whereas trap-neuter-release never reduced the number of cats to near zero within the 30-year time frame of the model. The abandonment of domestic cats reduced the cost effectiveness of both trap-neuter-release and trap and euthanize. Trap-neuter-release was approximately twice as expensive to implement as a trap and euthanize program. Results of sensitivity analyses suggested trap-neuter-release programs that employ volunteers are still less cost-effective than trap and euthanize programs that employ paid professionals and that trap-neuter-release was only effective when the total number of colony cats in an area was below 1000. Reducing the rate of abandonment of domestic cats appears to be a more effective solution for reducing the abundance of feral cats. Nuestra meta fue determinar si es más rentable controlar la abundancia de gatos ferales con programas de captura-esterilización-liberación o con programas de captura y eutanasia. Utilizando STELLA 7, software para modelar sistemas, modelamos cambios a lo largo de 30 años en la abundancia de gatos en una colonia feral en respuesta a cada método de manejo, así como de los costos y beneficios asociados con cada uno. En el modelo incluimos los costos asociados con la alimentación, el cuidado veterinari