Planning and optimizing neutering programs for free-roaming cat populations: An interactive tool for cost-effective management in closed systems

The management of free-roaming cat (Felis catus) populations is a complex
eco-sociological dilemma. Cats with outdoor access pose significant
threats to wildlife through direct predation and indirect effects, leading
some conservationists to advocate for stringent control measures,
including lethal methods for managing unowned cat populations. However,
public sentiment, alongside evidence that lethal methods often lack
long-term efficacy and cost-effectiveness, often supports the adoption of
non-lethal methods, such as Trap-Neuter-Return (TNR). In certain European
countries, TNR is the only legally permissible method. Despite its
widespread adoption, a limited understanding of cat population dynamics,
combined with inadequate planning and resource allocation, can lead to
ineffective outcomes, potentially exacerbating the growth of cat
populations. We used the free-roaming cat population (both unowned and
owned cats) on Linosa —a small Mediterranean island of high biodiversity
importance —as a case study. Census data were collected over three
consecutive years, and a Bayesian statistical model was developed to
estimate population dynamics and assess the varying impacts of neutering
efforts over time, extending the analysis to 60 months beyond the latest
census. The model also evaluated different budget scenarios based on the
intensity of neutering efforts applied. The model highlighted the
importance of high-frequency, female-focused neutering efforts to achieve
long-term population control and cost efficiency. Additionally, it
demonstrated that in our study population, such intensive efforts improved
the precision of population estimates, thereby reducing uncertainty in
management outcomes. To translate the model to an accessible tool to
conservation planners, animal welfare organizations, and policymakers, we
developed an interactive and user-friendly dashboard, available at
https://bgtemp.wixsite.com/catspva. This tool allows users to customize
scenarios by inputting initial estimates of the free-roaming cat
population and its characteristics. We believe this interactive and
practical approach provides an essential framework for planning and
implementing neutering campaigns of free-roaming cats, helping
decision-makers to address this urgent issue in a timely and
cost-effective manner.