Modelling the population control of the domestic cat: an example from an island in Brazil

Abstract

The domestic cat is an invasive species that often causes great impacts where introduced due to its high predatory and reproductive potential, especially on islands. In this study, carried out on Ilha Grande (RJ, Brazil), we aimed to: i) estimate the population density of domestic cats, ii) calculate the number of animals preyed upon annually by domestic cats, and iii) evaluate the efficiency of methods to control the cat population. We used the Vortex program to project the population growth of domestic cats in fifty years, and simulated different scenarios of population control (without control, castration, spay and harvest). Population density of owned cats was 662 cats/km 2 . The annual predation rate was 1.97 prey animals/cat which is an average of 1497.96 prey/year. The population would only be reduced if 70% of females were spayed or removed annually. Measures to control the domestic cat population must be undertaken urgently, since uncontrolled growth of this predator has the potential to seriously impact the biodiversity of Ilha Grande.Keywords: invasive species, Felis catus, predation rate, population density, castration simulation. Modelando o controle populacional de gato doméstico: um exemplo de uma ilha no BrasilResumo O gato doméstico é uma espécie invasora que frequentemente causa grandes impactos onde é introduzido, em razão do seu alto potencial predatório e reprodutivo, especialmente em ilhas. Com este estudo realizado na Ilha Grande-RJ, Brasil, tivemos como objetivos: i) estimar a densidade populacional de gatos domésticos; ii) calcular o número de animais predados anualmente por gatos domésticos, e iii) estimar a eficiência de métodos para o controle da população de gatos. Nós utilizamos o programa Vortex para projetar o crescimento da população de gatos em 50 anos e simulamos diferentes cenários de controle populacional: sem controle, castração, esterilização de fêmeas e remoção de indivíduos. A densidade populacional de gatos que possuem donos foi de 662 gatos/km 2 . A taxa anual de predação foi de 1,97 animais predados/gato, ou seja, uma média de 1497,96 presas/ano. A população de gatos pode ser reduzida apenas se no mínimo 70% das fêmeas forem esterilizadas ou removidas anualmente. Medidas para o controle populacional de gatos domésticos devem ser tomadas com urgência, uma vez que o crescimento descontrolado da população desse predador tem o potencial de causar graves impactos à biodiversidade da Ilha Grande.Palavras-chave: espécie invasora, Felis catus, taxa de predação, densidade populacional, simulação de castração.

Simulating Free-Roaming Cat Population Management Options in Open Demographic Environments

“…This suggests that attempts to mitigate contributing human behaviors (e.g., allowing owned cats to roam freely, abandoning unwanted cats) must be implemented concurrently with sound biological management. While a subset of earlier studies of FRC population management have included just one or two of these processes (e.g., [16] – [18] [20] – [22] , our study is the only one to incorporate the full range of demographic processes we believe are necessary to evaluate management options in a biologically realistic manner. Similarly, while a selection of previous studies have used simpler modeling tools to evaluate the efficacy of different contraception options on FRC population dynamics [14] , [20] , our detailed examination of contraception in the context of the biological realism just described yields a more robust comparison among population management alternatives ( Figure 4 ).…”

Spatial distribution and risk factors for Toxoplasma gondii seropositivity in cattle slaughtered for human consumption in Rondônia, North region, Brazil

“…per km 2 ) (IBGE, 2015). There are studies demonstrating a positive correlation between density of the human population and number of domestics cats (Denny and Dickman, 2010;Lessa and Bergallo, 2012). In others words, if the population of humans is high, the domestic cat population is also high.…”

Predation of Birds by Domestic Cats on a Neotropical Island

“…This is true even under domiciliary conditions -living in close association with humans in anthropic areas, where all their biological requirements are intentionally met [1] -or in semi-domiciliary conditions -a lesser association, where they have free access to the external areas of the residence and the possibility of exploiting available resources. Regardless of their feeding and behavioral relationship with man, cats may still display opportunistic predation behavior [2][3][4][5]. For this reason, cats have been indicated as one of the main causes of the decline of other species in different areas of the world [3][4][5][6][7][8][9][10][11][12].…”

“…Regardless of their feeding and behavioral relationship with man, cats may still display opportunistic predation behavior [2][3][4][5]. For this reason, cats have been indicated as one of the main causes of the decline of other species in different areas of the world [3][4][5][6][7][8][9][10][11][12]. Research has also highlighted the significant impact of predation by cats on native fauna, especially regarding birds in insular environments [8][9][10][11].…”