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==The Impact of Predation==
 
==The Impact of Predation==
 
===Impact in the UK===
 
===Impact in the UK===
In a study of domestic cat predation in the UK, the estimated mean predation rate was estimated at 18.3 per cat per year, with 65% of households reporting no prey brought back in a given year (falling to 22% when averaged over several seasons <ref name="Thomas">Thomas, R.L., Fellowes, M.D.E, Baker, P.J. (2012) Spatio-Temporal Variation in Predation by Urban Domestic Cats (''Felis catus'') and the Acceptability of Possible Management Actions in the UK. ''PLOS One''. 7(11), 1-13.</ref>. The same study found that only 20% of cats returned 4 or more dead prey annually. A retrospective study by <font color="red">Bowen</font color> found an average prey return rate of 3.3 birds and 12 rodents per cat per year for households where cats had outdoor access, with 44.6% never returning a bird, and 39.6% never returning a rodent. In the same study, the amount of birds observed in a garden correlated significantly with the level of environmental enrichment provided in a garden (bird feeders, scattered food and nesting boxes), as well as the amount of natural features present (long grass, trees, wild flowers, bushes). However, the number of birds caught did not correlate with scores for the amount of birds observed in the owner’s garden. This is supported by findings from Thomas ''et al''<ref name ="Thomas" /> that the numbers of five bird species was not correlated with level of their predation. The predation of robins was only just significantly correlated with observed numbers (p=0.046). This may relate to some aspect of the vulnerability of this species when feeding and nesting, but the result would also become insignificant when measures are applied to counteract the problem of multiple comparisons in the study. It appears that improving a garden to attract and support bird numbers does not increase the general risk of predation.
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In a study of domestic cat predation in the UK, the estimated mean predation rate was estimated at 18.3 per cat per year, with 65% of households reporting no prey brought back in a given year (falling to 22% when averaged over several seasons <ref name="Thomas">Thomas, R.L., Fellowes, M.D.E, Baker, P.J. (2012) Spatio-Temporal Variation in Predation by Urban Domestic Cats (''Felis catus'') and the Acceptability of Possible Management Actions in the UK. ''PLOS One''. 7(11), 1-13.</ref>. The same study found that only 20% of cats returned 4 or more dead prey annually, and that the numbers of five bird species was not correlated with level of their predation. The predation of robins was only just significantly correlated with observed numbers (p=0.046). This may relate to some aspect of the vulnerability of this species when feeding and nesting, but the result would also become insignificant when measures are applied to counteract the problem of multiple comparisons in the study. There was also a significant inverse correlation between mean annual predation rate, cat population and housing density; the number of prey returned was lower in highly residential areas with high cat population density<ref name ="Thomas" />.
 
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The study by Thomas<ref name ="Thomas" /> also showed a significant inverse correlation between mean annual predation rate, cat population and housing density; the number of prey returned was lower in highly residential areas with high cat population density.
      
===Impact in other countries===
 
===Impact in other countries===
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