Okay if you want to be precise, the mass of the density function of cats over uk locations is largely in urban areas, while the mass of the density function of

Okay if you want to be precise, the mass of the density function of cats over uk locations is largely in urban areas, while the mass of the density function of bird-habitat-value is much more spread over the whole landscape, which is also true of agriculture. Risk to birds will be proportional to the dot-product of the bird-habitat-value density function with that of a risk factor, and since the density function of agriculture is much more correlated with that of bird-habitat-value than it is correlated with that of cats, so changes in agriculture are likely to be the greater factor in changes in bird population.