Sorry Lacb, yes I did look at the linked site and it was interesting.

However, I wasn't too convinced by the pie charts. The study found that in Bristol scavenged food made up 64% of the diet and in London it was 34%. That is a big variation for no obvious reason. I think you would need more studies to be able to come to any definite conclusion.

Also, the proportion of wild mammals making up the diet of Bristol and London foxes was relatively small at 4.9% in the former and 13.1% in the capital. This included all wild mammals. Probably not much of a range in London but that would certainly include mice of which there are plenty in SE23.

As for urban foxes being shy I don't think that is really the case. The foxes I see locally don't seem too bothered by human presence. During the cold spell a couple of weeks ago they were particularly brazen.