DEFRA does not carry out annual surveys of fox numbers by county and is not aware of any measures of absolute numbers of red fox (‘Vulpes vulpes’) per county.
However, information on game bags (foxes taken e.g. by shooting) is provided by the Game and Wildlife Conservation Trust’s national gamebag census. The analysis of mammal data from this annual survey is funded by the Joint Nature Conservation Committee as part of its surveillance programme. It provides an index of bag density for this species at a UK, country and regional scale and can be used to indicate what the population trend might be. The gamebag data for foxes over the last 10 years fluctuates, but the overall trend appears to be stable or slightly increasing.
The results of this scheme are available in a report entitled “Participation of the National Gamebag Census in the Mammal Surveillance Network”. A copy of this has been placed in the House Library.