[Relations between fox populations and halting the rabies in North Rhine-Westphalia]

Since Sylvatic rabies started in North Rhine-Westphalia in 1953 many epidemics have occurred, only in mid-mountain areas. As a characteristic, epidemics halted, in each case at the limit between big game (in south-east) and small game (in the north-west) hunting areas. The fact that rabies died out when reaching these limits is surprising for, according to the number of foxes killed in small game hunting areas, there was a fox density which usually does not allow the epidemic to stop. Explanation of this phenomenon could be the different hunting methods. Indeed in small game hunting areas 80% of killed foxes are cubs or sub-adults. Which means that most of the growing population is destroyed early enough, in contrast with big game hunting areas where less than half of the killed foxes are cubs or sub-adults. This is why in big game hunting areas, better conditions are found for rabies appearance than in the other type of hunting area. Studying the number of foxes killed, these relations are described for three regions of North Rhine-Westphalia. It is obviously very important in rabies control that, besides other measures, growing foxes are killed in priority.