Partridges in Hungary 1922-1933.
Abstract
We discovered some data on partridge counts and bags from the Duke of Esterházy's estate surrounding the present town of Fertöd south-east of Lake Fertöd (Neusiedlersee). The counts cover the years 1922-1933, and the bags 1931-1939. There were also data on cropping and field size. In those days the field size was much smaller than now, 85% of the fields were less than 6 ha compared to a present day mean of 50 ha. No pesticides were used, and crop diversity was very high.
Analysis of the data suggested a density of 8 pairs per km2, an average brood production rate of 69%, an extraordinarily high chick survival rate of 75% and an annual adult survival rate, including shooting, of 32%. The adult survival rate was reduced in one year by severe winter weather, but the population size very quickly recovered. About 25% of the birds were shot per annum which, together with those captured for restocking elsewhere amounted to a yield of 44% or 23 per km2 per annum. The most likely cause of the decline of the partridge in Hungary is pesticide use with an additional effect of nest predation. We compared these results with the situation in the current LAJTA Project. At Lajta the recovery will have the highest chance of sustained success if pesticide reduction mechanisms remain combined with improved nest predation control. Raptors have, however, increased fourfold or more. At present there is no clear evidence that they are significantly reducing overall numbers of partridges, but it is possible this is the case. Proportionately, more partridges are now dying of predation of all causes than formerly were shot. This subject demands urgent new research otherwise the partridge may effectively be lost.