Monitoring Grey Partridge (Perdix perdix) Populations in Poland: Methods and Results

Abstract

The grey partridge ( Perdix perdix ) population in Poland is monitored by the Polish Hunting Association. Apart from information on hunting bag in the whole country (1981-2002), also demographic data are collected every year in selected areas (50-150 km²) located in various regions of Poland (three such areas in 1987-1990, 12 in 1991-1997, and 19-41 in 1998-2003). In the monitoring areas, spring partridge density (call counts in March/April), reproductive success (counts of adult and young birds in August) and annual survival rate of adult birds were estimated. The annual partridge hunting bag in Poland varied from 24,000 to 293,000 individuals between 1981 and 1992, and decreased to 20-22,000 birds in the years 2000-2002. In the 1990s, the average spring density of grey partridge in Poland showed a 3-fold decrease. In the early 2000s, 0.5 to 10.5 pairs per km2 were recorded in individual areas. The reproductive success of partridges (annual values ranging between 1.2 and 3.4 young per adult) decreased through the years 1987 to 2002. The annual survival rate of adult birds (annual values ranging between 25 and 38%) did not show any significant trends during the monitoring period. The decrease of reproductive success and consequently the observed population decline probably resulted mainly from increased abundance of nest and hen predators, particularly red foxes.