Causes of the decline of the partridge in Europe and North America and recommendations for future management.
The partridge has declined in numbers wherever populations have been monitored. In Britain the mean decline of spring stocks has been 80% since 1952. Trends in the spring stock indicate a 75% decline over the same period in Europe and North America. Declining populations had significantly higher chick mortality rates. No other mortality in declining populations was higher than prior to the decline. It is evident that chick mortality rates vary in response to the abundance of their insect food in cereal crops. Experimental work has demonstrated that the indirect effect of herbicides on the insect food of the chicks is currently a major limiting factor for many partridge populations in Britain. The above explanation together with the evidence presented from other countries can be proposed as hypothesis for the whole world range. Where herbicides are the cause of the high chick mortality their omission from cereal headlands would remedy the situation. Detailed recommendations for a restoration of partridge numbers are presented. They concern methods of evaluation of habitat suitability and nesting cover quality, reducing chick mortality and nest predation, rationalisation of shooting.