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Providing evidence to improve practice

Individual study: Grey partridge Perdix perdix chick survival and insecticide use on farmland on the South Downs, Sussex, England

Published source details

Aebischer N.J. & Potts G.R. (1998) Spatial changes in grey partridge (Perdix perdix) distribution in relation to 25 years of changing agriculture in Sussex, U.K. Gibier Faune Sauvage, Game Wildlife, 15, 293-308


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Revert arable land to permanent grassland Bird Conservation

A controlled before-and-after study in 1970-94 in a 28 km2 area of arable farmland in Sussex, England (Aebischer & Potts 1998), found that grey partridge Perdix perdix numbers declined rapidly on arable fields in 1987-94, following their reversion to grassland, beginning in 1987 (average of 6.5 coveys/km2 in 1970-86 vs. 1.1 coveys/km2 in 1987-94). There was a considerably smaller decline on arable fields that were not reverted to grassland (average of 4.9 coveys/km2 in 1970-86 vs. 2.5 coveys/km2 in 1987-94). The reversed fields went from being more favoured by partridges before reversion to less favoured afterwards, equating to a 23% per year decrease in relative habitat quality on the reversion fields.

 

Reduce pesticide or herbicide use generally Bird Conservation

A controlled before-and-after study in 1989-94 in a 28 km2 area of arable farmland in Sussex, England (Aebischer & Potts 1998), found significantly higher survival rates of grey partridge Perdix perdix chicks on 21 km2 with irregular insecticide applications, compared to a 7 km2 farm with insecticide applications four times a year (average of 34% survival on low application farms vs. 22% on high application farm). Before the start of intensive insecticide application (1970-88), there was no difference between areas (27% survival on low application farms vs. 30% on intensive application farm).

 

Convert or revert arable land to permanent grassland Farmland Conservation

A controlled before-and-after study from 1970 to 1994 in Sussex, England (Aebischer & Potts 1998), found that grey partridge Perdix perdix numbers declined rapidly on arable fields following their reversion to grassland, which began in 1987 (average 6.5 coveys (flocks)/km2 in 1970-1986 vs 1.1 coveys/km2 in 1987-1994). There was a considerably smaller decline on arable fields that were not reverted to grassland (average 4.9 coveys/km2 in 1970-86 vs 2.5 coveys/km2 in 1987-1994). Fields that were reverted had been favoured by partridges prior to reversion, in comparison to arable fields, but were less favoured after reversion, equating to a 23% per year decrease in relative habitat quality. Fields in a 28 km2 area were surveyed for grey partridges in late August/early September after the autumn harvest by driving across fields at dawn and dusk and mapping the position of each observation.

 

Reduce fertilizer, pesticide or herbicide use generally Farmland Conservation

A site comparison before-and-after study from 1989 to 1994 in Sussex, England (Aebischer & Potts 1998) found that survival rates of grey partridge Perdix perdix chicks were significantly higher on 21 km2 of arable farmland that received irregular insecticide applications, compared to a 7 km2 farm with insecticide applications four times a year (average 34% survival on low application farms vs 22% on high application farm). Before the start of intensive insecticide application (1970-1988), survival on the farm had been similar to, or higher than, that on the surrounding farms (27% survival on low application farms vs 30% on intensive application farm). Chick survival rates (up to the age of approximately six weeks) were calculated each year and compared between areas with intensive and irregular insecticide applications. A long-term data set (1970-1988) collected prior to this study was used to investigate chick survival prior to insecticide application on the intensive application farm.