Action: Restrict certain pesticides or other agricultural chemicals for birds
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A small scale study found that Pyrazophos reduced chick food abundance more than other foliar fungicides. A before-and-after study from Spain found that the population of griffon vultures Gyps fulvus increased in the study area following multiple interventions including the banning of strychnine.
Certain agricultural chemicals such as DDT, diclofenac and strychnine are now know to be extremely harmful to birds, either by direct poisoning, or interfering with reproduction. Many of these chemicals are now restricted or prohibited, but many others still remain in use. For example, some organophosphates such as monocrotophos are used to control insect pests and have caused mass poisoning incidents in raptors and cranes Grus spp. (Goldstein et al. 1999; Pain et al. 2004).
Goldstein, M. I., Lacher, T. E., Woodbridge, B., Bechard, M. J., Canavelli, S. B., Zaccagnini, M. E., Cobb, G. P., Scollon, E. J., Tribolet, R. & Hooper, M. J. (1999) Monocrotophos - Induced mass mortality of Swainson’s Hawks in Argentina, 1995–96. Ecotoxicology,8, 201–214.
Pain, D. J., Gargi, R., Cunningham, A. A., Jones, A. & Prakash, V. (2004) Mortality of globally threatened Sarus cranes Grus antigon from monocrotophos poisoning in India. Science of the Total Environment, 326, 55–61.
Supporting evidence from individual studies
A small scale study of cereal fields treated with foliar fungicides in the UK (Sotherton & Rands 1987) found that chick food insect abundance was reduced to a greater extent following applications of Pyrazophos compared to other fungicides. Compared to untreated crops, chick food insects were reduced by 31-70% in crops treated with Pyrazophos, 10% with Propiconazole and 3% with Triadimefon applications. The effect of Pyrazophos was greater when applied at an earlier growth stage (GS37: 70%; GS50: 45%; GS60: 31% reduction). Following Pyrazophos applications, total predatory arthropods were reduced by 25-48%; aphid specific predators 35-84% (17% with Triadimefon) and parasitoids 34-55%. Fungicides were sprayed at GS 50 in winter wheat in 1984. Pyrazophos was also sprayed at GS60 in spring barley (1984) and GS37 in winter barley (1985). Chick food insects were sampled by sweep nets or suction sampling.
A before-and-after between 1969 and 1989 in the western Pyrenees, Spain (Donazar & Frenandez 1990), found that the population of griffon vultures Gyps fulvus increased from 282 pairs (in 23 colonies) in 1969-75 to 1,097 pairs (46 colonies) in 1989 following the initiation of multiple conservation interventions including the banning of strychnine, a major cause of vulture mortality, in 1984. Additional surveys in 1979 and 1984 found 364 pairs (in 26 colonies), 589 pairs (32 colonies) respectively. This study is also discussed in ‘Habitat protection’, ‘Use legislative regulation to protect wild populations’ and ‘Provide supplementary food to increase adult survival’.
- Sotherton N.W. & Rands M.R.W. (1987) Pesticide science and biotechnology. Proceedings of the 6th international congress of pesticide chemistry. Ottawa, Canada, 10-15 August 1986, 433-436.
- Donázar J.A. & Fernández C. (1990) Population trends of the griffon vulture Gyps fulvus in Northern Spain between 1969 and 1989 in relation to conservation measures. Biological Conservation, 53, 83-91