DESCRIPTION OF TOXINS Sample Clauses

DESCRIPTION OF TOXINS. Insecticides Bird species that inhabit farmland or use farmland during migration are at risk of exposure to insecticides. Waterfowl and some gamebirds, which feed on agricultural foliage, are at potential risk. Granivorous passerines are attracted to pesticide-treated seeds. Birds that feed on agricultural pests, such as grasshoppers and earthworms, are at risk if these species take up pesticides and are then consumed by birds. The likelihood of exposure to insecticides is influenced by a number of factors, including cultivation practices, pest types, crop types, pesticide form, and migratory bird ecology (diet and habitat preferences). Exposure may be reduced by using particular forms of pesticides, e.g., liquid over granular forms, and changing application periods for when migratory birds are not likely to be present (which can be effective given the low persistence of many of the second generation pesticides). If a migratory bird is likely to be exposed, the toxicity of the pesticide is significant. The broad-spectrum nature of organophosphates and carbamates (the most common insecticides) places any bird at risk of lethal or sub-lethal effects if it happens to be in the vicinity at the time of application, or shortly thereafter, or if it comes into contact with exposed prey. Many of the highly toxic insecticides to birds, such as carbofuran, have been removed from the market in developed countries as a result of population declines in some bird species. Much of the effects, both sub-lethal and lethal, recorded in the literature are related to the use of these now highly regulated compounds. This could indicate that the situation has improved in areas where these highly toxic compounds are no longer used or that other substances have not yet been studied. The implications of sub-lethal effects from exposure to second generation agricultural insecticides are little understood and are difficult to study in the field. Migratory birds may be particularly susceptible to sub-lethal effects from insecticides, which may cause reduced movement and affect migratory orientation. Further research should focus on assessing these effects on populations. Neonicotinoids have become a main replacement for the carbamates and organophosphates in many countries. Further research to understand their impacts on birds as well as monitoring of migratory bird mortality incidents associated with the use of neonicotinoids and other insecticides are needed.