ABSTRACT
Sometimes, the focus of our efforts is protection of individuals, particularly in studies of humans or legally protected species such as endangered species. The Migratory Bird Treaty involving the United States, Canada, and United Kingdom is one such case that prohibits the taking of individual birds of specic listed species. More often, effects to individuals are measured with the intent of predicting consequences to populations: the primary goal of most ecotoxicologists is assuring persistence and vitality of populations within ecological communities. Such has been the context for recent studies of population declines or collapses of invertebrates (e.g., Chan et al. 2008; EFSA 2013a-c), birds (Donald et al. 2001; Rattner et al. 2004), and amphibians (Sparling et al. 2001). As an example, now drawing much-deserved interest are the declines in insect pollinator populations worldwide, e.g., Figure 10.1. Another recent example is the drop in populations of oriental white-backed vulture (Gyps bengalensis) in India notionally due to the use of the drug diclofenac on cattle. In this instance of drug pollution, vultures feeding on treated cattle die of kidney failure (Balmford, 2013).
