On the Use of Surrogate Species in Conservation Biology

Abstract

Conservation biologists have used surrogate species as a shortcut to monitor or solve conservation problems. Indicator species have been used to assess the magnitude of anthropogenic disturbance, to monitor population trends in other species, and to locate areas of high regional biodiversity. Umbrella species have been used to delineate the type of habitat or size of area for protection, and flagship species have been employed to attract public attention. Unfortunately, there has been considerable confusion over these terms, and several have been applied loosely and interchangeably. We attempt to provide some clarification and guidelines for the application of these different terms. For each type of surrogate, we briefly describe the way it has been used in conservation biology and then examine the criteria that managers and researchers use in selecting appropriate surrogate species. By juxtaposing these concepts, it becomes clear that both the goals and selection criteria of different surrogate classes differ substantially, indicating that they should not be conflated. This can be facilitated by first outlining the goals of a conservation study, explicitly stating the criteria involved in selecting a surrogate species, identifying a species according to these criteria, and then performing a pilot study to check whether the choice of species was appropriate before addressing the conservation problem itself. Surrogate species need to be used with greater care if they are to remain useful in conservation biology.

Cross-taxon congruence in tree, bird and bat species distributions at a moderate spatial scale across four tropical forest types in the Philippines

“…As this study shows, that would mean that an area exceptionally rich in tree species would lose its protected status. We therefore argue caution in using limited biodiversity data as a basis for protected area management decisions and join with other authors (Prendergast and Eversham 1997;Caro and O'Doherty 1999;Lindenmayer et al 2002;Hess et al 2006) to caution against the use of indicator taxa as surrogates for biodiversity at fine levels of spatial scale.…”

Assessment of risk of insect-resistant transgenic crops to nontarget arthropods

“…Key species or guilds that are representative of different functional groups are known in most systems and appropriate surrogates can therefore be selected. Despite recognized limitations 31 , the application of the surrogate concept is widely applied in related fields including regulatory toxicity testing 28,29,32,33 and environmental monitoring [34][35][36] . In addition, the risk assessment may consider species with special aesthetic or cultural value or species classified as threatened or endangered.…”

Selection criteria for flagship species by conservation organizations

“…In addressing whether the use of a charismatic species can influence attitudes towards habitats, it was necessary to select a suitable flagship species according to the selection criteria provided by the qualitative phase. Although it has been suggested that it may be difficult to identify a species featuring all of the desirable characteristics of a flagship species (Simberloff 1998;Caro & O'Doherty 1999;Caro et al 2004), we chose the great spotted woodpecker as a suitable candidate. Woodpeckers are found throughout the study area, are not commonly seen yet remain visible, are medium-sized birds, and are perceived to be compatible with humans.…”