A novel approach based on Information Theory to rank conservation strategies: an application to amphibian metapopulations (with discussion)

Habitat fragmentation, reduction and degradation as well as the quality of habitat connecting environments are critical for species persistence. Spatially explicit metapopulation models considering environmental effects are natural candidates for modelling population viability. However, metapopulations share the inherent uncertainties of the population concept with vague field population definitions. The recognition of the fuzzy nature of populations leads to operational definitions for management purposes. To deal with scarce information and uncertainties in predictions of intervention effects, Adaptive Management is useful. Accordingly, the synthesis of monitoring information is performed with models whose features are continuously adapted to the level of available information. To derive useful indices for conservation strategy evaluation, we propose a novel approach based on the Kullback-Leibler information measure. This is used to evaluate strategies aimed at the conservation of amphibians in an alpine Rhine valley region (Canton of the Grisons, Switzerland) and it is applied to outputs from an incidence function model for 'Bufo bufo" and "Rana temporaria". For these species, establishing four additional breeding sites along the Rhine river is a better strategy than placing two additional sites in intensively cultivated land. Artificial ponds in residential areas contribute to species conservation, and transfer of individuals to new sites has advantages over reliance on spontaneous colonization. "Bufo bufo" and "R. temporaria" reacted similarly to conservation measures, possibly due to their quite similar ecologies.