Context-dependent local movements of the blue-tailed damselfly, Ischnura elegans: effects of pond characteristics and the landscape matrix

The loss of ponds and the fragmentation of their surrounding landscape negatively impacts the biodiversity of wetlands, such as damselflies. They are short-distance dispersers and can be influenced by the quality of suitable habitats and the landscape matrix. The aim of this study was to test the effect of the environmental context (i.e. pond characteristics and the surrounding landscape) on movements and survival probability in a damselfly species, Ischnura elegans . Three approaches (i.e. capture-mark-recapture, individual tracking and translocation studies) were performed in Northwestern France. The characteristics of ponds did not influence damselfly survival. However, the landscape context affected movements within ponds, and between ponds. Individuals from open-field ponds moved over longer distances than individuals from urban ponds. Moreover, in cases of disturbances, such as a pond drying up, movements from one pond to another were observed only in the open-field context. The ecological quality of the pond did not appear to affect survival of individuals, probably because I. elegans has a high tolerance to changes in ecological factors. However, higher local movements depend on the degree of openness of the landscape. Landscape context is hence a key issue in damselfly conservation planning and in maintaining ecological continuities, such as along greenways and blueways, and specifically the degree of landscape openness during pond creation.