Population dynamics of the butterfly Pyrgus armoricanus after translocation beyond its northern range margin

Description

Poster presentation

Abstract:
Translocation experiments can be used to study the factors limiting species’ distributions and to infer potential drivers of successful colonisation during range shifts. To study the expansion
dynamics of the butterfly Pyrgus armoricanus in southern Sweden and to find out whether its distribution was limited by climate, translocation experiments were carried out within and 50-60 km beyond its natural range margin. Populations were monitored for eight years following the translocation. Although most translocation attempts failed, P. armoricanus was able to survive in two sites north of its current range limit. One of them eventually led to expansion and establishment of a viable metapopulation. Translocation success appeared to be independent of latitude, suggesting that climate is not the main factor determining the current northern distribution limits of this butterfly. Population growth and secondary spread in the expanding population was positively related to patch area, connectivity and negatively related to barriers to dispersal. Local habitat quality seemed to be less important, although microclimate may play a role in colonisation success. The limited success of the translocation and the importance of a well-connected patch network suggest that the current distribution of P. armoricanus is limited by its low dispersal ability combined with the fragmentation of its habitat, making it unlikely to track its changing climatic niche. Assisted migration could be an effective tool for such species, but long-term evidence for its effectiveness is not yet available.

Period	2019
Event title	SCAPE 2019: 33rd Annual Meeting of the Scandinavian Association of Pollination Ecology (SCAPE)
Event type	Conference
Location	Höör, SwedenShow on map