PARENT SESSION
Organized Oral Session 2: Measuring landscape connectivity - tool for species conservation
Organizer(s): P Kindlmann, F Burel, and J Baudry
Monday, August 8, 8:00 AM - 11:30 AM, Meeting Room 510b, Level 5, Palais des congrès de Montréal

Behavioural aspects of landscape connectivity: Experimental tests and genetic validation in the Natterjack toad.

Stevens, Virginie^*,1, Polus, Emmanuelle¹, Verkenne, Catherine ¹, Baguette, Michel¹, ¹ Catholic University Louvain (UCL) - Biodiversity Research Centre, Louvain-la-Neuve, Belgium

ABSTRACT- Due to their habitat requirements, pond-breeding amphibians often present some patchy distribution at the landscape scale. Recovery efforts for those species have therefore to take into account the local population level but also the landscape-scale dynamics, because local populations vary greatly in size, experience frequent breeding failure, are subject to extinction or to habitat deterioration, and rely on recolonisation. In that context, the assessment of dispersal in real landscapes and that of the interaction between landscape structure and dispersal behaviour are among the most challenging questions. Because of enormous practical costs and difficulties, it is yet hard to conduct experiment at the landscape scale or to track dispersers in real landscapes. We present here a study combining micro-landscape experiments - designed to evaluate the movement behaviour of juvenile natterjack toads (Bufo calamita) - and the assessment of dispersal for this species in a real landscape through indirect (molecular) method. We used the results of our experimental studies to model a cost-distance analysis for the natterjack in a landscape of Southern Belgium, and we assessed the least-cost path between the natterjack habitats in that landscape. The natterjack populations inhabiting those habitats were sampled for the genetic study. Individuals of four populations were scored for 9 polymorphic microsatellite loci, and the genetic structure inferred from individual genotypes was then confronted to the results of the cost-distance analysis. Particularly, we searched for correlations between genetic distances and dispersal estimates on the one hand and geographic distances (euclidian distances and several least-cost distances obtained under different scenarios) on the other hand.

Key words: functional connectivity, natterjack toad, dispersal behaviour, microsatellite