Population divergence of life history traits in the endangered green toad: implications for a support release programme B. Rogell, A. Berglund, A. Laurila & J. H ¨ oglund Population Biology and Conservation Biology/Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden Keywords local adaptation; peripheral populations; genetic diversity; amphibians. Correspondence Bj ¨ orn Rogell, Population and Conservation Biology/Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Norbyv ¨ agen 18D, SE-75236 Uppsala, Sweden. Tel: +46 18 471 2637; Fax:+46 18 471 6424 Email: bjorn.rogell@ebc.uu.se Editor: Mark-Oliver R ¨ odel Received 13 February 2011; revised 10 March 2011; accepted 10 March 2011 doi:10.1111/j.1469-7998.2011.00843.x Abstract There is an increasing awareness that adaptive differences among local popula- tions may affect the success of translocation programmes. A mismatch in habitat quality of the target localities and in the local adaptations of the translocated individuals may reduce the success rate of the translocation programme. The green toad Bufo viridis is the most threatened amphibian in Sweden and has been the focus of an extensive translocation programme of eggs, tadpoles and juvenile toads to several localities with apparently favourable conditions for green toads. However, the success of these measures has been poor. In this study, we investigated the extent of local adaptation in the green toad by examining population divergence and the effect of thermal and saline conditions on larval performance in four Scandinavian populations. In a common garden experiment, we measured larval survival and development as well as the occurrence of spinal deformations. In addition, we quantified pond temperature and water salinity, two important environmental variables for larval performance in anurans in the breeding ponds as well as in seven additional localities included in the conservation programme. We found significant variation among the localities in water tempera- ture and salinity, and significant among-population divergence in larval life history traits and spinal deformations, including both trait means and plastic responses to salinity and temperature. The available evidence suggests that at least part of this divergence is adaptive. We did not find direct support for local adaptation affecting the success of the translocations, however, we argue that the population origin and the impact of rearing conditions on the fitness-related larval traits should be taken into account in the introduction measures of the Swedish green toad conservation programme as well as in translocation programmes in general. Introduction When natural populations become threatened or extinct, translocations (here defined as releases of non-native ani- mals in order to replace locally extinct populations or enhance population sizes of threatened populations) are a widely used practise in conservation biology (Griffith, 1989; Armstrong & Seddon, 2008; Germano & Bishop, 2009). The positive effects of translocation actions on population size are often due to pure demographic effects (Smith, Peterson & Houston, 2003; Creel, 2006); however, several studies have found associations between translocations and in- creased individual fitness, such as increased fecundity (Mad- sen, Stille & Shine, 1996; Westemeier et al., 1998) and loss of defects (Pimm, Dollar & Bass, 2006) after translocations. Although an efficient management tool, translocations are controversial because artificially induced gene flow might not only reduce the genetic load through the addition of genetic variation, but also disrupt local adaptations (e.g. Boulding & Hay, 2001; Tufto, 2001; Tallmon, Luikart & Waples, 2004). As local adaptation is common in natural populations (Leinonen et al., 2008), there is a risk that translocated individuals are maladapted to their new envir- onment, or that the existing local adaptations are swamped by gene flow caused by the released individuals (Tufto, 2001; Ashley et al., 2004; Tallmon et al., 2004; Kinnison, Hendry & Stockwell, 2007). The global decline of amphibians is a major conservation concern, and translocations are often used in conservation programmes to support or restore amphibian populations (Germano & Bishop, 2009). Amphibians differ from many other vertebrate groups in their limited dispersal ability and use of ponds and other freshwater habitats for breeding. The breeding habitats often differ widely in characteristics Journal of Zoology Journal of Zoology 285 (2011) 46–55 c  2011 The Authors. Journal of Zoology c  2011 The Zoological Society of London 46 Journal of Zoology. Print ISSN 0952-8369