Early View (EV): 1-EV Patterns of synchrony in natterjack toad breeding activity and reproductive success at local and regional scales Aurélie Aubry, Emeline Bécart, John Davenport, Deirdre Lynn, Ferdia Marnell and Mark Emmerson A. Aubry, E. Bécart, and M. Emmerson (m.emmerson@qub.ac.uk), Environmental Research Inst., Univ. College Cork, Lee Road, Cork, Ireland. ME also at: School of Biological Sciences, Medical and Biological Centre, Queen’s Univ. Belfast, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland, UK. – J. Davenport, School of Biological, Earth and Environmental Sciences, Univ. College Cork, Distillery Fields, Cork, Ireland. – D. Lynn and F. Marnell, National Parks and Wildlife Service, 7 Ely Place, Dublin 2, Ireland. Empirical studies of the spatiotemporal dynamics of populations are required to better understand natural luctuations in abundance and reproductive success, and to better target conservation and monitoring programmes. In particular, spatial synchrony in amphibian populations remains little studied. We used data from a comprehensive three year study of natter- jack toad Bufo calamita populations breeding at 36 ponds to assess whether there was spatial synchrony in the toad breed- ing activity (start and length of breeding season, total number of egg strings) and reproductive success (premetamorphic survival and production of metamorphs). We deined a novel approach to assess the importance of short-term synchrony at both local and regional scales. he approach employs similarity indices and quantiies the interaction between the temporal and spatial components of populations using mixed efects models. here was no synchrony in the toad breeding activity and reproductive success at the local scale, suggesting that populations function as individual clusters independent of each other. Regional synchrony was apparent in the commencement and duration of the breeding season and in the number of egg strings laid (indicative of female population size). Regional synchrony in both rainfall and temperature are likely to explain the patterns observed (e.g. Moran efect). here was no evidence supporting regional synchrony in reproductive success, most likely due to spatial variability in the environmental conditions at the breeding ponds, and to diferences in local population itness (e.g. fecundity). he small scale asynchronous dynamics and regional synchronous dynamics in the number of breeding females indicate that it is best to monitor several populations within a subset of regions. Importantly, variations in the toad breeding activity and reproductive success are not synchronous, and it is thus important to consider them both when assessing the conservation status of pond-breeding amphibians. Studies describing the spatiotemporal dynamics of popula- tions can help to better understand the efect of environmen- tal factors, such as climate change and habitat diversity, on a range of demographic parameters such as the distribution of species, their abundance and their reproductive behaviour. Spatial synchrony in particular refers to correlated luctuations of time-varying demographic traits of geographically distinct populations (Liebhold et al. 2004). hree mechanisms are com- monly suggested to inluence population synchrony (Liebhold et al. 2004): 1) regional stochasticity can have a synchronising efect through the spatial correlation of random factors such as rainfall and temperature (e.g. ‘Moran’ efect), 2) regular dis- persal among populations can synchronise luctuations, and 3) trophic interactions with other species (e.g. predation) that are synchronous or mobile can have synchronising efects. he synchrony of abundance among plant and animal populations has been widely reported (Ranta et al. 1995, Williams et al. 2003, Petranka et al. 2004). However, only a few studies have simultaneously investigated the syn- chrony of abundance and associated demographic properties (Semlitsch et al. 1996, Trenham et al. 2000, Tavecchia et al. 2008). he study of the dynamics of these demographic parameters is particularly important as it can provide some explanations for the observed synchrony in population abundance (Tavecchia et al. 2008). Empirical studies of the spatiotemporal dynamics of amphibian populations are required to understand better the natural luctuations in the abundance and reproductive success of populations, which can be particularly marked for amphibians (Pechmann et al. 1991, Green 2003). Long- term amphibian research and monitoring programmes ( 15 yr) have usually focused on the monitoring of one or a few isolated populations (Meyer et al. 1998, Blaustein et al. 2001), or the monitoring of many ponds within the same region (Loman and Andersson 2007). Some populations have been monitored simultaneously at larger geographical scales but usually for shorter periods ( 5 yr) (Hecnar and M’Closkey 1997, Greenberg 2001). Based on the available empirical data, it is therefore diicult to assess the relative importance of spatial and temporal variability for amphib- ian population dynamics. As for many other taxa, there is a crucial need for more empirical work on the dynamics of amphibian species at multiple scales (e.g. local vs regional) in order to better understand the efect of spatial structure on Ecography 35: 1–11, 2012 doi: 10.1111/j.1600-0587.2011.06912.x © 2011 he Authors. Journal compilation © 2011 Ecography Subject Editor: Carsten Rahbek. Accepted 1 July 2011