This is a repository copy of Population and evolutionary dynamics in spatially structured seasonally varying environments. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/133818/ Version: Published Version Article: Reid, Jane M, Travis, Justin M. J., Daunt, Francis et al. (3 more authors) (2018) Population and evolutionary dynamics in spatially structured seasonally varying environments. Biological reviews of the cambridge philosophical society. pp. 1578-1603. ISSN 0006-3231 https://doi.org/10.1111/brv.12409 Reuse This article is distributed under the terms of the Creative Commons Attribution (CC BY) licence. This licence allows you to distribute, remix, tweak, and build upon the work, even commercially, as long as you credit the authors for the original work. More information and the full terms of the licence here: https://creativecommons.org/licenses/ Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Biol. Rev. (2018), 93, pp. 1578–1603. 1578 doi: 10.1111/brv.12409 Population and evolutionary dynamics in spatially structured seasonally varying environments Jane M. Reid1∗ ,JustinM.J.Travis1, Francis Daunt2, Sarah J. Burthe2, Sarah Wanless2 and Calvin Dytham3 1School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, U.K. 2Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, U.K. 3Department of Biology, University of York, Heslington, York YO10 5DD, U.K. ABSTRACT Increasingly imperative objectives in ecology are to understand and forecast population dynamic and evolutionary responses to seasonal environmental variation and change. Such population and evolutionary dynamics result from immediate and lagged responses of all key life-history traits, and resulting demographic rates that affect population growth rate, to seasonal environmental conditions and population density. However, existing population dynamic and eco-evolutionary theory and models have not yet fully encompassed within-individual and among-individual variation, covariation, structure and heterogeneity, and ongoing evolution, in a critical life-history trait that allows individuals to respond to seasonal environmental conditions: seasonal migration. Meanwhile, empirical studies aided by new animal-tracking technologies are increasingly demonstrating substantial within-population variation in the occurrence and form of migration versus year-round residence, generating diverse forms of ‘partial migration’ spanning diverse species, habitats and spatial scales. Such partially migratory systems form a continuum between the extreme scenarios of full migration and full year-round residence, and are commonplace in nature. Here, we first review basic scenarios of partial migration and associated models designed to identify conditions that facilitate the maintenance of migratory polymorphism. We highlight that such models have been fundamental to the development of partial migration theory, but are spatially and demographically simplistic compared to the rich bodies of population dynamic theory and models that consider spatially structured populations with dispersal but no migration, or consider populations experiencing strong seasonality and full obligate migration. Second, to provide an overarching conceptual framework for spatio-temporal population dynamics, we define a ‘partially migratory meta-population’ system as a spatially structured set of locations that can be occupied by different sets of resident and migrant individuals in different seasons, and where locations that can support reproduction can also be linked by dispersal. We outline key forms of within-individual and among-individual variation and structure in migration that could arise within such systems and interact with variation in individual survival, reproduction and dispersal to create complex population dynamics and evolutionary responses across locations, seasons, years and generations. Third, we review approaches by which population dynamic and eco-evolutionary models could be developed to test hypotheses regarding the dynamics and persistence of partially migratory meta-populations given diverse forms of seasonal environmental variation and change, and to forecast system-specific dynamics. To demonstrate one such approach, we use an evolutionary individual-based model to illustrate that multiple forms of partial migration can readily co-exist in a simple spatially structured landscape. Finally, we summarise recent empirical studies that demonstrate key components of demographic structure in partial migration, and demonstrate diverse associations with reproduction and survival. We thereby identify key theoretical and empirical knowledge gaps that remain, and consider multiple complementary approaches by which these gaps can be filled in order to elucidate population dynamic and eco-evolutionary responses to spatio-temporal seasonal environmental variation and change. * Author for correspondence at address 1 (Tel.: +44 1224 274224; E-mail: [email protected]). Biological Reviews 93 (2018) 1578–1603 2018 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Partially migratory meta-populations 1579 Key words: demographic structure, density-dependence, eco-evolutionary dynamics, life-history variation, meta-population, movement ecology, partial migration, plasticity, population viability, seasonal migrant, vital rate. CONTENTS I. Introduction ..............................................................................................1579 (1) Spatio-temporal population dynamics in seasonally varying environments ...........................1580 (2) Population dynamic theory and models that do not consider seasonal migration .....................1581 (3) Population dynamic models that consider obligate seasonal migration ...............................1582 (4) Objectives ............................................................................................1582 II. Seasonal migration as a variable life-history trait and demographic rate .................................1583 III. Basic scenarios and models of partial migration ..........................................................1584 IV. Concept and properties of a ‘partially migratory meta-population’ .......................................1586 (1) A partially migratory meta-population ...............................................................1586 (2) ‘Partially migratory meta-population’ as an overarching conceptual framework .....................1587 (a) Partial migration, reproduction and survival .............................................................1588 (b) Partial migration and dispersal ........................................................................1588 (c) Partial migration and density ..........................................................................1589 (d) Structure, heterogeneity and individual variation in migration versus residence ................................1591 (e) Eco-evolutionary dynamics involving partial migration ....................................................1592 V. Requirements and opportunities for modelling dynamics ................................................1593 (1) Progression of modelling approaches .................................................................1593 (2) An illustrative individual-based model ................................................................1594 VI. Requirements and opportunities for empirical data ......................................................1596 (1) Current knowledge and requirements ................................................................1596 (2) Approaches to addressing empirical objectives .......................................................1598 VII. Conclusions ..............................................................................................1599 VIII. Acknowledgments ........................................................................................1599 IX. References ................................................................................................1599 X. Supporting Information ..................................................................................1603 I. INTRODUCTION populations utilising spatially structured seasonally varying environments, and hence to understand and forecast popu- Almost all wild populations utilise geographical ranges lation responses to spatio-temporal seasonal environmental where environmental capabilities to support key life-history change (Runge & Marra, 2005; Fryxell & Holt, 2013; stages, and hence to maintain demographic rates that Small-Lorenz et al., 2013; Selwood et al., 2015; Rushing et al., underlie population growth rate, vary both spatially and 2017; Van de Pol et al., 2017). These objectives are increas- temporally. The ubiquitous spatial variation in habitat ingly imperative because climate models predict widespread and environmental suitability is overlain by stochastic changes in means and variances in seasonal conditions and among-year variation