Gene-flow within a butterfly metapopulation: the marsh fritillary Euphydryas aurinia in western Bohemia (Czech Republic)

Abstract

In human-altered landscapes, species with specific habitat requirements tend to persist as metapopulations, forming colonies restricted to patches of suitable habitats, displaying mutually independent within-patch dynamics and interconnected by inter-colony movements of individuals. Despite intuitive appeal and both empirical and analytical evidence, metapopulations of only relatively few butterfly systems had been both monitored for multiple years to quantify metapopulation dynamics, and assayed from the point of view of population genetics. We used allozyme analysis to study the genetic make-up of a metapopulation of a declining and EU-protected butterfly, Euphydryas aurinia, inhabiting humid grasslands in western Czech Republic, and reanalysed previously published demography and dispersal data to interpret the patterns. For 497 colony x year visits to the 97 colonies known at that time, we found annual extinction and colonisation probabilities roughly equal to 4%. The genetic diversity within colonies was intermediate or high for all assessed parameters of population genetic diversity and hence higher than expected for such a habitat specialist species. All the standard genetic diversity measures were positively correlated to adult counts and colony areas, but the correlations were weak and rarely significant, probably due to the rapid within-colony population dynamics. Only very weak correlations applied to larval nests numbers. We conclude that the entirety of colonies forms a well-connected system for their majority. Especially in its core parts, we assume a metapopulation structure with a dynamic equilibrium between local extinction and recolonization. It is vital to conserve in particular these structures of large and interconnected colonies.Implications for insect conservation: Conservation measures should focus on considering more in depth the habitat requirements of E. aurinia for management plans and on stabilisation strategies for colonies, especially of peripheral ones, e.g. by habitat restoration.

Combining modelling, field data and genetic variation to understand the post-reintroduction population genetics of the Marsh Fritillary butterfly (Euphydryas aurinia)

“…2). It was not possible to sample the precise donor location due to the time that had elapsed since they were collected and the intermittent site occupancy by the species, given its metapopulation ecology (Junker et al 2021). However, the broad geographical areas were known and two populations within these areas (Tayvallich and Mull) were sampled to represent the original Scottish donors.…”

Within-habitat vegetation structure and adult activity patterns of the declining butterfly Euphydryas aurinia

“…It forms multiple genetic lineages across its large Palaearctic range (Tolman and Lewington 2009;Junker et al 2015;Korb et al 2016), utilises multiple larval host plants (Singer et al 2002;Meister et al 2015;Ghidotti et al 2018), and inhabits diverse biotopes, from Mediterranean xeric scrub (Munguira et al 1997; to subalpine meadows . In Western and Central Europe, it mainly inhabits humid oligotrophic grasslands (Hula et al 2004;Bulman et al 2007;Pielech et al 2017;Junker et al 2021). Threats by habitat loss are augmented by gregarious larval development, linked to prominent abundance fluctuations (Schtickzelle et al 2005;Bulman et al 2007;Botham et al 2011;Zimmermann et al 2011a;Johansson et al 2020), and vulnerability to inappropriate vegetation management, such as uniform cuts of the occupied meadows in autumn (Hula et al 2004) or too intensive grazing (Johansson et al 2019).…”

“…Threats by habitat loss are augmented by gregarious larval development, linked to prominent abundance fluctuations (Schtickzelle et al 2005;Bulman et al 2007;Botham et al 2011;Zimmermann et al 2011a;Johansson et al 2020), and vulnerability to inappropriate vegetation management, such as uniform cuts of the occupied meadows in autumn (Hula et al 2004) or too intensive grazing (Johansson et al 2019). In functioning metapopulation systems, local extinctions are compensated by a good dispersal ability, allowing recolonisation of sites over 10 km apart (Warren 1994;Zimmermann et al 2011b;Junker et al 2021).…”

“…So far, studies targeting E. aurinia focused mainly on consequences of its metapopulation dynamics, i.e., modelling of colonisation/extinction probability (Wahlberg et al 2002;Schtickzelle et al 2005;Bulman et al 2007;Zimmermann et al 2011b), genetic population structure (Wang et al 2003;Sigaard et al 2008;Davis et al 2021;Junker et al 2021;Pertoldi et al 2021), and larval habitat requirements (Anthes et al 2003;Tjørnløv et al 2015, Psechera andWarren 2018). The patterns of habitat use by adults remain rather neglected, despite existing evidence that the structuring of adult habitats influences multiple vital aspects of many Nymphalidae (e.g., Janz 2005;Swartz et al 2015;Sielezniew et al 2019;Vrba et al 2021), including representatives of the Euphydryas genus.…”

Developmental Transcriptome Analysis of Red-Spotted Apollo Butterfly, Parnassius bremeri

“…The Apollo butterfly, which includes ten different species, prefers to live in mountain meadows and pastures, especially in cold winters and warm summers. These butterflies also serve as models for the study of metapopulations, population genetics and gene flow [ 3 ].…”