Butterfly species differing in mobility show different structures of dispersal‐related syndromes in the same fragmented landscape

Abstract

International audienceMobility varies strongly between and within species, reflecting diff erent dispersal strategies. Within species, such differences can imply suites of traits associated in syndromes. Different syndrome structures have been found within species among populations differing in the selective pressures they are exposed to. Similarly, we expect species differing in mobility to show diff erent syndrome structures in response to similar selective pressures such as landscape fragmentation. Using butterflies originating from the same fragmented landscape, we investigated the differences in mobility syndrome between four common butterflies (Pyronia tithonus , Pararge aegeria Maniola jurtina , Pieris rapae) known to differ in their mobility. We expected individuals from the less mobile species to display a resident strategy because of high dispersal cost in this fragmented landscape, and individuals from the more mobile species to display a larger range of movement strategies. Moreover, as syndromes can only be detected whenever individuals differ in their dispersal strategies, we expected mobility syndromes to be observable only in populations where dispersal polymorphism is maintained. We thus expected stronger correlations between mobility-related traits in more mobile species. Using three mobility tests in controlled conditions designed to measure different components of mobility, we showed that mobility-related traits were indeed correlated only in the most mobile species. The absence of correlation in the less mobile species may be explained by a low variation in movement strategies, dispersal being counter-selected

Sexual differences rather than flight performance underlie movement and exploration in a tropical butterfly

“…Thus, males showed a clearly increased flight performance and propensity compared with females in both experiments. Berwaerts et al, 2002Berwaerts et al, , 2008Ducatez et al, 2014). These results are closely in line with the morphological differences found (see earlier) and suggest differential selection pressures between the sexes (Gilchrist, 1990;Berwaerts et al, 2002Berwaerts et al, , 2006Ducatez et al, 2014).…”

“…These differences might, on the one hand, arise from morphological/physiological differences, as males typically show traits associated with an increased flight performance; on the other hand, they might arise from behavioural differences, potentially resulting from differential selection pressures (Gilchrist, 1990;Berwaerts et al, 2006;Saastamoinen et al, 2012;Ducatez et al, 2014). These differences might, on the one hand, arise from morphological/physiological differences, as males typically show traits associated with an increased flight performance; on the other hand, they might arise from behavioural differences, potentially resulting from differential selection pressures (Gilchrist, 1990;Berwaerts et al, 2006;Saastamoinen et al, 2012;Ducatez et al, 2014).…”

Emigration propensity and flight performance are decoupled in a butterfly

“…, Ducatez et al. ). Males often show traits associated with increased flight ability and have been shown to be more active than females in many butterfly species (Berwaerts et al.…”

“…Note that morphological differences may have important consequences for flight performance (Arnold 1983, Gilchrist 1990, Berwaerts et al 2002, and even for dispersal and colonization success in butterflies (Hill et al 1999, Sekar 2012. For instance, sexes may differ in flight or dispersal ability / behavior due to differential selection pressures or strategies (Gilchrist 1990, Berwaerts et al 2002, Ducatez et al 2014. Males often show traits associated with increased flight ability and have been shown to be more active than females in many butterfly species (Berwaerts et al 2002, Ducatez et al 2014.…”

“…For instance, sexes may differ in flight or dispersal ability / behavior due to differential selection pressures or strategies (Gilchrist 1990, Berwaerts et al 2002, Ducatez et al 2014. Males often show traits associated with increased flight ability and have been shown to be more active than females in many butterfly species (Berwaerts et al 2002, Ducatez et al 2014. Nevertheless, females could be the more dispersive sex (Fischer et al 1999) as (1) single mated females are, in contrast to males, able to found a new population; and (2) females may emigrate more readily to escape from male harassment or as a risk-spreading strategy by distributing their eggs over a wider area (Hill et al 1999, Hopper 1999, Trochet et al 2013.…”