Population history and life history influence the migration rate of female Glanville fritillary butterflies

Abstract

This study examines the causes of emigration from small fragments of suitable habitat in a species that has a distinct metapopulation structure, frequent turnover of local populations, and substantial migration among local populations and currently unoccupied habitat fragments. We conducted a field experiment in which 727 individuals of the Glanville fritillary butterfly (Melitaea cinxia) originating from four regions were marked and released simultaneously in a natural environment. In three of the four source regions, larvae for the experiment were collected from dozens of small local populations, some of which had been established in the previous summer (new populations), whereas the remaining populations were older. In two of the source regions, female butterflies prefer a host plant (Veronica spicata) that is not present in the release area, where there is only Plantago lanceolata, the preferred host plant of females from the other two source regions. We found that migration rate of males was unrelated to any of the factors studied in this experiment. In contrast, two factors influenced the migration rate of females. First, Veronica‐preferring females had higher emigration rate than Plantago‐preferring females from the Plantago‐containing release patches, demonstrating that the individual perception of habitat quality significantly influences the migration rate of females. Second, females from newly‐established populations were more dispersive than females from older populations, supporting the notion that metapopulation processes (recurrent colonizations) select for increased migration. The observed migration rate was not correlated with any body size measurements, and thus the observed differences in migration rate were apparently caused by differences in the behaviour of female butterflies rather than in their flight capacity.

Geographical variation in wolf spider dispersal behaviour is related to landscape structure

“…Apart from changes in morphological design, habitat fragmentation as such (Schooley & Wiens 2004) may thus induce selection pressures that affect behavioural traits closely linked to dispersal and hence lead to reduced mobility and gene flow (e.g. Thomas et al 1998;Van Dyck & Matthysen 1999;Hanski et al 2002). Furthermore, our results suggest that selection forces in fragmented habitats can alter within-species dispersal propensity in a similar way as between species (Bonte et al 2003d), indicating that microevolutionary changes in aeronautical behaviour can overrule evolutionary changes at the species level.…”

Heritability of dispersal rate and other life history traits in the Glanville fritillary butterfly

“…Furthermore, and importantly for the present study, females originating from newly-established populations have higher early-life mobility than old population females when mobility was measured in a large outdoor population cage Saastamoinen, 2007b). These results have been explained by females establishing new populations, especially at isolated habitat patches, having greater dispersal propensity and/or dispersal capacity than the average female (Hanski et al, 2002). This assumes that variation in dispersal propensity and/or capacity is due to one or more heritable traits, but so far direct measurements of heritability of any relevant traits have been lacking.…”

“…However, there is much variation in the flight capacity among individuals (Saastamoinen, 2007b), and in particular Hanski et al (2002Hanski et al ( , 2004 have shown that females originating from newly-established isolated populations are more dispersive in the field than those originating from old populations (based on a common garden mark-release-recapture experiment in the field). Comparable conclusions were drawn from a theoretical model and from physiological studies on the [ATP]/…”

Causes and consequences of animal dispersal strategies: relating individual behaviour to spatial dynamics

“…Kuussaari et al, 1996 ;Hanski et al, 2002;Schneider, Dover & Fry, 2003). Experimental food supplementation decreased the emigration propensity of juvenile northern goshawks Accipiter gentilis (Kennedy & Ward, 2003).…”