Understanding the migration ecology of European red admirals Vanessa atalanta using stable hydrogen isotopes

Abstract

Tracking migratory movement of small animals with variable migration patterns is difficult with standard mark–recapture methods or genetic analysis. We used stable hydrogen isotope (δD) measurements of wings from European red admirals Vanessa atalanta to study several aspects of this species’ migration. In the central part of southern Europe we found large differences in δD values between red admirals sampled in autumn and spring supporting the hypothesis that reproduction takes place in the Mediterranean region during winter. There was also an apparent influx to southern Europe in the spring of individuals with a more southerly origin, since many samples had higher δD values and similar to those expected from coastal areas of North Africa. We found a clear seasonal difference in the δD values of red admirals sampled in northern Europe. Spring migrants arriving in northern Europe generally had high δD values that indicated a southerly origin. In autumn, δD values suggested that red admirals were mostly from regions close to the sampling sites, but throughout the sampling period there were always individuals with δD values suggesting non‐local origins. The migration pattern of this species is supposedly highly variable and plastic. δD differences between individuals in the western part of Europe were generally small making migratory patterns difficult to interpret. However, butterflies from western Europe were apparently isolated from those from north‐eastern Europe, since δD values in the western region rarely corresponded to those of autumn migrants from the north‐east. Use of δD data for inferring butterfly migration in Europe is complex, but our study showed that this technique can be used to help uncover previously unknown aspects of red admiral migration.

Combination of morphometric and isotopic tools for studying spring migration dynamics in Episyrphus balteatus

“…The variability in the dD H values among individuals within sampling sites was similar to the inter-individual variability observed in other studies in sampling groups whose geographical origins were known. In our study, the standard deviation associated with dD H values at a particular sampling site for a given month ranged from 2.25 to 5.18, similar to the standard deviations observed in other studies on insect species , Brattströ m et al 2010. This suggests that the individuals collected at each sampling point in our study mostly originated from a location that was not far away, and included no-or a very low proportion of-long-range immigrants.…”

“…This relationship has previously been shown in many bird species in Europe (Hobson et al 2009, Marquiss et al 2012) and in some insect species (Brattströ m et al 2010). The work of Ouin et al (2011) was the first one to establish this relationship in a third trophic level consumer.…”

“…The dD W values also vary over the year, and this seasonal variation has to be taken into account when inferring the geographical origin of migratory organisms (Brattströ m et al 2010). We used the Online Isotope in Precipitation Calculator (OIPC) (Bowen 2013) to acquire interpolated amount-weighted monthly dD W values for the rainwater at our sampling sites (Bowen et al 2005 …”

“…Consequently, it is suitable for efficiently tracking movements only at large scales, e.g., at a continental scale (Farmer et al 2008). The dD ratio has been successfully used to determine migration patterns in various insect species and in various parts of the world, including the monarch butterfly Danaus plexippus (L.) in North America (Wassenaar and Hobson 1998), the dragonfly Pantala flavescens (Fabricius) in the Indian Subcontinent (Hobson et al 2012a), and the red admiral butterfly Vanessa atalanta (L.) in Europe (Brattströ m et al 2010). Ouin et al (2011) investigated the possibility of using dD ratio to study the migration of the aphidophagous hoverfly Episyrphus balteatus (De Geer) in Europe.…”

Long-distance autumn migration across the Sahara by painted lady butterflies: exploiting resource pulses in the tropical savannah

“…These clusters explained 92% of the variation and represented the potential groups of natal origin. The five natal areas were related to eastern-central Europe ( [11] was then converted to a spatially explicit butterfly wing isoscape by using a calibration relationship determined for known-origin butterflies across the western Palaearctic [12]. Probability density surfaces were obtained using the complete individual spatial probability surface (no odds ratio used).…”