Changing demography and dispersal behaviour: ecological adaptations in an alpine butterfly

Abstract

High mountain ecosystems are extreme habitats for all organisms and therefore demand specific adaptations. In this context, we studied the ecology of the butterfly Euphydryas aurinia debilis in the High Tauern (Austria) and compared the obtained data against the ecology of the species in lower elevation habitats. We performed mark-release-recapture studies over the entire flight periods (end of June to end of July) in 2007 and 2008 to analyse the fundamental ecological parameters of a population. The demography of males and females was similar in both years, and no indication of typical protandry was detected. We observed a generally low dispersal of the individuals in both years, but males dispersed significantly more than females in 2008; this finding of low vagility was supported by allozyme analyses. Furthermore, butterflies survived periods of several days of continuously closed snow cover without any indication of increased mortality rates. In these three traits, this alpine population of E. aurinia apparently has ecological and physiological adaptations to the extreme requirements of high-altitude habitats and strongly deviates from the lower elevation populations.

Demography of adults of the Marsh fritillary butterfly, Euphydryas aurinia (Lepidoptera: Nymphalidae) in the Czech Republic: Patterns across sites and seasons

“…Recruitment was protandrous, as is recorded in many studies of temperate butterflies with discrete generations, including E. aurinia (e.g., Fric et al, 2010;Junker & Schmitt, 2010). A notable exception with no signs of protandry is that of an alpine population studied by Junker et al (2010).…”

“…A higher male catchability is frequently recorded in butterfly MRR studies (Schtickzelle et al, 2002;Baguette & Schtickzelle, 2003;Zimmermann et al, 2009;Kadlec et al, 2010), including those on E. aurinia (Schtickzelle et al, 2005;Junker & Schmitt, 2010;Junker et al, 2010), probably due to their more conspicuous activity, whereas the factorial response of catchability to time is due to variation in weather and marking effort (Schtickzelle et al, 2002;Vlasanek et al, 2009). In any case, if averaged across all years and systems, 16% of the males and 10% of the females were captured (mean of p's in Table 4).…”

“…Boggs, 1987;Nève et al, 1996;Wahlberg et al, 2002;Zimmermann et al, 2009;Fric et al, 2010). For E. aurinia the CLM approach was used to estimate adult numbers in diminishing populations in Belgium (Schtickzelle et al, 2005), in a highly abundant but fragmented population in Portugal (Junker & Schmitt, 2009) (both single seasons) and in a population inhabiting extreme conditions above the timberline in the Alps (Junker et al, 2010) (two seasons). Among other butterflies, particularly relevant are studies of the Argynnini nymphalids Proclossiana eunomia (eight seasons: Schtickzelle et al, 2002) and Boloria aquilonaris (three seasons, four systems: Baguette & Schtickzelle, 2003).…”

“…A notable exception with no signs of protandry is that of an alpine population studied by Junker et al (2010). Protandry results from evolutionary pressure on males to mate with recently emerged females and it is proposed that this may be outweighed by the selection advantage of both sexes emerging synchronously in extreme environments.…”

Has the currently warming climate affected populations of the mountain ringlet butterfly, Erebia epiphron (Lepidoptera: Nymphalidae), in low-elevation mountains?

“…The adult numbers typically peak when there are still many males present and female numbers are just building up (Soulsby & Thomas, 2012), ensuring that the sexes meet in suffi cient numbers. Such synchronisation is more prominent if there are some common triggers for pre-adult development, such as weather-controlled diapause termination and less prominent if disrupted by bouts of unfavourable weather (Junker et al, 2010).…”