Phenology of high-arctic butterflies and their floral resources: Species-specific responses to climate change

Abstract

Current global warming is particularly pronounced in the Arctic and arthropods are expected to respond rapidly to these changes. Long-term studies of individual arthropod species from the Arctic are, however, virtually absent. We examined butterfly specimens collected from yellow pitfall traps over 14 years (1996–2009) at Zackenberg in high-arctic, north-east Greenland. Specimens were previously sorted to the family level. We identified them to the species level and examined long-term species-specific phenological responses to recent summer warming. Two species were rare in the samples (Polaris fritillary Bolo-ria polaris and Arctic blue Plebejus glandon) and statistical analyses of phenological responses were therefore restricted to the two most abundant species (Arctic fritillary, B. chariclea and Northern clouded yellow Colias hecla). Our analyses demonstrated a trend towards earlier flight seasons in B. chariclea, but not in C. hecla. The timing of onset, peak and end of the flight season in B. chariclea were closely related to snowmelt, July temperature and their interaction, whereas onset, peak and end of the flight season in C. hecla were only related to timing of snowmelt. The duration of the butterfly flight season was significantly positively related to the temporal overlap with floral resources in both butterfly species. We further demonstrate that yellow pitfall traps are a useful alternative to transect walks for butterfly recording in tundra habitats. More phenological studies of Arctic arthropods should be carried out at the species level and ideally be analysed in context with interacting species to assess how ongoing climate change will affect Arctic biodiversity in the near future.

High-Arctic butterflies become smaller with rising temperatures

“…Smaller body size in these Arctic species could have significant consequences for their population dynamics by leading to decreased dispersal capacity or lower fecundity and fitness. B. chariclea has already demonstrated a significant shift towards earlier and shorter flight seasons at Zackenberg [18] and both B. chariclea and C. hecla are considered under extremely high climate change risk by the Climatic risk atlas of European Butterflies given future bioclimatic models [23]. While these models include dispersal capacity, in situ adaptation to climate change or plasticity may enable some populations of a species to persist.…”

Interaction webs in arctic ecosystems: Determinants of arctic change?

“…To assess the species-specific phenological responses, we have quantified the onset, peak, and end of the flight time of two abundant species of butterflies at Zackenberg. We found that the phenology of the arctic fritillary Boloria chariclea is advancing while the northern clouded yellow Colias hecla is not (Høye et al 2014). The arctic fritillary is thus more accurately tracking changes in the timing and duration of the flowering season than the northern clouded yellow.…”

Spatiotemporal snowmelt patterns within a high Arctic landscape, with implications for flora and fauna

“…Indeed, plant and insect populations may be strongly affected by small-scale variation (Badik et al 2015), and the local timing of snowmelt has been proposed to have a major influence on local species occurrence (Leingärtner, Krauss, and Steffan-Dewenter 2014). Yet research on the impact of snow conditions on phenology typically uses average conditions: temperature and snow conditions characterized by either single weather stations for large areas or by longer-term averages across sites (Høye et al 2014;Iler et al 2013;Kudo and Ida 2013). Conflicting with such descriptions is the finding that the exact timing of snowmelt will vary in space and time, with spatiotemporal consistency likely affecting consistency in the timing of local phenological events and demographic processes (Bowden et al 2015b).…”