Cold adaptation across the elevation gradient in an alpine butterfly species complex

Abstract

1. Temperature acts as a major factor on the timing of activity and behaviour in butterflies, and it might represent a key driver of butterfly diversification along elevation gradients. Under this hypothesis, local adaptation should be found along the elevation gradient, with butterflies from high elevation populations able to remain active at lower ambient temperature than those from low elevation. 2. The warming‐up rate and the thoracic temperature at take‐off of 123 individuals of the Alpine butterfly species complex Coenonympha arcania – C. macromma – C. gardetta were recorded in controlled conditions. 3. Warming‐up rate increased with elevation in C. arcania: high‐elevation males of C. arcania were able to warm up more quickly compared to low‐elevation ones. 4. High‐elevation C. gardetta had a darker underwing pattern than low‐elevation ones. This high‐elevation species was significantly smaller (lower weight and wing surface) than the two other species and had a faster warming‐up rate. 5. This study's results suggest that the ability to warm up quickly and to take flight at a high body temperature evolved adaptively in the high‐altitude C. gardetta and that low temperature at high altitude may explain the absence of C. arcania, while the hybrid nature of C. macromma is probably the explanation of its elevation overlap with both the other species and its local replacement of C. gardetta.

Climate change effects on animal ecology: butterflies and moths as a case study

“…Across ectotherm taxa, warming global temperatures often appear to result in smaller body size (Ohlberger, 2013 ; Coulthard et al ., 2019 ) by shortening development time (Sheridan & Bickford, 2011 ). Larger bodies have also been shown to reduce the time needed to raise body temperature for flight activity in cold environments (Nève & Després, 2020 ), an adaptation that may not confer the same advantages with increasing temperatures. In the Arctic butterflies Boloria chariclea and Colias hecla , decreases in body and wing size were observed in response to 17 years of rising summer temperatures in Greenland (Bowden et al ., 2015 ).…”

Strong differences in egg heat tolerance between closely related lowland and alpine butterfly species

“…In butterflies, the effect of such strong temperature gradient at small geographic scale have been studied at both microevolutionary (e.g. Montejo‐Kovacevich et al, 2019; Klockmann & Fischer, 2017; Nève & Després, 2020; Vrba et al, 2022) and macroevolutionary scales (Kleckova et al, 2014; Leingärtner et al, 2014; Nève & Després, 2020). Experimental approaches to study temperature tolerance often focussed on the adult stage, but stressors such as thermal extremes can affect life stages differently.…”

Body size, not species identity, drives body heating in alpineErebiabutterflies

“…The physiological optima are, in turn, also affected by the active choice of ambient temperature and daily activity patterns of different species of butterflies (Kingsolver, 1983) and other insects, such as beetles (Gallego et al, 2018). The interplay among behaviour, morphology and physiology on thermoregulatory strategies has been observed also at the inter-population level in butterflies (Nève & Després, 2020) and intra-population level in grasshoppers (Forsman, 2000). Further, thermoregulatory behaviour of butterflies is tightly connected with morphology as behaviour prevents, for example, overheating of living cells distributed in the wings veins (Tsai et al, 2020).…”