From global change to a butterfly flapping: biophysics and behaviour affect tropical climate change impacts

Abstract

Difficulty in characterizing the relationship between climatic variability and climate change vulnerability arises when we consider the multiple scales at which this variation occurs, be it temporal (from minute to annual) or spatial (from centimetres to kilometres). We studied populations of a single widely distributed butterfly species, Chlosyne lacinia, to examine the physiological, morphological, thermoregulatory and biophysical underpinnings of adaptation to tropical and temperate climates. Microclimatic and morphological data along with a biophysical model documented the importance of solar radiation in predicting butterfly body temperature. We also integrated the biophysics with a physiologically based insect fitness model to quantify the influence of solar radiation, morphology and behaviour on warming impact projections. While warming is projected to have some detrimental impacts on tropical ectotherms, fitness impacts in this study are not as negative as models that assume body and air temperature equivalence would suggest. We additionally show that behavioural thermoregulation can diminish direct warming impacts, though indirect thermoregulatory consequences could further complicate predictions. With these results, at multiple spatial and temporal scales, we show the importance of biophysics and behaviour for studying biodiversity consequences of global climate change, and stress that tropical climate change impacts are likely to be context-dependent.

Microclimate predicts within‐season distribution dynamics of montane forest birds

“…In montane landscapes, complex terrain could create buffered ‘microrefugia’ (Dobrowski, ). Microclimate heterogeneity may be an important factor in providing options for behavioural adaptation (Bonebrake et al ., ) in the face of regional climate changes. Stable populations in heterogeneous landscapes could stem from increased options for tracking microclimate (Oliver et al ., ).…”

“…Animals may adjust their use of local habitat in ways that allow them to persist in the face of climate change without necessitating broad-scale range shifts (Kearney et al, 2009). Landscapes with little climatic variability provide fewer possibilities for new behaviour (Bonebrake et al, 2014) such as shifts in habitat or diet.…”

Fluctuating temperatures and ectotherm growth: distinguishing non-linear and time-dependent effects

“…Numerous recent studies have used thermal performance curves to predict the fitness and ecological responses of ectotherms under future climate scenarios (Deutsch et al, 2008;Sinervo et al, 2010;Huey et al, 2012;Kingsolver et al, 2013;Bonebrake et al, 2014;Vasseur et al, 2014). For example, thermal performance curves for fitness (measured at constant temperatures over a generation) have been used to predict geographic patterns in fitness responses of insects to climate change, including diurnal fluctuations in temperature (Deutsch et al, 2008;Vasseur et al, 2014).…”

The effectiveness of common thermo-regulatory behaviours in a cool temperate grasshopper

“…Rapid and reversible, it enables an organism to control its exposure to conditions at a small scale and maintain body temperatures that may be substantially different to ambient (May, 1979). The effectiveness of behaviour in regulating body temperatures is therefore an important determinant of the abundance and distribution of a species, particularly in variable environments and under changing climatic conditions (Bonebrake et al, 2014). Rather than being highly sensitive to climate change by virtue of their ectothermy, many insects and other small ectotherms may in fact be tolerant of increasing temperatures, with behaviour having the potential to alleviate the impacts of climate change (Kearney et al, 2009).…”