An assessment of direct and indirect effects of climate change for populations of the Rocky Mountain Apollo butterfly (Parnassius smintheus Doubleday)

Abstract

Climate change is occurring and insects are responding. Current challenges for ecologists and managers are predicting how organisms will respond to continuing climate change and determining how to mitigate potential negative effects. In contrast to broad scale predictions for climate change involving the distribution of species, in this article we highlight the many ways in which local populations of the Rocky Mountain Apollo butterfly (Parnassius smintheus Doubleday) are predicted to respond to climate change. Using experimental and observational data collected over the past 15 years, we detail both direct and indirect effects. In addition, we identify limitations in our knowledge restricting the ability to predict how populations will respond to climate change. Some changes, such as warmer winter temperatures, may have beneficial effects; however, most of the effects of climate change will be detrimental. Variability in snow cover during the overwintering period and habitat loss due to forest encroachment have the largest potential negative effects.

Butterfly dispersal in inhospitable matrix: rare, risky, but long-distance

“…In turn, non-dispersal mortality, which translates into life expectancy of adult butterflies living in their habitat patches, was most likely shaped by casespecific factors. We believe that the underlying reason was the variation in weather patterns among the investigated metapopulations, which is a typical driver of butterfly life expectancy (Casula and Nichols 2003;Nowicki et al 2009;Matter et al 2011). Interestingly, however, distinctively short adult life expectancies were recorded in earlier studies on M. teleius and M. nausithous in the region (Nowicki et al 2005a, b), which implies that they may either be heritable traits or reflect less favourable climatic conditions.…”

A hierarchical perspective on the diversity of butterfly species' responses to weather in the Sierra Nevada Mountains

“…Greater snow pack might benefit species directly by increasing the probability of overwinter survival (Matter et al 2011). Alternatively, snow pack might have an indirect, positive effect on host plants and nectar resources (Boggs and Inouye 2012).…”

“…Warmer average overnight temperatures in winter generally have a positive impact on butterfly species. This might be directly related to adverse physiological effects of extreme low temperatures on overwintering stages for resident species (Matter et al 2011). FIG.…”

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

“…This may adversely affect overwintering butterfl y larvae, despite their hiding in short grass tufts like those of E. epiphron (Sonderegger, 2005). In the Canadian Rockies, Matter et al (2011) report that less reliable snow cover imperils populations of another mountain butterfl y, Parnassius smintheus. Recording adult Erebia cassioides on the Pollino Massif, Italy, Scalercio et al (2014), detected that an increase in snow cover at high altitudes and less reliable snow at low altitudes results in higher population densities of the species at alpine altitudes and lower population densities at the timberline, relative to the situation in the 1970s.…”

“…Perhaps the best long-term data available to date has targeted butterfl y communities inhabiting the Sierra de Guadarrama mountains in Spain (maximum altitude: 2428 m), where upslope shifts in community composition attributable to climatic warming have been detected (e.g., Wilson et al, 2005Wilson et al, , 2007. On the Kananaskis Ridge in Canada, the ascending timberline genetically isolates individual mountaintop populations (Keyghobadi et al, 2005) and desynchronizes their population dynamics (Roland & Matter, 2007;Matter et al, 2011). In Britain, Franco et al (2006 report loss of low altitude colonies of the alpine species, Erebia epiphron (Knoch, 1783), whereas higher altitude populations seemed unaffected.…”