Regional differences in thermoregulation between two European butterfly communities [Software]

The “Scripts” folder contains: The “Analysis” folder, with several R scripts with the required code to reproduce all statistical analyses. This was originally done with R 4.1.3. The "worldclim_analysis.R" script can be used to reproduce the analysis of WorldClim data to characterise the climate of both Catalonia and Great Britain; the "GAM_models_buffering_mechanisms" can be used to reproduce the GAM models; the "Master_script.R" script contains the rest of analyses. The “CAMS_solar_radiation_data_download” folder, with multiple Python scripts used to automate the download of the solar radiation data from CAMS. Note that, to be able to use these, the reader will have to register on the CAMS website and obtain access credentials, and then replace the “credentials_file” variable at the beginning of each Python script with the path to the file containing the credentials. More details are available at: https://ads.atmosphere.copernicus.eu/api-how-to

Understanding how different organisms cope with changing temperatures is vital for predicting future species' distributions and highlighting those at risk from climate change. As ectotherms, butterflies are sensitive to temperature changes, but the factors affecting butterfly thermoregulation are not fully understood. We investigated which factors influence thermoregulatory ability in a subset of a Mediterranean butterfly community. We measured adult thoracic temperature and environmental temperature (787 butterflies; 23 species) and compared buffering ability (defined as the ability to maintain a consistent body temperature across a range of air temperatures) and buffering mechanisms to previously published results from Great Britain. Finally, we tested whether thermoregulatory ability could explain species' demographic trends in Catalonia. The sampled sites in each region differ climatically, with higher temperatures and solar radiation but lower wind speeds in the Catalan sites. Both butterfly communities show nonlinear responses to temperature, suggesting a change in behaviour, from heat-seeking to heat avoidance, at approximately 22 °C. However, the communities differ in the use of buffering mechanisms, with British populations depending more on microclimates for thermoregulation compared to Catalan populations. Contrary to the results from British populations, we did not find a relationship between region-wide demographic trends and butterfly thermoregulation, which may be due to the interplay between thermoregulation and the habitat changes occurring in each region. Thus, although Catalan butterfly populations seem to be able to thermoregulate successfully at present, evidence of heat avoidance suggests this situation may change in the future.

Funding provided by: Spanish National Research Council Crossref Funder Registry ID: https://ror.org/02gfc7t72 Award Number: JAEINT_20_00248

Funding provided by: Departament de Recerca i Universitats Crossref Funder Registry ID: https://ror.org/01gbnem66 Award Number: FI-1 00556

Funding provided by: Ministerio de Ciencia, Innovación* Crossref Funder Registry ID: Award Number: PID2020-117739GA-I00 MCIN / AEI / 10.13039/501100011033

Funding provided by: Isaac Newton Trust Crossref Funder Registry ID: https://ror.org/02gn6ta77 Award Number: RG89529

Funding provided by: Wellcome Trust Crossref Funder Registry ID: https://ror.org/029chgv08 Award Number: RG89529

Funding provided by: University of Cambridge Crossref Funder Registry ID: https://ror.org/013meh722 Award Number: RG89529

Funding provided by: Natural Environment Research Council Crossref Funder Registry ID: https://ror.org/02b5d8509 Award Number: NE/V007173/1

Funding provided by: Ministerio de Ciencia, Innovación y Universidades Crossref Funder Registry ID: http://dx.doi.org/10.13039/100014440 Award Number: FPU22/02358

Funding provided by: European Social Fund Plus Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100004895 Award Number: FI-1 00556

Peer reviewed