DOI: 10.5061/dryad.w0vt4b8t4
title: Thermal tolerance in Drosophila: repercussions for distribution, community coexistence and responses to climate change

description: Here we combined controlled experiments and field surveys to determine if
 estimates of heat tolerance predict distributional ranges and phenology of
 different Drosophila species in southern South America.  We
 contrasted thermal death time curves, which consider both magnitude and
 duration of the challenge to estimate heat tolerance, against the thermal
 range where populations are viable based on field surveys in an 8-yr
 longitudinal study.  We observed a strong correspondence of the
 physiological limits, the thermal niche for population growth, and the
 geographic ranges across studied species, which suggests that the thermal
 biology of different species provides a common currency to understand how
 species will respond to warming temperatures both at a local level and
 throughout their distribution range.  Our approach represents a
 novel analytical toolbox to anticipate how natural communities of
 ectothermic organisms will respond to global warming.
description: <i>Fieldwork and heat
 tolerance assays </i> In this study, adult flies of
 <i>D. simulans</i>, <i>D. hydei</i>, <i>D.
 subobscura</i> and <i>D. immigrans</i> were collected
 during the Austral spring and summer of 2018 and 2019 from eleven
 localities in Chile. Then, 15 laboratory population lines were established
 in the laboratory. Under controlled conditions, we measured heat knockdown
 times of individuals belonging to each population. We complemented our
 dataset with measurements of thermal tolerance previously obtained in our
 research group<i>. </i> <i>Estimation of heat
 tolerance across species and populations</i> We employed thermal death-time
 (TDT) curves to quantify and compare heat tolerance across populations and
 species. For this purpose, linear models between assay temperatures and
 knockdown or death times were fitted to estimate the coefficients of the
 TDT curves. Linear models also included the ambient temperature from each
 locality as a predictor. <i>Study of the thermal
 niche for population growth</i> We combined monthly estimates of
 population size for 16 drosophilid<i> </i>species in Santiago
 (Chile) with mean ambient temperature records for the 1984 – 1991 period.
 With this dataset, we adjusted the population growth rate depending on
 ambient temperature following a quadratic regression. Afterward, we
 standardized the knockdown time for 1 h and 12 hours using the TDT
 coefficients to define a consistent critical temperature window among
 species. Finally, we predicted how different <i>Drosophila</i>
 species will be affected by warming conditions combining the equations
 obtained from quadratic regression with historical records of daily
 temperatures.
description: This dataset contains:  - 11 Excel files with
 temperature data of each sampling locations (actual period).
 - 8 CSV files with temperature data in Santiago (the period
 between 1984-1991). -1 Excel file with heat tolerance
 data ("tolernce.xlsx") -1 Excel file with
 phenology data ("phenology_drosophila.xlsx")
 -1 R-file with the R-code to repeat the analysis and plots of the
 article.