DOI: 10.5061/dryad.v7g7d
title: Data from: Phenological shifts in hoverflies (Diptera: Syrphidae): linking measurement and mechanism

description: An understanding of ecological and evolutionary responses to global
 environmental change requires both a robust measurement of the change that
 is occurring and a mechanistic framework for understanding the drivers of
 that change. Such a requirement provides a challenge because biological
 monitoring is often ad hoc, and mechanistic experiments are often
 performed under highly simplified conditions. This study integrates
 multiple datasets to evaluate our current knowledge of the measurement and
 mechanism of phenological shifts in a key pollinator taxon: the hoverflies
 (Diptera: Syrphidae). First, two large, complementary and independent
 monitoring datasets are used to test for trends in phenology: an ad hoc
 national recording scheme containing &gt;620,000 records, and
 standardised monitoring with consistent methods over 30 years. Results
 show that ad hoc and standardised recording data give quantitatively the
 same value for phenological advance in hoverflies (ca. 12 days°C-1 on
 average at the beginning of the flight period), supporting the value of
 biological recording for the measurement of global ecological change.
 While the end of the flight period appears static in ad hoc recording, the
 standardised dataset suggests a similar advance as in the beginning of the
 flight period. Second, an extensive traits dataset and a novel database of
 laboratory-derived developmental data on Syrphidae (153 published studies)
 are used to test for mechanistic patterns in phenological shifts. The only
 species trait that influenced phenology was voltinism, where species with
 more generations per year exhibit stronger phenological advances. We
 demonstrate considerable variation in the laboratory-derived sensitivity
 to temperature but this does not match field-derived measures of
 phenology. The results demonstrate that, as for many taxa, we have a
 strong understanding of the patterns of global ecological change but that
 we currently lack a detailed mechanistic understanding of those processes
 despite extensive research into the fundamental biology of some taxonomic
 groups.
description: Table S1 - Barcoding
 data used in tree constructionTable S1: Codes for
 sequences used in the construction of the NJ tree for hoverflies (Diptera:
 Syrphidae). See Figure S1 for the finished neighbour joining tree and the
 main text for the analytical procedures by which those sequences were
 processed.Table S1 - Barcoding
 data.xlsxTable S2 -
 Temperature-development dataThis file contains an
 extensive synthesis of temperature-development records from laboratory
 experiments involving the rearing of Syrphidae. Contained within the Excel
 file are (i) a spreadsheet with the data extracted from the papers, (ii) a
 metadata worksheet with definitions of the columns, and (iii) a full
 bibliography of the studies involved.Table S3 - HRS species
 specific dataTable S3: Full dataset
 of relationships between temperature, date, and flight periods in
 hoverflies derived from the Hoverfly Recording Scheme.Table S4 - Phenology
 shifts vs zeroTable S4: Results of
 statistical analysis to test for a difference between samples of
 phenological responses (PC=Pearson correlation, Reg=regression
 coefficient) of different parts of the flight period (5=5th percentile,
 50=50th percentile, 95=95th percentile) and zero. Results are all from
 generalised least squares analysis with a floating intercept, fitted
 without phylogenetic autocorrelation ("Uncontrolled") and using
 two different hoverfly phylogenies.Table S5 - All traits
 analysisTable S5: Results of
 statistical analysis to test for an effect of species traits on
 phenological responses (Pearson correlations between annual temperature or
 year). Results are all from generalised least squares analysis with a
 floating intercept, fitted without phylogenetic autocorrelation
 ("Uncontrolled") and using two different hoverfly phylogenies.
 "--" indicates no data due to the presence of only one trait
 value in that dataset. Significant results are highlighted in
 bold.Table S6 - Owen species
 specific dataTable S6: Full dataset
 of relationships between temperature, date, and flight periods in
 hoverflies derived from standardised recording (see main text for
 details).