Classification of the verifications based on photos that were uploaded by participants and on identification of photographs by seminar attendees at the British Science Festival.

<p>Precision is the proportion of submitted identifications which were correct; miss rate is the proportion of records which were of a colour group but were incorrectly identified. Precision was separated as into ‘colour type’ and bumblebee, i.e. the proportion of records submitted as that colour type which were correct to colour type or correctly identified as a bumblebee, respectively. The full mis/classification matrix is in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150794#pone.0150794.s006" target="_blank">S2 Table</a>.</p

The number of records received per 10km grid square in the UK to show the spatial spread of participation.

<p>The number of records received per 10km grid square in the UK to show the spatial spread of participation.</p

The importance of the different variables on the reported rate of bumblebees (standardised for five minutes on a lavender 37 cm in diameter, i.e. the average in this study).

<p>Except for variation in the variable of interest, the rates are shown relative to locations in towns, very close (<30cm) to other flowers, on English lavender and on days with full sun and no wind.</p

The proportion of the number of colour types reported according to the number of bumblebees counted per observation.

<p>Only observations up to counts of 20 are shown. The rapid rise in the number of colour types reported with increasing number of observations, and the large proportion of observations with all six colour types reported, suggested there was a propensity to over-report the true number of colour types, although this could not be independently verified.</p

Distinction between species based on colour group based on [35, 39, 41].

<p>Distinction between species based on colour group based on [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150794#pone.0150794.ref035" target="_blank">35</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150794#pone.0150794.ref039" target="_blank">39</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150794#pone.0150794.ref041" target="_blank">41</a>].</p

Observed vs. fitted range change values.

<p>Values for “uncorrected range change”, recording effort level 1. Fitted values are weighted means across the set of top GLM models with ΔAIC<4. The dashed unity line indicates equality of observed and fitted values. Species with the largest residuals have been labelled.</p

Grasshopper and related species range sizes in 1980–9 and 2000–9 and calculation of range change measures.

<p>The figure plots range sizes in 1980–9 vs. 2000–9 (as logit-transformed proportions of squares occupied) for four levels of recording effort. “Uncorrected range change” was defined as the absolute change in range size, i.e. residual distances from the (black) 1:1 unity lines. “Corrected range change” was defined as change in range size relative to the mean change across species, i.e. as the (standardised) residual distances from the linear regression lines (solid grey for all species, dashed grey for species excluding the two with particularly large range change values, <i>C</i>. <i>discolor</i> and <i>M</i>. <i>roeselii</i>).</p