As part of my ongoing efforts to provide feedback to contributors I produced a set of graphs this morning for the UK Hoverflies Facebook group. They tell quite an interesting story for developing hoverfly activity in April. Real activity seems to have started a few days earlier than 2014 and to have continued to gain pace for much of the month (Figure 1). This contrasts with 2014 where there was a bit of a dip mid-month. In both years, however, there was a strong dip towards the end on the month.
|Figure 1. Centred 3-day running means for the number of hoverfly records from photographs in April 2014 and 2015.|
|Figure 2. log2 representation of records of hoverflies recorded from photographs in 2015. Species represented by single records are not represented by a column owing to the use of log2|
|Figure 3. The relative abundance of species within the photographic dataset for hoverflies in April 2015: over 60% of the species are represented by 9 or fewer records.|
|Figure 4. absolute numbers of records of photographs that cannot be identified to species with a 3-day centred running mean super-imposed.|
|Figure 5. Total numbers of representatives within Tribes (red) with numbers of individual genera (blue) reported at log2 scale. Single records are not represented on the scale, hence some gaps.|