Finally someone said it!
The other factor that needs pointing out is that the data driving all these models is incredibly wobbly. It’s being modelled rather than directly mapped because there just isn’t the data to directly map it. Insects are a specialist-requiring group in general and, though we’re working on ways to involve ‘citizen science’, without guidance and quality control the data is worse than useless. To make things more complex, recording has changed so quickly and in so many ways that attempting to control for recorder effort, the main focus of a lot of current models, is a nightmarish task. This is the graph of how many records BWARS holds for each year (ignore the drop at the end, that’s down to them not completing the import for that time period yet). Then to further complicate things, this is how all these records break down per taxa. The first 11 taxa hold 25% of the total data.
The reality of all this is that we know so very very little and we need more data. But we can’t just take any data since, as I’ve said before, these are specialist-requiring animals. The models which are being run are able to be run because the data held in these schemes is subjected to a number of verification checks and quality controls (all done by volunteer experts). Are there declines? Yes. But be very cautious placing exact numbers on them.