BTO BirdTrack - Weekly Reporting Rate for Swift

The Reporting Rate graphs for the last 3 years are no longer updated by the BTO. Instead, you can see the reporting rate for any region, any year, and any species. Although this gives a lot more flexibility, you have to work for it.

First go to:

Explore data
Then hit the Reporting Rate button.

Fill in the Region (e.g. Britain & Ireland), Species (e.g. Swift) and Series (=year, say 2017)
Then hit 'Add plot'.

The Region 'United Kingdom' is not available.

You could now fill in a different year, for example 2007.
Hit 'Add plot' and 'Show graph' again and you can see what happened in the 10 years in between.

You could select 'Historical' for the aggregated reporting rates for all years before the current year to compare with the current year or any other years.

As well as comparing years, you could compare Regions and Species.

Reporting rate trend
We have calculated the trend in average Reporting rate for Britain and Ireland for the summer months (May to July) . Note that changes in Reporting rate underestimate changes in the population, so the ~30% decline from 2007 to 2019 represents a much larger decline in the Swift population, as shown by BBS (~43% between 2007 and 2018). However, this is a useful corroboration of the BBS trend.