I have been studying diurnal migration at Caldene fields for many years and it is interesting to note how the population trends of some finch fluctuate year by year.
I thought I would look specifically at three common finches the Goldfinch, Chaffinch and Greenfinch which are locally common and breeds in the local area. However, in autumn these finches migrate through our area allowing counts which gives yearly data on the numbers of individual passing through.
Yearly totals on the left.
Years on the bottom
My data is not definitive but give an ‘indication’ into how well the species has done in a particular year.
It’s interesting to analyse the data which shows the Goldfinch is the commonest finch observed and in 2016 it appears to have been a good year. In addition I have noted an increase of local flocks of feeding Goldfinches.
The Chaffinch is not as common on passage as the Goldfinch but migration counts increased fairly dramatically in 2017 & 18. The reason I believe this has happened is that there has been a good influx of continental Chaffinches arriving to spend the winter here especially this year.
The Greenfinch nationally is down in numbers and the downward trend started around 2012 and sadly numbers have not really increased although they appear to have leveled out during the last two years at this site. There are no longer any sizable flocks of feeding Greenfinch observed in our recording area.