For the last eight years I have surveyed breeding populations of farmland birds on a square kilometre of green belt south of Addenbrooke’s Hospital in Cambridge, to assess the levels of the biodiversity of an area close to the city.
Over the eight years I have in total recorded 90 bird species. These include 17 of the 18 farmland bird indicator species for the Sustainable Development Strategy, of which 13 are breeding, and 18 red list species of high conservation concern, of which 10 have bred. My most recent survey of the area – which you can download below – showed exceptional numbers of grey partridge in the autumn (right) and corn bunting (above), as well as good numbers of skylark (below left), linnet and yellowhammer (below centre). Yellow wagtail (below right) also breed. Grey partridge declined by 92% between 1970 and 2013 and corn bunting by 89% while yellow wagtail declined by 67%, skylark by 59%, yellowhammer by 56% and linnet by 55%.
In 2019 the area supported a grey partridge population of at least 13 spring pairs/km2 and 80+ birds/km2 in autumn. The arable farms typical of Cambridgeshire support between 0 and 5 pairs/km2 and 0–20 birds/km2 in the autumn.
Corn buntings also did particularly well in 2019, with 10 pairs. This is an important population – there are just 11,000 birds in the UK and its recent extinction in Ireland risks being repeated in large parts of Britain if its breeding sites are not protected. The RSPB’s nearby Hope Farm had 2 pairs in 2016 in 1.8km2.
In addition, the site supports a thriving population of water voles, both in the start of Hobsons Brook, and in the ditch that runs alongside the cycle path.
In 2019 I also surveyed butterfly populations in the area and recorded brimstone, comma (below right), common blue, Essex skipper, gatekeeper (below left), green-veined white, holly blue, large skipper, large white, meadow brown, orange tip, painted lady, peacock, red admiral, ringlet, small heath, small tortoiseshell, small white and speckled wood (below centre).
You can download a copy of my most recent report (2019) here:
My report for 2018 is here:
My report for 2017 is here:
My reports for 2016 are here:
My reports for 2015 are here: