For the last seven 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.
This summer the field on the hospital side of the cycle path has been wonderfully wild – this morning I heard 3 corn buntings there (right) and saw 2 (possibly 3) pairs of reed buntings. A yellowhammer was also singing and several skylarks.
Over the seven years I have in total recorded 87 bird species. These include 16 of the 18 farmland bird indicator species for the Sustainable Development Strategy, of which 13 are breeding, and 17 red list species of high conservation concern, of which 10 have bred. My 2017 survey of the area – which you can download below – showed exceptional numbers of grey partridge in the autumn (right), as well as good numbers of skylark (below left), linnet, yellowhammer (below centre) and corn bunting. Yellow wagtail (below right) also breed. Grey partridge declined by 92% between 1970 and 2013 and corn bunting by 90% while yellow wagtail declined by 67%, skylark and linnet by 60%, and yellowhammer by 55%.
‘The square km south of Addenbrookes has this year supported a grey partridge population of at least 11 spring pairs/km2 and 85 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 last year, with 8 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.
This summer I have also been surveying butterfly populations in the area. I have so far 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, speckled wood (below centre).
You can download a copy of my report for 2017 here.
My reports for 2016 are here:
My reports for 2015 are here: