In 2018 and 2019 I carried out bird surveys of Coombe Bissett Down for the Wiltshire Wildlife Trust. Alas the third year of the planned survey in 2020 was cancelled due to Covid restrictions.

In both years I carried out two sorts of surveys:

Firstly, breeding bird surveys. This involved four visits of between five and six hours each carried out between April and June. This involved walking the whole reserve and plotting on a plan the location of all birds seen or heard. At the end of the season, the data from all visits is collated, and a plan for each individual breeding species is created showing the location in which they were recorded over all four visits. This methodology is known as territory mapping and seeks to provide a best estimate of the numbers of pairs of each species breeding on the reserve.

Secondly, winter bird surveys. This involved carrying out a survey of about four hours each in November and December of each year. It is a simple count of the numbers of birds seen and heard on the reserve together with some overflying the reserve.

What do the results show?
With regard to breeding birds, in 2018 there were considered to be 22 species breeding on the reserve and in 2019 there were 26. Total species recorded in the breeding season, including some overflying were 42 and 40 respectively. Some species like red-legged partridge, pheasant and skylark were recorded but are not included in the species breeding as their territories are very difficult to plot; that said, skylark and pheasant are very likely to breed somewhere on the reserve. Breeding species recorded were very much as anticipated and show what a rich habitat the reserve provides. It was particularly pleasing to record 10 pairs of yellow bunting (yellowhammer) in 2018 and 12 in 2019. Blackcap was also particularly well represented with seven pairs in 2018 and 12 in 2019. We tend to think of blackbirds as garden birds, but the combination of thick hedges and short grassland on the reserve are clearly much to their liking with 16 and 19 pairs recorded in the survey years. The reserve is also clearly important for common birds such as robin, wren and dunnock, and the agricultural buildings hold a thriving colony of about 10 pairs of house sparrows. Single pairs of buzzard, green and great-spotted woodpeckers also nest on the reserve with a small number of pairs of whitethroats and chiffchaffs.

In winter, the total number of species recorded were 40 in 2018 and 42 in 2019. Once again it was very pleasing to record good numbers of yellow buntings with a maximum of 53 birds in November 2019. Linnets also peaked in that month with 51 birds recorded, most being in a single flock feeding on thistle seeds. The large number hawthorn bushes on the reserve are a magnet for winter thrushes which feed on their berries. In November 2018, 497 fieldfares and 220 redwings were recorded, but a month later these numbers had dropped to 61 and 50 respectively, probably as a result of most of the berries having been eaten. Large numbers of blackbirds also frequent the reserve in winter; in contrast numbers of song thrushes are always very modest. Large numbers of birds seem to briefly visit the reserve in winter, it is a common sight to see large numbers of rooks jackdaws and woodpigeons on some occasions but very few on another. In November 2018 I counted several flocks of feeding starlings totalling 670 birds, the following month there were none! Of the scarcer winter species, two wintering blackcaps were recorded in December 2018, two brambling in November 2018 and six corn buntings in December 2019. Finally of course, to warm the heart of any winter birdwatcher, red kites are increasingly being recorded over the reserve.

Above: Fieldfare, Pete Blanchard

Banner: Red kite, Dave Kilbey