ready. You are currently on: Metadata: Common bird index

Metadata: Common bird index


Research Institute for Nature and Forest (INBO), in cooperation with Natuurpunt Study vzw


Common bird index: this index describes the trend for a selection of common bird species since the start of the Flanders General Breeding Birds (ABV) monitoring network in 2007, for which the reference year 2007 is set at 100%. There are 3 categories: common farmland birds, common forest birds and birds that breed in a variety of habitats, the generalists. Each indicator is based on the geometric mean of the indices of its individual species.

Species list of common farmland birds: Barn swallow, Yellowhammer, Yellow wagtail, Grasshopper, Meadow pipit, Black-tailed godwit, Lapwing, Common linnet, Grey partridge, Eurasian tree sparrow, European stonechat, Eurasian oystercatcher, Common kestrel, Eurasian skylark, Eurasian curlew. Prior to the 2022 analysis, the indicator’s species list was adjusted at Europe’s request. Black Redstart, White Wagtail and Icterine Warbler, all species with a much wider distribution than just farmland, were taken out so that the resulting set of species conforms to the species list of the European farmland indicator. The numbers included for the years prior to 2022 also relate only to the adjusted species list.

Species list of common forest birds: European pied flycatcher, Eurasian nuthatch, Short-toed treecreeper, Tree pipit, Common buzzard, Willow warbler, Eurasian jay, Common redstart, Goldcrest, European green woodpecker, European greenfinch, Great spotted woodpecker, Mistle thrush, Stock dove, Common cuckoo, European crested tit, Northern willow tit, Common nightingale, Eurasian sparrowhawk, Common chiffchaff, Garden warbler, Eurasian golden oriole, Coal tit, Black woodpecker, Eurasian blackcap.

Species list of breeding birds in diverse habitats: Eurasian Magpie, Common pheasant, European greenfinch, Great spotted woodpecker, Dunnock, Common wood pigeon, House sparrow, Western jackdaw, Great tit, Common blackbird, European blue tit, European robin, Common starling, Long-tailed tit, Eurasian collared dove, Common chaffinch, Eurasian wren, Song thrush, Carrion crow.

Remarks on quality

The identified trends are based on standardised counts of breeding birds, performed by volunteers in 1x1 km squares (UTM grid) defined in advance. Each sample box is counted in a 3-year cycle and the data are collected online via (in Dutch)(opens in new window). The evaluation of the trend is based on a statistical trend analysis.

To the statistics