Increasing species

Population changes of species for which our best long-term trend estimate from CBC/BBS (usually over 50 years) or from WBS/WBBS (a maximum of 42 years) shows an increase of more than 50% are shown in Table C1. There are 30 species listed, the same as in BirdTrends 2018; however the increase for Oystercatcher is now just below the cut-off and it has been replaced in the table by Coal Tit which is now just above the cut-off. Twenty of the species have more than doubled their population size over the periods in which they have been monitored (24–50 years).

Table C1 Long-term population increases of greater than 50% from CBC/BBS (1967-2017) or WBS/WBBS (1975-2017), using the best survey for each species

Species Period
Source Change
Alert Comment
Buzzard 50 CBC/BBS England 850 540 3013    
Greylag Goose 24 WBS/WBBS waterways 461 187 1754    
Great Spotted Woodpecker 50 CBC/BBS UK 387 275 646    
Shelduck 31 CBC to 1999 300 94 787   Small sample
Collared Dove 45 CBC/BBS UK 299 154 475    
Blackcap 50 CBC/BBS UK 297 231 393    
Mute Swan 50 CBC/BBS UK 270 71 845    
Nuthatch 50 CBC/BBS UK 268 185 441    
Stock Dove 50 CBC/BBS England 237 135 413    
Green Woodpecker 50 CBC/BBS England 162 87 263    
Woodpigeon 50 CBC/BBS UK 162 33 442    
Mallard 50 CBC/BBS UK 154 93 220    
Goosander 36 WBS/WBBS waterways 148 53 322    
Coot 50 CBC/BBS UK 142 43 427    
Carrion Crow 50 CBC/BBS England 137 89 178    
Canada Goose 36 WBS/WBBS waterways 137 37 511    
Goldfinch 50 CBC/BBS England 131 70 198    
Jackdaw 50 CBC/BBS UK 130 56 222    
Wren 50 CBC/BBS UK 117 88 145    
Chiffchaff 50 CBC/BBS UK 110 73 170    
Reed Warbler 50 CBC/BBS UK 99 31 334    
Magpie 50 CBC/BBS UK 98 62 152    
Long-tailed Tit 50 CBC/BBS England 96 36 177    
Pheasant 50 CBC/BBS England 94 52 166    
Great Tit 50 CBC/BBS UK 90 65 115    
Sparrowhawk 42 CBC/BBS England 87 9 229    
Pied Wagtail 50 CBC/BBS UK 57 17 124    
Goldcrest 50 CBC/BBS England 54 -12 242    
Robin 50 CBC/BBS UK 52 39 69    
Coal Tit 50 CBC/BBS UK 50 -3 147    

Table C1 is led by Buzzard, by a wide margin, but it should be noted that seven of the fastest-increasing species in this report are actually not included here, because their monitoring data cover too short a period. The UK's non-native population of Ring-necked Parakeets is estimated to have risen by 1710% (more than a 18-fold increase) over the 22 years 1995–2017. Arguably, however, this is more a conservation problem than a success! Mandarin Duck (+54% over 2007-17) is another fast-increasing non-native species. Undoubted success stories are the growth during 1995–2017, estimated through BBS, of Barn Owl (+289%), Gadwall (+213%) and the re-introduced Red Kite (+1624%). Little Egret has increased by more than 20-fold during 1995–2017. Though the trajectory has been moderated by recent cold-weather-related setbacks, attention should also be drawn to the rapid rise of Cetti's Warbler, a recently established native species, which CES now estimates to have increased by 988% during 1992–2017.

Four groups stand out among the increasing species: corvids – especially Carrion Crow, Magpie and Jackdaw; doves – Collared Dove, Stock Dove and Woodpigeon; woodpeckers and other smaller species of woodland and gardens; and some waterbirds. Corvids appear to have benefited from changed gamebird management practices in recent years, and the larger doves from the increased acreage of brassica crops (particularly oilseed rape).

The majority of the third group are species primarily of woodland that are also common in gardens in some areas: Great Spotted Woodpecker, Green Woodpecker, Nuthatch, Blackcap, Wren, Great Tit, Coal Tit, Long-tailed TitGoldcrest and Robin. The reasons for these increases are presently unclear but may, in many cases, relate to improved feeding opportunities in gardens. Pied Wagtail has increased in numbers by 57% on CBC/BBS plots over 50 years, but declined by 66% on WBS/WBBS plots over the past 42 years, although the CBC/BBS index is likely to be most representative of the UK population as a whole. Reed Warbler, also an insectivore, has been expanding its range northwards and westwards and might be benefiting from climate change. Declines on CES plots suggest the benefits might not be universal, with the habitat quality in 'core' sites possibly decreasing, while warming climates facilitate the colonisation of new sites.

A number of species associated with freshwater habitats are becoming more abundant, although differences between their ecological requirements make it unlikely that there is a single causal factor common to all. For Mallard, the CBC/BBS increase was matched by a WBS/WBBS increase of 169% over 42 years. The long-term increases recorded for Mute Swan on both CBC/BBS and WBS/WBBS plots are likely to be the result, at least in part, of banning the use of lead weights by anglers, which took effect in 1986. Greylag Goose, Shelduck, Canada Goose, Coot and Goosander are other wildfowl among this report's increasing species.

Two widespread raptors have shown remarkable recoveries from low population levels after the banning of certain poisonous farmland pesticides in the early 1960s, assisted by lower levels of illegal predator control. Buzzards increased in England by 850% between 1967 and 2017, with an increase of 46% over the last ten years alone. Sparrowhawks, too scarce for CBC to monitor until the mid 1970s, show a 87% increase over the 42-year period from 1975 to 2017. However, their recovery appears to have been completed earlier than Buzzard's, and the population is now in moderate decline (for unknown reasons), prompting a lower level alert to be raised over the 25-year period (see Latest long-term alerts).

While Pheasant holds a place in this table, its increase in census data has been driven largely by increasing, but poorly quantified, scale of releases of artificially reared poults for shooting. Corvids, and other generalist predators, may also have benefited, exploiting both through the food provided for poults and the high mortality of poults, resulting in an abundant level of carcasses.


This report should be cited as: Woodward, I.D., Massimino, D., Hammond, M.J., Harris, S.J., Leech, D.I., Noble, D.G., Walker, R.H., Barimore, C., Dadam, D., Eglington, S.M., Marchant, J.H., Sullivan, M.J.P., Baillie, S.R. & Robinson, R.A. (2019) BirdTrends 2019: trends in numbers, breeding success and survival for UK breeding birds. BTO Research Report 722. BTO, Thetford.