Increasing species

Population changes of species for which our best long-term trend estimate from CBC/BBS (usually over 49 years) or from WBS/WBBS (a maximum of 41 years) shows an increase of more than 50% are shown in Table C1. There are 30 species listed, one more than in BirdTrends 2017; the increase for Oystercatcher is now both just above the cut-off. Twenty-three of the species have more than doubled their population size over the periods in which they have been monitored (23–49 years).

Table C1 Long-term population increases of greater than 50% from CBC/BBS (1967-2016) or WBS/WBBS (1975-2016), using the best survey for each species

Species Period
(yrs)
Source Change
(%)
Lower
limit
Upper
limit
Alert Comment
Buzzard 49 CBC/BBS England 844 532 3328    
Greylag Goose 23 WBS/WBBS waterways 478 187 1351    
Great Spotted Woodpecker 49 CBC/BBS UK 378 250 591    
Collared Dove 44 CBC/BBS UK 306 167 480    
Shelduck 31 CBC to 1999 300 94 787   Small sample
Blackcap 49 CBC/BBS UK 288 224 383    
Mute Swan 49 CBC/BBS UK 260 57 839    
Nuthatch 49 CBC/BBS UK 251 135 391    
Stock Dove 49 CBC/BBS England 223 128 372    
Green Woodpecker 49 CBC/BBS England 174 114 314    
Mallard 49 CBC/BBS UK 167 114 238    
Woodpigeon 49 CBC/BBS UK 157 28 448    
Canada Goose 35 WBS/WBBS waterways 154 30 609    
Coot 49 CBC/BBS UK 154 69 463    
Goosander 35 WBS/WBBS waterways 142 66 327    
Carrion Crow 49 CBC/BBS England 138 101 197    
Jackdaw 49 CBC/BBS UK 130 42 294    
Wren 49 CBC/BBS UK 128 99 156    
Chiffchaff 49 CBC/BBS UK 121 84 187    
Goldfinch 49 CBC/BBS England 120 68 190    
Long-tailed Tit 49 CBC/BBS England 107 52 206    
Reed Warbler 49 CBC/BBS UK 104 35 292    
Magpie 49 CBC/BBS UK 100 62 151    
Sparrowhawk 41 CBC/BBS England 98 17 250    
Pheasant 49 CBC/BBS England 90 48 162    
Great Tit 49 CBC/BBS UK 89 64 117    
Pied Wagtail 49 CBC/BBS UK 74 26 136    
Goldcrest 49 CBC/BBS England 72 -2 230    
Robin 49 CBC/BBS UK 57 44 74    
Oystercatcher 41 WBS/WBBS waterways 51 13 157    

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 1480% (more than a 15-fold increase) over the 21 years 1995–2016. Arguably, however, this is more a conservation problem than a success! Mandarin Duck (+414%) is another fast-increasing non-native species. Unmitigated successes are the growth during 1995–2016, estimated through BBS, of Barn Owl (+238%), Gadwall (+171%) and the reintroduced Red Kite (+1457%). Little Egret has increased by more than 20-fold during 1995–2016. 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 1243% during 1990–2016.

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, Long-tailed Tit 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 74% on CBC/BBS plots over 49 years, but declined by 62% on WBS/WBBS plots over the past 41 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 the major causal factors are common to all. For Mallard, the CBC/BBS increase was matched by a WBS/WBBS increase of 178% over 41 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 a remarkable 844% between 1967 and 2016, with an increase of 55% over the last ten years alone. Sparrowhawks, too scarce for CBC to monitor until the mid 1970s, showed a 98% increase over the 41-year period from 1975 to 2016. However, their recovery appears to have been completed earlier than Buzzard's, with the population currently in shallow decline.

While Pheasant holds a place in this table, its increase in census data has been driven largely by the hugely increasing scale of releases of artificially reared poults for shooting, from which the corvids may also have benefited.