Population changes of species for which our best long-term trend estimate from CBC/BBS (usually over 46 years) or from WBS/WBBS (a maximum of 38 years) shows an increase of more than 50% are shown in Table C1. There are 29 species listed, one fewer than in recent years: the increase for Tufted Duck is now just below the 50% cut-off. Nineteen of the species have more than doubled their population size over the periods given (20–46 years).
Table C1 Long-term population increases of greater than 50% from CBC/BBS (1967-2014) or WBS/WBBS (1975-2014), using the best survey for each species
Great Spotted Woodpecker
CBC to 1999
|Table C1 Long-term population increases of greater than 50% from CBC/BBS (1967-2014) or WBS/WBBS (1975-2014), using the best survey for each species|
|Great Spotted Woodpecker||46||CBC/BBS UK||396||251||621|
|Greylag Goose||20||WBS/WBBS waterways||391||130||1049|
|Collared Dove||41||CBC/BBS UK||343||203||572|
|Shelduck||31||CBC to 1999||300||94||787||Small sample|
|Mute Swan||46||CBC/BBS UK||253||70||706|
|Canada Goose||32||WBS/WBBS waterways||212||51||826|
|Stock Dove||46||CBC/BBS England||194||105||355|
|Green Woodpecker||46||CBC/BBS England||184||111||307|
|Carrion Crow||46||CBC/BBS England||128||81||201|
|Great Tit||46||CBC/BBS UK||102||79||132|
|Long-tailed Tit||46||CBC/BBS England||87||41||167|
|Reed Warbler||46||CBC/BBS UK||83||25||290|
|Pied Wagtail||46||CBC/BBS UK||60||19||116|
|Coal Tit||46||CBC/BBS UK||58||-19||156|
Table C1 is led by Buzzard, by a wide margin, but it should be noted that six 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 1181% (more than a 12-fold increase) over the 18 years 1995–2013. Arguably, however, this is more a conservation problem than a success! Unmitigated successes are the growth during 1995–2013, estimated through BBS, of the reintroduced Red Kite (+874%) and of Barn Owl (+219%). Little Egret and Gadwall, included in this report for the first time in 2014, have increased by an estimated 139% and 112% respectively but in this case over just the recent ten-year period. Though the trajectory has been moderated considerably by recent cold-weather-related setbacks, attention should also be drawn to the rapid rise of Cetti's Warbler, a newly established native species, which CES now estimates to have increased by 379% since 1987.
Four groups stand out among the increasing species: corvids – 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 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, Great Tit, Wren, Long-tailed Tit and Coal Tit. The reasons for these increases are presently unclear. Pied Wagtail has increased in numbers by 60% on CBC/BBS plots over 46 years, but declined by 63% on WBS/WBBS plots over the past 38 years. The former index is likely to be more 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.
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 194% over 38 years. The long-term increases recorded for Mute Swan on both CBC/BBS and WBS/WBBS plots are likely to be the result of banning the use of lead weights by anglers, which took effect in 1986. Greylag Goose, Shelduck, Canada Goose, Tufted Duck, Coot and Goosander are other wildfowl among this report's increasing species. Oystercatchers have increased by 54% on WBS/WBBS plots over the last 38 years. This finding is consistent with the results of the most recent survey of Breeding Waders of Wet Meadows which found that numbers of Oystercatchers using these habitats in England and Wales increased by 51% between 1982 and 2002 (Wilson et al. 2005).
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 by shooting interests. Buzzards increased in England by a remarkable 726% between 1967 and 2013, with a rapid increase of 71% over the last ten years alone. Sparrowhawks, too scarce for CBC to monitor until the mid 1970s, showed a 115% increase over the 38-year period from 1975 to 2013. However, their recovery appears to have been completed earlier than Buzzard's, with the population currently stable or 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.
This report should be cited as: Robinson, R.A., Marchant, J.H., Leech, D.I., Massimino, D., Sullivan, M.J.P., Eglington, S.M., Barimore, C., Dadam, D., Downie, I.S., Hammond, M.J., Harris, S.J., Noble, D.G., Walker, R.H. & Baillie, S.R. (2015) BirdTrends 2015: trends in numbers, breeding success and survival for UK breeding birds. Research Report 678. BTO, Thetford. www.bto.org/birdtrends