Wider Countryside Report 
Header
BTO Blueline
Main WCR menu image Site navigation menu item Results overview menu item Other info menu item BTO website menu item
BTO Blueline
 BBWC Home > Key Findings

Key findings

• Declining species

• New alerts

• Positive changes

• Reduced breeding success

• Increased breeding success

• Early breeding


Declining species

In the current report, there are 24 species for which the best long-term trends provide alerts to statistically significant population declines of greater than 50%.

These are Grey Partridge, Lapwing, Snipe, Woodcock, Redshank, Turtle Dove, Cuckoo, Little Owl, Lesser Spotted Woodpecker, Skylark, Tree Pipit, Yellow Wagtail, Whitethroat, Willow Warbler, Spotted Flycatcher, Willow Tit, Marsh Tit, Starling, House Sparrow, Tree Sparrow, Linnet, Lesser Redpoll, Yellowhammer and Corn Bunting.

Starling © John Harding

CBC/BBS indicate with high confidence that the Starling breeding population in England has decreased by around 85% since 1967

Except for Little Owl, which as an introduced species is not eligible for conservation listing, all these rapidly declining species are already red or amber listed on the recently revised Population Status of Birds (PSoB, BoCC3) list. Despite ostensibly meeting a red-list criterion for population decline, the following species are, for various reasons, listed only as amber: Snipe, Woodcock, Redshank, Whitethroat and Willow Warbler. For several of the species listed, long-term trend data are available only for England, where BTO has more volunteers to record information. Different long-term trends could be operating in other parts of the UK. Data for Lesser Redpoll, Tree Pipit, Snipe and Woodcock, are particularly limited geographically.

A further nine species trigger lower-level alerts, as a result of statistically significant long-term declines of between 25% and 50% over periods of 25 to 41 years. These are Common Sandpiper, Meadow Pipit, Grey Wagtail, Dipper, Dunnock, Song Thrush, Mistle Thrush, Goldcrest and Bullfinch. All of these species are on the current amber list on account of their population declines, except for Song Thrush, which remains red listed, and Dipper and Goldcrest, which remain on the green list.

In addition, Little Grebe (-39% since 1975), Curlew (-35% since 1967) and House Martin (-61% since 1967) have also declined by more than 25%, but raise no alerts because the confidence intervals around their change estimates are too wide.

Three additional species monitored only over shorter periods have also decreased by more than half. Nightingale, which has long been amber listed, is on course to meet red-list criteria, having decreased by 53% since 1995). Whinchat has decreased by 57% and Pied Flycatcher by 50% over the same period. These two species, along with Swift (-29%) were newly amber listed for population declines at the 2009 review but are now showing 13-year changes so severe in BBS squares that red listing may be warranted.

Discussion sections 4.2 and 4.3


Recent alerts and alert changes

Snipe © Nigel Clark

Long-term data on Snipe breeding along waterways show an estimated decline of 93%. BBS data show recent increase within the remaining range.

There are few changes to the alerts that were raised by the 2009 version of this report and all are listed here.

The decision has been taken to include the long-term WBS/WBBS trends for Snipe in this report. These easily exceed the threshold for a high alert for both the 33-year and 25-year periods. Little Owl now raises a high alert for the 25-year period, its percentage decline now being just greater than 50%. Goldcrest becomes an alert species in this report, because its 25-year decline is now just over the 25% threshold. It should be noted, though, that this species has a history of wide population fluctuations and that long-term estimates of its trend are rather unstable.

CES trends for Lesser Redpoll and Yellowhammer, which both raised high alerts in last year's report, have now been dropped because of dwindling sample sizes. The CES trend for Willow Tit no longer raises a high alert, the percentage decline having moved from >50% into the 25–50% range. CBC/BBS data for all these three species continue to raise high alerts.

Discussion section 4.2.3


Positive changes

For eight species that meet red or amber criteria for population decline over the long term – Little Grebe, Lapwing, Skylark, House Martin, Meadow Pipit, Grasshopper Warbler, Bullfinch and Yellowhammer – decline has started to level off, or has ceased, during the recent ten-year period.

Six formerly declining species – Grey Wagtail, Dunnock, Song Thrush, Whitethroat, Tree Sparrow and Reed Bunting – have shown significant positive trends over the last ten years. Where the earlier decline had been steep or long-lasting, however, as for the red-listed Tree Sparrow, population levels remain severely depleted despite recent increase.

The recent increase in the red-listed Song Thrush is particularly encouraging. Reed Bunting was also red listed until 2009, but its recent postive trend has allowed it to move to the amber list. It is no longer clear that the species meets any Birds of Conservation Concern listing criteria.

Buzzard ©  George H Higginbotham

Buzzard heads the table of fastest long-term increases, with growth in the English population estimated at 606% since 1967

Although falling short of the 24 species that have at least halved over the long term, there are 18 species that have more than doubled over similar periods (usually 41 years). These are Mute Swan, Canada Goose, Shelduck, Mallard, Tufted Duck, Sparrowhawk, Buzzard, Stock Dove, Woodpigeon, Collared Dove, Green Woodpecker, Great Spotted Woodpecker, Reed Warbler, Blackcap, Great Tit, Nuthatch, Jackdaw and Carrion Crow.

Five additional species monitored only over shorter periods have more than doubled (while three equivalent species have more than halved). Stonechat has increased by 168% in the UK since 1995, and Cetti's Warbler by 244% since 1998. Three species that have benefited from introduction have shown some of the most rapid increases: Greylag Goose (+410% since 1993), Red Kite (+418% since 1995) and the non-native Ring-necked Parakeet (+696% since 1995).

Discussion section 4.4


Reduced breeding success

Nightjar © John Bowers

Reproductive output has decreased for the red-listed Nightjar

A new summary figure, Fledglings Per Breeding Attempt (FPBA), introduced in the 2009 report, represents the mean number of young leaving each nest in a given year. Ten species exhibit negative trends in FPBA over the past 20 years or more, indicating that reproductive output has decreased over time, including four BoCC3 red-listed species (Nightjar, Spotted Flycatcher, Linnet, Yellowhammer), four amber-listed species (Dunnock, Willow Warbler, Bullfinch, Reed Bunting) and two green-listed species (Great Tit, Chaffinch). While productivity of Nightjar, Willow Warbler, Great Tit, Reed Bunting and Linnet has been falling since the mid 1960s, declines in breeding success of the remaining five species have occurred over the last 15–20 years.

Productivity declines in the migrant Nightjar, Willow Warbler and Spotted Flycatcher may be driven by changes in habitat and/or climate on the African wintering grounds or by declining insect numbers in the UK. Alternatively, climatic warming may have resulted in a developing asynchrony between laying dates and the availability of insect prey on the breeding grounds. Long-distance migrants are thought to be particularly susceptible to such disjunction but residents may also be affected, which may explain the falling productivity of Great Tit and Chaffinch, although the possibility of a density-dependent decline cannot be excluded for these rapidly increasing species.

Studies of declining Linnet, Reed Bunting and Yellowhammer populations have identified winter food availability as a key factor, and loss of condition during the winter could depress subsequent breeding success. These species, along with Dunnock and Bullfinch, may also have suffered from a loss of scrub habitat mediated at least in part by increasing numbers of deer.

CES ringing data indicate that productivity has fallen by more than 30% for eight of the species monitored by this scheme (Blackbird, Song Thrush, Garden Warbler, Sedge Warbler, Blue Tit, Great Tit, Goldfinch). Declines in FPBA for both Great Tit and Reed Bunting suggest that the reduced numbers of juveniles are the result of a reduction in the productivity of individual attempts rather than of changes in the number of breeding attempts or in post-fledging survival rates. Three species (Song Thrush, Sedge Warbler and Reed Bunting) have experienced significant population declines, either on CES sites or more widely.

Discussion section 4.5


Increased breeding success

Increasing breeding performance may be helping to drive population expansion of a number of rapidly increasing species: the predatory Sparrowhawk and Buzzard; the columbid Stock Dove; the corvids Jackdaw, Magpie and Carrion Crow; the resident insectivores Pied Wagtail, Grey Wagtail, Robin, Long-tailed Tit and Nuthatch; and the migrant insectivores, Redstart and Reed Warbler. Six further species (Kestrel, Skylark, Dipper, Starling, House Sparrow and Tree Sparrow) are exhibiting significant increases in productivity as populations decline, which may be due to density dependence.

Discussion section 4.5

Stock Dove © John Harding

Breeding success is improving for Stock Doves


Early breeding

Magpie © Jill Pakenham

On average, Magpies are now laying
30 days earlier than in 1968

Data from the Nest Record Scheme provide strong evidence of shifts towards earlier laying in a range of species, linked to climate change. We have now identified 39 species that, on average, are laying between 5 and 30 days earlier than in the mid 1960s. The species involved represent a wide range of taxonomic and ecological groups, including raptors (Kestrel– 8 days), waterbirds (Moorhen – 5 days), waders (Oystercatcher – 6 days), migrant insectivores (Pied Flycatcher – 11 days, Swallow – 9 days), resident insectivores (Robin – 8 days, Blue Tit – 8 days), corvids (Magpie – 30 days) and resident seed-eaters (Greenfinch – 15 days).

For some species these shifts towards earlier laying may be insufficient to track seasonal advances in food availability. Recent research has shown that significantly stronger phenological responses to climate change are displayed at lower than at higher trophic levels, increasing the potential for disjunction and resulting population declines (Thackeray et al. 2010).

Discussion section 4.5.3

Next page – Contents

BTO blue divider
 

BTO Home | JNCC Home
 © British Trust for Ornithology. Charity No 216652 (England and Wales).Charity No SC039193 (Scotland)
Company Limited by Guarantee No 357284 (England and Wales).
Registered Office: The Nunnery, Thetford, Norfolk IP24 2PU, UK.
Terms and Conditions
| Privacy Statement          Email:


This report should be cited as: Baillie, S.R., Marchant, J.H., Leech, D.I., Renwick, A.R., Joys, A.C., Noble, D.G., Barimore, C., Conway, G.J., Downie, I.S., Risely, K. & Robinson, R.A. (2010). Breeding Birds in the Wider Countryside: their conservation status 2010. BTO Research Report No. 565. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Iain Downie, Mandy T Andrews and Laura Smith: Last updated 15.11.2010