BTO - Breeding Birds of the Wider Countryside: Discussion 4.3

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4.3

Ten-year trends and evidence for species recovery

If the status of species that have shown long-term declines was now improving we would expect to find more positive trends in recent years compared with the earlier part of the time series. To examine this we list here the best change estimates over the most recent ten-year period for which we have estimates (1992-2002) for all of the declining species listed in the previous section of this report (Table 4.3).

Table 4.3 Best estimates of population change over the last 10 years (1992-2002) for all species identified as having long-term declines of greater than 25%.

Species	Period (yrs)	Source	Change (%)	Lower limit	Upper limit	Alert	Comment
Lesser Redpoll	10	CBC/BBS England	-71	-90	-54	>50
Willow Tit	10	CBC/BBS UK	-60	-76	-41	>50
Tree Pipit	10	CBC/BBS England	-55	-70	-35	>50
Lesser Spotted Woodpecker	10	CBC to 1999	-51	-75	-22	>50	Small sample
Little Grebe	10	WBS waterways	-49	-65	-30	>25	Small sample
Turtle Dove	10	CBC/BBS UK	-48	-58	-36	>25
Cuckoo	10	CBC/BBS England	-46	-51	-40	>25
Starling	10	CBC/BBS England	-46	-50	-41	>25
Corn Bunting	10	CBC/BBS UK	-45	-60	-30	>25
Grey Partridge	10	CBC/BBS UK	-43	-52	-31	>25
Spotted Flycatcher	10	CBC/BBS UK	-43	-54	-29	>25
Woodcock	10	CBC to 1999	-40	-62	-11	>25	Small sample
Redshank	10	WBS waterways	-39	-52	-23	>25	Small sample
Yellow Wagtail	10	CBC/BBS UK	-38	-60	-27	>25
Willow Warbler	10	CBC/BBS England	-29	-35	-22	>25
Yellowhammer	10	CBC/BBS UK	-26	-32	-20	>25
Common Sandpiper	10	WBS waterways	-24	-37	-12
Meadow Pipit	10	CBC/BBS England	-23	-38	-6
Skylark	10	CBC/BBS England	-21	-26	-16
House Sparrow	10	CBC/BBS England	-21	-33	-11
Tree Sparrow	10	CBC/BBS England	-20	-65	0
Lesser Whitethroat	10	CBC/BBS UK	-17	-28	-2
Bullfinch	10	CBC/BBS UK	-12	-21	-2
Marsh Tit	10	CBC/BBS UK	-11	-26	4
Reed Bunting	10	CBC/BBS UK	-11	-19	3
House Martin	10	CBC/BBS England	-9	-39	27
Red-legged Partridge	10	CBC/BBS UK	-9	-20	3
Lapwing	10	CBC/BBS UK	-8	-22	7
Mistle Thrush	10	CBC/BBS UK	-8	-15	3
Kestrel	10	CBC/BBS England	-6	-19	6
Linnet	10	CBC/BBS England	-6	-18	4
Dunnock	10	CBC/BBS UK	16	9	24
Song Thrush	10	CBC/BBS UK	20	11	26
Grey Wagtail	10	WBS waterways	23	11	35
Whitethroat	10	CBC/BBS UK	43	29	55
Nightingale	10	CES adults	44	.	.		Small sample
Goldcrest	10	CBC/BBS England	66	30	85

See Help for information on what the categories mean

The 37 species listed include 16 from the red list, 16 declining species that are amber-listed on account of population declines and 5 species that are not formally listed as declining. Six species, Dunnock, Song Thrush, Grey Wagtail, Whitethroat, Nightingale and Goldcrest show positive trends over the last 10 years. The figure for Nightingale should be treated with caution as it is based on a small amount of data from CES sites. The steady increase in the red-listed Song Thrush since about 1997 is particularly encouraging.

The rate of decline of 25% over 25 years that is used as a threshold for amber listing is equivalent to a decline of 10.9% over 10 years (assuming both have the same annual rate of change). A further six species, House Martin, Red-Legged Partridge, Lapwing, Mistle Thrush, Kestrel and Linnet, have negative ten-year changes involving declines of less than 11%. None of the 10-year declines for these six species are statistically significant. Thus our data suggest that the declines of these species appear to be levelling off although there is as yet no clear indication of recovery.

Ten-year changes for the remaining 25 species in Table 4.3 indicate ongoing declines, with rates equivalent to at least 25% over 25 years. Four species, Lesser Redpoll, Willow Tit, Tree Pipit and Lesser Spotted Woodpecker, have declined by more than 50% over the last 10 years alone. The on-going declines of so many of the species listed in Table 4.3 must be a cause of serious conservation concern.

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This report should be cited as: Baillie, S.R., Marchant, J.H., Crick, H.Q.P., Noble, D.G., Balmer, D.E., Beaven, L.P., Coombes, R.H., Downie, I.S., Freeman, S.N., Joys, A.C., Leech, D.I., Raven, M.J., Robinson, R.A. and Thewlis, R.M. (2005) Breeding Birds in the Wider Countryside: their conservation status 2004. BTO Research Report No. 385. BTO, Thetford. (http://www.bto.org/birdtrends) Pages maintained by Susan Waghorn and Iain Downie: Last updated 18 January, 2006