Breeding Birds in the Wider Countryside 2000: Yellowhammer

YELLOWHAMMER Emberiza citrinella

Conservation Listings

Long term trend

Unlisted/Green
Biodiversity Steering Group
Conservation Concern List

UK: Rapid decline
Farmland: Moderate decline
Woodland: Rapid decline
Scrub (CES): Rapid decline

Status Summary

Yellowhammer abundance began to decline on farmland in the mid-1980s and the decline has continued ever since, the CBC trend being replicated in the CES and BBS results. The woodland CBC trend shows a longer term decline, perhaps showing problems for the species in this secondary (perhaps sink) habitat before they were apparent in the preferred farmland habitats. Yellowhammer breeding performance has tended to increase and there is some evidence that survival rates have been lower during the period of decline (Siriwardena et al. 1998b, 2000b). In addition to increases in clutch and brood size, nest failure rates have fallen: the proportion of nests failing at the egg stage (15 days, comprising 12 days incubation + 3 days laying) fell from 55% to 38%, and at the chick stage (12 days) from 45% to 38%. Overall the failure rates from egg laying to fledging fell from 75% to 62%; these values are relatively high, probably because later season nests, which tend to be more successful (Kyrkos 1997), are probably under-represented in the NRS dataset - such a factor is unlikely to affect overall trends. Reductions in winter seed food availability as a result of agricultural intensification (for example, the loss of winter stubbles and declining weed densities) are widely believed to have contributed to the decline.

Table of population changes for Yellowhammer

Source	Period (yrs)	Years	Plots (n)	Change (%)	Lower limit	Upper limit	Alert	Comment
CBC all habitats	30	1968-1998	133	-54	-63	-45	>50
	25	1973-1998	134	-56	-63	-47	>50
	10	1988-1998	111	-44	-51	-39	>25
	5	1993-1998	105	-23	-30	-18
CBC farmland	30	1968-1998	75	-42	-55	-29	>25
	25	1973-1998	73	-45	-56	-36	>25
	10	1988-1998	69	-40	-48	-32	>25
	5	1993-1998	66	-23	-28	-16
CBC woodland	30	1968-1998	34	-74	-85	-59	>50
	25	1973-1998	35	-74	-84	-61	>50
	10	1988-1998	28	-60	-76	-44	>50
	5	1993-1998	25	-34	-56	-11	>25
CES adults	14	1984-1998	23	-58	.	.	[>50*]
	10	1988-1998	25	-35	.	.	[>25]
	5	1993-1998	23	-15	.	.
CES juveniles	14	1984-1998	12	-73	.	.	[>50*]	Small sample
	10	1988-1998	13	-69	.	.	[>50*]	Small sample
	5	1993-1998	12	-35	.	.	[>25]	Small sample
BBS UK	5	1994-1999	982	-16	-20	-11
BBS England	5	1994-1999	853	-15	-20	-11
BBS Scotland	5	1994-1999	86	-13	-28	6
BBS Wales	5	1994-1999	35	-31	-52	-2	(>25)	Small sample

The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB

Table of productivity information for Yellowhammer

Variable	Period (yrs)	Years	Mean annual sample	Trend	Predicted in first year	Predicted in last year	Change	Comment
Clutch size	30	1968-1998	44	Linear increase	3.38 eggs	3.53 eggs	0.15 eggs
Brood size	30	1968-1998	69	Curvilinear	2.96 chicks	3.19 chicks	0.23 chicks
Daily failure rate (eggs)	30	1968-1998	66	Curvilinear	0.0517 nests/day	0.0317 nests/day	-0.02 nests/day
Daily failure rate (chicks)	30	1968-1998	51	Curvilinear	0.0479 nests/day	0.0385 nests/day	-0.0094 nests/day
Laying date	30	1968-1998	26	None				Small sample
Percentage juveniles (CES)	14	1984-1998	26	Smoothed trend	113 productivity index	100 productivity index	-11%
Percentage juveniles (CES)	10	1988-1998	28	Smoothed trend	194 productivity index	100 productivity index	-49%[>25]
Percentage juveniles (CES)	5	1993-1998	26	Smoothed trend	88 productivity index	100 productivity index	14%

The report should be cited as: Baillie, S.R., Crick, H.Q.P., Balmer, D.E., Bashford, R.I., Beaven, L.P., Freeman, S.N., Marchant, J.H., Noble, D.G., Raven, M.J., Siriwardena, G.M., Thewlis, R. and Wernham, C.V. (2001) Breeding Birds in the Wider Countryside: their conservation status 2000. BTO Research Report No. 252. BTO, Thetford. (http://www.bto.org/birdtrends)

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Last updated: Last updated: 9 April, 2001

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