BTO - Breeding Birds of the Wider Countryside: Dunnock

DUNNOCK
Prunella modularis

• Population
changes

• Productivity
trends

• Additional
information

Conservation listings

Europe: no SPEC category (concentrated in Europe, conservation status favourable)
UK: amber (25–50% population decline)
UK Biodiversity Action Plan: priority species

Long-term trend

UK, England: moderate decline

UK population size

2,163,000 territories in 2000 (1988–91 Atlas estimate updated using CBC/BBS trend: BiE04, APEP06)

Status summary

Dunnock abundance fell substantially between the mid 1970s and mid 1980s, after a period of population stability. Some recovery has occurred throughout the UK since the late 1990s, but the species is still amber listed. The cause of the decline remains unknown. In many lowland woods, canopy closure in the absence of forest management and increasing browsing pressure from deer are likely to have reduced the suitability of the habitat for this species (Fuller et al. 2005). There has been little variation in survival rates over time (Siriwardena et al. 1998a). Clutch and brood sizes increased as the population fell. Egg-stage nest faliure rates are currently increasing, and are of NRS concern (Leech & Barimore 2008). Numbers have fallen widely in Europe since 1980 (PECBMS 2007).

Population changes

CBC/BBS England graph

Table of population changes for Dunnock

Source	Period (yrs)	Years	Plots (n)	Change (%)	Lower limit	Upper limit	Alert	Comment
CBC/BBS UK	39	1967-2006	703	-33	-42	-22	>25
	25	1981-2006	978	-6	-17	5
	10	1996-2006	1910	23	18	28
	5	2001-2006	2024	9	6	12
CBC/BBS England	39	1967-2006	582	-37	-46	-26	>25
	25	1981-2006	805	-10	-22	0
	10	1996-2006	1555	20	16	24
	5	2001-2006	1632	8	6	12
CES adults	22	1984-2006	94	-1	-16	14
	10	1996-2006	105	2	-6	10
	5	2001-2006	95	-2	-9	7
CES juveniles	22	1984-2006	91	-19	-37	4
	10	1996-2006	103	-8	-17	0
	5	2001-2006	95	-12	-20	-5
BBS UK	11	1995-2006	1769	23	18	28
	10	1996-2006	1822	22	18	27
	5	2001-2006	2024	10	7	13
BBS England	11	1995-2006	1440	18	13	23
	10	1996-2006	1478	19	15	24
	5	2001-2006	1632	10	7	12
BBS Scotland	11	1995-2006	115	39	14	64
	10	1996-2006	119	33	10	53
	5	2001-2006	128	10	-7	24
BBS Wales	11	1995-2006	140	40	19	68
	10	1996-2006	146	36	19	59
	5	2001-2006	170	16	6	26
BBS N.Ireland	11	1995-2006	62	90	37	136
	10	1996-2006	68	51	19	76
	5	2001-2006	82	0	-9	13

CES adult abundance graph

CES juvenile abundance graph

BBS UK graph

BBS England graph

BBS Scotland graph

BBS Wales graph

BBS N Ireland graph

Productivity trends

Table of productivity changes for Dunnock

Variable	Period (yrs)	Years	Mean annual sample	Trend	Modelled in first year	Modelled in 2006	Change	Comment
Clutch size	38	1968-2006	99	Linear increase	3.94 eggs	4.2 eggs	6.6%
Brood size	38	1968-2006	106	Linear increase	3.48 chicks	3.63 chicks	4.5%
Daily failure rate (eggs)	38	1968-2006	143	Curvilinear	2.51% nests/day	2.48% nests/day	-1.2%
Daily failure rate (chicks)	38	1968-2006	117	None
Laying date	38	1968-2006	79	Linear decline	May 3	Apr 29	-4 days
Juvenile to Adult ratio (CES)	22	1984-2006	98	Smoothed trend	115 Index value	100 Index value	-13%
Juvenile to Adult ratio (CES)	10	1996-2006	109	Smoothed trend	114 Index value	100 Index value	-13%
Juvenile to Adult ratio (CES)	5	2001-2006	99	Smoothed trend	122 Index value	100 Index value	-18%

Clutch size graph

Brood size graph

Egg nest failure graph

Chick nest failure graph

Laying date graph

CES productivity graph

Additional information


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This report should be cited as: Baillie, S.R., Marchant, J.H., Leech, D.I., Joys, A.C., Noble, D.G., Barimore, C., Grantham, M.J., Risely, K. & Robinson, R.A. (2009). Breeding Birds in the Wider Countryside: their conservation status 2008. BTO Research Report No. 516. BTO, Thetford. (http://www.bto.org/birdtrends) Pages maintained by Iain Downie, Mandy T Andrews and Laura Smith: Last updated 18.02.2009