BTO - Breeding Birds of the Wider Countryside

BLUE TIT
Parus caeruleus

Conservation listings

Europe: no SPEC category (concentrated in Europe, conservation status favourable)
UK: Green

Long-term trend

UK, England: shallow increase

Distribution maps

Maps and statistics from British and Irish
atlases can be viewed here.

Status summary

Blue Tit populations have increased in abundance, in parallel with those of Great Tits, with brief pauses in the long-term upward trend. The recent years of the CBC/BBS index show fluctuations but no clear trend. Food provision by humans during winter and availability of nest boxes, which may reduce egg and nestling predation, have both increased and may have contributed to the rise in population. A substantial decline in productivity, revealed by the CES, has accompanied the population increase.

Table of population changes for Blue Tit

Source Period
(yrs) Years Plots
(n) Change
(%) Lower
limit Upper
limit Alert Comment

CBC/BBS UK 35 1967-2002 594 32 18 45

25 1977-2002 755 13 3 22

10 1992-2002 1544 8 5 12

5 1997-2002 2038 -1 -3 2

CBC/BBS England 35 1967-2002 494 31 13 46

25 1977-2002 626 10 -1 20

10 1992-2002 1270 5 2 9

5 1997-2002 1658 -2 -4 1

CES adults 18 1984-2002 94 6 . .

10 1992-2002 108 9 . .

5 1997-2002 108 -3 . .

CES juveniles 18 1984-2002 93 -30 . . [>25]

10 1992-2002 108 -18 . .

5 1997-2002 108 -13 . .

BBS UK 9 1994-2003 1710 18 13 22

BBS England 9 1994-2003 1389 10 6 15

BBS Scotland 9 1994-2003 120 64 38 95

BBS Wales 9 1994-2003 141 19 5 35

BBS N.Ireland 9 1994-2003 53 73 27 136

Table of productivity information for Blue Tit

Variable	Period (yrs)	Years	Mean annual sample	Trend	Predicted in first year	Predicted in last year	Change	Comment
Clutch size	34	1968-2002	83	None
Brood size	34	1968-2002	135	Linear decline	8.32 chicks	7.5 chicks	-0.82 chicks
Daily failure rate (eggs)	34	1968-2002	134	Linear decline	0.0053 nests/day	0.0021 nests/day	-0.0032 nests/day
Daily failure rate (chicks)	34	1968-2002	115	None
Laying date	34	1968-2002	116	Linear decline	day 123	day 117	-6 days
Percentage juveniles (CES)	18	1984-2002	98	Smoothed trend	158 productivity index	102 productivity index	-37%[>25]
Percentage juveniles (CES)	10	1992-2002	113	Smoothed trend	130 productivity index	102 productivity index	-23%
Percentage juveniles (CES)	5	1997-2002	113	Smoothed trend	108 productivity index	102 productivity index	-8%


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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