BTO - Breeding Birds of the Wider Countryside: Spotted Flycatcher

SPOTTED FLYCATCHER
Muscicapa striata

• Population
changes

• Productivity
trends

• Additional
information

Conservation listings

Europe: SPEC category 3, declining
UK: red (>50% population decline)
UK Biodiversity Action Plan: click here

Long-term trend

UK, England: rapid decline

UK population size

63,700 territories in 2000 (1988–91 Atlas estimate updated using CBC/BBS trend: BiE04, APEP06)

Status summary

Spotted Flycatchers have declined rapidly and consistently since the 1960s according to census data, and the decline is also reflected in the trend revealed by CES. Productivity measures indicate lower clutch and brood sizes and greater nest losses at the egg and chick stages, which raise NRS concern (Leech & Barimore 2008), and a decrease overall in the ratio of juveniles to adults. Demographic modelling shows that decreases in the annual survival rates of birds in their first year of life are most likely to have driven the decline (Freeman & Crick 2003). Decreasing survival rates may have been caused by deteriorations in woodland quality, particularly leading to declines in the large flying insects that are food to the flycatcher, or by conditions either on the wintering grounds or along migration routes (Fuller et al. 2005). Since trends have been similar across UK regions and habitats, however, it is more likely that the decline has been driven by factors operating outside the UK. Spotted Flycatchers are estimated to have declined by 59% across Europe during 1980–2005 (PECBMS 2007). A predator 'control' experiment has indicated that the abundance of nest predators may be determining the breeding success of Spotted Flycatchers, especially in woodland, where nest success was lower overall than in gardens (Stoate & Szczur 2006). Another study using nest cameras has identified avian predators, especially Jays, as responsible for most nest losses (Stevens et al. 2008).

Population changes

Table of population changes for Spotted Flycatcher

Source	Period (yrs)	Years	Plots (n)	Change (%)	Lower limit	Upper limit	Alert	Comment
CBC/BBS UK	39	1967-2006	121	-86	-90	-80	>50
	25	1981-2006	142	-81	-86	-75	>50
	10	1996-2006	222	-32	-38	-16	>25
	5	2001-2006	196	-18	-27	-3
CBC/BBS England	39	1967-2006	93	-87	-92	-82	>50
	25	1981-2006	105	-82	-87	-75	>50
	10	1996-2006	159	-32	-44	-16	>25
	5	2001-2006	136	-23	-32	-10
CES adults	22	1984-2006	15	-30	-75	32		Small sample
	10	1996-2006	13	13	-51	79		Small sample
	5	2001-2006	13	31	-24	94		Small sample
CES juveniles	22	1984-2006	11	-56	-86	-15	>50	Small sample
BBS UK	11	1995-2006	202	-37	-46	-23	>25
	10	1996-2006	206	-35	-42	-21	>25
	5	2001-2006	196	-20	-29	-2
BBS England	11	1995-2006	144	-37	-48	-21	>25
	10	1996-2006	146	-34	-44	-20	>25
	5	2001-2006	136	-22	-32	-11

Productivity trends

Table of productivity changes for Spotted Flycatcher

Variable	Period (yrs)	Years	Mean annual sample	Trend	Modelled in first year	Modelled in 2006	Change	Comment
Clutch size	38	1968-2006	81	Curvilinear	4.22 eggs	4.15 eggs	-1.7%
Brood size	38	1968-2006	130	Curvilinear	3.61 chicks	3.6 chicks	-0.3%
Daily failure rate (eggs)	38	1968-2006	122	Curvilinear	1.77% nests/day	1.88% nests/day	6.2%
Daily failure rate (chicks)	38	1968-2006	109	Linear increase	0.98% nests/day	1.43% nests/day	45.9%
Laying date	38	1968-2006	72	None
Juvenile to Adult ratio (CES)	22	1984-2006	21	Smoothed trend	133 Index value	100 Index value	-25%
Juvenile to Adult ratio (CES)	10	1996-2006	18	Smoothed trend	119 Index value	100 Index value	-16%	Small sample
Juvenile to Adult ratio (CES)	5	2001-2006	16	Smoothed trend	149 Index value	100 Index value	-33%	Small sample

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