Breeding status of Red-billed Choughs Pyrrhocorax pyrrhocorax in the UK and Isle of Man in 2014

Figures & data

Table 1. Distribution of Chough known historic breeding locations across UK and Isle of Man and survey coverage achieved in each region.

		Number of		Number of sites (%)
Country	County	known breeding locations	1-km squares	visited twice	(%)	visited at least twice	(%)	visited less than twice	(%)	visits unrecorded	(%)
Scotland	i. Islay	109	92	57	(52)	84	(77)	6	(6)	19	(17)
	ii. Colonsay	33	20	16	(48)	33	(100)	0	(0)
	iii. Jura	3	3	1	(33)	1	(33)	2	(67)
	iv. Dumfries & Galloway	2	2	2	(100)	2	(100)	0	(0)
	Scotland total	147	117	76	(52)	120	( 82)	8	(5)	19	(13)
Wales	A. Anglesey	76	41	19	(25)	54	(71)	22	(29)
	B. Caernarfon	168	86	25	(15)	98	(58)	70	(42)
	C. Denbighshire	5	4	0	(0)	4	(80)	1	(20)
	D. Meirionnydd	42	22	8	(19)	23	(55)	19	(45)
	E. Montgomery	9	8	2	(22)	2	(22)	7	(78)
	F. Ceredigion	54	36	8	(15)	23	(43)	31	(57)
	G. Pembrokeshire	142	109	112	(78)	138	(96)	4	(3)
	H. Glamorgan	17	14	4	(24)	6	(35)	11	(65)
	Wales total	513	320	178	(35)	348	( 68)	165	(32)
Isle of Man (2014/15)		206	99	171	(83)	180	(87)	20	(10)	6	(3)
Northern Ireland		1	1	1	(100)	1	(100)		(0)
England		13	11	10	(77)	12	(92)	1	(8)
Total		880	548	436	(49)	661	(75)	194	(22)	25	(3)

Table 2. UK and Isle of Man population estimates and regional estimates (number of breeding pairs) from two standard visits and using all additional information. Breeding pairs were classified as possible (poss), probablr (prob) or confirmed (conf) base don the criteria given in Appendix. The discrepancy (%) between these estimates is included to show the influence of additional information on estimates (>2 standard surveys & colour ring records). The percentage of the UK and Isle of Man population in each area (based on confirmed and probable totals using all additional information) and the number of non-breeding birds are also shown.

		Number of breeding pairs based on two standard visits			Total number of breeding pairs based on two standard visits		Total number of breeding pairs based on all information		Discrepancy (%)		% UK & Isle of Man population	Number of non-breeding birds
Country	County	Poss	Prob	Conf	Conf & Prob	Conf & Prob & Poss	Conf & Prob	Conf & Prob & Poss	Conf & Prob	Conf & Prob & Poss		No.	%*
Scotland	i. Islay	8	2	44	46	54	48	52	4	−4	11	39	27
	ii. Colonsay	2	1	6	7	9	8	10	14	11	2	6	23
	iii. Jura	0	0	0	0	0	0	0			0	0
	iv. Dumfries & Galloway	0	0	0	0	0	0	0			0	0
	Scotland total	10	3	50	53	63	56	62	6	−2	13	45	27
Wales	A. Anglesey	5	2	33	35	40	40	41	14	3	9	16	16
	B. Caernarfon	14	4	74	78	92	87	90	12	−2	20	64	26
	C. Denbighshire	0	0	2	2	2	2	2	0	0	0	1	20
	D. Meirionnydd	1	1	16	17	18	18	18	6	0	4	39	52
	E. Montgomery	0	0	0	0	0	0	0			0	0
	F. Ceredigion	6	0	21	21	27	27	29	29	7	6	15	21
	G. Pembrokeshire	15	7	49	56	71	58	73	3	3	13	64	30
	H. Glamorgan	4	0	4	4	8	4	8	0	0	1	7	30
	Wales total	45	14	199	213	258	236	261	11	1	55	206	28
Isle of Man (2014/15)		23	24	108	132	155	133	160	1	3	31	111	26
Northern Ireland		0	0	1	1	1	1	1	0	0	0.2	0
England		2	1	6	7	9	7	9	0	0	2	3	14
UK and Isle of Man Total		80	42	364	406	486	433	493	7	2		365	27

*Based on counts of non-breeding birds and the sum of possible, probable and confirmed breeding pairs (multiplied by two to represent individuals).

Figure 1. (a) Geographical areas referred to in the text in relation to the current and historic distribution of Choughs in the UK and Isle of Man (Wales areas A–H: A. Anglesey, B. Caernarfon, C. Denbighshire, D. Meirionnydd, E. Montgomery, F. Ceredigion, G. Pembrokeshire, H. Glamorgan. Scotland areas i–iv: i. Islay, ii. Colonsay, iii. Jura, iv. Dumfries & Galloway, v. Mull). (b) Distribution of Chough breeding pairs in 2014. Grey 10-km squares show areas of continued occupancy in 2002 and 2014. Range loss and expansion indicated by downward and upward pointing triangles, triangles overlaid squares show net increase and decrease in number of pairs within occupied squares (light grey = 1–2pairs, mid grey = 3–5 pairs, dark grey = 6–8 pairs).

Table 3. Nest location and nest type in Scotland, Wales and Isle of Man occupied by confirmed, probable and possible breeding pairs of Choughs and % change between 2002 and 2014 by country.

Nest location	Country	Scotland (%)	Wales (%)	Isle of Man (%)	Total (%)
Coast	2002*	68 (82)	205 (82)	142 (95)	415 (86)
	2014	45 (73)	223 (85)	146 (91)	414 (86)
	% change	−34	9	3	0.5
Inland	2002*	15 (18)	46 (18)	8 (5)	69 (14)
	2014	17 (27)	38 (15)	14 (9)	69 (14)
	% change	13	−17	75	0
Nest type
Artificial	2002	33 (40)	67 (27)	18 (12)	118 (25)
	2014	41 (67)	71 (27)	31 (19)	143 (30)
	% change	24	6	67	20
Natural	2002	50 (60)	178 (73)	132 (88)	360 (75)
	2014	20 (33)	190 (73)	129 (81)	339 (70)
	% change	−60	8	−2	−5

*2002 figures for nest location vary slightly from Johnstone et al. (2007) due to improved knowledge of specific nest sites and differences in GIS methods used to identify coastal and inland sites.

Table 4. Change in numbers of Choughs breeding in UK and Isle of Man between surveys 1992, 2002 and 2014. Percentage population shown in brackets. Grey shading indicates counties referred to in text as north and mid-Wales.

		Confirmed and probable breeding pairs based on two standard visits						% change
Country	County	1992^1 (%)		2002 (%)		2014 (%)		1992–2014	2002—14
Scotland	i. Islay	69	(23)	56	(14)	46	(11)	−34	−18
	ii. Colonsay	9	(3)	14	(4)	7	(2)	−22	−50
	iii. Jura	2	(0.6)	0	(0)	0	(0)	−100
	iv. Dumfries & Galloway	1	(0.3)	1	(0.3)	0	(0)	−100	−100
	v. Mull	1	(0.3)	0	(0)	0	(0)	−100
	Scotland total	82	(27)	71	(18)	53	(13)	−35	−25
	A. Anglesey	13	(4)	37	(9)	35	(9)	169	−5
	B. Caernarfon	56	(18)	80	(20)	78	(19)	41	−3
	C. Denbighshire	0	(0)	2	(0.5)	2	(0)	Increase	0
	D. Meirionnydd	8	(3)	16	(4)	17	(4)	113	6.3
	E. Montgomery	4	(1)	1	(0.3)	0	(0)	−100	−100
	F. Ceredigion	15	(5)	25	(6)	21	(5)	29	−16
	G. Pembrokeshire	53	(17)	46	(12)	56	(13)	6	22
	H. Glamorgan	1	(0.3)	1	(0.3)	4	(1)	300	300
	Wales total	150	(50)	208^2	(53)	213	(55)	42	2
Isle of Man		68	(22)	114	(29)	132	(32)	94	16
Northern Ireland		2	(0.6)	1	(0.3)	1	(0.2)	−50	0
England		0	(0)	1	(0.3)	7	(2)		600
UK and Isle of Man Total		302		395^2		406		34	3

¹1992 estimates: regional totals for Scotland – unpublished data and Wales – Green & Williams 1992. Isle of Man, Northern Ireland and England as published in Johnstone et al. (2007).

²Two visit 2002 totals for UK and Isle of Man and Wales are four fewer than that reported in Johnstone et al. (2007) due to duplicate nest sites being erroneously included.

Table

Behaviour	Code	Breeding evidence
Single on ground	SG	NONE*
Single flying	SF
Pair flying	PF
Pair on ground	PG	POSSIBLE
Single birds; one in, one out	1-1
Pairs; two in, two out.	2-2
Carrying nest material	CM	PROBABLE
Male feeding female	MF
Mating	MT
Visits to potential nest sites One in, two out	1-2
Nest with eggs	NE	CONFIRMED
Visits to potential nest sites Two in, one out	2-1
Visits to potential nest sites One in & stays in	1-0
Bird carrying faecal sac or eggshell	FE
Nestlings heard begging	NH
Nestlings seen in the nest	NY
Fledged young	FY
Family group	FG

Johnstone, I., Thorpe, R., Moore, A. & Finney, S. 2007. Breeding status of Choughs Pyrrhocorax pyrrhocorax in the UK and Isle of Man in 2002. Bird Study 54: 23–34. doi: 10.1080/00063650709461453

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Green, M. & Williams, I. 1992. The status of the Chough Pyrrhocorax pyrrhocorax in Wales in 1992. Welsh Birds 6: 77–84.

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