Coal Tit - autumn irruptions

 Parus ater - TITW PENDDU - Breeding resident, unusual on the islands

Although basically a sedentary species, the coal tit is prone to irruptive/eruptive behaviour following particularly good breeding seasons.  In such years, they are often seen along the open coast, and even reach the offshore islands, usually in October. During a large irruption of tits in 1957, more than 100 coal tits passed through Skokholm.

More recent such occurrences include:

1988 - Unusually high numbers reported after the breeding season, when many joined mixed tit flocks on the open coast and penetrated to both Skomer and Skokholm

1989 - Up to 15 seen at Skomer 30 Sept - 23 Oct and 4 reached Skokholm on 12 Oct.

1991 - Reached Skomer in greater than usual numbers, & total of 171 bird-days logged Sept-Nov. Up to 15 also reached Skokholm.

1994 - Island records: Skomer 22,23,& 25 September with a max of 10; one Skokholm 15 Oct; 3 Ramsey 11 Oct

1997 - Eruptive and irruptive from Sept, when many flocks Seen around the coast at places like Strumble Head, Porthclais, St. Bride's and Castlemartin, with up to 170 reaching Ramsey, up to 14 Skomer and one Skokholm. Several exhibited the bluish-grey mantles of the Fenno-Scandian form, P. a. ater but most showed the olive-grey of P. a. britannicus.

1999 - One reached Ramsey 24 Oct; singles Skomer 24 June, 5-6 Oct, 25 Oct and I Nov, with 7 on 14 Oct and up to 9 between 17 & 20 Oct.

2001 - 1-4 reached Skomer on 11 dates, 21 Sept – 20 Oct (JGB), and singles Ramsey on 6 dates, 25 Sept – 20 Oct (SA)

2003 - Oct passage noted from Skomer and Ramsey. 50+ noted Porth Clais 3 Oct.

2008 - On Ramsey singles on 27 and 29 Sept, 3 Oct and 2nd Nov with 2 on 27th Oct and 3 on 1 Oct. This mini invasion represented the first records for 5 years. On Skomer: a single on September 25th. Three present on October 3rd and two on the 8th and 16th.

2010 - Three on Skomer on 7th and 12th Oct and two on 17th Oct, one on Ramsey on 9th Oct and two on the 11th Oct.

2015 - Max counts: 20 Dale Air Field on 25 Sept and 50 in off the sea on Ramsey on 30 Sept.

Records extracted from the Pembrokeshire Bird Reports

British Coal Tit - 1949 status

Parus ater britannicus

Common resident, but does not visit islands except isolated record of one remaining Skokholm from 8 Nover 1930 to 6 March 1931.

R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society

Coal Tit - 2012 - Irish race hibernans

Parus ater hibernans

On 22^ND October in the Blackthorn scrub above the Youth Hostel at St Davids , a Coal Tit was observed by M Young-Powell, showing the lemon yellow cheeks and yellowish underparts of the Irish race ‘hibernans’. It turned out that a similar bird had been trapped and Photographed on Bardsey in 2006.

The Irish race of Coal Tit ‘hibernans’ differs from the Mainland British form ‘Parus ater britannicus  ‘ by having yellow below and in the cheeks as compared to white cheeks and warm buff breast sides.

Coal Tits used to breed on Tresco in the Isles of Scilly but they died out and they are now very rare visitors to the Scilly archipelago. In the autumn of 2012, Coal Tits started arriving on St Agnes in north-westerlies  and were watched on the rocks out at Horse Head; unfortunately I was on Bryher for the day. They remained on St Agnes and also appeared on other islands for the next week or so. Numbers reached the twenties on St Agnes alone. They showed the characteristic yellow cheeks and dirty yellow underparts of ‘hibernans’.

It has been suggested that similar plumages can occur in birds found in south-west Scotland, maybe around the Solway Firth. This may have relevance to the Bardsey record but seems unlikely to be the source for the invasion of the Scillies in 2012 and the clearly related St David’s bird. At present a decision  doesn’t seem  to have been made  regarding the origin of these birds – over to the Welsh Rarities Panel.

Photo of Bardsey bird in April 2004 by Steve Stansfield

MYP 30/05/2013

Coal Tit - 2003-07

The county breeding population was estimated to lie in the range of 500–700 pairs at the end of the 1984-88 survey. This estimate tried to make allowances for the disparity between densities in conifer plantations and those found elsewhere. It assumed a density of 50 pairs per tetrad in conifer plantations and two to three pairs per tetrad elsewhere. Subsequent experience suggested this under estimated the occupation of non-conifer habitats. This resulted in a lower mean density than the UK average used in the 1988-91 National Atlas, which also showed a relative abundance map showing Pembrokeshire as having a lower than national average. Scaling this proportionally suggests the county figure could have been about 1,100 pairs at that time.

The BBS found there was a 16% reduction in population in Wales between 1994 and 2007, which if applied to the revised 1988 figure for Pembrokeshire, suggests there were about 900 pairs during the 2003-07 survey. However clear felling of conifer plantations took place during the years of the 2003-07 survey which must have reduced Coal Tit numbers. This is not reflected in the survey returns, for some plantations were surveyed before the fellers moved in. To what degree the Pembrokeshire breeding population has been reduced has yet to be evaluated, requiring future study.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads) 

Red = breeding confirmed = 70

Orange = breeding probable = 120

Yellow = breeding possible = 19

Total tetrads in which registered = 209 (42.7%)

Coal Tit - 1994

Breeding resident

Known to Mathew (1894) and Lockley et al. (1949) as a common resident, today the Coal Tit breeds throughout the woodlands of Pembrokeshire, being most numerous in the conifer plantations. These plantations largely post-date the previous avifaunas, and this additional habitat has contributed to the species becoming more numerous than formerly. At an estimated average of two to three pairs per tetrad generally and 50 pairs per tetrad in the plantations, the total breeding population is probably 500­ 700 pairs.

Coal Tits are prone to eruptive behaviour during autumns following productive breeding seasons, and are then seen on the open coast, and reach the offshore islands of Ramsey, Skomer and Skokholm. They were particularly numerous in the autumn of 1991 when they were noted along the cliffs of the mainland; up to seven reached Skomer and 15 were recorded at Skokholm.

 

Fieldwork 1984-88 (based on 478 tetrads) 

Red = breeding confirmed = 78

Orange = breeding probable = 69

Yellow = breeding possible = 52

Total tetrads in which registered = 199 (41.6%)

Donovan J.W. & Rees G.H (1994), Birds of Pembrokeshire

Coal Tit - 1970s breeding

Red = breeding confirmed

Orange = breeding probable

Yellow = breeding possible

Coal Tit - 1980s winter atlas

The BTO winter atlas showed that Coal Tit were present in most 10km squares during the winters of 1981-82, 1982-82 and 1983-84.

The darker the colour, the higher the relative total count for each 10km square.  The darkest blue represents over 18 birds in a day. Probably numerically under recorded in dense conifer plantations during winter when they do not normally reveal themselves by singing.

Graham Rees 

Coal Tit - 1894

Parus britannicus

A common resident. Mr. Dix considered it more common than he had ever met with it in England, and in our locality it was certainly an abundant species. The nests we found were always lined with a thick welt of rabbit's fur.

Mathew M.A. 1894, Birds of Pembrokeshire and it's Islands