Grasshopper Warbler – first and last dates

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant.

YearFirst dateLast dateNotes
200016 April28 September 
200112 April12 SeptemberA min. of 2 pairs bred Castlemartin Range.
20026 April20 SeptemberWidespread reports for April & May; max. 5 Strumble Hd 21 Apr, 6 Skomer 21/22 Apr, 4 Fishguard – Dinas 24 Apr, 4 Rhoslanogfach 26 Apr. In autumn: singles, Castle Martin 28 July, Gelly 5 Aug, Skomer 20 Sept – only records received
20034 April21 SeptemberWidespread spring records at mainly coastal sites.
200411 April31 OctoberRecorded widely Apr-May, mainly at coastal sites.
200521 April1 August7 singing Goodwick Moor 24 April
200621 April25 SeptemberRecorded from 12 sites during Apr with 6 reported from suitable breeding habitat thereafter.  The first autumn migrant Skokholm 6 Aug and the final record Skomer 25 Sept.
200712 April Some 100 records across the county April – September, with the highest counts being of 7 singing males at Goodwick on 21 April, 3+ pairs breeding pairs at Llangloffan Fen.
200812 April31 August18 singing birds Teifi Marshes on 8th June
200910 April20 SeptMax count was of five at Pencarnen on 18 April
20109 April9 October 
20112 April1 October 
201220 April Max count was of eight singing birds at Trefieddan Moor on 2nd May
201312 April8 August 
201412 April25 SeptemberA total of six reeling at Trefeiddan Moor at midnight on 1st May
201515 April2 OctoberLast recorded Marloes Mere on 31st July and on Skomer on 1st & 2nd Oct.
201611 Aprilnot reported after June.Recorded from at least 13 1km squares, with breeding evidence from at least 7 of these. 
20177 April25 SeptemberRecorded from at least 26 1km squares. Presence of singing males noted from half of these but no confirmed breeding reported.  Single seen on The Smalls 19th & 21st April.
201813 April24 SeptemberReported from at least 23 1km square locations. Breeding evidence at five of these was limited to reeling birds only.
20198 April26 AugustReported from 29 locations. Breeding evidence was reported from six locations. Largest counts received were of three: at Teifi Marshes 8 Apr, The Gann 1 June & Llangloffan Fen NNR 22 June, and on passage on Skokholm 1 May.

Records extracted from the Pembrokeshire Bird Reports which may contain more detail.

More about the Grasshopper Warbler in Pembrokeshire

Grasshopper Warbler – 2003-07 breeding

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant. Not recorded from December to March

Comparison with previous atlas:

1984-882003-07
Breeding confirmed82
Breeding probable7083
Breeding possible1111
No of tetrads occupied89 (of 478)96 (of 490)
Percentage of tetrads18.6%19.6%

Interpretation of the comparative results of the two surveys is difficult. Young conifer plantations occupied during the earlier survey had matured to a state of unsuitability by the latter one. The BBS found an increase, on a UK national basis, of 68% since 1994 and by 24% between 2006 and 2007. This may have been in response to favourable conditions at their African wintering grounds resulting in increased survival.

The 1988-91 National Atlas indicated maximum abundance in Pembrokeshire, so it seems safe to apply the UK wide BBS figure to the county plot. This being so, there were probably 480 – 670 pairs breeding in Pembrokeshire at the end of 2007, compared with an estimated 400 pairs in 1988.

Graham Rees (County bird recorder 1981 to 2007)

Rees G.H., Haycock R.J., Haycock A, Hodges J.E., Sutcliffe S.J., Jenks P, and Dobbins R. 2008, Atlas of Breeding Birds in Pembrokeshire 2003-07. Pembrokeshire Bird Group.

More about the Grasshopper Warbler in Pembrokeshire

Grasshopper Warbler – 1994

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant. Not recorded from December to March

Map produced by the West Wales Biodiversity Information Centre
1984-88
Breeding confirmed8
Breeding probable70
Breeding possible11
No of tetrads occupied89 (of 478)
Percentage of tetrads18.6%

The Grasshopper Warbler was a summer visitor with a local breeding distribution to both Mathew (1894) and Lockley et al. (1949), the latter noting that it was a scarce passage migrant on the islands in spring but had only once been recorded in autumn.

Now they are regular in spring between 7 April and early June, sometimes occurring in considerable numbers on the headlands. They sing from cover but also from exposed perches, and up to 40 have been recorded in a day at Skokholm.

Grasshopper Warblers are still locally distributed (see map), occupying patches of rank growth such as fen, common and scrubby grassland, a commodity that has diminished during the years with the development of intensive farming. They also nest in young conifer plantations including those at Wiston Wood and Pantmaenog Forest. The number occupying suitable habitat varies according to how they fare on migration and in their sub-Saharan winter quarters. On the evidence found during the Breeding Birds Survey of 1984-1988 an average density of four pairs per tetrad, based on singing birds, suggests a total population in Pembrokeshire of 400 pairs. However, this is almost certainly an underestimate.

Grasshopper Warblers are less numerous in autumn than they are in spring, with small numbers passing through coastal areas between 27 July and 21 October. One was recorded at Skokholm on 7 November 1968.

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

More about the Grasshopper Warbler in Pembrokeshire

Grasshopper Warbler – 1949

Locustella naevia naevi

Local summer visitor, recorded at St David’s, Solva, Haverfordwest, Goodwick, Dinas, Tenby marsh, Casltemartin Corse, Amroth, Clynderwen, Gwaun Valley, and Teifi mouth.  Scarce passage migrant on islands in spring; but only once recorded there in autumn.

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

More about the Grasshopper Warbler in Pembrokeshire

Grasshopper Warbler – 1894

Locustella navia

A summer visitor, scarce and very local.

We never detected the singular and not-to-be-mistaken song of this species at Stone Hall. The Rev. Clennell Wilkinson pointed out to us a field near his rectory at Castle Martin in a corner of which he had found a Grasshopper Warbler’s nest several summers in succession, an instance of the attachment of the bird to a certain locality. Sir Hugh Owen has informed us that he has seen this species at Goodwick. Mr. Dix writes: “the first time I heard this bird in Wales was one afternoon in July, 1866 — it was just within Carmarthenshire, in a boggy place overgrown with alders and rushes — since then I have heard the bird near Whitechurch, in a similar locality. Last year two males came for a few evenings in July close to this house (Llwynbedw, Kenarth, Llandyssil); “they were in two small clumps of blackthorn about forty yards from each other; they began their peculiar whirring note about dark, when I have stood within a few feet of them without their being the least disturbed. “The Grasshopper Warbler has been noted by the Rev. C. M. Phelps, near Tenby, and Mr. E. W. H. Blagg has informed us that he detected some there in June, 1887.

Mathew M.A. 1894, Birds of Pembrokeshire and its Islands

More about the Grasshopper Warbler in Pembrokeshire

Grasshopper Warbler

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant. Not recorded from December to March

Grasshopper Warbler – first and last dates

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant. Year First date Last date Notes 2000 16 April 28 September   2001 12 April 12 September A min. of 2 pairs bred Castlemartin Range. 2002 6 April 20 September Widespread reports for April & May; max. 5 Strumble Hd 21 Apr, 6 Skomer […]

Grasshopper Warbler – 2003-07 breeding

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant. Not recorded from December to March Comparison with previous atlas: 1984-88 2003-07 Breeding confirmed 8 2 Breeding probable 70 83 Breeding possible 11 11 No of tetrads occupied 89 (of 478) 96 (of 490) Percentage of tetrads 18.6% 19.6% Interpretation of the comparative results […]

Grasshopper Warbler – 1994

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant. Not recorded from December to March 1984-88 Breeding confirmed 8 Breeding probable 70 Breeding possible 11 No of tetrads occupied 89 (of 478) Percentage of tetrads 18.6% The Grasshopper Warbler was a summer visitor with a local breeding distribution to both Mathew (1894) and […]

Grasshopper Warbler – 1949

Locustella naevia naevi Local summer visitor, recorded at St David’s, Solva, Haverfordwest, Goodwick, Dinas, Tenby marsh, Casltemartin Corse, Amroth, Clynderwen, Gwaun Valley, and Teifi mouth.  Scarce passage migrant on islands in spring; but only once recorded there in autumn. R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society More about the Grasshopper Warbler […]

Grasshopper Warbler – 1894

Locustella navia A summer visitor, scarce and very local. We never detected the singular and not-to-be-mistaken song of this species at Stone Hall. The Rev. Clennell Wilkinson pointed out to us a field near his rectory at Castle Martin in a corner of which he had found a Grasshopper Warbler’s nest several summers in succession, an instance of the attachment of […]

Grasshopper Warbler

Locustella naevia – TROELLWR BACH – Breeding summer visitor and passage migrant. Not recorded from December to March