Wednesday 24 June 2009

MARSH WARBLER in OXFORDSHIRE

OTMOOR RSPB (OXFORDSHIRE) (1500-1700 hours)

Phil Barnett 'phoned me last night informing me that he had just discovered a singing MARSH WARBLER at Otmoor RSPB reserve - a mega rare bird in the county and the perhaps the first record in over 20 years. As it was nearing 2100 hours, I decided to wait and visit today. Hearing it was still present late morning, I ventured out from the car park in the searing heat of the afternoon sun. It was a long walk too - taking me about 20 minutes to cover the mile or so walk out to between the first and second screens. Roger Wyatt had been on site since early morning and as I joined him, he explained that the bird had only given brief glimpses throughout all of the intervening period. The bird was commuting between the reedbed just over the raised bank and the dense hedgerow bordering the main footpath about equidistant between the two observation screens. It was singing as soon as I arrived and in fact continued almost non-stop until I departed. Unlike the Hertfordshire bird I had seen and heard this week, this bird had a full repertoire and was mimicking a whole host of species including Sedge Warbler, Goldfinch, Common Whitethroat, Blackcap, Wren, Great Tit and Common Blackbird. The song was also typically loud and was delivered from quite high in the hedgerow.

Seeing the bird was a different matter though and for much of the time, it afforded just brief glimpses, mainly in flight. At one stage however it moved to near the top of the hedge and I was able to get full views of it for about a minute. It then flew over our heads and into the reedbed. Little detail was noted however, other than it being a very pale brown in colour on the upperparts and being bright orange-yellow on the lower mandible.

A single 'purring' EUROPEAN TURTLE DOVE was present in the hedgerow 300 yards west of the car park, whilst 2-4 HOBBIES were hunting for dragonflies and other insects over the main marsh continuously. At least 15 post-breeding Lapwings overflew the lagoons whilst Sedge Warbler, Western Reed Warbler, Common Whitethroat, Bullfinch and Yellowhammer were all recorded.

ACCESS INSTRUCTIONS

Otmoor RSPB is not signposted and is a difficult reserve to find..It is best accessed from the B4027, easily reached from the main A40 roundabout in Headington, at the eastern end of the city. Taking the road towards Horton, turn left (signposted Beckley) on to Woodperry Road after 0.5 miles and continue for 0.7 miles into the village. Turn right on the High Street at the 'Abingdon Arms' public house and then turn left after 100 yards on to Otmoor Lane. The latter road is in a serious state of disrepair and ridged high in the middle and requires extreme attention and care. Continue for 1 mile to where a gate enters the reserve car park proper.

From here, follow the RSPB trail for 1700m. After you pass the first screen, the track bears sharp right. From here, continue for 200 yards from where the bird can be heard.

PREVIOUS MARSH WARBLER RECORDS FOR OXFORDSHIRE
(Acknowledgements: Brucker, Gosler & Heryet 1992, Birds of Oxfordshire, and Ian Lewington, pers. comm.)

The Marsh Warbler bred in Oxfordshire intermittently until 1960, with William Warde Fowler describing the progress of a small colony of up to four pairs in an Osier bed near his home in Kingham from 1890 until 1904 when the habitat was destroyed. One of the interesting discoveries he made during this period was of a Common Cuckoo's egg in one nest in 1898; the first time the Marsh Warbler had been recorded as a host species in Britain. Breeding was not noted again in the county until 1920, but from then until 1947 single nests were found in 11 summers along the Thames and Kennet river valleys and at Sandford Sewage Farm. There has been only one record of breeding since then, in 1960, when a pair reared a single youngster. A juvenile was also ringed at Sonning Gravel Pits in 1964.

There have been just four records prior to this one since 1965 -:

1) A singing male in South Oxon on 28 May 1973 (P.D.Goriup)

2) A singing male at Radley GP from 6-14 June 1981.

3) A singing male at Somerton on 8 June 1983 (Andy Collins)

4) A singing male at Otmoor NR on 29 June 2000 (Jon Baker)