April Review

Bonaparte's Gull at Blenheim Park, courtesy of Roger Wyatt

From its opening day the peak passage month of April drew a steady stream of regular annual migrants back to or through Oxfordshire. Amongst all these arrivals there were several notable records, while some other birds seemed a little reluctant to go on their way.

Farmoor Reservoir was on form throughout as the county's finest birders patrolled the twin concrete bowls and Thameside meadows in search of the unusual. Three sightings stood out there. On 8th an Arctic Skua was pictured flying low over F2 before departing to the north. Then on 13th only Oxon's fourth Little Bunting was noted briefly by the Pinkhill Meadow reserve, but didn't linger or co-operate for anyone's camera. The most recent past records of that scarce tundra breeder were in 2017 and 1993.

Arctic Skua at Farmoor Reservoir, courtesy of Jonathan Mercer
Click on any image to enlarge

Pale 1w flava-type Wagtail on Farmoor causeway, courtesy of Roger Wyatt

Yellow Wagtail is a complex that can keep the most expert amongst birders busy at this time of year, since up to 16 intricately distinguishable taxa occur across the northern hemisphere. On 24th an individual in an unusual state of moult was spotted on the causeway that seemed a good candidate for Eastern Yellow Wagtail, a recently split former sub-species whose home range is eastern Asia. This puzzle prompted much discussion within the county birding community though no consensus has been reached as to the ID.

Courtesy of Badger.

Notwithstanding that trio of tantilizers, our bird of the month had to be the adult Bonaparte's Gull that was discovered at Blenheim Park on 12th, remaining until 22nd. One of the more frequent north-American gulls with some 230 national records to date, this individual drew plenty of admirers during it's time with us. Through that interlude it was seen to almost complete its moult into summer plumage as the pictures below show. This was the sixth Oxon record, all of which have been this century and in April or May; a decent number for an inland county.

Bonaparte's Gull, courtesy of Nic Hallam

Bonaparte's Gull, courtesy of Ewan Urquhart

An intriguing episode concerning two wandering White Stork unfurled during the review period. The first un-ringed one was observed circling over the Otmoor reserve and subsequently seen feeding on the nearby MoD land, then what was presumably the same bird was viewed in flight near Tackley, all on 7th.

White Stork over Otmoor, courtesy of John Reynolds

The second bird was in the south-east of the county at Cholsey and by the River Thames at Shillingford on 8th and 9th. This later Polish-ringed individual escaped from a rehabilitation centre in Norfolk following an injury, and had been viewed around the south-east of England in the weeks leading up to its almost expected visit to Oxfordshire. This is the second Polish-ringed escapee to find its way into the county following the individual which arrived at RSPB Otmoor on 25th July 2016.

White Stork at Shillingford, picture courtesy of Roger Wyatt
Video courtesy of Badger

In north-Oxon the Whooper Swan remained in the Upper Cherwell Valley throughout the month, commuting regularly between Borrow Pit to the north-east of Grimsbury Reservoir and nearby fields where it associated with grazing Mute Swans. Though this is late in the season, April records are not unprecedented. A juvenile remained at Otmoor until 7th in 2018 and an adult at Chimney Meadows until 17th in 2005.

Whooper and Mute Swans, picture courtesy of Mike Pollard
Video courtesy of John Friendship-Taylor

Another lingerer more usually associated with winter was Short-eared Owl at RSPB Otmoor, where a pair were viewed a number of times between 5th and 17th. There also through April two male Bittern boomed out the reserve's raison d'etre to the satisfaction of stalwart birders and delighted novice visitors alike.

Short-eared Owl on Otmoor, courtesy of Nick Truby

Amongst the regular passage migrants the best performers were perhaps Little Gull through Farmoor Reservoir, and Ring Ouzel on the Chilterns escarpment. The review period witnessed one of the busiest national movements of the former in many years. During it Farmoor watchers recorded seven or more birds on eight separate days between 8th and 22nd, with numbers peaking at 12 on 14th.

Little Gulls at Farmoor (above), courtesy of Peter Alfrey
and a first winter (below), courtesy of Jeremy Dexter

Mediterranean Gulls at Farmoor, courtesy of Jim Hutchins

Eight more Little Gull were logged at the LWV West Oxford Sailing Club lake on 8th, and three at Grimsbury Reservoir on 9th. Mediterranean Gull continued to feature through April, with several records from Farmoor between 3rd and 22nd; and at Otmoor on 19th. An errant Kittiwake passed through Farmoor on 8th.

Ring Ouzel at Linky Down, courtesy of Steve Burch

The year's first Ring Ouzel arrived at the regular staging post of Linky Down on April 1st, no fooling! Then the same male bird and sometimes one more were reported there for the next several days. Three males were noted between 8th and 10th before things rather took off from 12th to 15th with up to seven "Rouzels" passing through on those dates. So this was a solid county passage for the species at that site, with the last record occurring on 22nd. Two more birds were seen in Long Meadow, Otmoor on 19 & 20th, with other sightings coming from Wootton near Woodstock on 16th and Blewbury Downs on 26th.

Grasshopper Warbler at Otmoor, courtesy of Jim Hutchins

By the Easter holiday weekend 10 different Warblers were being watched or heard at Otmoor and elsewhere, as is usual by that stage of the spring passage season. Amongst those the enigmatic Grasshopper Warbler is perhaps the species that retains the greatest mystique and is hence the most sought. Two set up territory as in recent years along the RSPB reserve's visitor trail to the screens, with another in the car park field.

Grasshopper Warbler at Farmoor, courtesy of Ewan Urquhart

Meanwhile at Farmoor a "Gropper" took up residence by the Thames on rough ground between the Pinkhill reserve and lock, a little upstream from territories of recent seasons. One more was located at the regular site of Cholsey Marsh on 24th. Transient Wood Warbler were found towards month's end at Freeland on 28th and for an impressive third year running in Spiceball Park, Banbury on 29th.

Wood Warbler at Spiceball Park, courtesy of Colin Wilkinson

The Best of the Rest

Courtesy of Badger.

Where wildfowl were concerned the stand-out records began with a pair of Common Scoter on Farmoor II (5th) and three more at Appleford GPs on 9th. Garganey were noted briefly at Otmoor on 11th and 19th, with another at LWV Pit 60, Standlake on 27th; and Shelduck continued to frequent Port Meadow and other sites. Mandarin remained a feature at Sonning Eye GPs, while pairs were also reported at Waterstock near Thame on 17th and throughout the month at Blenheim.

Bar-tailed Godwit on Otmoor, courtesy of Paul Tomlinson

Whimbrel at LWV Pit 60, courtesy of Mick Cunningham

Wader passage was perhaps steady but largely unremarkable, at least in terms of the quantity of pictures published herein. Various familiar species were tracked through wetland and flooded sites including Bicester Wetland Reserve, Chinnor Cement Works and especially the diligently watched Port Meadow. But Otmoor produced possibly the best two records of less frequent species with a Spotted Redshank there on 21st and a Bar-tailed Godwit on 24th. Another "Barwit" visited Pit 60 on 29th where Whimbrel was also logged, with a third record coming from Chinnor on 30th. Nine more Whimbrel moved through Farmoor on the month's final day. Maybe this group will justify fuller treatment in the next review, sightings allowing.

Osprey over Farmoor Reservoir, courtesy of Jeremy Dexter

Moving on to raptors, northward bound Osprey were few and far between with just two sightings at the beginning of the month, both over Farmoor on 2nd and 5th. New Marsh Harriers were seen at Grimsbury Reservoir on 9th, Farmoor from 13th and PIt 60 on 24th; while the resident birds on Otmoor performed for their audience as always. Also at Otmoor Hobby first appeared on 20th. There were others at Pit 60, Chinnor Cement Works and Hinksey Park to month's end; with four at Sonning Eye GPs on 28th.

Arctic Tern at Farmoor, courtesy of Nick Truby

Sandwich Tern at Grimsbury Reservoir, courtesy of John Friendship-Taylor

The first Common Tern of 2019 were recorded at Farmoor late in the day on 5th, with the first Arctic Tern record also coming from there on 9th. Three Black Tern made their own debut at West Oxford Sailing Club on 19th, then small numbers moved through Farmoor from 21st. Arctic Tern passage peaked there over the holiday weekend when 24 dropped in on 20th, then 46 or more on Easter Day. A Little Tern was seen at Farmoor two days later on 23rd, and a Sandwich Tern at Grimsbury Reservoir on  28th.

Yellow Wagtail at Farmoor, courtesy of Steve Burch

Regular Yellow Wagtail came in from the first day of April. These and others of their genus are a popular draw with photographers each year and especially on the causeway at Farmoor. This year the continental sub-species of Pied, White Wagtail also featured prominently, with a best tally of eight birds present on 5th. There were three records of the Yellow / Blue-headed hybrid Channel Wagtail between 7th and 13th.

White Wagtail at Farmoor, courtesy of John Workman
and Channel Wagtail (below), courtesy of Jeremy Dexter

Amongst other passerines, some winter finches just hung in there a little longer: a 30-plus Brambling flock being located at Highmoor Common near Nettlebed on 5th, while a soon to depart Siskin visited a garden in Thame on 8th. From the opposite direction Common Redstart began to be noticed mid-month with sightings from Otmoor, Oven Bottom and Lark Hill, Wantage all on 13 & 14th. The third of those sites also produced five Wheatear on 14th and the year's first Whinchat records from 26th.

Wheatear at Lark Hill, Wantage, courtesy of Steve Burch

The Ring-necked Parakeet pair in Oxford's Marston Ferry Meadows have bred as expected. Lastly, no April review would be complete without mention of that true harbinger of spring, the Cuckoo. Sightings of the last-named have come from Otmoor and several other locations in the second half of the month. 

Otmoor Cuckoo, courtesy of Nick Truby

That was a lot of records and pictures to sift through and I hope I have got everything right. Now just a few passage season weeks remain before some birders might deem to dabble in low season botany or lepidoptery, or like axed politicians opt to spend more time with their families until all this fires up again in late July. Hopefully there may be a similarly stimulating range of sightings or better next month in May, before the summer recess sets in.


Peter Law