Rare Bird Alert weekly round-up: 04 - 10 July 2012

The week's highlights:
Caspian Terns in Suffolk, Dorset and Norfolk
White-winged Black Tern performs in Dorset
Marsh Sandpipers in Shetland and Devon
River and Paddyfield Warblers perform a remarkable summering double-act

The long-predicted summer lull finally kicked in. After the excitements of the last two weeks, it was perhaps reassuring to see a return to more normal summer fare, with, more predictably for July, terns and waders finally topping the bill. However, this made it a little more tricky to nominate the ‘headline birds’ this week!

If the birds had gone a little quiet, however, the same could not be said for the weather. This week saw a continuation of the now familiar pattern - a constant procession of Atlantic lows bringing muggy, occasionally blustery, conditions and lots more rain. Indeed the rainfall was the week’s main feature, bringing further flooding to many parts, especially to the Midlands and the North, the very places which saw bad flooding only the other week.

Headline birds
Caspian Tern is a quintessential July rarity so it is not surprising to see this species take top billing this week. Despite the northern European population now being at a very low ebb, this magnificent tern still manages annual appearances in Britain but, as ever, its presence is often frustratingly brief. This is a highly mobile species, fond of rapid and apparently random wandering and often commuting between feeding areas many miles apart. Such was the case this week as the first of this week’s run of records, at Minsmere, Suffolk on 6th, was only a short-stayer. It was found mid-afternoon but stayed only a little over twenty-five minutes before flying off south, only for a Caspian Tern to be discovered at Brownsea Island, Dorset in the late evening. This too was a short-stayer, with no sign next morning. Further tantalising sightings, albeit reported late, then came from Wissington Beet Factory, Norfolk on 7th and flying past Cley, also Norfolk, later the same day. How many (or few) individuals might have been involved in this spate of sightings or where one will pop up next remains to be seen.

A reappearance at Brownsea Island (there was one there last summer too) is a useful reminder that Caspian Terns often favour particular sites, either because they are good at selecting the optimum feeding habitat or, perhaps more likely, because we are seeing repeat visits by the same individuals. There is, most notably, a long run of Caspian Tern records from both Breydon Water and Hickling Broad, both Norfolk, over a period of more than twenty years and it is tempting to assume that the same bird accounted for a number of these records. The Wissington record is also a reminder that this is a species which can turn up well inland, with records now coming from most counties in Britain.

Though not normally a headline rarity, this week’s Marsh Sandpiper at Virkie and then at nearby Loch of Hillwell, Shetland on 7th was a truly exceptional record, only the second for the county (the first being at Strand Loch, Gott as long ago as 4th-6th May 1969). Another was reported belatedly from north of Plymouth at Blaxton on the Tavy Estuary (and then at Blaxton Meadow Marsh) on 5th but there was no further sign of it. Early autumn is of course a classic time slot for this species which has amassed 141 records in Britain and Ireland to the end of 2010.

On Fair Isle, Shetland the lingering River Warbler and Paddyfield Warbler in Fair Isle’s observatory garden made this easily the best garden of the week. It is tempting to think that this remarkable summering double-act may be linked to their late arrival dates, the River Warbler having arrived on 11th June and the Paddyfield Warbler on 30th.

Much more in the full online round-up
- Caspian Tern analysis and blast from the past
- White-winged Black Tern great photos
- Sabine's Gull in Hertfordshire
Plus lots of great photos, analysis, and predictions...