Black-bellied Dipper at Sywell Country Park

Found by Geoff Simons, Senior Countryside Ranger, Northamptonshire’s first Dipper for twenty-four years was identified at Sywell Country Park yesterday, on 29th February.

It’s still there today and what a great little bird it is! It was first located in the by-wash cascade – the overflow from the dam – where it flows through the visitor car park, at 13.35. It then flew up the overflow, under the bridge and on toward the dam. Geoff was kind enough to put the news out immediately but by the time the first birder arrived on site, little more than an hour later, it was nowhere to be seen, despite a search of the full length of the overflow system.

Subsequently relocated at 15.25, it appeared beyond the overflow, in the stream just outside the country park, about forty metres from the entrance gate. Due to the overgrown nature of the stream, it proved difficult to observe from the narrow road bridge but it was quickly identified as the nominate race cinclus i.e. Black-bellied Dipper from mainland Europe (principally Fenno-Scandia). A news update was put out, allowing many local birders to catch up with it before sunset.

Black-bellied Dipper, Sywell CP, 29th February 2020 (Stuart Mundy)
Black-bellied Dipper, Sywell CP, 1st March 2020 (Steve Fisher)

Dipper is an extremely rare visitor to Northants and most of the previous occurrences have been in autumn and winter, with the notable exception of a one-off breeding record of an adult (British race gularis) feeding young in a nest at Edgcote on 19th July 1975.

Although the Sywell bird is only the third confirmed Black-bellied Dipper for the county, it seems highly likely that most of the previous records are of this race, as a result of their autumn/winter occurrence pattern.

Monthly distribution of records. Background image: Black-bellied Dipper, Sywell CP, 1st March 2020 (Mike Alibone)

However, an up-to-date summary from the British Birds Rarity Committee here states subspecific identification is less than straightforward, especially as nominate cinclus may have some restricted chestnut on the belly and may therefore approach the appearance of hibernicusgularis or aquaticus, while it appears that some birds within the presumed range of hibernicus in western Scotland (and potentially some gularis too) may lack any chestnut, therefore resembling nominate cinclus. The subspecies aquaticus (central Europe) is highly variable and it is not clear how a vagrant might be distinguished.

For the moment, BBRC is taking the pragmatic view that birds with little or no chestnut on the belly in eastern Britain (particularly in the Northern Isles and lowland south-east England away from the range of gularis) are likely to be nominate cinclus but other claims may have to await further investigations on the variation of plumage shown by all the races likely to occur in Britain.

Fortunately, our Sywell bird falls into the three categories of right time, right place, right appearance, so there is little doubt it is cinclus. How long it will remain there is anybody’s guess but one long-stayer was present in the vicinity of Desborough Water Mill from 21st January to 24th March 1979. Potential disturbance from the general public at Sywell could be instrumental in hastening its departure but more pointedly, today’s unfortunate, near-fatal attack by a Sparrowhawk may also have some influence …

 

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