Tuesday 3 April 2018

A Very Strange Twitch Indeed 1st April 2018

Easter Sunday found myself and Moth heading for the outskirts of southwest London for a very strange twitch indeed. Our destination was the affluent suburb of Richmond upon Thames where a Lesser Whitethroat had been discovered, spending the winter in the back gardens of some hugely expensive houses just down the road from Kew Gardens. One particular back garden seemed to be most favoured, in a road called Selwyn Avenue. The back garden was reached by a short and narrow alleyway which served as an access to dustbins and ran around the back of this and the neighbouring gardens.

The Alley leading to the back of the gardens
The Lesser Whitethroat is suspected to be of the race S.c halimodendri that is found in Central Asia and is colloquially called Desert Lesser Whitethroat. Unfortunately the only reliable way to find out is to sample its DNA. By chance Franco, a former twitcher of some fame and no little notoriety lives nearby and has managed to collect some faeces from the bird which also visits his garden and he has sent off the sample to Dr Martin Collinson at Aberdeen University to analyse and provide a definitive answer. Currently the verdict is being eagerly awaited.

The results of the analysis has subsequently proved this bird to be a Siberian Lesser Whitethroat S.c. blythi, which is a sub species of Lesser Whitethroat.

Parking the car nearby we found the inconspicuous alleyway and walked down it feeling some trepidation and not a little unease about our presence amongst all this conspicuously wealthy housing.To be frank this is the kind of birding I do not particularly relish as I always feel anxious about being so close to homes and potentially  invading their privacy but apparently the residents were sanguine about the temporary invasion of birders seeking the Lesser Whitethroat.

Moth awaiting the arrival of the Lesser Whitethroat
We waited for about thirty minutes as various garden birds such as Chaffinches, Starlings, Great and Blue Tits, Blackbirds, Robins and even a Woodpigeon appeared and disappeared in the garden and then the Lesser Whitethroat flew into a large Holly tree on our right and we had our first view of this obviously pale, slim warbler moving through the dark green holly leaves, before it moved across the alleyway into its favourite small garden and finally descended onto some half full feeders by a fence.The opportunity to view it was strictly limited as the privacy of the gardens was guarded by fencing above head height but there was a tiny gap in the fence where you could look through and view the feeders and this gave us our best views of the Lesser Whitethroat.

Lesser Whitethroat-possibly of eastern race halimodendri
It was strikingly pale, almost sandy on its upperparts and its pure white throat stood out against the buff underparts. Also noticeable was its yellow eye and long tail. It hung around the feeders for a while, picking at the food, finally being seen off by the inevitable truculent Robin. We waited for it to return and while we did Moth found a male Blackcap in another tree which also dropped down to the feeders.

The Lesser Whitethroat returned briefly to the feeders but then disappeared again and having seen the bird well we were happy to go. Frankly it was a relief, even though we had been told the residents were not concerned about birders loitering in the alleyway so long as their privacy was respected. We were the only birders there and the garden it most favoured, I was told, belonged to a house owned by the Environmental Editor of The Guardian no less, so maybe our concern was misplaced.

We left Richmond at around noon, passing the huge stadium at Twickenham and made our way west to Staines Reservoir which was relatively close by. Our objective was to get a second view of the Horned Lark from North America that has been residing at Staines Reservoir since last November. The last time we visited it was bitterly cold and the views we got were not that great so this time we resolved to try and rectify this.

Today, although cold, it was much calmer and with little wind as we followed the central Causeway to roughly about half way where a small cluster of birders were hanging cameras over the railings obviously looking at and photographing the Horned Lark. Having been here for so long most birders have seen the lark at least once and many, like us, have taken the opportunity to re-visit it. 

When we got to the birders, the Horned Lark, almost immediately, flew further along the reservoir bank  and for the next few minutes was very flighty indeed, moving up and down and often feeding on the Causeway itself rather than feeding along its usual area  on the retaining wall sloping down to the water of the southern basin.

Horned Lark-female
Eventually it settled down and commenced to feed in earnest but proceeded to frustrate us as it fed just under the lip of the grass where it joined the moss covered shelving concrete and was consequently only partially visible or even invisible for long periods. 

It was difficult to follow as it scuttled along, hunched over on flexed black legs, vigorously digging out the moss to find any invertebrates hidden beneath. It was rarely still, virtually constantly on the move, but finally it began to show itself more readily and moved away from the concealing vegetation, although it was obvious it was happiest when hidden from view by the various plants springing up all over the moss covered concrete.

The Horned Lark is a female and as such does not have the strong face patterning and obvious feathered horns of a male. Rather its head is a suffusion of yellow  and white with ill defined black head and breast markings but with the obvious white forehead and supercilium that mark it out as so different. The rest of the plumage did not seem to have changed much from the last time we saw it. Maybe the breast streaking was a little more sharp and the dark streaks on its unremarkable brown upperparts were stronger.The fore flanks and mantle had also taken on a not unattractive pinkish brown blush.

Its extreme rarity is what makes it so special and guaranteed to attract birders for as long as it remains

Although still considered a sub species of Horned Lark which also includes our confusingly named Shore Lark, it is thought likely to be re-categorized as a separate species sometime in the near future, hence its attraction to birders.

Whatever it is, species or sub species, if accepted it is going to be a first for Britain.

Subsequent DNA analysis from a feather picked up from this bird has confirmed it is one of the American races of Horned Lark.

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