Sunday, 26 November 2017

An American Horned Lark at Staines Reservoir 25th November 2017

On Friday evening I looked at my RBA (Rare Bird Alert) app just before bedtime to see what birds had been reported during the day and was intrigued to see a late entry about a 'probable' American Horned Lark being found at Staines Reservoir in Surrey.

I turned out the light and went to sleep thinking no more about it.

Saturday morning was crisp, sunny and the sky a crystal clear blue. Beautiful and just the day to clear up all those little domestic chores that had been mounting up.

I consulted my RBA app as I do, first thing every morning, just to see what was about but with no firm intention of doing anything about it even if there was.

There was the usual long list of Hawfinch sightings from all over the southern half of England as the unprecedented invasion of Hawfinches from mainland Europe continues. Presumably there has been a failure of their food supply in their normal haunts and they are forced to seek pastures new such as England to survive.

Near the top of the RBA list, there it was again, a report of the probable American Horned Lark still at Staines Reservoir at 7.30am this morning. So, it was still there and my resolve about the chores began to weaken. 

Horned Lark used to be included on the British List under the name North American Horned Lark based on a specimen claimed to have been obtained from South Uist in the Outer Hebrides, Scotland by the now largely discredited Richard Meinertzhagen and unsurprisingly this record was later removed. There have been at least two subsequent claims of Horned Larks being found in Britain. The first was of one commuting between St Agnes and Tresco, Isles of Scilly, England from 2nd-31st October 2001.The second was at Askernish in South Uist, Scotland from 9th-11th October 2014 but neither have been accepted. 

There has also been a claim of a possible one in County Down, Northern Ireland, UK in 1998 and another in Iceland in 1981 but again neither record was conclusively proved.

If accepted this latest individual at Staines Reservoir would be the first record ever for Britain.  

My good intentions began to waver even more as I considered all of this.

Horned Lark, or Shore Lark which is what we call it here, is a widespread species, its range extending across Europe, Scandinavia, North Africa, Asia and North America. Currently it is  'lumped' i.e the species is divided into a considerable number of subspecies which are listed under one species called Horned Lark in the rest of the world and Shore Lark here in good old Blighty, but this may well change, as the current taxonomic status of the Horned/Shore Lark group is in a state of flux, with DNA evidence indicating the potential for no less than six species to be recognised, five in the Palearctic and one in the Nearctic. If this were to happen then 'our' Shore Lark would become a single species Eremophila flava and probably lose the name Shore Lark and all the Nearctic (North American) subspecies would be lumped as one species called North American Horned Lark Eremophila alpestris. The remaining four potential species would presumably come from subspecies in other parts of its Palearctic range.

Presently, depending on what authority you consult, there are at least forty two subspecies of Horned Lark described. Most are non migratory. The bird at Staines is considered probably to be from one of the two northern and migratory North American subspecies, either Eremophila alpestris alpestris or E.a. hoyti.

I have only, to my knowledge, seen two subspecies of Horned Lark, the ones that visit us here in Britain in small numbers every winter E.a.flava and currently called Shore Lark and the subspecies that inhabits The Atlas Mountains in Morocco E.a.atlas, which look very different to those that come from Scandinavia and /or Asia to winter in Britain.

The North African race of Horned Lark E.a atlas Oukameiden Morocco 2013

Shore Lark E.a. flava Norfolk England 2011

Shore Lark E.a flava Spurn England  2016
Probable American Horned Lark  E.a alpestris or E.a.hoyti  
Staines England 2017
I pondered the situation further over a slice of toast and decided that the chores could wait and I would go and see, what for me would be a new bird and one that might possibly one day become a species. Although it would be nice to get a new bird on my list I was anxious to view the bird in the flesh and see just what differences in plumage and appearance it presented, compared to the more familiar Shore Larks that I had seen in Norfolk a week ago.

I duly set off for Staines Reservoir, a very familiar site to me, as many years ago I used to work at Heathrow Airport which is adjacent to the reservoir and would spend my lunch hours watching birds from the mile long central Causeway that divides the two huge, northern and southern basins of water that comprise Staines Reservoir.

The journey was simple on a Saturday morning, as compared to the traffic mayhem of a weekday the roads were being only lightly used, and after an hour I turned off the M25 and found myself parking by the small western entrance gate to Staines Reservoir. The parking here is restricted and unofficial, being just a tiny, muddy, unsurfaced area by a busy road, that can accommodate no more than five cars.

I was amazed that I could find a space to park here as I assumed that many people would want to come to see this supposed American Horned Lark.

I had got everything together from the car and was just about to go through the gate when a large Mercedes drew up alongside me and an Australian lady, with husband driving, asked me if I could tell her where the M25 was. They had just arrived from Australia on a flight this very morning, hired a car and wanted to get to Hastings in East Sussex. She had a map that the car hire company had given her but they were now completely lost. I gave them directions which were basically to go back the way they had come and turn left at the first roundabout. I even held up the traffic on the road whilst they made a U turn. Suitably thankful they headed off for Hastings while I headed up the steep incline to get to the Causeway.

My diversion with the Australian couple had occupied about fifteen minutes and the walk along the Causeway was another five minutes. I could see around twenty birders, two to three hundred metres distant, clustered by the railings on the left side of the Causeway, peering over where the American Horned Lark was presumably feeding on the concrete bank of the northern basin.

Just as I got to them a small brown bird flew up and over me, calling. It sounded a bit like a Shore Lark but the call was markedly different to the Shore Larks I had seen and heard in Norfolk just eight days ago. I followed the bird's flight and it landed distantly on an area of exposed mud in the southern basin, which is currently drained for repair.

I quickly got the scope erected and soon had the lark in my scope. Its behaviour was the same as any Shore Lark, shuffling about on bent legs, low to the ground, picking at morsels it found on the mud.The light was truly awful as I was looking south with the sun shining into my eyes but I could see enough to note this bird had very little yellow on its head but looked predominantly white on its forehead and  cheeks and the black mask was not that obvious.

I watched and then it flew directly into the sun and was lost to view by everyone. Oh dear. I had hoped for better than this but at least I had seen it but any thoughts or aspirations of quietly studying its plumage were for now just a forlorn hope.

After the lark had flown I stood on the Causeway with my fellow birders scattered along the Causeway, all of us not sure quite what to do now. It was bitterly cold as a northwest wind with nothing to hinder it blew across the blue waters of the northern basin and into my face.The sun shone bright but there was no warmth from it. I hunkered down into my cosy RAB goose feather lined jacket thanking the fates that I had also remembered to don a thermal vest. My experiences at my local Farmoor Reservoir in Oxfordshire had taught me well!

The mile long Causeway between the North basin on the left 
and the South basin on the right. The Horned Lark favoured 
the bank on the left side of the Causeway behind the railings

My body was warm but my exposed face was beginning to freeze into a rictus and my eyes began to water as, cold and disconsolate I mused on the fact that if I had not spent time with the Australian couple I would have seen the lark close to and on the ground, though I was glad I had been able to assist them and would have had it no other way. Nonetheless I mused, if there is justice in this world then by rights my good citizen act should be rewarded by the lark returning immediately and giving me stunning views. I smiled a wry smile, reflecting if only life were so straightforward.

There was, however, cause for slight optimism that the lark might return, by way of talking to another birder next to me. I learnt from him that the lark had been around for possibly three weeks but mainly on the nearby Queen Mary Reservoir which was entry by permit only, but lately it had taken to favouring Staines Reservoir, where access to the Causeway is unrestricted due to it being a public footpath.

The birder told me the lark had once before disappeared, earlier this morning, flying over to the adjacent King George's Reservoir on the other side of the road but had then returned and given great views as it fed on the weedy and shaded concrete bank by the Causeway where we now stood, on the southern side of the Staines Reservoir's north basin.

I could but hope. I stood firm and tried to ignore the persistent chilling wind, turning my back to it and stomping my feet to keep some form of circulation going. In a flight of unjustified and fanciful optimism I got my camera from my bag and hung it on the railings as if this very act would will the lark to return. It didn't. Slowly other birders trickled away, the cold wind and lack of action disheartening them and becoming too much to bear. I had arrived at just after nine thirty, seen the bird for less than five minutes and now it was ten thirty and not looking good.

Other birders were arriving to replace those leaving but there was never more than twenty to thirty of us present. Passing birders asked me if I had seen the lark and I told them yes, but not very well, and recounted how it had flown off. Pied Wagtails, no more than small dark silhouettes against the bright sun as they flew over the Causeway to land on the concrete banks, set off mild hopeful stirrings amongst us that each one might be the lark returning but we were always to be disappointed.

A lady birder I had spoken to earlier returned, having revived herself with a coffee and a warm up in her car. Very sensible too but I stood firm and just held on. It was getting attritional but I just had to hope the lark would stick to its routine of disappearing and then suddenly returning.

It was now eleven o clock. I met a birder, Keith, who I vaguely knew from a previous twitch to North Uist and we passed the time of day as other birders loafed about, leaning on the railings and chatting or looking at the planes taking off from nearby Heathrow Airport. Huge triangular, red, white and blue tails of parked British Airways planes rose, like immense shark's dorsal fins, above the trees on the northern perimeter of the reservoir.

A small dark shape rocketed low over the Causeway, as I chatted with Keith and landed on the concrete bank behind the railings. We both said in unison, incredulously,  'That was it wasn't it?' It was. The American Horned Lark had returned.  Scopes were left standing where they were as this was a bins and camera situation, it was so close.

We peered over the railings. There was no real crush as there were so few of us. The lark shuffled along amongst the weeds and moss that were eking out an existence in the cracks of the cold grey concrete bank.

The lark when I first saw it was facing away and superficially looked very dark brown and streaky above but this could have been due to the bank being in the shade. It was about the size of a Skylark, possibly a fraction smaller and kept low to the ground.

When it turned its head I could see it had a pale yellow throat but the rest of its head had no yellow at all, the yellow being replaced by white and there was only a scruffy black mask and upper breast band. The subtleties of its different plumage details were beyond me as I have no experience of Horned Larks from North America but I am told the flank colouring and contrasting whiter underparts, the neater breast streaking, darker upperparts with broader streaking on the head and mantle, subtle colour differences such as a pinker tone to the sides of the breast and on its rump, differences in the lesser and median wing coverts, darker primaries and secondaries and less yellow on the face are all pointers to a Horned Lark of either of the two subspecies alpestris or hoyti. All in all it would appear that a Horned Lark of the two subspecies mentioned is more contrastingly marked, with neater stronger markings than the Shore Larks we get here in Britain.

We will just have to wait and see what the verdict is from those who have extensive experience of Horned Larks and their plumage, but for now I was just keen to study this bird for future reference and resisted coming to a firm opinion that at best would be ill informed. All I can say is that it looked like no other Shore Lark I have seen and I have seen quite a few.

It showed little alarm but was unsettled, obviously not finding its current situation to its liking. It would pick at the ground desultorily for a few minutes but then fly along the bank for fifty metres to change position but always remained faithful to the bank. We followed, dragging our scopes and tripods with us but in the end everyone just left their scopes where they were and followed the lark as it regularly flew back and fore along the bank looking for a spot to its liking.

Finally it settled down amongst the weeds and moss and started feeding in earnest. From the photos I took it showed it was finding, amongst other things small caterpillars in the moss. It was noticeable it did not relish being out on the exposed concrete but would seek shelter behind the low growing plants.

We duly followed it from our position on the Causeway as it busied along from one plant to the next where it would dig around in the leaves and moss for prey. For twenty minutes it fed and then, calling loudly, the call still sounding strange, it flew off across the northern basin towards King George's Reservoir and was gone from view.

This was my cue. It was time to go and get something warm to drink to ease the chill before heading for home.