Thursday, 14 November 2013

Dotterel delight

Dotterel (Jesús Porras)
It was impossible to resist. The wonder that is the birders' grapevine (here in Extremadura through an email group) brought the news that a friend of mine, Ricardo Montero, had found a group of Dotterel about an hour or so from our house. The following day, another friend, Jesús Porras went to relocate them and posted the above photo on his Facebook page (IberianNature Guías de Naturaleza). Now Dotterel, which have the rather spendid Spanish name Chorlito Carambolo, are truly delightful birds which I have long wanted to see in Extremadura. Indeed it has been many years since I have encountered the species - I used to watch them sometimes on spring passage on the east of England. In spring, the plumage is very striking with rusty orange underparts and, like that other curious group of waders, the phalaropes, the males are duller than the females and take the lead role in incubation and care of the young. Similarly they can be unusually tame. The Dotterel is a species that breeds on high mountains and which passes through Extremadura on passage in very small numbers. They stopover at sites of thin soils, stony ground with sparse vegetation or well-grazed sward. It is thought that these resting places may be traditional, but the challenge is that the extent of such habitat in Extremadura is vast and these stopovers may be just for a few days. This means that the species goes largely undetected here, with some years no records at all, despite birders visiting suitable habitat and carefully checking fields at the right times of year.

Jesús had given me excellent directions and I got out of the car and gazed across what looked like perfect Dotterel country. A quick glance produced several Lapwing and Calandra Lark, but no sign of anything else. So I walked back along the track about a hundred metres and then systematically scanned across the fields as I returned to the car. Three Griffon Vultures and a Black Vulture had become airbourne and effortlessly rose on a hidden thermal. The sky was cloudless and the light conditions superb. I stood by the car again and this time looked again at the first area, where the habitat had seemed most promising. And there they were! A group of four Dotterel in their greyer non-breeding plumage had emerged from a belt of dry thistles onto open ground. Feeding like true plovers, they took a few paces and then stopped, then a few more paces before another stop and a peck on the ground. At least two others were further off, amongst the thistles still. I stood delighted and mesmerised by these wonderful birds, with their almost swollen creamy superciliums, black beady eyes and the suggestion of a pale necklace hanging across the breast. I was intrigued as well: are they here on a stopover, or perhaps  for the whole winter? The species winters in North Africa, but it has been known to stay in a few places  in Spain as well. This site had all the appearance of being potentially a good area. And as I watched them, memories came back of my earlier sightings, a long time ago, on fenland fields in eastern England, which apart from the sense of space, bore little similarity to these rough sparse Spanish pastures, especially since as I watched the Dotterel my ears soaked up as well the sounds of sandgrouse and a multitude of Calandra Larks. And I marvelled at the luck of Ricardo who had found these proverbial needles in the haystack and recognised his generosity at passing the news of his discovery on.

Saturday, 9 November 2013

Thick-knees at roost

Stone Curlew (David Palmer)
Despite being widespread on the open plains, Stone Curlews (or Eurasian Thick-knees, as they are sometimes called) can be tricky to find in the spring. This is partly because of their wonderfully cryptic plumage and their preference for bare open ground, which on a sunny day will be bathed in heat haze by mid-morning, meaning that ground-dwelling birds will, as it were, dissolve in the shimmer. It is not helped also by the fact that Stone Curlews are mainly nocturnal, so one will be looking for birds at their most inactive period of the day: standing motionless or, worse still, sitting down flat on the ground. In autumn and winter, on the other hand, the task is much easier, and this is because, like many birds outside the breeding season, the Stone Curlew forms winter communal roosts. So with little heat haze to worry about, once one has found the roost, one should be able to enjoy prolonged views of often rather sleepy thick-knees. The roost sites tend to be traditional, a cultural transmission down through the years and across generations of Stone Curlews. What is interesting is how often these sites persist as chosen roosting areas, even though some of the features which might have made them attractive have disappeared. One roost which I first became acquainted with about eight years ago, had all the appearance of a classic site with large pebbly patches on the ground, wheat stubble and some widely spaces trees at the edge. The field then became converted to a solar farm, with huge solar panels covering the terrain. This was too much for the Stone Curlews. But instead of moving off to a less-disturbed area, they merely moved barely a hundred metres. This roost is now in rough pasture, in a rather impoverished-looking tree-plantation, beside a busy (for local standards) main road and next to derelict buildings used by local youngsters for mini-raves on a Saturday night. Weekends will also witness greyhounds being exercised there. It is hard to imagine a less attractive place for Stone Curlews. Indeed at first glance, it is easy to assume that your misgivings are well-founded as the first one is often quite hard to spot. Suddenly though something catches your eye, a hunched shape, with striking yellow legs and half-closed, rather dozy, yellow eyes, as depicted beautifully in David Palmer's photo above taken at this particular roost.

Once you have seen one, nearby shapes also metamorphose into Stone Curlews, some sitting on the ground, others like the first standing hunch-backed, a few taking a few paces walk. Ten birds..twelve...fifteen.. in view. But it takes a passing danger, perhaps a Marsh Harrier drifting overhead to get a true estimate of the numbers there. Seventy or eighty take flight, descending soon afterwards on a glide with their rather long gull-like wings.

I often wonder where they all come from. I know of two other roosts of similar size not more than a few kilometres away. Together the number of wintering Stone Curlew in these three roosts must exceed the breeding population within a similar radius. We do know that birds from northern Spain move further south in the winter and the Spanish population is supplemented by wintering birds from places like France and England. But until a bird turns up bearing a coloured-ring, I will only be able to guess the origin of them at this roost, although I can more safely assume that this communal roost will comprise the same birds from one year to the next, showing a site faithfulness or philopatry, which offers survival advantages drawn from familiarity with a particular area, its resources and risks.

On last Friday evening I was in Trujillo, undertaking parental duties waiting to collect our teenage son Patrick from a classmate's birthday party. As I sat in the car, I could hear the continuous sound of Spotless Starlings, still making a racket a couple of hours after nightfall from their communal roost site in a stand of trees in a town park. After a day feeding out on the plains, hundreds upon hundreds arrive at dusk. One theory about the function of such communal roosts is that they offer means for hungry starlings to obtain information about the best local food sources, presumably they follow well-fed birds out to the pastures the following morning hoping that they will be led to the right places.  And I could only imagine the type of communication going on between these garrulous birds, well past their bed-time. In fact so much noise was coming from the roost that it took me a few minutes to register a different sound altogether. Trying to block out the starlings I could now recognise the unmistakeable sonorous deep hoot of an Eagle Owl. I walked along the street in the direction of the sound, looking upwards.  And there, perched on top of a tower, seemingly oblivious to the sight and sound of traffic and people was the Eagle Owl, the street lamps catching, as it turned its face, its caramel-coloured eyes. I could even see the pale bases of the throat feathers each time it hooted. It sat there for half an hour, calling two or three times a minute, before silently gliding off on its broad wings to hunt. The nocturnal predator was on the move over the rooftops, as the diurnal starlings at last settled down in their roost.