Stone Curlew (Burhinus oedicnemus): the Stone Runner.
IT IS THE ABILITY OF THE STONE CURLEW to blend so perfectly into its surroundings that led a warden on one of the birds' Norfolk heathland strongholds to declare to me one day, "all birdwatchers are blind and can't see a thing!" He was of course referring to the birdwatchers failed attempts at picking out these birds in the grassy, sparsely vegetated Breckland heaths of Norfolk that they prefer.
The stone curlew belongs to the family of birds called Burhinidae, also known as thick-knees, of which there are nine species worldwide, and all share remarkably similar characteristics, including large, bulging, orb-like yellow eyes that not only distinguish them from all other birds, but also provide them with the quality of vision they need for their mostly crepuscular and nocturnal lifestyle.
Viewing these birds in the field is no easy task, as referred to earlier, even for the experienced ornithologist. It is often their fluting 'coo-lee' call that gives them away at first, most often heard during the dim light of dawn and dusk. The call echoes across the dusty Breckland landscape and is capable of carrying a mile or more on a still day. A careful study of your surroundings may then reveal one of these streakily plumaged birds skulking about its nesting site.
There is no doubt that the Norfolk Wildlife Trust National Nature Reserve at Weeting Heath is the best place in the county to view these rare birds in the field. However, they are wary creatures and can be easily disturbed from the nest, even by an observer as much as 400-metres away. For this reason, the viewing of nesting stone curlew for any length of time should not be practised from roadside verges or gateways, but rather in the comfort of a properly constructed observation hide. In fact, the best chance of watching stone curlew for any length of time is often during the autumn when they gather in groups of up to one-hundred birds. These are pre-migration gatherings that occur before the long journey back to warmer climes.
The term thick-knee is not altogether accurate for this family of birds -- it is in fact the inter-tarsal joint that appears swollen, the equivalent of a person's ankle.
With the encroachment of arable land onto the barren grass heath and warren scarred landscape of the Brecks, the stone curlew has taken to stony arable fields to supplement the lack of its favoured nesting locations, and it should be no surprise to observe breeding pairs going about the business of procreation on suitable farming estates. These arable locations are now as vital to the birds' survival as were their once abundant heathland domains.
Arriving from their over-wintering grounds of Northern Africa as early in the year as March, it is thought that stone curlew pair for life, and even return to the same breeding territory season upon season. The courtship display can be quite elaborate and includes bowing, touching of bills and excitedly running about picking up straws, small stones and even rabbit droppings that the slightly larger male will deliver to the female; a gift to furnish the otherwise unlined scrape in the ground that is used as a nest.
Taking a break from incubating the single remaining egg in its nest, a stone curlew enjoys the evening sunshine. Remarkably, for a bird that blends so well into the heathland landscape, it rarely remains still for a moment. (Photograph taken under licence from Natural England.)
Contented stone curlew parents sit on a nest containing their newly hatched chick. Stone curlew nests normally contain two eggs, yet on this occasion only one hatched. The other, rotten and infertile, was rolled away from the nest, probably to avoid infection. (Photograph taken under licence from Natural England.)
... the stone curlew has taken to stony arable fields to supplement the lack of its favoured nesting locations...
Only hours old, a stone curlew chick crouches low in its nest scrape, waiting for the parent birds to return with their offerings of food and shelter. Within days, it was upwardly mobile and led away from its natal home. (Photograph taken under licence from Natural England.)