STONE CURLEW AT BLACKBUSHE?

Contributed by Norma Dowling for the Society's annual exhibition in 1999

QUESTION: Could we have rare thick-knees nesting on the common?

The Stone Curlew, also called a thick-knee because of its thickened tarsal joint, is a rare summer visitor to Southern Britain. It is like a large plover with a very large yellow eye and thick yellow legs. The birds are not related to the Curlew but do have a curlew-like whistle, often heard at night. They are not easy to spot because they are mainly nocturnal and because they are camouflaged by sandy brown feathers with darker streaks. Stone Curlews are found on sandy wastes, bare downland and stony ground.

FACT: Sighting at Blackbushe Airport

The Stone Curlew had not previously been reported in our area but in an Ornithological Report for the Fox Farm Planning Inquiry, in 1996, Note 1 Mike Read reported:-

FACT: Main Breeding Areas

Main breeding areas in Britain for these strange, rare birds are Porton Down, a nature conservation area in Hampshire belonging to the MOD; Dorset; Wiltshire; Berkshire and the Brecklands of Norfolk.

Their numbers have declined over the last 150 years because of habitat loss and loss of nests through agricultural operations.

FACT: Numbers now increasing

In 1985 the RSPB began a project and reported only 150-160 nesting pairs and declining numbers. Now, however, Stone Curlews are beginning a slow recovery. Careful studies over many years have led to a greater understanding of the factors affecting nesting success and careful management in the light of these findings is having results.

On Porton Down, which has 12% of the UK population, there were 26 pairs in 1997. Working with RSPB over 10 years, nesting data has been collated including weather, pest control and rabbit count data, and, more recently, detailed information on habitat selection. This has shown a link between numbers of breeding pairs of Stone Curlews and numbers of rabbits in the previous spring.

High rabbit numbers result in grazing pressure which uncovers flints and pieces of chalk. This bare ground is good for camouflage of eggs. Increased numbers of rabbits also means an increase in invertebrates attracted by the many droppings and would provide plenty of food at the chick stage.

The RSPB, MAFF and English Nature are continuing to work with landowners in East Anglia and Wessex (which includes Hampshire) to manage small areas of about two hectares for Stone Curlews under the Countryside Stewardship Scheme. The Wokingham & Bracknell RSPB group is giving financial support to a Berkshire initiative. Last year there were eight breeding pairs of Stone Curlews there but they only produced four young. The target for 2010 is 15 breeding pairs. One of our Society members, Irene Draper, visited an area on the Berkshire Downs recently and saw one adult Stone Curlew and two chicks. She describes the area as small, bare and unsown, in the centre of a cereal crop, and with a population of hares.

The RSPB reported that in 1998 the total in the United Kingdom was over 200 pairs, the highest number since 1975. This means that the UK Biodiversity Action Plan Note 3 is two years ahead of schedule.

QUESTION: What was the bird doing at Blackbushe?

Mike Read makes two suggestions: the bird could have been looking for a mate or a territory, or it could have been one of a nearby pair visiting the area to feed. Its presence would normally be unobserved as Stone Curlews are mainly nocturnal feeders.

QUESTION: Could Blackbushe Airport support nesting Stone Curlews?

Section F, referred to in his report, is described by Mike Read as entirely short-sward grassland (unlike the other areas...which contain more rank grasslands). Although other sites in Hampshire, and Berkshire for instance, are on chalk downland, the Brecklands of Norfolk which are the main Stone Curlew stronghold are acid heathland with similarities to Blackbushe. One site even has an airport. This is RAF Lakenheath, where birds do not appear to be unduly bothered by low flying fighter-bombers.

Is there a significant rabbit population on Blackbushe to lead to a supply of invertebrates to feed chicks? Much of the area is stony because of the soil structure, the earlier use as runways and roadways but are these areas large enough or suitable for attracting a Stone Curlew to nest? Another rare, Annex I bird that does seem to find our area suitable is the woodlark and this also requires short rabbit-grazed turf for feeding so perhaps there is sufficient food. Also on Blackbushe there are two further Annex I birds that occur: the Dartford Warbler and the Nightjar. If these three are doing well, why not the Stone Curlew? As mentioned, the UK Biodiversity Action Plan is two years ahead of schedule, if all goes well it may reach the target of 300 breeding pairs of Stone Curlews by 2010. Could Yateley play a part in this success story?

QUESTION: Could you discover our fourth Annex I bird?

Could there be breeding pairs on Blackbushe already? Remember, Stone Curlews are migrants. They arrive here from southwest Europe or north Africa in mid March and leave in early October. (Though in 1769 the Selborne naturalist, Gilbert White, reported hearing one call as late as 31st October.) Mike Read saw one at 6.40 am so you need to be out early (or late) and have sharp eyes. Please report your sightings!

TAIL-PIECE

John Wyatt, who has been studying Stone Curlews at Thetford, Norfolk over many years, spoke at an RSPB Wokingham and Bracknell group lecture. He said radio transmitters have been used in the study and mothers have been heard conversing with their chicks, still inside eggs, in order to synchronise hatching. This is important to avoid predation on the open ground where the birds nest. The chicks, known as nidifugous, are born with their eyes open and a good covering of camouflaging feathers. Newly hatched Stone Curlew chicks are soon up and running.

Acknowledgements