Look out for flying displays

The British Trust for Ornithology is launching a survey of Ringed and Little Ringed plovers during the birds' breeding season and is asking for the public's help. The BTO says it is important that the birds should be monitored regularly as the British Isles and Ireland together hold around 80 per cent of the temperate breeding population.

The Ringed plover favours coastal sites but may also seek out gravel pits and rivers while breeding. The more populous Little Ringed plover is the much more likely to be seen in the Oxfordshire area, especially the flooded gravel pits in the Thames corridor.

The Little Ringed plover is a summer migrant. The female lays a clutch of about four eggs. Although there is only likely to be one brood, replacement clutches are often needed as a result of losses to predators.

The Little Ringed plover is a delicate, rather slim-bodied bird, about 16cm in length. It can be best distinguished from the Ringed plover, which is more dumpy and some 2cm longer, by the absence of the Ringed plover's striking white wing bar, which is visible when it is in flight.

The male and female Little Ringed plover are similar in colouring, both having sandy-brown upperparts and white underparts. They have a black collar and breast band, and black and white markings on the head. The black elements on the head are duller in the female than in the male. The bill is black, the legs yellow and a particular characteristic is the yellow eye-ring. Juvenile birds and adults in winter colouring - not seen here - have the black plumage replaced by sandy-brown; the breast band is incomplete and the leg and eye-ring colours are duller in quality. The call is described as a 'pee-oo', 'pip-pip' sound and the song a trilling elaboration of calls.

Other differences in colouring seen in the Ringed plover are an orange bill with a black tip and the legs orange-yellow. Its sound is a soft 'tuu-eep' which also forms the basis of its song.

This will be the second concurrent survey of these two species. The first national survey was over 20 years ago so considerable changes will have taken place since then.

"They can adapt and advance very rapidly," said Greg Conway, organiser of the survey. "Observers will be looking out for signs during the breeding season of their presence. They are quite vocal - there should be flying displays and young birds may be seen."

The last survey, in 1984, revealed around 8,540 pairs in the British Isles, of which only 2,390 were in England. Wales had an estimated 220 pairs and Northern Ireland 130, while the greatest numbers, two-thirds, were in Scotland, where there were 5,800. The most dense population in Scotland was in the Hebrides, where the sandy beaches and low grassland are really suited to breeding.

The first pair of Little Ringed plovers in the British Isles nested not too far from Oxfordshire, at Tring reservoirs, Hertfordshire, in 1938. Since then, breeding numbers have increased steadily and their range westwards and northwards.

The expansion was initially slow, with only three pairs recorded in 1944, but the number rose to 30 in 1950, 74 in 1956 and by 1967 to 223. The population had spread to 154 sites in 26 counties. A survey covering just this species in 1973, studying numbers summering in Britain, revealed a further 100 per cent increase to at least 467 at 261 localities. The 1984 survey showed 370 sites spread throughout England and Wales, with estimates of more than 600 summering pairs; there were no breeding records from Scotland or Northern Ireland.

The starting point for this year's survey will be from an estimate in the late 1980s and early 1990s of up to 1,070 pairs. The objectives are threefold: to obtain updated population estimates for both species. The Ringed plover is now on the Birds of Conservation Concern Amber list.

to investigate the distribution and habitats. The 1984 survey revealed that there had been a decline in local and regional populations of Ringed plovers. Since the 1970s there had also been a spread from the coast inland. For the Little Ringed plover, more likely to be at home in Midland counties, the aim will be to determine by how much the species has expanded its range and how it is making use of gravel pits and reservoirs. These man-made habitats are holding the majority of breeding pairs.

To carry out a census of numbers at all Sites of Special Scientific Interest (SSSIs) and Special Protection Areas (SPAs) which are already designated for their importance for Ringed plovers. No sites are designated for Little Ringed plovers.

While much of the survey work will be carried out by BTO members at specific sites, the organisation will welcome reports from anybody who is able to identify these species at specific locations.

The Little Ringed plover chooses bare ground in which to nest, in an area close to water - just what gravel pits can provide.

The BTO's co-ordinators for Oxfordshire are John Melling, for the south of the county, and Frances Buckel for the north.

John said: "Like many waders, Little Ringed plovers like to nest in open areas. They crouch down over their eggs or young and have from their position a good range of view to see any predators.

"When faced with such danger, they have a distraction display - a 'broken-wing' display. They leave the nest and move away very slowly, giving the predator the suggestion that they might be an easy target - and when they have drawn it sufficiently far away they fly off at their normal speed."

Particularly favoured sites for bringing up young are islands in lakes or pits as they can be safe from predators such as foxes.

One of the difficulties of maintaining suitable sites, explained John, is the fact that once vegetation has grown up on what was bare ground, it will not be so favourable.

In areas where nature reserves have been created at former gravel sites, attention has been paid both to the islands and to the sides of banks to provide the right conditions, not only for the Little Ringed plover but also for other species that will benefit. Gravel is important, so, in some cases, where possible, vegetation is kept in check and areas re-gravelled.

The survey is taking place from now until July, the breeding season. At observed sites, recorders will make three site visits to count the number of adult birds and estimate the number of breeding pairs.

Anybody who would like to take part in the survey can contact Greg Conway at the BTO on 01842 750050 or by e-mail at greg.conway@bto.org.