SITES

	Greatham, Teesside, UK
	West Site, Billingham, UK
	Grimsby, Humberside, UK
	Calais, France
Habitats on Calais Site Invertebrates Birds Biodiversity Management
	Huelva, Spain
	Scarlino, Italy
	Teluk Kalung, Malaysia
	Umbogintwini, South Africa
	Lake Charles, USA
	Burnie, Tasmania

Index by Category

Appendices

References

Calais, France

Birds

Based on a visit 6-7 June 2001 twenty-eight species of birds are known from the Tioxide site at Calais. Almost certainly a considerably greater variety will be recorded with additional surveys. The Calais site is situated on the English Channel coast and is very favourably placed to act as a resting and feeding area for migrant birds during spring and autumn.

Along the Channel coast of France from Dunkirk south to the bay of the Somme there are numerous sites where migrant birds congregate (van den Berge & La Fontaine 1996). The sea buckthorn thickets on the Tioxide property are ideal shelter and will almost certainly attract migrants during the spring and autumn seasons.

The birds already known from the site are given in Table 22.

A number of the birds occurring on the Calais site are of particular interest.

Grey Partridge (Perdix perdix)
Grey Partridge prefers open land with hedgerows and grassy banks and avoids areas of dense cover. Northern France remains the stronghold for Grey Partridge in Europe with breeding populations in some areas of up to 30 pairs / km² (Reitz 1992). Nevertheless, even in northern France the bird is still not as common as it was in the past (Hagemeijer & Blair 1997). In other parts of Europe however, there has been a very serious decline over the past 50 years with decreases as high as 90% in Britain, the Netherlands and Germany (Hagemeijer & Blair 1997). Reduced habitat and more intensive farming practices leading to fewer young per breeding pair are considered to be amongst the main reasons for the bird's decline (Potts 1986). Partridge numbers are mainly limited by availability of insect food for their chicks and reduced cover for nesting sites. Undeveloped areas of industrial sites however, can provide good nesting habitat and food for both young and adult birds. Consequently in some areas, such as northeastern UK, industrial land is a stronghold for Grey Partridges displaced from adjacent farmland.

Small numbers of Grey Partridge, up to three birds, were recorded on the Calais site on 6-7 June 2001. The birds seemed to prefer the eastern part of the site where the sea buckthorn thickets opened out into short grassland and areas of bare ground. All the birds seen were adults but it is possible that Grey Partridge does breed on the Tioxide property.

Turtle Dove (Streptopelia turur)
The Turtle Dove is the only European member of the family Columbidae that is a long distance migrant. The birds that nest in Europe over-winter in sub-tropical Africa. Since the mid 1970s there has been a dramatic decline in the Turtle Dove population over most of its range, with up to 50% reduction in breeding numbers in Britain and France. In Britain the bird has almost disappeared as a nesting species in some northeastern parts of its range (J K Smith pers. obs.). However, notwithstanding the reduction of Turtle Dove in France over the past 30 years, the French breeding population is still second only to that of Spain (Hagemeijer & Blair 1997).

Numerous reasons have been suggested for the dramatic decline of Turtle Dove. These include two of the criteria invariably cited as major causes for the demise of many species; habitat loss and the excessive use of pesticides, the latter reducing insect prey which is required especially for young birds. For the Turtle Dove in particular excessive hunting pressure is also considered to be another important detrimental factor. This is especially so in the Mediterranean region where many thousands of Turtle Doves are killed by hunters, and in some areas by bird netters, during their spring and autumn migration periods. The birds which migrate through the eastern Mediterranean probably suffer the most since hunters on Malta have for many years taken a particularly high toll of Turtle Doves (Bannerman & Vella-Gaffiero 1976).

Environmental changes in the birds' wintering grounds in Africa could also be an important factor in the birds’ survival. Long periods of drought in these regions has probably resulted in a considerable reduction of available food and the over exploitation of the acacia woodland e.g. for firewood has reduced the birds' winter habitat (Hagemeijer & Blair 1997). In an attempt to halt and reverse the decline in the UK English Nature has undertaken an ecological study of the species (Calladine et. al. 1997).

Fragmented woodland and scrub with bare ground for feeding have been found to be the most favoured habitat (Cramp 1985). The study of breeding sites carried out by Calladine et. al. showed that 65% of nests were in hawthorn, ca. 14% in elder and the remainder in various other trees and shrubs. All the nests found were between 1.3 m to 3.5 m above the ground with a median height of 2.2 m.

Turtle Doves also require very short vegetation (10 cm or less) for feeding or if longer vegetation is present this must be very sparse (less than 20% cover). The birds will, however, feed on grain fallen from standing crops (Calladine et. al. 1997).

Turtle Dove was quite common on the site with at least 10 birds present. Birds were seen in the sea buckthorn thickets and the areas of poplar and willow woodland.
On the 7 June a number of birds were watched in display flights over the buckthorn. No nest or obviously young birds were recorded but it would seem likely that Turtle Dove breeds on the site, sea buckthorn thickets has been recorded as a nesting habitat for this species.

Nightingale (Luscinia mergarhynchos) [SPEC Cat 4, Threat Status S(P)]
A member of the thrush family the Nightingale is rather a plain looking bird, its most distinctive visible feature being a rufous coloured tail. It is very skulking and secretive and generally keeps to dense cover. The bird habitually feeds on the ground and when feeding it sometimes ventures into the open. Although visually undistinguished the Nightingale has a remarkable very rich, musical and varied song and as its name suggests sings both at night and during the day. It is mainly for its song that this bird has such a wide charismatic appeal.

France has the highest population of Nightingales in Europe with about 1 million breeding pairs (Cramp et. al. 1988) This would appear to be a large population but the bird has suffered a decline in numbers since the 1930s due principally to habitat loss (Hagemeijer & Blair 1997). The French population would now appear to be stable, but it must still be regarded as vulnerable and the bird and its habitat still need to be conserved.

Habitat
Nightingales like dense cover in which to display, sing and nest and old studies in Britain suggest that they have a preference to thorn thickets (Hartham 1934). More recent work, however, has suggested that the habitat requirements are more critical than merely thick cover. Primarily a ground, a rich ground zone seems to be a regular feature of Nightingale habitat (Simms 1978).

As part of a detailed study of Nightingales in England the British trust of Ornithology (BTO) has shown that the ideal habitat are thickets with a dense canopy cover that extends to extensive ground cover around the edges. The centre of the thickets should have bare or sparsely vegetated ground with leaf litter where the birds can feed (see Figure 17).

At least three Nightingales were found in the buckthorn areas to the south of the site. It is possible that more birds were present but song was much reduced this late in the season that made locating birds difficult. Although nesting was not proven it would seem extremely likely that Nightingales do nest on the site. Nightingales are recorded as breeding birds of buckthorn habitats in Europe (Cramp 1988).

Black Redstart (Phoenicurus ochruros) [protected under EC Wild Birds Directive, not a Species of European Conservation Concern and has a Threat Status as “Stable”]
Black Redstarts prefer warm, dry habitats avoiding cool, wet or densely wooded areas. The bird prefers areas where the vegetation is sparse and its natural environment is mainly exposed rocky habitats on hill and mountainsides that have little plant cover.
In northern Europe however, it has colonised man-made structures occurring in villages, towns and even large cities, it is also frequently found on industrial sites. It is uncommon in Britain, but a number of pairs that do occur are found on works sites (Frith & Gedge 2000). In the Netherlands a survey in 2000 in the Zwijndrech area found 13 breeding pairs, ten of which were on industrial properties including the ICI Quest site (W. Punt pers. com.). These artificial habitats seem to provide the optimum micro-climate the birds’ require (Williamson 1975).

The abundance and convenience of song posts and nesting sites in walls, roofs of buildings etc. has led to the birds close commensalism and the preference of industrial sites above those of parks and highly landscaped areas. The birds do however, like access to some open spaces such as railway sidings for their wide ranging display flights (Hagemeijer & Blair 1997). In June 2000 a pair of Black Redstarts had nested and were feeding fledged young along the north boundary of the site. Another Black Redstart was seen in the south part of the site.

Crested Lark (Galerida cristata) [SPEC 3, Status Declining]
Two Crested Larks were recorded and it is possible that the species nests.
Although still an abundant species populations of Crested Lark have declined and the birds range has contracted in most of western and central Europe since 1979. This decrease is considered to be due mainly to the intensification of agriculture resulting in a loss of suitable habitat.

Crested Lark prefers open, dry habitats that are flat or gently sloping with low and sparse vegetation cover of not more than 50% (Cramp et. al. 1988). Originally Crested Lark was a bird of desert areas but over the years it has expanded into various man-modified areas that simulate its original desert habitat (Cramp 1988) and these include industrial sites (Tucker et.al. 1994).

The bird has decreased in parts of northern France such as the area of the Somme since the 1960s, this being attributed to the increased mechanisation of farming practices and the increased use of insecticide (Triplet 1981). The conservation of even small populations of Crested Lark, especially in the northern parts of its range such as those on the Tioxide property at Calais, is therefore of considerable biodiversity value.

Linnet (Carduelis cannabina) [Spec 4]
Linnets are frequent over much of the site with 20-30 birds being present. They were particularly common at the southern end where the presence of young birds showed that they had successfully nested.

Linnets are another species that is particularly associated with sea buckthorn habitats (Tucker et. al. 1997). This is still a widely distributed bird in Europe, but in some regions there has been a decrease in breeding populations, particularly in the northern parts of its range. The population in France however, appears to be stable.