Tag: 2008

North Merseyside Biodiversity Action Plan
Red Squirrel Sciurus vulgaris

1 Current status
1.1 National

Once ubiquitous in Britain, the Red Squirrel has undergone a drastic decline during the last 100 years. Following the introduction of North American Grey Squirrels in the nineteenth century, Red Squirrels have been lost from most of southern and central England. They are now essentially restricted to parts of Scotland and the north of England with small isolated populations elsewhere. There is no sign that their rate of decline is slowing.

Squirrel pox virus carried by Grey Squirrels is now proven to be the main threat to the Red Squirrel’s survival.

1.2 Local
In North Merseyside the Red Squirrel remains relatively widespread. The key stronghold is in Sefton where the coastal woodlands support higher than average population levels. The population extends into the urban areas of Southport, Formby, Crosby and Blundellsands. Regular monitoring of the Sefton Coast Woodlands Red Squirrel population has shown a relatively stable population of around 800 – 1200 animals. Population estimates are worked out using ‘distance’ techniques and represent minimum numbers. Natural fluctuations occur in any small mammal population due to variations in over-wintering and breeding success.

This number is further boosted by an estimated population of around 600 animals in the urban areas and Buffer Zone Woodlands, Recent losses have occurred in both the Sefton Coast Woodlands and Buffer Zone due to squirrel pox.

There are small numbers in Knowsley and St. Helens. Surrounding populations in West Lancashire are under severe threat and some have become extinct.

When faced with competition from Grey Squirrels, Red Squirrels have been shown to compete for longer in conifer forests with a mix of tree species and a diverse age structure of trees to ensure continuity of food. The presence of large-seeded broadleaved trees (oak, chestnuts, beech and hazel) aids Grey Squirrel colonisation and threatens Reds.

North Merseyside Biodiversity Action Plan
Water Vole Arvicola terrestris

1 Current status
1.1 National

The water vole is found throughout Britain but is confined mainly to lowland areas near water. Once common and widespread, it has suffered a severe decline in both numbers and distribution. A national survey in 1996-98 estimated an 89% loss since 1939, with a projected 94% loss by 2000.

The British population is estimated to have declined by 88% over the seven year period between the two national surveys of 1989-90 and 1996-98.
The Water Vole is a Priority Species in the UK BAP because of its declining population.

1.2 Local
The national survey of 1989-90 located water voles at 75% of Merseyside sites. A 1999-2000 survey found water voles present in 53% of all suitable North Merseyside locations. Liverpool has little suitable habitat for water voles, whereas 75% of sites in St Helens were positive. In Knowsley, Sefton and St. Helens water voles are relatively common on canals, rivers, brooks and ditches. It appears that North Merseyside, together with neighbouring areas, remains a stronghold for water voles. If they are declining locally, it is almost certainly at a much slower rate than nationally.

North Merseyside Biodiversity Action Plan
Urban Birds

1.1 National
Although only a small proportion of the country’s birds is found in urban areas, for very large numbers of people they provide their main contact with wildlife. Most species are not truly urban but woodland birds that have adopted parks and gardens as their home.

One such species, the Song Thrush, is in serious decline in the countryside but is holding its own in urban and suburban areas. Feeding garden birds is a major recreational activity, as indicated by the huge numbers of people who contribute to the BTO and RSPB garden bird surveys.

A small number of species, including House Sparrow, House Martin and Swift, are truly urban in that they breed almost entirely in or on buildings. Starlings are also highly dependent on buildings for nest sites. All these species are believed to be in significant decline but survey difficulties in urban areas have meant that scientific data have been difficult to assemble. However, both House Sparrow and Starling were added to the list of UK BAP Priority Species in 2007 because of their declining populations. Monitoring data suggest a 64% reduction in House Sparrow numbers since 1977 and some surveys put this decline at closer to 90% in urban areas. Starling numbers have declined by 72% since 1970 and House Martins by 32%. Information on Swifts is difficult to obtain but the Breeding Bird Survey indicates a decline of 26% since 1994.

1.2 Local
The North Merseyside conurbation supports a remarkable diversity of breeding and wintering bird species. Breeding Peregrine Falcons and Ravens are amongst the more spectacular of these. The largest numbers of birds are found in lightly managed greenspaces but parks, gardens and buildings are also important. One iconic species, Black Redstart, has been lost as a breeding bird since the 1990s but several others, notably Nuthatch, Long-tailed Tit and Jay, have successfully colonised urban areas.

House Sparrows and Starlings continue to breed in all areas of urban North Merseyside. During 1997-2000 House Martins bred in 80 out of 140 tetrads, mostly in the outer areas where supplies of mud necessary for nest-building are available. Swifts are more restricted in their distribution and bred in only 55 tetrads.

Local population sizes and trends of most species are not known but a sample survey in 2001-2002 estimated that a total of 11,400 pairs of House  Sparrows nested in North Merseyside. House Sparrows have almost completely disappeared from large areas of inner city Liverpool in the past 10 to 15 years but strong populations persist in many St Helens, Crosby, Southport and north Liverpool.

North Merseyside Biodiversity Action Plan
Song Thrush Turdus philomelos

1 Current status
1.1 National
Although still common and widespread, the Song Thrush went into dramatic decline in the mid-1970s with an estimated reduction in numbers of 73% in farmland and 49% in woodland between 1968 and 1993. Overall numbers fell by 50% between 1970 and 2005 but more recently have increased by 17% between 1994 and 2006. The decline is believed to have been more marked in the north of the country.

The species is partly migratory with many British birds wintering in southern Europe and being replaced by Scandinavian breeders. The causes of the breeding decline are believed to be linked to a very high level of mortality of first-winter birds. Recent research indicates that Song Thrushes may need to produce up to five broods per year in order to maintain their population level and that recent habitat changes have reduced them to an average of 2-3 broods a year.

The Song Thrush is a Priority Species in the UK BAP on account of its population decline.

1.2 Local
Anecdotal evidence suggests a large decline in North Merseyside in recent years but the species remains widespread, breeding in 90% of surveyed  tetrads in 1997-2000 and absent only from the most built-up areas.

The North Merseyside population was estimated at 500 breeding pairs during 1997-2000. These were mostly quite thinly spread with an average  density of about one pair per square kilometre, similar to the average for the whole of Lancashire. Liverpool supports the highest densities with closer to 1.5 pairs per sq. km. The largest concentrations occur in suburban areas of south Liverpool and Blundellsands, and in the Prescot  Reservoir/Eccleston Mere area of St. Helens – perhaps suggesting that gardens and parkland are crucial local habitats.

North Merseyside Biodiversity Action Plan
Skylark Alauda arvensis

1 Current status
1.1 National
The Skylark is amongst the most widespread of open country breeding birds with an estimated UK population of 1,785,000 pairs in 2000. Up to 25 million northern European birds may join the UK residents in winter. Nonetheless, the UK breeding population is in sharp decline. Numbers on  lowland farms fell by 75% between 1972-1996. Recent studies indicate similarly steep declines in upland habitats. The overall UK population declined by 53% between 1970 and 2005 and by 15% between 1994 and 2006.

The Skylark is a Priority Species in the UK BAP on account of its declining
population.

1.2 Local
Skylarks continue to breed throughout North Merseyside wherever suitable habitat remains and are absent only from the most heavily built-up areas.
Breeding was confirmed in 109 tetrads (78%) in 14 10km squares in 1997-2000. The breeding population in 1997-2000 was at least 750 pairs, roughly 0.5% of the UK population. (Knowsley = 130, Liverpool = 75, Sefton = 300, St. Helens = 250). They breed at an average density of about 1.5 pairs per square kilometre – similar to Lancashire as a whole. The extent of recent decline in North Merseyside is not known but it probably reflects the national situation.

The Sefton Coast between Blundellsands and Cabin Hill NNR supports densities of up to 37 pairs per square km – amongst the highest known in the UK lowlands. Farmland around Rainford also supports above average densities (up to 8 pairs per square km). Smaller, but still notable densities are found in Speke/Garston, Tarbock and farmland between St. Helens and Kirkby. Small populations persist in urban areas including at Otterspool and the Rimrose Valley.

Large winter concentrations occur on stubble fields, saltmarshes and strandlines.

North Merseyside Biodiversity Action Plan
Bats (Pipistrelle Pipistrellus pipistrellus/pygmaeus, Brown Longeared
Plecotus auritus, Whiskered/Brandt’s Myotis mystacinus/brandtii,
Natterer’s Myotis nattereri, Daubenton’s Myotis daubentonii, Noctule
Nyctalus noctula)

1 Current status
1.1 National
All seventeen species of bat resident in the UK are in decline. The most common, the Pipistrelle suffered population losses of up to 70% between 1978 and 1993 but it remains widespread with an estimated UK pre-breeding population of 2 million. Common Pipistrelle (Pipistrelle pipistrellus) is no longer a UK BAP Priority Species since its population is thought to be stable in the UK. Brown long-eared, Soprano Pipistrelle (Pipistrellus pygmaeus) and Noctule are UK BAP Priority Species due to a decline in numbers.

1.2 Local
Pipistrelles are widely distributed throughout North Merseyside, occurring in all four districts, and are the species most people come into contact with – they are the species most often found roosting in buildings and feeding in urban areas. Brown Long-eared and Noctule Bats are less common but are also found throughout North Merseyside. Daubenton’s Bats feed almost exclusively over water.

Therefore their distribution is localised and has been recorded from Sefton, Liverpool and St Helens. Whiskered/Brandt’s and Natterer’s Bats are rare locally. Whiskered has been located in Sefton and St Helens and Natterer’s only in St. Helens so far.

No information exists about the size of or changes in local populations but it is believed these mirror national trends. A survey and monitoring scheme (Liver Bats)was initiated in north Merseyside in 2007 to try to gauge the size and status of local populations.

North Merseyside Biodiversity Action Plan
Bluebell Hyacinthoides non-scripta

1 Current status
1.1 National
Britain has 20% of the world’s Bluebell population and, consequently, it is a plant that is often thought of as being characteristically British. The easily recognised and richly scented flowers, which bloom between April and June, also occur in pink and white forms. They are widespread throughout the United Kingdom, but are absent in Orkney and Shetland. They grow in humid habitats and are adapted to shade provided within woodland. They are also found in hedgerows. In the damper west it is also a common
coastal plant in open situations.

Even in comparatively isolated locations, hybridisation with the introduced Spanish form H. hispanica is not uncommon. This form is much stouter, with less nodding and more bell-like flowers.

1.2 Local
Good local examples include Clinkham and Red Brow Wood in St. Helens, and Croxteth Park in Liverpool. Landlife have information on native colonies and, in the past, all forms have been surveyed by the Liverpool Botanical Society. Many local records are of the hybrid form and distinct native colonies of any size are often hard to find, although it is present in 44 tetrads in North Merseyside.

North Merseyside Biodiversity Action Plan
Brown Hare Lepus europaeus

1 Current status
1.1 National
Whilst still a relatively common species, the brown hare has undergone a population decline from the end of the 19th century. A post-war increase in numbers was followed by a severe decline from the1960s to 1980s when the population appeared to stabilise.
The first national hare survey carried out by Bristol University estimated the prebreeding population to be around 800,000, approximately 20% of the Victorian era. The study concluded that the decline was faster and more severe in the western pastoral regions of the country.
Game bag figures indicate a decline in the number of hares shot between 1961 and 2004 across the UK but show a general increase between 1995 and 2004 in England. The decline across Wales appears to continue.

1.2 Local
There is no population estimate for North Merseyside. However, hares are commonly found on farmland throughout the area.
Consistent with national trends, populations are likely to have declined. Agrienvironmental schemes have had a good take up, particularly in the north of St Helens Borough. This should assist with hare conservation.

North Merseyside Biodiversity Action Plan
Corn Bunting Miliaria calandra

1 Current status
1.1 National
The UK population of Corn Bunting declined by 90% between 1970 and 2005. The most recent national survey gave a population estimate of 16-23,000 territorial males in 1993. This is likely to be significantly lower now, as the Breeding Bird Survey recorded a continuing decline of 32% between 1994-2005. Concurrent with the population decline has been a large contraction in the species’ range, with population collapses over much of central and SW England and Scotland. The highest densities in the UK are found on flat, open arable land and chalk downland. The Corn Bunting is a Priority Species in the UK BAP, due to its rapid population decline.

1.2 Local
The magnitude of the local population decline is not known. Certainly, a decline is indicated from the changes in the peak counts of wintering flocks. The North Merseyside population was estimated at 200 pairs in 1997-99.
The species remains widespread on farmland in the area, but in variable densities. Small populations are found on the edge of the conurbation at Speke, Croxteth, Aintree and Netherton. The highest population densities, reaching a maximum of 4-5 pairs per square kilometre, occur on arable farmland in Sefton, Knowsley and St. Helens. This is the southern part of a fairly continuous area of approximately 200 square kilometres of mosslands, most of it outside Merseyside, which holds the largest population of Corn Buntings in North West England, estimated in 1997-99 to total 1200 pairs, 5% to 7.5% of the UK population. The distribution of birds within this area is typically patchy.

The highest densities, around Altcar Withins and Little
Crosby, are similar to the highest densities so far recorded in North West Europe. Most of the UK population makes only local movements of a few kilometres between breeding and wintering areas. Therefore, wintering distributions are likely to be similar to breeding distributions on a coarse scale in North Merseyside. There are local re-distributions, for example of birds onto the dunes at Crosby in winter, where there is no breeding population.

North Merseyside Biodiversity Action Plan
Dark Green Fritillary Argynnis aglaja

1 Current status
1.1 National
Like many other fritillary butterflies the caterpillars of the Dark Green Fritillary feed exclusively upon violets. The adults are in flight between June and August and feed on a variety of flowers.
The species remains widespread but local. It has suffered local declines in recent years but is less severely threatened than several other fritillaries.

1.2 Local
Dark Green Fritillaries used to be common on the Sefton Coast sand dunes but are now much scarcer, being confined to an area between Birkdale and Hightown. Previous inland sites have all seemingly been lost.