SPECKLED WOOD Pararge aegeria in the Priory, Sale, 2008

PETER B. HARDY, PHILLIP M. KINDER, LIMMUEL HARDY

LOCATION OF THE SITE

The "Priory", or "Priory Gardens" as the boards by the gates name it, or "Priory woods" as the local residents have long tended to call it unoffricially, is a complex of woodland and grassland between Dane Road and the M-60 motorway in Sale, Cheshire, SJ7992/8092 (vice-county 58), under the jurisdiction of the Mersey Valley warden service. It consists of an old woodland comprising the remains of the formal gardens that belonged to Sale Hall Priory, plus further land added to the public space following construction of the motorway (originally M62, later M63 and currently M60) in 1974. The current area of the whole site is 14.15 hectares; prior to the motorway widening in 2004-6 it was 17.67 hectares. Its average altitude is 25 m above sea level. The first two of the maps below show the site as it was before the motorway widening in 2004-6; the second map shows the 100m grid squares and their numbers. The third map shows the site after the motorway widening. The fourth map is an aerial view of the site, believed taken in 2004, when the destruction to widen the motorway was just starting, at the eastern end of the site.

DESCRIPTION AND HISTORY OF THE SITE

The original woodland is at the south-centre of the site; it falls within parts of the 100 metre squares SJ797924, 797925, 798924, 798925 and its area is 1.30 hectares; it consists of widely-spaced mature trees mainly deciduous and including an enormous hollow beech, but also four venerable yews, and in the memory of PBH is very little changed from how it was in his childhood in the 1950s. Where canopy is dense there is little ground cover, though there is a distinct glade, into which sunlight penetrates for most of the day, in the centre of the wood in SJ797925, and further small glades in the east of the wood in SJ798924. In these glades the ground is largely covered by short grass with some brambles. There is some sapling growth beneath the canopy; the wood has seen very little in the way of “management” over the years. Clearly, it is this part of the Priory which contains the most mature woodland.

Most of what lies to the north of the original woodland is reclaimed tips. From the 1950s until the early 1970s the active council tip gradually spread northwards from the former boundary of the wood over the flat meadows of the flood-plain, then used for grazing cattle and sheep, towards the river. On the east the tip reached an unsurfaced lane, named on some maps as "Cow Lane" though it never bore this name on any sign-board, leading from Arnesby Avenue to a farm beside the river; the southern section of this old lane remains as a public footpath through SJ800925 and 801926 to the new footbridge over the motorway.

In 1974 the motorway was constructed, severing the old lane and effectually bringing to an end the flat grazing meadows. Tipping had ceased in SJ797926, 797927, 797928, 798925, 798926, 798927, 799926, 799927, 800926 and 801926; fast-growing tall trees had been planted along the slopes of the tip, on the north-west side (SJ796926, 796927), the south-west side immediately to the north-east of the original woodland and the gardens to the west of it (SJ797926, 797925 and 798925), in a due north-south row along the entrance track (SJ799925) and in a due west-east line along the southern edge of the eastern section immediately north of a horse-farm (SJ799926 and 800926); thicker woodlands of smaller trees were planted and/or evolved naturally in the north-west section (SJ797927, 797928) and at the north-eastern side, that is on the west of the old lane and to the south of the motorway (SJ800926 and 801926). A further belt of trees extended north-eastwards from the edge of the original woodland towards the motorway in SJ798926, and a thinner belt developed running in a north-west to south-east direction across SJ798926. There were thus four main blocks of grassland between the belts of trees: the most westerly, in SJ797926, comprising medium-length rough grass and some tall herbs; the next to the east, in SJ798925 and 798926, including more longer grass and large patches of brambles especially on the western edge, this with the last one forming a central plateau bordered by trees; north of these two, mainly in SJ798927 and extending into 799927, grassland sloped slightly downward to the north-east towards the motorway; the grass was shorter and the whole more open; in the low-lying patch close to the motorway boundary some damp ground developed which in the 1990s was ideal habitat for Pieris napi and Anthocharis cardamines, but was destroyed in the motorway widening in 2003-6; further east, in SJ799926 and 800926, a further plateau bounded to the north by a developing woodland edge was for some years used as a hay-meadow; but following the total destruction of the woodland during the motorway widening, and subsequent planting of a token new wood, the mowing seems to have ceased and latterly the grass has become rougher and mixed with sedges and rushes, and some damp ground has evolved.

To the west of the original "Priory", and formerly entered by a separate gate from Dane Road in SJ796925, was a private tip owned by Bethell's, and tipping continued on this site long after it had ceased on the council tips - indeed right up to the early 1990s. More than fifty years ago, children used to climb over the boards at the back of the gardens (belonging to certain obliging householders!) in SJ795927 or 795928 to reach a pond, well to the west of what was then the limit of the tipping area, and in the extreme south-western corner close to the railway line, and hunt for hours for frogs, newts and all manner of wildlife; some nicknamed the location the "World of Insects". Over the years the access over the boards was closed off, and the tip steadily advanced and the pond disappeared under it. In the early 1990s, when tipping eventually ceased, it again became possible to enter the site; the tip was in a much younger state of regeneration than the council tip and unlike the latter the regeneration had not been assisted by the application of any topsoil. The site - which extends over SJ795927, 795928, 795929, 796926, 796927, 796928, 796929, a small part of 797927 and a fragment of 795926 - was further disturbed in 1994 when used as a base for the construction company "Kilroy"; but following that it has moved through several stages of regeneration and is now largely covered in scrub, with tree belts on the west side (SJ795928 and 795929) and the south-west side bordering the gardens in Lynn Avenue (SJ796926, 795926, 795927, 795928); some rough grassland remains especially in SJ795928 and SJ796927, whereas quite dense woodlands have developed in the east of SJ796926 and the north of SJ795928. This sector was not officially included in the public open space until 2006, after the motorway widening, at which point the original entrance on Dane Road was securely gated and an alternative public entrance was constructed via some steps up the slope at the extreme west end of the extension of the woodland behind the gardens on Dane Road.

Prior to the motorway widening in 2003-6, there was a deep gully between the north-eastern edge of the former Bethell's tip and the motorway embankment (SJ795929 and 796929), which in itself formed a valuable south-west-facing slope at this point; the gully was good butterfly habitat especially for the spring Pierids and the motorway bank a good thermoregulating and adult feeding site for Nymphalines especially in early spring and autumn; the gully was filled in and a great deal of habitat lost during the motorway widening. A little further to the south-east, however, in SJ796928, there remains a wide, shallower gully, with a steep, wooded slope on the south-west side up to the former Bethell's tip and a much gentler slope, largely vegetated with tall herbs, brambles and some open woodland, to the former council tip on the north-east side.

The contour lines, shown in orange on the post-motorway-widening map, denote 25m; the blue shown on the same map in the lower-altitude sections represents drains, usually water-filled.

In the 1990s, the land to the east of the old lane (SJ801925, 801926, 802925, 802926, 803924 and 803925) became the "Priory nature reserve", and was a fine mixture of wetland, woodland of varying ages and some grass and tall herb elements. The motorway widening destroyed a good half of this "reserve" and completely altered the character of the remainder; nevertheless some interesting habitats are developing out of it. Above a large stagnant pond, the land rises to the north-west to a steep-grassy bank terminating in a high wooden fence bordering the motorway; this grass has been largely planted with tree whips (which to date have not made much growth headway); further east, behind the houses on Arnesby Avenue, is a narrow strip of land between the slope up to the motorway and the garden fence, with a shallow and normally dry drainage ditch at the bottom and many low non-native shrubs planted along the side of the drain. Trees overhang from several of the gardens so that the strip is in a way analogous to a deep woodland ride. In the west section, where the motorway embankment has smothered the former reserve, the new grassy slopes have been planted with tree whips, as a token compensation for destroying the woodland (we are uncertain whether we believe this planting to be worthwhile, but how it will develop only time will tell).

Following the motorway widening; squares SJ798928, 800297 and 802926 no longer have any of their area within the site, and SJ795929, 796929, 797928, 798927, 799927, 800926, 801926, 802925 and 803925 have been drastically reduced.

METHODS

Throughout the 2008 season, from the date when the first P. aegeria was noted (30th April) until the date when the last was noted (5^th October) we visited the site whenever an opportunity presented, noting details of weather (temperature, insolation, wind), the location where each butterfly was seen (we aimed to measure it to a ten-figure grid reference, using a Garmain “Geko” GPS machine), the biotope, vegetation, substrate, aspect (where a feature such as a slope, woodland edge, glade or similar was involved), the behaviour(s) of the butterflies concerned and the height above ground at which those behaviours occurred.

Commencing at the end of August 2008, when the butterfly season was beginning to run down, we visited each 10 m square within the Priory, using the “Geko” to obtain its position, and made a visual estimate of the percentage of the square which was bare ground, the percentage which was covered in grass (potential hostplant), the percentage of canopy cover, and the percentage covered by any potential nectar source: we treated as potential sources bramble Rubus fruticosus agg. (flowers and fruit), thistle Cirsium arvense/vulgare, ragwort Senecio jacobaea, Michaelmas daisy Aster x salignus and buddleia Buddleja davidii, the only plants which we have observed P. aegeria using in the Mersey Valley.

To achieve even coverage of the entire site throughout the recording season was clearly impossible. For most of the time we were limited to the network of public paths running through the site, and those nearer the entrance were clearly visited more than those further away. We also have to admit to a certain bias towards the locations most favoured by the butterflies, though we did our utmost to ensure that others were not neglected. Some parts however were very difficult of access (huge patches of brambles; impenetrable grass/tall-herb communities; fenced newly-planted woodland; low-lying parts under water). Nevertheless, we do feel that our results give a fair picture as to what parts of the complex P. aegeria does, and does not, use.

SCALES OF MAPPING

The next map shows all the records of the Speckled Wood Pararge aegeria during 2008, mapped at a resolution of 10 m. This is a far finer scale than that used in any of the county or regional atlases.

By mapping the same records at a resolution of 5 m, a more accurate impression of the butterfly's distribution - and the considerable areas within the site which it does NOT inhabit, begin to show. These maps also show the paths in the Priory; the main ones are shown as continuous lines and the minor ones - probably not all of them are "official" - as dotted.

The following map is of 10 m squares on a scale of 9 shades of grey, the lightest denoting 1 visit only during the butterfly season (which in this project was from 30th April, the date when the first P.aegeria was seen in the Priory , to 5th October, when the last was seen), the second lightest 2 to 4 visits, the third 5 to 7 visits, the fourth 8 to 10 visits, the fifth 11 to 13 visits, the sixth 14 to 16 visits, the seventh 17 to 19 visits, the eighth 20 to 22 visits, and the darkest 23 to 31 visits. Squares left blank were not visited during the butterfly season - though all were visited during the winter to map the vegetation.

The next map is again on a 9-point scale, ranging from very light green to almost black. The lightest green denotes grass with no (or not more than 5%) tree canopy; the second lightest 10 to 15% canopy; the third 20 to 25%, the fourth 30 to 35%; the fifth 40 to 45%; the sixth 50 to 55%; the seventh 60 to 65%; the eighth 70 to 75%; and the ninth and darkest 80 to 100% canopy cover.

The next map aims to show the maturity of the woodland, based on the size of the largest tree in each 10 m square. The lightest green denotes grassland with no trees or shrubs; the second lightest grassland with newly-planted tree whips; the third shrubs (whether naturally growing or, in most cases, planted); the fourth scrub; the fifth denotes that the largest tree in the 10m square has a trunk diameter of less than 10 cm; the sixth, the largest tree with a diameter of 10 to 24 cm; the seventh 25 to 49 cm; the eighth 50 to 99 cm, and the ninth and darkest 100 cm or over. This map also marks the 10m squares in the adjacent road (Dane Road) in grey, and marks in blue the 10 m squares in which there is normally a large amount of standing water.

The final map, below, shows the combined distribution of plants used as nectar sources by P.aegeria. The lightest green denotes that not more than 5% of the area of the 10 m square is covered by one or other of the plant species listed in the heading - regardless of whether a butterfly has actaully been seen using them or not; the second lightest 10 to 15%; the third 20 to 25%, the fourth 30 to 35%; the fifth 40 to 45%; the sixth 50 to 55%; the seventh 60 to 65%; the eighth 70 to 75%; and the ninth and darkest 80 to 100% cover - this last category mainly comprising the large patches of brambles. P.aegeria often uses bramble fruit (ripe blackberries) as a source of nutrition, as well as the flowers.

RESULTS OF THE SURVEY

The following are tabulations of the data which we recorded

Total P.aegeria seen in the Priory during the 2008 season (first sighting 30.4.2008, last 5.10.2008)

• 360

Biotopes and numbers of P.aegeria observed

• Mature woodland (closed canopy) - 7
• Mature woodland (edge) - 5
• Mature woodland (glade) - 83
• Mature woodland (ride) - 3
• Semi-mature woodland (closed canopy) - 3
• Semi-mature woodland (edge) - 145
• Semi-mature woodland (glade) - 16
• Semi-mature woodland (ride) - 23
• Young woodland (edge) - 14
• Young woodland (glade) - 9
• Grassland and short/tall herb community - 12
• Grassland near but not adjacent to woodland edge) - 7
• Scrub - 6
• Linear bottom of slope between motorway and gardens) - 28
• Hedge on south-east edge of wood by road - 1
• Road bounding site on south-east side - 2
• Gardens adjoining site - 2
• Unsurfaced car-park - 2

(total more than 360 as some were observed in more than one class)

Vegetation (or other feature) above or on which P.aegeria were observed

• Bare ground - 16
• Cut grass or moss - 12
• Short uncut grass or short herbs - 87
• Tall grass or tall herbs (e.g. nettles) - 73
• Low shrubs (e.g. bramble) - 72
• Tall shrubs - 21
• Trees - 136
• Road surface - 4
• Motor car - 1

(total more than 360 as some were observed in more than one class)

Substrates upon which P.aegeria (for resting, thermoregulation (basking), roosting or feeding

• Soil - 7
• Brick - 1
• Live leaves - 119
• Dead/dry leaves - 4
• Live stems - 2
• Dead stem - 1
• Twig - 1
• Flowers - 12
• Seed heads - 6
• Grass - 50
• Dry grass - 1
• Log - 1
• Metal - 1

(total much less than 360 as only includes settled butterflies)

Height above ground at which P.aegeria were observed, whether in flight or settled, and numbers of butterflies

• <2cm (less than 1") - 17
• 2 - 10cm (1" - 4") - 15
• 10- 50 cm (4" - 1' 6") - 89
• 50cm - 1m (1' 6" - 3') - 140
• 1m - 2m (3' - 6') - 115
• > 2m (6' +) - 89
•  
• (total more than 360 as some were observed in more than one class)

Aspect of location and numbers of P.aegeria seen

• E - 53
• N - 46
• NE - 7
• NW - 6
• S - 136
• SE - 14
• SW - 16
• W - 35
•  

• (total less than 360 as not all habitats had distinct aspects)

Behaviours and numbers of occasions witnessed

• Direct linear flight - 70
• Search flight - 143
• Inspection - 10
• Resting - 41
• Basking - 97
• Nectaring - 16
• Interaction with same species - 85
• Interaction with different species - 8
• Disturbance by recorder; previous behaviour not seen - 53
• Attempted courtship - 6
• Walking - 1
• Vertical descent from tree roost - 1
•  

• (total more than 360 as some were observed in more than one class)
• The following behaviours, all of which clearly must occur, were not noted: roosting; copulation; mud-puddling; oviposition; disturbance by other animal or insect; undergoing predation.

Shade temperatures and numbers of P.aegeria seen

• 11° - 1
• 13° - 4
• 15° - 14
• 16° - 14
• 17° - 54
• 18° - 80
• 19° - 46
• 20° - 55
• 22° - 64
• 23° - 17
• 25° - 5
• 27° - 6
•  

• [Total butterflies 360]

Weather conditions and numbers of P.aegeria seen

• Cloud - 62
• Cloud, some sun - 57
• Could/bright - 1
• Cloud/haze - 15
• Hazy - 1
• Heavy cloud - 5
• High cloud - 6
• High cloud/brief sun - 1
• Slight rain - 3
• Sun - 114
• Sun, some cloud - 95
•  

• [Total butterflies 360]

Wind and numbers of P.aegeria seen

• Nil - 116
• Very light NE - 4
• Very light NW - 7
• Very light E – 6
• Very light W - 7
• Very light, direction  not recorded - 8
• Light E - 36
• Light NW - 22
• Light SE - 34
• Light SW - 48
• Light W - 6
• Light, direction  not recorded - 15
• Moderate SW - 27
• Moderate/strong NE - 6
• Moderate/strong SW - 3
• Moderate/strong W - 11
• Strong NW - 4
•  

• [Total butterflies 360]

Sexes of P.aegeria recorded

• M - 79
• F - 41
•  

• (others, sex unknown)

The months in 2008 when butterflies were seen, with the numbers of recording days when the site was visited (in brackets) and the total numbers of P.aegeria seen each month

• April (1) - 2
• May (12) - 66
• June (8) - 40
• July (8) - 24
• August (9) - 146
• September (10) - 80
• October (2) - 2
•  

• [Total butterflies 360]
• On two of the above recording days, one in July and August, no butterflies were seen. Visits to the site before 30th April (the date when the first P.aegeria was seen) and after 5.10.2008 (the date when the last was seen) have not been included.

Starting times of the recording walks and numbers of P.aegeria seen

• 9 a.m. - 7
• 12 noon - 69
• 1 p.m. - 87
• 2 p.m. - 62
• 3 p.m. - 38
• 4 p.m. - 78
• 5 p.m. -19
•  

• [Total butterflies 360]
•