MOLE VALLEY NATURAL HISTORY AUDIT BUTTERFLIES

More documents

Recommendations

Info

Mole Valley Agenda 21, Nature Conservation Sub-Group MOLE VALLEY NATURAL HISTORY AUDIT BUTTERFLIES: Distribution and Status 1995/6 Species: Silver-spotted Skipper It is difficult to separate populations of this species, which inhabits a number of small patches of suitable habitat along the downs, with movement of adults between patches. The Mole Gap probably acts as a barrier which few individuals cross, with metapopulations on either side. The species is vulnerable to loss of habitat; these losses may not be detected without careful monitoring by experts familiar with the requirements of the butterfly, but if available habitat were to fall below a critical level the entire metapopulation could die out very rapidly. Codes indicate maximum numbers seen on a single visit: A=1, B=2-9, C=10-29, D=30-99, E=100+. In 1995/6 the species was breeding in the following places: Population to west in Guildford Borough at Hackhurst and Colekitchen. White Downs area. National Trust. (Includes Blatchford Down TQ103487, Old Simms Field TQ105486, Old Plantation TQ107486, Chalk Quarry to east of road TQ114486, Great Down TQ117488, Chalkpit Field TQ119489, Wholecombe TQ123492, Lamb Leys TQ124495, Ranges TQ126495). Numbers up to C per visit. Currently very heavy rabbit grazing is rendering much Festuca ovina unsuitable even for this short turf specialist and there is potential for increases if rabbit numbers decrease, for instance due to Viral Haemorrhagic Disease. Denbies Hillside National Trust. Small populations in the Big Field TQ135500 (B-C), odd individuals seen in the Brow TQ146502 and Secretary's Field TQ149502. Box Hill National Trust. strong populations (C-D) on all grassland areas on north side of Hill, where Festuca sward is common. Smaller populations (A-B) on Viewpoint slopes and Dukes on the south side, where there is less Festuca currently in suitable condition. Mickleham Downs National Trust. TQ180535. Small population (B). Headley Warren TQ190538 (Private). Medium-sized population in Downs Field (C). Headley Heath, Chalk Slope area National Trust. TQ195533. Small population in South Paddock and on Terraces (B). Brockham Warren TQ198512. SCC. Good population (C) on old chalk workings. Betchworth Quarry TQ205155 Privately owned landfill area. Unsurveyed population on small patches of grassland, some inaccessible. Dawcombe Nature Reserve TQ215525. Currently owned by Smith Kline Beecham and managed by Surrey Wildlife Trust. Medium population (C) breeding mainly in the two compartments (known as A and B) at the north end of the reserve. Buckland Hills TQ228525-TQ233523. Privately owned by Buckland Estates. Population currently low due to excessive rabbit grazing in parts, and threatened in parts due to scrub/tree growth. Most threatened part of the Surrey SSS population. Juniper Hill TQ237520. NT. Population currently low due to excessive rabbit grazing. Mole Place TQ237522. Small area private land above Juniper Hill. Small pop. (B). Further population on Colley Hill to East, in Reigate & Banstead Borough.
Mole Valley Agenda 21, Nature Conservation Sub-Group MOLE VALLEY NATURAL HISTORY AUDIT BUTTERFLIES: Distribution and Status 1995/6 Species: Marbled White Codes indicate maximum numbers seen on a single visit: A=1, B=2-9, C=10-29, D=30-99, E=100+. White Downs. National Trust. Areas as for Silver-spotted Skipper. Numbers currently low due to excessive rabbit grazing, with A, B or C seen per visit. Numbers likely to increase if lower rabbit populations lead to taller sward. Denbies Hillside. National Trust. Found on all the grass compartments. Sward currently undergoing changes due to scrub removal, pony grazing, fluctuating rabbit populations. Marbled White populations generally strong with C or D seen per visit to most compartments. Higher numbers (E) may be seen in Steers Field, adjoining NT Car Park at TQ142503 Box Hill National Trust. Can be found on all grass compartments. Strong populations on south slopes (Viewpoint slopes, Dukes) with D or E per visit on each. Lower numbers on the northern areas. Mickleham Downs TQ180535. National Trust. (C) -on grassland at top of slope. Cherkley Wood TQ187542, TQ 183547. Private. (C). Headley Warren TQ190538. Private. Up to C per compartment at present. The main grassland areas are currently very heavily rabbit grazed and Marbled White numbers can be expected to rise if sward height increases. Headley Heath, Chalk Slope Area National Trust. TQ195533. Small population. (B). Brockham Warren. SCC. TQ198512. Small population. Most grass too short. (A/B). Dawcombe Nature Reserve. TQ215525. Has become established in last 2-3 years, with numbers seen rising each year. In 1996 up to 20-30 seen per visit over whole site. Mole Place Private. TQ237522. Marbled White not seen here until 1995 (B). By 1996 well established (30 seen on one visit). Claypit on south side of Inholms Lane, North Holmwood. TQ175473. B seen 1996. The Marbled White has not been recorded from the Betchworth Quarry or Buckland Hills areas in 1995/6, but is probably present in low numbers, and could increase if rabbit levels decrease. Single specimens seen in 1995/6 at: Polesden Lacey (NT) TQ182522; Hammonds Copse (field adjoining woodland) TQ 213442; on rough ground on north side of Trig Street, west of Newdigate, TQ190418
Page 1: Mole Valley Agenda 21 - Nature Cons
Page 6: Mole Valley Agenda 21, Nature Conse

MOLE VALLEY NATURAL HISTORY AUDIT BUTTERFLIES

Create successful ePaper yourself

Delete template?

Save as template?