The Lincolnshire Branch of Butterfly Conservation has two important, current Conservation Projects in hand. The 'Limewoods Brown Hairstreak Project' has been running for 20 years, & the 'Grizzled Skipper Survey in South-west Lincolnshire', has been running for 4 years.
CONSERVATION WORK PARTIES:
Although all the Conservation Work Parties are listed separately under Events, readers might find it helpful, as a quick reference, to have these listed all together here. For full details, please refer to the Events section. Always check with the Contact person beforehand.
Snakeholme Pit Nature Reserve
2022: Saturday 2 April - 10.00am - 3.00pm
Contact: Collette Tait (collettetait1@hotmail.com)
THE LIMEWOODS BROWN HAIRSTREAK PROJECT IN BRIEF:-
In 1994, Pete Smith found his first Brown Hairstreak egg 'over-wintering on a protruding Blackthorn branch on a hedgerow near 'Fiveways' in Chambers Farm Wood.' Since then, as more was learned about the status and distribution of the butterfly, together with the Forestry Commission, the woodland has been managed to promote this rare species. Rotational coppicing of Blackthorn stands produced vigorous young growth favoured by the butterfly. Widening of the wood rides and conifer removal opened up areas too shady for the species. Egg counts were made each year with amazing results. Ten years later, in 2004, nearly 300 were found. The final total for this 2013-14 year has resulted in 3786 eggs! These are spread over a number of colonies in various Lincolnshire woods.
Pete writes: 'Adult Brown Hairstreak burtterflies, always elusive & hard to see, are increasingly observed by visiting enthusiasts, who travel from quite some distance to see our local population.' (Photo: ©Iain Leach)
THE LIMEWOODS BROWN HAIRSTREAK PROJECT IN DEPTH:-
Early Beginnings …
Pete Smith writes: ‘One bright and cold December morning back in 1994 I was strolling around Chambers Farm Wood when I happened to find my first ever Brown Hairstreak egg, over-wintering on a protruding blackthorn branch on a hedgerow near ‘Fiveways’. This was to prove to be the starting point of what would become a long term study and management project, later to be known as the ‘Limewoods Brown Hairstreak Project’ - now in its 21st year’.
Back in the early 1990’s the Brown Hairstreak butterfly was in a precarious state in mid-Lincolnshire, having been virtually unrecorded since 1985 at formerly occupied sites in the area. The finding of eggs at Chambers was a major discovery, and soon a small number of enthusiasts were searching the Blackthorn hedges for eggs of this species. Survey work confirmed that a small colony was present, centred around the ‘Fiveways’ area, and from this point on, egg counts were made each winter to monitor the species.
As we learned more about the status and distribution of the butterfly, we began to advise Forest Enterprise on how best to manage the woodland for this rare species, and a management plan was soon in place. This advised rotational coppicing of Blackthorn stands to produce the vigorous young regrowth favoured by egg-laying Brown Hairstreak females, plus ride-widening and conifer removal to open up areas that were too shady for the species, along with the maintenance of key ‘master-tree’ areas of mature oak and ash.
Progress …
By 1998 we had got much better at finding Brown Hairstreak eggs, and a good impression was building of the core breeding areas at Chambers. During the winter of 1998/99 there was opportunity to survey a large area of the Limewoods for the presence of the Brown Hairstreak. All sites with historic records were surveyed, plus other potential sites within the area. Sadly, almost all sites proved negative for the presence of this butterfly, but there was to be good news... During a visit to New Park Wood (a former stronghold in the 1970’s), a very small number of eggs were found at a ride intersection.
It seemed unlikely that these few eggs had been the result of a stray female from Chambers, and further searches resulted in the discovery of a large, hitherto un-recorded Brown Hairstreak colony, breeding mainly on private farmland to the south of North Spring Wood.
Number of Known Colonies Increasing …
So, back in 1998 there were just two, known colonies in the Limewoods. Survey work continued at both colonies over the next few years, and habitat management commenced at Chambers to improve both the quantity and the quality of suitable breeding areas. This management work continued over the years, helped by volunteer workers from the Lincoln Conservation Group, RAF cadets, Butterfly Conservation, BTCV and others. By 2005, some significant large areas of ideal breeding habitat were developing. The Brown Hairstreak responded fabulously to the work, and annual egg counts increased dramatically.
The Chambers colony was increasing to the point that there was evidence of dispersal away from the wood, and hopes were high that new sites may be colonised. Over the next few years additional habitat development in the local area proved to be highly beneficial to the fortunes of the Brown Hairstreak butterfly in the Limewoods.
The Heritage Lottery Funded ‘Lincolnshire Limewoods Project’, a five-year project commencing in May 2006, enabled further improved habitat management, including woodland ride widening, new plantations and the planting of linkage hedgerows between woods.
In 2006 a small number of eggs were found on the edge of Scotgrove Wood. None were found during 2007, but a small number were again found in 2008. By 2009, following some prior ride-widening and coppicing within the wood, good numbers of eggs were found here. Scotgrove Wood became our third Limewoods Brown Hairstreak site, and several eggs were found on a roadside hedge equidistant from Scotgrove and the New Park/North Spring colony, suggesting natural spreading.
Further Expansion …
The Lincolnshire Wildlife Trust reserve extension at Goslings Corner Wood, following acquisition and planting up of former farmland
adjacent to the wood, had provided another ideal area of potential habitat for the Brown Hairstreak, and a good numbers of eggs were discovered here during the winter of 2010. This site became our fourth Limewoods colony and has gone from strength to strength over the past couple of years. This year’s egg count for this site looks like being well over 500! The site is being sympathetically managed for the Brown Hairstreak, and we have high hopes that the species will do well here for the foreseeable future.
A few years back, the Woodland Trust acquired some land adjacent to the College Wood complex. This has been planted up, leaving a lovely wide border around the South-east of Glad Wood, where some fabulous potential Brown Hairstreak habitat has developed; eggs were found here in 2011. College wood became our fifth current Limewoods Brown hairstreak site, and continues to be occupied in 2013.
Current Position …
So, we have gone from a state of near extinction back in the early 1990’s, to a situation where we currently have 5 Brown Hairstreak colonies in the Limewoods area. Additional single egg records from Snakeholme Pit and Camshaws plantation in recent years, plus a small number found in Southrey Wood in 2011 (the first since the 1950’s) suggest that the species is still moving out and attempting to colonise new areas.
The future currently looks bright for the Brown Hairstreak in the Limewoods! Woodland management continues. The final egg count for 2013-2014 stands at 3,786!
It has been a fabulous 20 year journey, and to date we have found and mapped the distribution of more than 13,000 Brown hairstreak eggs, covering 25, 1km Ordnance Survey grid squares. Adult Brown Hairstreak butterflies, always elusive and hard to see, are increasingly observed by visiting enthusiasts, who travel from quite some distance to see our local population.
So if you happen to be out in the Lincolnshire Limewoods in late summer ….. keep your eyes open!
We are very grateful to the Forestry Commission for their help, support and encouragement over the years.
(Photos of Brown Hairstreak butterfly & the Egg Count Chart by ©Pete Smith; that of Brown Hairstreak eggs by Lawrie Poole)
GRIZZLED SKIPPER SURVEY: SOUTH-WEST LINCOLNSHIRE IN BRIEF:
Concern had been expressed regarding the state of the Grizzled Skipper in South-west Lincolnshire. In the ten years from 2000, there had been only 10 recorded sightings of the butterfly, apart from the main stronghold in Twyford Woods, where it was seen regularly in good numbers.
Up to eighteen volunteers looked for the butterfly each Spring from 2010 - 2013 with considerable success. Disused railway lines, quarries and airfields were targeted. Pooling the results for these years, the teams probably found some 15 new, viable small colonies. There seemed to be the possibility of 4 more smaller colonies.
GRIZZLED SKIPPER SURVEY: SOUTH-WEST LINCOLNSHIRE IN DEPTH:
The Butterfly ...
The Grizzled Skipper butterfly basks with its wings wide open to the sunshine. In flight, its chequered wings seem blurred and it is quite hard to follow. It is on the wing from mid-April till June, with an occasional, partial, second brood in August. The strong colonies in Twyford Wood are pretty much at the butterfly's Northern limit. The Grizzled Skipper favours sparsely covered, chalky ground.
Its Food ...
The Grizzled Skipper caterpillars feed on the leaves of Wild Strawberry, Creeping Cinquefoil and Agrimony. Tormentil and small, low Blackberry bushes are less often used. These plants grow on chalky, sparsely planted ground. The Grizzled Skipper will often settle on bare earth.
The Concern ...
Our concern, as a Branch of Butterfly Conservation, was that whilst the Grizzled Skipper used to be quite a common butterfly in the County, there had been only 10 recorded sightings in the South-west of Lincolnshire from 2000 to 2009, other than those in Twyford Wood.
The Plan ...
In 2010, it was decided to survey the large area of the County in the Vale of Belvoir, to the West and South of Grantham. (From Long Bennington in the North to Carlby in the South, and from the County border with Nottingham & Leicestershire in the West, to the East Glen River in the East.) The idea would be to check out as much of the considerable, disused railway network as possible, and to include any disused quarries and airfields - without trespassing!
Articles posted on the local website and in the County Newsletter resulted in some 18 stalwart volunteers to help with the Survey. For the past four years, as soon as the first sighting had been made, usually at Twyford where two Transect Walks are undertaken, the 'Intrepids' were out looking & recording! We decided at the outset, that all species of butterfly seen, together with their numbers, would also be logged whilst we were about it!
The Results ...
The very detailed results were recorded centrally.
The Outcome ...
The conclusion was that there seem to be 10 perfectly viable colonies spread across the above target area, in addition to the Twyford Wood colonies. We felt we may well have found a further 4 colonies, as small numbers of the butterfly were seen annually at these additional locations too. No new colonies were found in 2015.
The discoveries have increased the known range of the Grizzled Skipper in the South-west of the County. It is a pleasure to realise that this prettily marked, little butterfly with its fairly fussy food requirements, and blurred flight, is probably thriving in parts of Lincolnshire quite well thank you - albeit in relatively small numbers.
Stats 1: Lincolnshire Early & Late Records, Highest Count
| Year | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 |
| Early Record | 28 April | 17 April | 30 April | 5 May | 21 April | 18 April | 3 May |
|
Highest Count |
23 May: 114 | 25 May: 25 | 24 May: 20 | 20 May: 22 | 25 May: 47 | 23 May: 22 |
15&22 May: 26 |
| Late Record | 17 June | 7 June | 28 June | 17 June | 22 June | 12 June | 15 June |
Stats 2: Some Sightings in 2016 other than in Twyford Wood:
| Date | Who | Where | Grid Ref. | No. of GS |
| 3rd May | Toby Ludlow | Willow Quarry | SK 99/18 | 1 |
| 4th May | Jim Ashton | Jackson's Pit | TF 05/20 | 1 |
| 4th May | Jim Ashton | Private Quarry nr Castle Bytham |
1 | |
| 12th May | Richard Davidson Lawrie Poole |
Little Ponton Quarry | SK 92/32 | 12 |
| 12th May | Toby Ludlow | Castle Bytham Quarry | SK 991180 | 1 |
| 30th May | Richard Smith | Barkston Junction (New Site for GS!) |
SK 915423 | 3 |
| 4th June | Peter Cawdell | Gonerby Hill Foot | SK 90/38 | 3 |
Stats 3: Some Sightings in 2015 other than in Twyford Wood:
| Date | Who | Where | Grid Ref. | No. GS |
| 24th April | Chris Howes | Grimsthorpe Estate | TF 04/21 | 1 |
| 29th April | Chris Howes | Jackson's Pit | TF 05/20 | 2 |
| 4th May | Dean Eades | Jackson's Pit | TF 05/20 | 2 |
| 8th May | Toby Ludlow | Little Ponton Quarry | SK 92/32 | 7 |
| 8th May | Toby Ludlow | Castle Bytham Quarry | SK 991180 | 5 |
| 8th May | Toby Ludlow | Willow Quarry | SK 99/18 | 4 |
| 17th May | Chris Howes | Jackson's Pit | TF 05/20 | 1 |
| 26th May | Jim Ashton | Grimsthorpe Estate | TF 04/21 | 3 |
| 31st May | Peter Cawdell | Castle Bytham Quarry | SK 991180 | 1 |
Stats 4: Some sightings in 2014 other than in Twyford Wood:
| Date | Who | Where | Grid ref | No. GS |
| 5th May | Chris Howes | Jackson's Pit | TF 05/20 | 1 |
| 18th May | Martin Kew | Castle Bytham Quarry | SK 991180 | 5 |
| 19th May | Peter Cawdell & Tehani | Little Ponton Quarry | SK 92/32 | 2 |
| 25th May | Lincs Branch Field Trip | Holywell Quarry | SK 987159 | 1 |
| 25th May | Lincs Branch Field Trip | Castle Bytham Quarry | SK 991180 | 6 |
| 2nd June | Chris Howes | Grimsthorpe Estate | TF 04/21 | 1 |
| 2nd June | Jane Ostler | Woolsthorpe Line | SK 917242 | 3 |
We are grateful to the Forestry Commission for their help, support and encouragement.
(GS photos by Pam Carter, Toby Ludlow & Lawrie Poole)