Essex in Heath Fritillary The 2015 October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 0 The Heath Fritillary in Essex – 2015 Report Introduction High degrees of management prevailed this winter in the remaining colonies, and hopes were high of an upturn in fortunes of the Heath Fritillary. The most intriguing site was Little Haven, where the attention was on the effects of the mass-starvation event of last year. The report details the winter management, larval and adult monitoring and cow- wheat distribution. West Wood (6a), Cottage Plantation (6b) and Thundersley Great Common have been included in this report as possible future sites. The Sites & Peak Counts Site Area (ha) Peak Counts Ref. Site Name (wood/heath) 2015 2014 2013 1 Hockley Woods 130.0 44 32 46 2a Hadleigh Great Wood 33.0 7 14 10 2b Dodds Grove 3.8 5 10 9 2c Belfairs Park 29.0 0 0 0 3 Pound Wood 23.0 7 20 25 4a Tile Wood 6.8 0 0 0 4b Whyburns Wood 7.1 0 0 0 5 Little Haven (Starvelarks Wood) 7.9 1 42 256 6a West Wood 33.1 n/a n/a n/a 6b Cottage Plantation 7.0 n/a n/a n/a 7 Thundersley Great Common 14.8 n/a n/a n/a October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 1 The Reserves 1. Hockley Woods Ownership: Rochford District Council Managed by: Rochford District Council Woodland area: 130.0 hectares Colonised area: Coups: 1.0ha Rides: 800m Population Trend: stable, following severe decline Population Status: At Risk Hockley Woods is the largest wood with a Heath Fritillary colony. The main colony has always centred along the rides in the south-east corner of the wood (Ride 1 (south) & Ride 2 (east)), although small numbers of Heath Fritillary butterflies have been observed in other parts of the wood in the past. Adult Population Trend After concerns over falling long-term peak counts, management in the key areas has been stepped up in the past 2 years to encourage an upturn in the fortunes of the Heath Fritillary. October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 2 Management – winter 2014/15 In the 2 previous years, long lengths of ride were coppiced and/or brushcut. The south side of Ride 1 (south) was coppiced in 2013/14 and has excellent cow wheat, but is relatively shaded. In 2014/15, extensive areas of Ride 2 (east) were brushcut, mainly on the north side. Most stools in each scallop were re-cut, except for the east end of Coup 9. There were also 2 half-coups newly coppiced in 2014/15; Plot 27 and Plot 27, along with a section of Ride 3 that formed a link to Ride 1 (south) Adult Count 2015 Recent management appears to have had a positive impact as transect results gave an increased peak count of 44 adults in 2015, compared with 32 in 2014. This is the only Essex woodland to have experienced an increased count in 2015. October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 3 Adult Distribution 2015 The main congregation area has been on Ride 2 (east). Here, the cow wheat is patchier than along Ride 1, but the scallops are more sunlit. Ride 1 (south) may have been used for egglaying last year and again in 2015 as transect figures early and later in the flight period had a higher proportion of adults than around the peak. Most encouraging was the sight of the 3 pioneering adults seen in newly-coppiced coup 28, late in the flight period. This large coup has a very dense band of cow wheat for the first third of the coppiced area most adjacent to Ride 3. There was also pioneering adult seen in the coup that was coppiced in 2013/14 where the cow wheat is more thinly scattered. Strangely, 2 adults were also seen around the compound area which hadn’t been coppiced for about 4 years. Continuing Management At a meeting on 15th October 2014, Rochford D.C. were concerned that they were receiving conflicting advice. Whilst Natural England advocated annual ride maintenance, Butterfly Conservation now advised sections on a 4-5 year rotation. This change had occurred in response to declining numbers and the perception that the annual brushcutting was not sustaining the population in the long term. The longer rotation is necessary to shade out the bramble and thicker grasses. Hockley Woods is more fertile than Little Haven and is therefore more reliant on continual coppicing. Where regular ride maintenance is necessary, it should preferably not all be carried out in one year. This can be used to promote some structure into the generic ride management. With 2km of rides to manage each year at Hockley, this can be brought into the Management Plan. October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 4 The east ride has had sizeable scallops created since 2012, with a progression towards the pond, and the work carried out in winter 2014/15 was extensive along the north edge of this ride. Work in 2015/16 will aim at coppicing the young stools in these scallops that were not done last winter. The SSSI designation is for the flora, including large stands of Sessile Oak. Due to most of the coppice being Hornbeam, the rotation is about 30 years, making it difficult to always coincide with the butterfly’s locality. However, the rides are substantial and aiming for 2 colonies is a feasible target. Rochford D.C. managed 2 smaller areas in 2014/15 (as practiced by Southend B.C. at Hadleigh Great Wood) but giving the same total area as a single coup. The intention in 2015/16 is to extend these same coups deeper into the woodland. On the face of it, this could prove better for 2 inter-dependent reasons. Firstly, it will provide consecutive succession habitats. Secondly, it should provide better opportunity for the Cow Wheat, which was mainly confined to a 15-metre width closest to the ride edge in Plot 28, to penetrate further into the woodland before succession crowds out the bare ground. Ride 1 (south) will also be opened up on its north side. It will be an interesting comparison between Hockley Woods (long rides) and Hadleigh Great Wood (scallops) - see how the different regimes work at the two sites. CONNECTIVITY of rides is most important as this will sustain the population through the poor years and get them into the coups. Consideration should be given to comparing pricing structures at the EWT woodlands, such as Pound Wood and Little Haven, where profit is made for coppiced products. Refer Marc Outten reserves manage for south east Essex. Current and Future Monitoring Larval searches are potentially useful in the new outlying coups to see whether it was females that dispersed to these areas. This should be conducted in early spring. Adult counts The UKBMS transect remains useful as it encompasses the main East and South rides. However, these sections are long and the more detailed work by Ashleigh Courage is particularly useful, showing adult congregations in the sunnier spots in preference to those with higher cow wheat density. The transect route is useful for other species within the woodland. Common Cow Wheat Monitor where cow wheat is coming up in new scallops. October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 5 Common Cow Wheat Surveys 2015 Experience at other colonies points to careful monitoring of cow wheat to ensure that is does not slowly diminish in density over time. October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 6 2a. Hadleigh Great Wood Ownership: Southend Borough Council Managed by: Southend Borough Council and Essex Wildlife Trust (from 2012/13) Woodland area: 33.0 hectares Colonised area: Coups: 2.5ha Rides: 500m Population Trend: severe decline Population Status: severely threatened Adult Population Trend In the period 2008-2012, the relationship between management and monitoring became disjointed, which appears to have sent the population into severe decline. Since then, a significant amount of targeted and varied management has taken place within Hadleigh Great Wood. This includes coppicing up to a hectare a year, brushcutting of rides and meadow areas and creating new scallops. However, there is an inevitable lag in the effects of recent management and the decline appears not yet to have been halted. Adult Count Dedicated photographic monitoring has revealed that perhaps only 8 individuals emerged in 2015, but more females were noted than in 2014. October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 7 Management & Common Cow Wheat Distribution 2015 Common Cow Wheat regeneration occurs in a new coup from the edge of the ride where it is already present. In subsequent years, the cow wheat advances incrementally into the coup, but scrub encroachment ultimately halts its progress. Therefore, the ride-side length of the coup appears more critical than the managed depth of the coup. This supports the scalloping model or the long-ride management model at Hockley. 2014/15 management took in extensive brushcutting of open grassland areas, new scallops on the main ride and re-established an old scallop by coup 9a. Coppicing occurred in the whole of coup 19. October 2015 “MANAGING RIDES AND KEEPING CONNECTIVITY IS THE MOST IMPORTANT MANAGEMENT ASPECT” 8 Adult Distribution Despite low abundance, a key management objective has been achieved in that the main congregation area has shifted away from the old main ride (between coups 2 and 7) that was turning into a meadow, and is now centered on recent coups (9a & 16a).