Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Knepp Wildland Project Annual biodiversity report and monitoring update 2007 Theresa Greenaway December 2007 Theresa Greenaway Ecological Consultant Woodcote, Chalk Road Ifold West Sussex RH14 0UE [email protected] Annual biodiversity report and monitoring update 2007 Contents 1. Introduction 2. Field work 3. Individual survey reports 3.1. Spring botanical survey of River Adur and Lancing Brook. 3.2. Botanical survey north of Hammer Pond, crossing Rainbow and 27 Acres fields. 3.3. Butterfly survey. 3.4. Fixed-point photography of the Knepp Estate 2005-2007. 3.5. Breeding birds 2007. 4. Discussion Appendices and maps Map 1. Bird survey, east-west transect. Map 2. Bird survey, north-south transect. Appendix 1. Species records 2007: Electronic version only. Appendix 2. Table of results comparing2005 & 2007 surveys, R. Adur & Lancing Brook. Appendix 3. Rainbow & 27Acre fields transect data 2007: Electronic version only. Appendix 4. Knepp butterfly surveys 2005-2007: Electronic version only. Appendix 5. List of bird species recorded on Knepp Castle Estate 2007. Appendix 6. Number of bird species registrations along each transect. 2 Annual biodiversity report and monitoring update 2007 1. Introduction The Monitoring Strategy (Greenaway, 2007) prepared in 2006 presented as detailed a monitoring programme as was possible within the constraints of a very limited budget. Some of the work commissioned for 2007 was baseline survey, adding to that carried out in 2005. The rest of the 2007 fieldwork repeated methodologies implemented in 2005. Until April 2007, the Knepp monitoring programme was being organised and managed by the Sussex Biodiversity Record Centre Survey Unit, and the results of the field work, where appropriate, continue to be digitised by the Record Centre. The 2007 fieldwork was funded by the Knepp Castle Estate. Because the budget was so limited, monitoring and survey work had to be strictly prioritised, and by no means all of the work begun in 2005 could be repeated. This will not necessarily compromise the eventual evaluation of the effects of the Wildland project on biodiversity. Some surveys, for example the extended Phase I vegetation survey, only need to be repeated at the most at 5-yearly intervals, as changes at this scale are unlikely to show up at shorter intervals. Specific taxa however may fluctuate in terms of diversity or size from year to year and more frequent monitoring will allow a far better analysis of the effects of grazing and other environmental factors. Notable in this group is the breeding bird survey, which ideally should be carried out every year. In addition to the work presented in this report, there have been a number of student projects carried out at Knepp in 2007. The results of these studies are not yet available but if possible will be included in future reports. Back to Contents 2. Field work. The fieldwork in Table 1 was commissioned and carried out in 2007. In addition, there were a number of surveys carried out by other individuals, either as part of independent projects or as casual observations made by visitors to the Estate. All species data received by T. Greenaway have been entered on an Excel Spreadsheet (Appendix 1). Back to Contents Table 1. Commissioned surveys, 2007. Survey Vascular plants of River Adur Transect N. of Hammer Pond Breeding bird survey Butterfly transect & fixed-point photography Project management Total Time (2007) May Cost £875 April & May July Surveyor Dolphin Ecological Surveys Dolphin Ecological Surveys Paul James Rich Howorth 2007-2007 Theresa Greenaway £400 £3,800 June 3 £550 £1,575 £400 3. Individual survey reports 3.1. Spring botanical survey of River Adur and Lancing Brook. Introduction The original botanical survey of parts of the River Adur and Lancing Brook that run through the Knepp Estate in West Sussex was carried out on 17 th August 2005 by Kate Ryland of Dolphin Ecological Surveys. An early season repeat of this survey was undertaken on 24th and 25th May 2007 using the same methodology, though more time was available for the field survey in 2007. The survey covered aquatic plants found within the channel, marginal species and plants growing on the banks of the watercourses up to the change of slope at the top of the banks. Aquatic vegetation was sampled at regular intervals along the watercourses using a grapnel. A table of the results of the 2005 and 2007 surveys (Appendix 2) shows the vascular plant species observed in each distinct section of the watercourses with a measure of their abundance given on the DAFOR scale (D = Dominant, A = Abundant, F = Frequent, O = Occasional, R = Rare, L = Locally). Results Submerged aquatic vegetation was almost absent from the stretches of river surveyed in 2007, but this is not unexpected at the beginning of the field season since many aquatics do not become evident until later in the summer. There was much less duckweed present in 2007 than was observed during the 2005 survey. A marked difference between 2005 and 2007 was the significant reduction in the amount fat duckweed in 2007, which may be a result of both seasonal factors and the much higher water levels in 2007 compared with the survey period in 2005. A greater volume of water in the channel (although much of the river was still very sluggish or static) combined with less extreme eutrophic conditions and cooler water temperatures than those in 2005 are likely to account for this observed difference. As predicted in 2005, carrying out a survey earlier in the season has produced additional botanical records for all four stretches of watercourse. These additional records tend to consist of a small number of early flowering wetland species (such as cuckoo-flower and ragged robin), identifiable sedges (false fox-sedge, greater pond-sedge) grasses and common herbaceous plants from the riverbanks. In summary the likely reasons for differences in the species lists for each section of the river between 2005 and 2007, especially the increased number of species recorded in 2007, are: Seasonal effects, including overall lower vegetation height on the riverbanks in spring allowing more ground level species to be seen. Recorder error/omissions from 2005. More time available for survey in 2007. 4 Real differences caused by habitat change. This applies particularly to section 4 where poplar plantation has been felled so there is much more light reaching the watercourse. Higher water levels and lower water temperatures in 2007. Some slight natural changes in bankside and marginal communities over a two-year period. The DAFOR scale is subjective and not especially accurate, though sufficient for the purpose of giving a picture of riparian plant communities present. However, it does not allow direct, accurate comparison of species abundance over time. Section 1 River Adur, Shipley Windmill to Capps Bridge (TQ144217 to TQ148217) There was much less duckweed in this section in 2007 and the only other aquatic plant recorded was yellow water-lily. The centre of the channel was clear of emergent vegetation for most of its length, in contrast to 2005. A continuous fringe of marginal plants was present, dominated by reed canary-grass, bulrush and branched bur-reed. It appears that some of the channel vegetation may have been mechanically cleared between 2005 and 2007. The riverbanks are steep in this section and access to the water’s edge is poor. The coarse vegetation on the banks is dominated by bramble and nettle. Section 2 River Adur, Capps Bridge to A24 (TQ148217 to TQ164207) There was more water in this section of the river in 2007 than in 2005, but nevertheless areas of low/no flow were present and the water was scummy in places between Tenchford and Pound Farm bridges and alga was locally frequent in the water upstream of the small weir and near the confluence with Lancing Brook. Downstream of the main weir, near the A24, there was little water in the channel and emergent vegetation was dense, dominated by reed canarygrass, branched bur-reed and common club-rush. Aquatic vegetation was very scarce, but some fragments of shining pondweed were retrieved and yellow water-lily was quite frequent. Fringed water-lily was observed in small quantities near the A24 in a similar location to 2005. Some common duckweed was present towards Capps Bridge but much less was observed in the downstream areas. Great yellow-cress was recorded in the same area as in 2005 and also appears to have spread downstream since the first survey and was observed in small quantities as far downstream as the footpath bridge. Section 3 Lancing Brook, Hammer Pond (TQ148208 to TQ144208) 5 Little change was observed in this section, though there are now some young black poplars planted in the wet grassland/fen area at the upstream extent of the section. The additional species recorded in this section include some wetland plants, probably overlooked in 2005, such as yellow flag, water horsetail, common spike-rush and false fox-sedge. Section 4 Lancing Brook, Hammer Pond to Tenchford Bridge/Adur confluence (TQ148208 to TQ153210) The main change in this section of Lancing Brook is the removal of the poplar plantation, which has allowed considerably more light to reach the channel. Additional species recorded include fool’s watercress, greater pond-sedge, gipsywort and fat duckweed (the only location where this latter species was recorded in 2007). Several grasses and herbaceous species were also added to the list for this section. Back to Contents Dolphin Ecological Surveys 6a Northfield Cottages Isfield Uckfield East Sussex TN22 5XN 01825 750645 [email protected] 6 3.2. Botanical survey north of Hammer Pond, crossing Rainbow and 27 Acre Fields. Location of transect (NE corner of first and last quadrats) Direction of Transect Description of Location TQ 14413 21140 to TQ 14427 21007 N-S From the western edge of Rainbow Field, near a small copse that adjoins the hedgerow, the transect runs southwards through the southern hedge into 27 Acre Field. The northern end of the transect starts at the foot of an oak tree, which has two larger oaks close together to its east, crosses the hedgerow through a gap between two moderate aged, closely spaced oaks that lie to the east of a larger oak with a barn owl nesting box in it. This additional transect was 140m long and was recorded using the same methodology as in 2005 when a series of transects were recorded across the Knepp Castle Estate. The purpose was to give baseline information on land taken out of arable production 2, 4, 6 and 8 years ago and not grazed. On 28th and 29th June 2007 a total of 70 contiguous 2m x 2m quadrats were recorded from the western edge of Rainbow Field through a hedgerow to 27 Acre Field. Unlike the previous transects a permanent marker was not installed, but accurate grid references were taken for the start and end points of the transect using a hand-held GPS unit. A description of the starting point and route of the transect is given above and also shown on a site map. The vascular plants recorded in each quadrat with a measure of abundance on the DOMIN scale are given in Appendix 3. On the recording sheets bent-grasses Agrostis spp. are usually grouped together due to impracticality of separating the species where both occur within quadrats in the time available. The vegetation recorded contains few surprises and comprises a mixture of relicts of cultivation, such as black grass Alopecurus myosuroides and annual species including scarlet pimpernel Anagallis arvensis in the more open, patchy, rabbit-grazed areas along with the developing coarse sward of opportunistic and largely wind-dispersed species. The average vegetation heights of each quadrat, as shown below, indicate how variable the sward height is across the fields. Grasses were generally abundant across the transect with Yorkshire fog Holcus lanatus and bent-grasses most prominent. At the southern end of the 7 transect the vegetation was almost entirely dominated by Yorkshire fog. Tall, coarse herbs, especially fleabane Pulicaria dysenterica, creeping thistle Cirsium arvense, ragwort Senecio jacobaea, curled dock Rumex crispus and sow-thistles Sonchus spp. occur across the whole transect, though in varied proportions in the different aged reversion swards. Smooth tare Vicia tetrasperma is an almost constant component of the vegetation across the transect. There are some signs of woody species becoming established in the fields with seedlings and young plants of oak Quercus robur, blackthorn Prunus spinosa, hawthorn Crataegus monogyna, bramble Rubus fruticosus and rose Rosa sp. found especially near the hedgerows. Two more notable species that were recorded were grass vetchling Lathyrus nissolia and the more surprising occurrence of two individual common spotted orchids Dactylorhiza fuchsii (in quadrats 22 and 40). These are both species of grassland rather than arable habitats, as is the common knapweed Centaurea nigra recorded in the 6 year-old margin of 27 Acre Field. In the table below the average vegetation height figures in brackets indicate extremes of height within the quadrat. Back to Contents 8 Rainbow and 27 Acre Fields Transect Quadrat No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 Average Vegetation Height (cm) 10 (60) 20 15 (2) 15 (2) 40 50 20 (50) 10 (50) 50 (10) 60 60 (10) 30 30 40 30 30 30 (2) 25 (2) 25 (2) 20 30 40 40 15 30 (2) 15 15 (25) 15 (25) 25 (2) 15 5 (25) 30 30 25 30 (5) 40 30 25 (10 + 40) 25 (10) 40 (2) 30 (10) 40 40 50 30 (5) 40 (5) 40 (5) 30 (5) 5 (20) Comments on Vegetation Structure The field margins tend to have a lower, closed, rabbit-grazed sward whilst the main parts of the field have a generally tall sward with localised patches of bare ground or low vegetation particularly where rabbit grazing is focused. Quadrats 48 and 49 fall on the wide, trampled path on the field margin between Rainbow Field and 27 Acre Field, which is part of a horse-riding route. Quadrats 50 and 51 cover the area between the path and the base of the hedgerow whilst quadrat 52 lies within the hedge and includes a large oak tree as well as blackthorn shrubs. Quadrats 53 and 54 cover the ditch on the south side of the hedge and the ditch margin, which have a tall, coarse flora. From the ditch margin and into the main part of 27 Acre Field the sward is at first patchy with many gaps but has an increasingly closed, tall sward characterised by a similar suite of species to Rainbow Field. The final 6 quadrats (65 to 70) have an almost uniformly closed, grass dominated sward with much thatch and reduced amounts of herbaceous species. 9 Quadrat No. 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 Average Vegetation Height (cm) 50 (20) 100 (0) 200 (10m +0) 200 (0) 40 (0) 10 (0 + 30) 20 (2 + 40) 30 (5) 25 30 (5) 40 40 (2) 25 (2) 40 30 30 50 50 40 40 40 Comments on Vegetation Structure Back to Contents Dolphin Ecological Surveys 6a Northfield Cottages Isfield Uckfield East Sussex TN22 5XN 01825 750645 [email protected] 10 3.3. Butterfly survey Introduction Butterflies have been monitored on the Knepp Estate by means of annual surveys in July as part of the overall monitoring strategy to assess the effects of the more natural grazing regime that has been implemented. The three surveys carried out to date, in conjunction with fixed point photo monitoring, have detected a total of 22 different species, whereas previous recording by Butterfly Conservation (BC) Sussex branch lepidopterists during 1995-2004 had registered 26 species (mostly the same ones). Methodology BC’s standard methodology for ‘Butterfly Site Recording’ has been used consistently as the basis for the simple fixed-route timed transect surveys of the main areas of the Estate subject to ‘re-wilding’, enabling population densities to be calculated. The rapid walking route, covered in a single day (thought to be approximately 21 km), was divided into 26 discrete parcels according to vegetation, habitat and management, and the length of time spent in each and the individual numbers seen of each butterfly species were recorded. The walking route taken and parcel approximate boundaries are reproduced in English Nature Research Report 693 Map 6 for reference. The weather conditions apparent at the time of survey of each parcel were also recorded, together with a summary of maximum temperature, wind speed and direction and amount of sunshine. Results The annual surveys are summarised as follows - see Appendix 4 for each year’s individual data tables for complete results and analyses. 2005 Moderate weather conditions over the 2 days of survey resulted in just 13 species being recorded, a relatively low number. Species diversity in the parcels ranged from 1-6, being highest in the woodland of Horsham Common (Parcel 8). A total of 901 individual butterflies were recorded across all parcels, two-thirds (611 individuals) of these being meadow browns Maniola jurtina and the remainder mostly gatekeepers Pyronia tithonus (198), both of which occurred in nearly all parcels with the former being found at an average density of 22.6 individuals per parcel. These species numbers were followed by small skippers Thymelicus sylvestris (35 individuals), small whites Pieris rapae (15) and silver-washed fritillaries Argynnis paphia (13). An average density of 1.81 individual butterflies per minute (all species) was recorded overall, with individual parcels ranging from 0.3-15.25 indivs/min, the highest relative abundance occurring in the temporary arable fallow (Parcel 23) and lowest in the recently cut new grassland (Parcel 22). 2006 The weather was ideal, hot and sunny with little wind, until late in the day by which point unfavourable conditions meant it was not possible to survey the last 3 parcels. 18 species were recorded in total, with species diversity in the parcels ranging up to 9 species (in the extensive grassland around Lodge 11 Farm, Parcel 4). A total of 559 individual butterflies were recorded across all parcels over the single day of survey, about one-third being meadow browns (214 individuals) and one-third gatekeepers (170) which both occurred in nearly all of the parcels that were surveyed, at an average density of 9.7 and 8.1 individuals per parcel respectively. Large whites Pieris brassicae were quite numerous (64 individuals), followed by moderate numbers (c. 15-25) of small skippers, common blues Polyommatus icarus, small whites and silver-washed fritillaries. An average density of 1.7 individual butterflies per minute (all species) occurred, with individual parcels ranging from 0.19-9.18 indivs/min, the highest relative abundance being in the small strip of long rank grassland (Parcel 7) and lowest again in the large area of recently cut grassland fields of Parcel 22. 2007 Moderate weather conditions prevailed this survey day, with part-cloud and windy gusts improving by mid-afternoon; the last parcels were surveyed quite late in the day however, by which time most individuals were roosting for the evening. A total of 16 species were recorded, species richness in individual areas ranging up to 8 species in grassland Parcel 4 and woodland Parcel 8. A high total number of 1192 individual butterflies were observed across the whole estate, due to large numbers of meadow browns (974 individuals) which again occurred in the great majority of the parcels at a very high average density of 37.5 individuals per parcel. Lower numbers of gatekeepers were seen (92 individuals), whereas a relatively high abundance of Essex skippers Thymelicus lineola(33) and silver-washed fritillaries (26) was evident, and ‘normal’ levels of large and small whites. A high average density of 3.15 individual butterflies per minute (all species) was found, with individual parcels ranging from 0.58-7.7 indivs/min in the different areas of Knepp Castle grassland (Parcel 1) and the Adur floodplain meadows (Parcel 19) respectively. The previous extreme locations of Parcels 4 & 8 (high) and 22 (low) were instead in the low-mid density range this year. Discussion Only limited significance can be attached to these one-off results for butterflies based on annual surveys, with limited scope for statistical analysis of trends given the low temporal sample size so far. However, some qualitative patterns can be highlighted between the years given their comparability in survey effort, timing and locations. The observations of changes in species diversity and abundance at Knepp Estate need to be set against regional trends recorded by Butterfly Conservation, to indicate to what degree they are specific to this location and hence potentially attributable to the change to low intensity naturalistic grazing management. A tentative conclusion can be drawn that the most recent survey in 2007 reflects a good summer for butterflies at Knepp in general, not just due to the very high abundance of the widely distributed meadow browns, which together with gatekeepers are so ubiquitous that they are unlikely be useful indicators of environmental conditions beyond a basic requirement for nonintensive grassland and hedges respectively. Essex/small skippers were found to have spread out from their wet grassland strongholds, being observed in 12 twice as many locations in 2007 as previously. Similarly, individuals of silverwashed fritillary (a ‘Species of Conservation Concern’ according to BC) have doubled in number over the survey period to 2007 and more significantly appear to have expanded from just 3 to 8 woods in this time. Given their preference for more mature shaded and less managed woodland, this attractive species is expanding generally in the region including at Knepp. Another woodland species of conservation interest, the white admiral (a proposed Biodiversity Action Plan species) was found as a single individual in the north-east woodlands in 2007, although it has been previously recorded by BC at Knepp. Brown argus Aricia agestis was also recorded as a single individual in 2007, in common with a previous BC record, a species which prefers less managed grassland and set-aside habitats. It is suggested that more detailed analysis of parcel and species densities could be carried out after a number of years of data collection, which hopefully will continue to be funded by the Knepp Estate working with the Sussex Wildlife Trust. As part of such quantitative analysis, parcel boundaries could be mapped using GIS and their areas calculated to generate a more robust assessment of relative butterfly densities spatially. Any attempts to relate this conclusively to management practices will be difficult, however, since detailed environmental measurements of parcel characteristics such as vegetation height and density and grazing intensity over time would be required to establish any correlations. Hence firm conclusions on the impacts of changed management at Knepp are likely to be hard to demonstrate as a cause and effect relationship. Back to Contents Rich Howorth West Weald Landscape Project Sussex Wildlife Trust Woods Mill Henfield West Sussex BN5 9SD 13 3.4. Fixed-point photography of the Knepp Estate 2005-2007. Introduction Annual series of photographs have been taken over three survey years on the Knepp Estate to enable visual comparison and detection of significant changes in the site’s structure and composition over time. Such an approach is extensively used as a general technique to monitor gross ecological changes in protected areas worldwide, its value increasing with repeated application over time (as for all long-term monitoring studies). Given that substantial changes in habitat composition might be expected from the introduction of the extensive semi-naturalistic grazing regime, this simple method should provide an adequate photographic record of the site’s evolution. Methodology The fixed-point photo register has been carried out along side the standardised annual survey of butterflies from 2005-2007, including a selection of points that represent the geographical range, habitat diversity, and management regimes apparent in the areas subject to naturalistic grazing. Views along linear boundaries were particularly chosen where changes in the interface between woodland and grassland, or grazed and ungrazed areas, might be most apparent in time. Some general landscape vistas were taken furthermore, taking advantage of any high elevations present. All photographs were taken using the same Olympus Mju-zoom 300 digital camera, always at the widest angle (35 mm equivalent) at high quality (3.2 megapixels) in a landscape orientation (with one exception) and angled down slightly to take in as much ground as possible. In the first instance, when the series was originally established, the direction of each shot was recorded using an approximate compass bearing and its location noted using a Garmin Mk 3 GPS unit (typical accuracy c. 5-10m) supplemented by a written description of the point. Subsequent photos were largely located and orientated visually, using this additional information as necessary. It should be noted that an additional point was added from 2006 (Point 35), and that in this same year 3 locations were inadvertently omitted from being photographed. The points series has been entered onto ArcView GIS as a data layer, so that the total of 35 fixed point photo locations could be mapped – see Table below for the (revised) photographic register and English Nature Research Report 693 Map 4. Preliminary Results & Recommendations The photographic records are stored on CD and are retained by Knepp Castle Estate. Little change is apparent from the photos alone after just 2 years, as might be expected, although it is clear from these and field visits that the new grasslands especially are developing and diversifying in structure and perhaps also plant species composition. Faunal interest may also be developing, the high numbers of grasshoppers being particularly notable. Changes within and at the boundaries of the woodland blocks is less readily apparent, with variable growth and erosion evident in different areas – indeed, field visits suggest that the high numbers of deer in the central area 14 have impacted considerably on the ground and shrub layers of some woodlands. Given the efforts invested in establishing this photographic series, it is important to continue its operation in the future on a regular basis. While the frequency need not necessarily be every year, given the relatively limited rate of change in vegetation structure and distribution apparent at Knepp, photo monitoring should be carried out at least every 2-4 years. However, since this monitoring has been combined efficiently with the annual butterfly surveys (which do need to be at least yearly), it is recommended to continue with yearly photo monitoring if resources allow. Back to Contents 15 Photographic register of Knepp Estate Photo 2005 2006 2007 Description Compass POINT_X POINT_Y no JPEG JPEG file JPEG file Bearing file nos. nos. nos. 1 719002 P1010001 P1010012 N view W of Kneppmill 5 515739 121680 Pond 2 719003 P1010002 P1010013 E view W of Kneppmill 100 515684 121923 Pond at S wood boundary 3 719004 P1010004 P1010014 SW view within 230 515586 122072 glade/ride of mixed woodland 4 719005 P1010005 P1010015 E view at S boundary of 100 515736 122284 Merrik Wood on wooden steps 5 719006 P1010006 P1010016 W view at N boundary 280 515770 122429 of Merrik Wood on wooden steps 6 719007 P1010007 P1010017 W view along ditch by 270 516064 122601 marshy grassland patch (image cropped slightly at LHS) 7 719008 P1010008 P1010018 S view at NE field corner 200 516105 122726 by wood and road 8 719009 P1010009 P1010019 W view at N fence 280 515808 122817 along A272 road at oak tree (image cropped slightly at base & RHS) 9 719010 P1010010 P1010020 S view at N fence by 180 515663 122818 planted cherry tree copse by lodge 10 719011 P1010011 P1010021 E view along road 90 515603 122856 hedge boundary 11 719012 P1010012 P1010022 N view half way up W 10 515232 122934 margin of Cricketing Field 12 719013 P1010013 P1010023 S view at end of T 200 515228 123230 junction of forest track between pine-ash & oak blocks (N.B. portrait layout) 13 719014 P1010014 P1010024 E view at S boundary of 90 515397 123327 pylon field beneath oak near gateway 14 719015 P1010015 P1010025 N view along woodland 10 515718 123736 ride at Horsham Common by pheasant coup 15 719016 P1010016 P1010026 E view at rides 100 515740 123837 crossroad, Horsham Common 16 719017 P1010017 P1010027 S view of more acid 220 516044 124021 16 17 719018 P1010018 P1010028 18 719019 P1010019 P1010029 19 719020 P1010020 P1010030 20 719021 P1010021 P1010031 21 719022 P1010022 P1010032 22 719027 P1010023 P1010033 23 719029 P1010024 P1010034 24 719030 P1010025 P1010035 25 719031 P1010026 P1010036 26 719035 27 719036 P1010029 P1010038 28 719039 P1010030 P1010039 29 719040 P1010031 P1010040 30 719041 P1010032 P1010041 31 719042 P1010033 P1010042 32 719043 - P1010043 33 719045 - P1010044 - P1010037 grassland at NE end of wood by pheasant coup S view at field margin with Bar Furzefield wood ENE view at 4th oak from boundary at N end of large field to Pondtail Farm (barn owl box fixed) N view on W side of entrance drive by shaded pond NNW view from pond E of Spring Wood at E end S view from pond E of Spring Wood at E end W view at S boundary of Spring Wood, hedgerow removed, adj to corner of deer fence in wood E view along pheasant fence just W of forest tracks intersection in Spring Wood N view along deer fence inside Matches Wood at SW end W view along deer fence inside matches Wood at N end at track junction E view at path through wood at S end of field by Spring Wood E view from N bank of R Adur at W end of field just below Capps Bridge N view from E bank of R Adur at midpoint of track to Pounds Bridge S view from E bank of R Adur at midpoint of track to Pounds Bridge W view from S bank of R Adur at end of line of oak trees from bridge track N view along deer fence in field bordering A24 road E view near gate in field just E of Swallows Farm S view from old trackway by E edge of 17 200 516375 123884 60 516298 123313 10 515554 122370 330 515335 122103 210 515335 122103 290 515077 122180 110 514981 122292 10 515243 122330 280 515420 122612 95 515142 122345 95 514919 121835 350 515181 121409 170 515181 121409 280 516293 120648 10 516245 120471 110 515711 120190 190 515804 120548 34 35 Jackson's Wood by boundary oak tree 719047 P1010036 P1010054 NW view from road gate near Medlays on old brick foundation P1010034 P1010045 Extra point from 2006: N view down footpath & pylon line, by first pylon in field near house (W of Jackson’s Wood) 310 515338 120877 30 515547 120653 Back to Contents Rich Howorth West Weald Landscape Project Sussex Wildlife Trust Woods Mill Henfield West Sussex BN5 9SD 18 3.5. Breeding birds 2007 Introduction A survey of the breeding bird communities present within two areas of the Knepp Castle Estate was carried out in spring 2007 following a similar survey in 2005. The purpose of this survey was to provide a comparison with the results of the previous survey in relation to the conversion of the estate from intensive arable to a more-natural grazing system. The survey was carried out by Paul James, former Recorder for the Sussex Ornithological Society and editor of Birds of Sussex and the annual Sussex Bird Report. He has previously been employed by the Royal Society for the Protection of Birds as a senior research assistant to carry out woodland bird surveys. More recently he has been contracted by a number of consultants and conservation bodies to carry out a variety of bird and other ecological surveys. Methodology As in the 2005 survey, two transects were surveyed: the first in the area north of the A272 and east of Shipley Road (Map 1, East-West transect) on 14 April, 3 & 22 May, and the second in the area south of Countryman Lane and west of New Barn Farm (Map 2, North-South transect) on 7 & 21 April and 13 May. Each visit was made in good weather and commenced approximately one hour after sunrise. The surveys were conducted by following the transects and recording the species encountered (by sight or sound) on large-scale maps (see Maps 1 and 2) using the standard Common Birds Census species and activity codes (Marchant 1983). Results Species recorded A total of 44 species was recorded on the Estate (see Appendix 5), 30 in area A (Map 1) and 32 in area B (Map 2). For details of the number of registrations of each species along each transect see Appendix 6. (Note that where a bird was recorded in the same place on each site visits, a single registration is shown on the map). Species of Conservation Concern Of the 44 species recorded during the survey, eight were Red List Species of High Conservation Concern and eight more were Amber List Species of Medium Conservation Concern (see Appendix 5 for details). Red list species are those that are globally threatened according to IUCN criteria; those whose population or range has declined rapidly in recent years; and those that have declined historically and not shown a substantial recent recovery. Amber list species are those with an unfavourable conservation status in Europe; those whose population or range has declined moderately in recent years; those whose population has declined historically but made a significant recent recovery; rare breeders; and those with internationally important or localised populations. Species that fulfil none of the criteria are green listed (Gregory et al 2002). 19 Discussion Species present The results of the survey again confirm that the estate supports a rich breeding bird community, including a significant number of species of both medium and high conservation concern. The results also confirm that there some marked differences between the bird communities present within the two study areas with species characteristic of overgrown hedgerows such as nightingale Luscinia megarhynchos, whitethroat Sylvia communis and yellowhammer Emberiza citrinella absent from area A. Although a comparison of the results for 2007 and 2005 reveals changes in the number of territories for most species, these are not considered significant in terms of the management of the estate and are probably attributable to population trends within each species. The continued presence of turtle dove Streptopelia turtur on the estate is most welcome given that numbers of this red listed species declined nationally by 29% over the period 2005 – 2006. Although not covered by the transect, mention should be made of the loss of nesting lapwing Vanellus vanellus from the fields to the west of transect in area B at approximately TQ 133207. The reasons for this loss are unclear though one local resident commented that the fields were much drier this year than in 2005, perhaps due to the unusually warm and dry April. Survey and reporting constraints Although the survey carried out gives a good indication of the species present and the approximate number of breeding territories along the transects, it should be seen as providing a ‘snapshot’ rather than a detailed picture given that only three field visits were made to each transect. By comparison, the BTO’s Common Birds Census (CBC), which is a mapping census during which all contacts with birds are plotted on a map, involves ten or more visits to a site in the breeding season (Marchant 1983). References Gregory, R.D., Wilkinson, N.I., Noble, D.G., Robinson, J.A., Brown, A.F., Hughes, J., Procter, D., Gibbons, D.W., and Galbraith, C. (2002). The population status of birds in the United Kingdom, Channel Islands and Isle of Man: an analysis of conservation concern 2002 – 2007. British Birds 95: 410 - 448. Marchant, J. (1983). BTO Common Birds Census Instructions. Maund & Irvine, Tring. Back to Contents Paul James 12 Phoenix Way Southwick West Sussex BN42 4HQ Tel: 01273 705367 Email: [email protected]. 20 4. Discussion The fieldwork carried out to date is of considerable interest but it is far too soon to enable a meaningful analysis of the data or to see any dramatic increase in species diversity. Changes in vegetation structure and overall species diversity under a regime of low-intensity, near-natural grazing by mixed herbivores are likely to occur fairly slowly as it is not expected that low numbers of grazing animals will initiate the level of changes seen under a more aggressive management regime. At a species level, population changes will occur at varying rates. Highly mobile species and generalists may show fairly rapid changes, but more sedentary species are likely to have a far slower population dynamic. Nevertheless, some interesting changes are already starting to appear. Species or groups of species whose numbers are likely to fluctuate rapidly are therefore those that should be monitored most frequently. Birds are a good example of such a group – which is why bird surveys are programmed to take place every other year; annually would be better if sufficient funding were available. The presence of turtle doves is of particular interest, as this species suffered a severe population decline nationally over 2005-2006. It is to be hoped that their numbers here increase in the years to come. It is also notable that barn owls have had a particularly successful breeding season in 2007. Barn owl chicks are counted and ringed annually by Barrie Watson (Sussex Ornithological Society), and 25 chicks were ringed this year – a record number. The slow development of a tussocky, more natural grassland structure following arable reversion is likely to have been a major contributory factor to the successful rearing of these chicks, as such grassland favours the small rodents that form a large part of the diet of barn owls. Changes in plant communities are likely to be far less apparent until a number of years have passed, although there is already some evidence of change in the vegetation structure. Scrub is developing in some of the wetter areas and in some places the hedgerows are spreading out. As mentioned above, much of the arable reversion grassland is gradually developing a tussocky structure. However, it is also apparent from three years of photography that much of the woodland, wood/field boundaries and open field in grazed areas, especially the deer park, are not yet developing a more natural structure. In the deer park, an area that has been out of arable longest, there is still no understorey or scrub development, and this area to date has remained essentially unchanged (Fig 1). If this remains the case in the deer park and the wider wildland area over the next few years it will indicate that grazing pressure is too high to permit woody plant regeneration, at least until there is a sufficient growth of unpalatable spiny species such as bramble, blackthorn and hawthorn. It could be instructive to monitor the distribution and spread of these three species over the wildland area – potentially a suitable student project. The data gathered since 2005 is very valuable and its importance to the project will increase over time, but only if there is support and funding for continuing the monitoring programme. 21 Fig 1. West view at south boundary of Spring Wood, hedgerow removed. 2005 2006 2007 Back to Contents Reference Greenaway, T. (2007) Monitoring Strategy for Knepp Castle Estate Wildland Project. Unpublished report, Sussex Biodiversity Record Centre Survey Unit. 22 Appendices and maps Back to Contents 23 Appendix 1. Species records, 2007: Available as Excel Spreadsheet, electronic version only. Back to Contents 24 Appendix 3. Rainbow & 27 Acre fields transect data 2007: Available as an Excel spreadsheet, electronic version only. Back to Contents 25 Appendix 4. Knepp butterfly surveys 2005-2007: available as an Excel spreadsheet, electronic version only. Back to Contents 26