Download Update 2007 - the Knepp Castle Estate

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.
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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