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2018 Annual Squirrel Monitoring Programme Results
Red squirrels captured on a trail camera in the Eden Valley, Cumbria, May 2018
Bonnie Sapsford
Northumberland Wildlife Trust
2
The spring 2018 annual squirrel monitoring programme has been funded by:
LIFE14 NAT/UK/000467
3
Summary
This report details the results of the annual red and grey squirrel monitoring
programme managed by Red Squirrels Northern England (RSNE), a Northumberland
Wildlife Project. The annual monitoring programme is conducted each spring during a
three month period from 1st March to 31st May across known red squirrel range in
northern England. Annual monitoring was established in 2012 and 2018 was the 7th
year of the programme. Methods used involved baited trail camera surveys, visual
transect surveys, and observed feeder surveys. Standardised monitoring was
undertaken in 290 tetrads (2km x 2km square) within woodlands and gardens. The aim
of the programme is to build a long-term dataset that will evidence changes that may
occur to red and grey squirrel range over time in areas where red squirrel conservation
activity takes place.
Overall results showed that red squirrels remain widely distributed across northern
England. Reds were detected in 42.4% of total sites surveyed and greys detected in
47.9%; a 3% decrease in red detection and a 5% increase in grey detection in
comparison to monitoring results in 2017. Results were analysed per county and also
per national park. In Cumbria, both species were widely detected (57.1% and 47.8%
respectively); this was reflected in the Lake District national park results. Red detection
in Northumberland overall was low (26.8%) in comparison to grey detection (50%).
Detection of reds was higher than greys within Northumberland and Yorkshire Dales
national parks. Results within red squirrel reserves and strongholds were similar to
those documented in 2017, with greys detected in the majority of sites within the Slaley
stronghold (77.2%) and reds detected in the majority of sites in both the Yorkshire
Dales (71.4%) and North Lakes (74.2%) strongholds. Within all reserves, red detection
was higher than grey detection.
Additional squirrel distribution maps were produced from standardised monitoring,
conservation activity records and public sightings between March and May 2018. Reds
were recorded in 350 tetrads and greys in 510. These maps provided a more complete
picture of squirrel distribution than the standardised monitoring results alone.
The completion of the 2018 annual monitoring programme is a significant achievement
and logistical challenge. 160 people, the vast majority volunteers, contributed to the
delivery of the programme. Successfully surveying 290 sites within a three month
period highlights the collective commitment of all involved.
Acknowledgements
The successful delivery of the monitoring programme would not be possible without the
significant contribution of both time and effort by volunteers. Acknowledgement is also
given to land managers who granted access to woodlands across the project area. The
contribution of additional records by red squirrel conservationists was significant;
these records helped to document current squirrel distribution in northern England.
4
Contents
1. Introduction ................................................................................................................................................................... 5
2. Methodology .................................................................................................................................................................. 6
3. Results .............................................................................................................................................................................. 7
3.1 Standardised monitoring .................................................................................................................................. 7
3.2 Comparison of standardised monitoring results between spring 2017 and spring 2018 ..... 9
3.3 Spring monitoring results 2012 to 2018 ................................................................................................. 10
3.4 County results ..................................................................................................................................................... 11
3.5 National park results ....................................................................................................................................... 11
3.6 Compiled records: standardised monitoring, conservation activity records & public
sightings........................................................................................................................................................................ 12
3.7 Red squirrel reserves and strongholds .................................................................................................... 13
3.8 Community involvement ................................................................................................................................ 15
4. Discussion .................................................................................................................................................................... 16
Appendix: Additional maps ....................................................................................................................................... 22
5
1. Introduction
Red Squirrels Northern England (RSNE) is a Northumberland Wildlife Trust project and
conservation partnership working across red squirrel range in northern England. The
annual monitoring programme, established by RSNE in 2012, surveys approximately
300 woodlands and gardens across northern England applying the same methods in the
same locations each spring. Involving 160 people, over 80% of which are volunteers, the
programme is one of the largest existing citizen science projects in mammal
conservation within the UK. Monitoring is conducted using three non-invasive
standardised methods: baited trail cameras, baited visual transects (walking through
woodlands and recording squirrels seen), and by observing squirrel visits to garden
feeders. The programme occurs each year within a three month period, between 1st
March and 31st May. 2000 surveys have now been completed since the initial baseline
programme in 2012. This report details results for 2018, representing the 7th
consecutive year of the programme.
The aim of the annual monitoring programme is to build a standardised, long-term
dataset that will evidence changes that may occur to red and grey squirrel range over
time. Any changes over time and space can be documented through detection and non-
detection of both red and grey squirrels during annual monitoring across the project
area. Repetition and standardisation of survey methods creates greater confidence in
the programme’s results and the longer the programme continues the more reliable
interpretation of results become. The detection and non-detection of both species
through standardised monitoring contributes towards an understanding of patterns in
red and grey squirrel distribution. This is in the context of a landscape in which grey
squirrels are managed as a conservation measure.
The scope of the monitoring programme is not to cover all of northern England or to act
as a population study. The programme focuses on interface areas where both species
may occur, within known red squirrel range, and provides a robust depiction of red and
grey squirrel distribution each year. Monitoring squirrel distribution using
standardised methods is essential for comparisons over time. Grey squirrel control
records, non-standardised monitoring data and public sightings are often difficult to use
for comparisons over time due to the significant variation in effort, both in time and
space. However, these additional records are invaluable for providing a more complete
picture of the distribution of red and grey squirrels than standardised monitoring
results provide alone. Therefore, for a more complete overview of distribution in time,
conservation activity records and sightings from a variety of sources across known red
squirrel range within the same time frame (1st March-31st May) were also used to create
additional distribution maps.
This report includes overall monitoring results in regards to red and grey squirrel
detection, changes in red and grey squirrel detection over time, and results within
different counties, national parks, red squirrel reserves and strongholds. It also
6
represents the extensive contribution of volunteers to the monitoring programme and
to the conservation effort across the north overall.
2. Methodology
The annual monitoring programme occurs each year in spring between 1st March and
31st May. The study area is located within current known red squirrel range across
northern England with surveys delivered primarily in woodland habitat; some located
within private gardens. No standardised monitoring was undertaken in east Lancashire,
other parts of Yorkshire or lowland County Durham as there is no current evidence of
red squirrel presence in these regions.
The Red Squirrels Northern England (RSNE) Monitoring Strategy, written in 2012,
identified a minimum sample size of 200 monitoring sites to reasonably detect changes
in squirrel range over time. Each survey site is located within a defined tetrad (a 2 x
2km square). During the 2018 programme 290 sites were surveyed. In brief, within
each tetrad, one survey was carried out during a 15 day period using one of the
following methodologies: baited trail camera survey, baited visual transect survey or
observed feeder survey. Of the 290 surveys completed this year, the number of surveys
per method is as follows: 232 trail cameras surveys, 38 visual baited transect surveys
and 20 observed feeder surveys. Sticky pads for hair collection were attached to the
underside of feeder box lids during trail camera and feeder surveys and within hair
tubes during visual transects. These hair samples provide a backup in the event of
camera failure or unclear images and improve the probability of detecting which species
is present at a survey site. Each survey method involves repeated visits to a site over 15
days, enabling the calculation of detection probabilities associated with each method
and habitat type. The implicit assumption is that no squirrels have entered or left the
tetrad (either by immigration/emigration or birth/death) during the 15 day survey
period. These survey methods are described in detail on the RSNE website, available to
download as pdfs at: http://rsne.org.uk/squirrel-monitoring-programme.
There were a minor number of changes to methods or exact locations this year for a
number of reasons: for example due to recent felling work or site access issues. Aside
from these enforced changes, surveys remained standardised within the same locations
and using the same methods, as in previous years, to enable comparisons over time.
Counties and national parks
To determine results within different counties and national parks, geographical
boundaries for each county and national park were used for analysis in GIS. Some
tetrads overlapped boundaries, therefore exact survey site grid references were used to
determine county or national park site allocation. Survey sites with grid references
outside a national park or county boundary were disregarded from that particular
analysis. One county (Tyne and Wear) was disregarded from county analysis as the
7
sample size within the county boundary was too low. Surveys conducted within red
squirrel range in the Merseyside area include two sites in the county of Lancashire.
Therefore, for the purposes of county analysis, Merseyside and Lancashire were
combined.
Compiled records and additional data
Current red and grey squirrel distribution maps produced in this report were compiled
from a variety of data sources, documenting red squirrel conservation activity between
1st March and 31st May 2018. In addition to standardised monitoring data, conservation
activity data includes grey squirrel control and non-standardised red and grey squirrel
monitoring (monitoring that does not adhere to the same methods used in the RSNE
monitoring programme). Records of grey squirrels trapped, shot or observed are
collected by the RSNE team, by local volunteers (mostly operating within the network of
groups under the banner of Northern Red Squirrels (NRS)) and by individuals working
for other conservation organisations or private estates. These records are submitted
periodically to RSNE using standardised recording forms. In addition, distribution maps
include sightings of red squirrels submitted directly to RSNE via the sightings page on
the RSNE website http://rsne.org.uk/sightings. Sightings of both red and grey squirrels
are also compiled by NRS groups and by other organisations. These are then submitted
to RSNE, and verified as far as possible. Verification of public sightings ensures place
names match the map location selected by record submitters on the website, followed
by whether the sighting is located within known current red squirrel range. Unusual
sightings are investigated to seek additional information, such as a description and
photograph. Public sightings failing these checks have not been included in analyses. All
records submitted to RSNE by June 30th 2018 were used to compile red and grey
squirrel distribution maps.
3. Results
3.1 Standardised monitoring
290 sites were monitored with red squirrels detected in 42.4% of total surveys sites and
grey squirrels detected in 47.9% of total survey sites. 30% of sites were red squirrel
only, 35.5% were grey squirrel only, and both species were detected at the same sites in
12.4% of surveys. No squirrels were detected in 22.1% of surveys. Overall results and
the geographical distribution of survey sites are displayed in Fig. 1.
8
Fig. 1. Results for all 290 survey tetrads from annual monitoring in spring 2018
9
3.2 Comparison of standardised monitoring results between spring 2017 and
spring 2018
The number of surveys completed in 2017 and 2018 were similar, with 294 completed
in 2017 and 290 completed during this year’s programme. In terms of results
comparison (Table 1), the number of surveys in which red squirrels were detected
decreased, from 45.2% in 2017 to 42.4% this year. The number of sites in which grey
squirrels were detected increased from 42.8% in 2017 to 47.9% this year. Site
occupancy over time (from 2012 to 2018) is further explored in section 3.3.
Table 1. Comparison of overall results between spring 2017 and spring 2018.
Number of tetrads and percentage of total number of sites
Result Spring 2017 Spring 2018 Change in number
Red only 99 (33.6%) 87 (30%) -12
Both red and grey 34 (11.5%) 36 (12.4%) +2
Grey only 92 (31.2%) 103 (35.5%) +11
No squirrels 69 (23.4%) 64 (22.1%) -5
Total red occupancy 133 (45.2%) 123 (42.4%) -10
Total grey occupancy 126 (42.8%) 139 (47.9%) +13
10
3.3 Spring monitoring results 2012 to 2018
The survey programme was established in spring 2012 and has provided standardised
monitoring each spring for seven years. An overall comparison of results from 2012 to
2018 is presented here (Fig. 2). For the purpose of this comparison, results from the
two autumn survey monitoring rounds (in 2012 and 2013) are not included. Spring
2012 is the baseline for the programme; however it is worth noting that considerably
fewer survey sites (255) were monitored in 2012 compared to subsequent surveys.
Fig. 2 Red and grey squirrel site occupancy for all spring surveys 2012-2018. Site
occupancy is shown as a percentage of the total number of surveys completed each year.
Site occupancy, or detection, over time demonstrates the fluctuations in range of both
species of squirrel across the study area. Following a measure of stability in red squirrel
range since 2015, this year red squirrel site occupancy decreased by 3% and grey
squirrel site occupancy increased by 5% in comparison to results in 2017. Results over
time demonstrate an increasing trend in grey squirrel site occupancy since 2016.
Results this year show a return to grey squirrel site occupancy levels detected in 2015.
11
3.4 County results
Results per county include surveys conducted only within current known red squirrel
range and sites are not located county wide (Table 2). The number of survey sites per
county varied, with totals detailed below. Northumberland contained the highest
number of survey sites whereas Merseyside and Lancashire contained the least. The
county of Tyne and Wear was not included in this analysis as the sample size within the
county boundary was too low.
Table 2. Results by county detailing the percentage of red and grey detection and total
number of sites surveyed within each county.
County No. of sites with reds
No. of sites with greys
No. of sites surveyed
Cumbria 68 (57.1%) 57 (47.8%) 119
Northumberland 37 (26.8%) 69 (50%) 138
North Yorkshire 11 (55%) 4 (20%) 20
Merseyside & Lancashire
7 (63.6%) 7 (63.6%) 11
Merseyside and Lancashire had the highest detection percentage of both red and grey
squirrels, yet the lowest number of sites surveyed. Cumbria had a high level of red
squirrel detection (57.1%) and Northumberland had the lowest detection percentage of
reds (26.8%). Grey squirrel detection was high in Northumberland (50%) and also in
Cumbria (47.8%). The greatest difference in detection percentages was within the
county of North Yorkshire.
3.5 National park results
Results displayed here include only survey sites located within each national park
boundary (Table 3). The Northumberland National Park (NNP) and Yorkshire Dales
National Park (YDNP) included 26 total survey sites within the national park
boundaries respectively. The Lake District National Park (LDNP) included a higher
number of total survey sites (57) in comparison to the other two parks.
Table 3. Results by national park detailing the percentage of red and grey detection and
total number of sites surveyed within each park.
National Park No. of sites with reds
No. of sites with greys
No. of sites surveyed
LDNP 35 (61.4%) 29 (50.8%) 57
NNP 11 (42.3%) 4 (15.3%) 26
YDNP 16 (61.5%) 4 (15.3%) 26
12
Results were generally positive for red squirrel detection in all three national parks
surveyed. The highest detection of red squirrels was within the YDNP (61.5%), followed
by the LDNP (61.4%). Grey squirrel detection in survey sites within the LDNP was
above 50%. The greatest difference in detection percentages was within the YDNP.
3.6 Compiled records: standardised monitoring, conservation activity records &
public sightings
Maps documenting red and grey squirrel distribution, or range, are included in the
appendix (Figs. 6 and 7). These maps were compiled by combining standardised
monitoring results with conservation activity records and public sightings between the
dates of 1st March and 31st May 2018. The contribution made by the addition of control
data and sightings data submitted to RSNE is detailed in Table 4. Note that grey squirrel
distribution data is mainly from the documentation of grey squirrel management.
Table 4. The number of tetrads with recorded red and grey squirrel detection for the
period March to May 2018. This data was combined to produce compiled distribution
maps (Figs. 4 and 5).
Number of tetrads
Standardised monitoring
Conservation activity records & public sightings
Total
Red squirrel 123 227 350
Grey squirrel 139 371 510
Conservation activity and public sightings data documented red squirrel detection in a
further 227 tetrads in addition to those detected during standardised annual
monitoring. Grey squirrels were recorded in an additional 371 tetrads over the same
period. The total number of tetrads in which grey squirrels were detected is higher than
the total number of tetrads in which red squirrels were detected.
13
3.7 Red squirrel reserves and strongholds
Reserves
Fig. 3. Standardised monitoring results in the 17 red squirrel reserves during the 2018
programme
Fig. 3 details the results from 63 survey sites located within 15 out of the 17 designated
red squirrel reserves. Two of the reserves were not surveyed (Raylees and Garsdale)
and only one site was surveyed at Kidland due to felling restrictions. Red squirrels were
detected in 13 reserves and grey squirrels were detected in five reserves. Reds were
present in 54% of all surveys within reserve woodlands and grey squirrels were present
in 27%. Out of the total reserves surveyed, red squirrels were the only species detected
in nine reserves during the monitoring programme. These include: Greenfield,
Greystoke, Kidland, Kyloe, Sefton, Uswayford, Whinlatter and Widdale. Grey squirrels
were detected in all three reserves within the Slaley complex, at one site in the
Thirlmere reserve, and at five sites within the Kielder reserve.
Strongholds
Several of the strongholds merge together, forming seven different stronghold
complexes that are geographically connected: (i) Kyloe, (ii) Harwood and Raylees
complex, (iii) Kielder complex, (iv) Slaley complex, (v) North Lakes complex, (vi)
Yorkshire Dales complex and (vii) Sefton Coast (see appendix, Fig.8).
0 5 10 15 20 25
Dipton/Dukeshouse
Garsdale/Mallerstang
Greenfield
Greystoke
Harwood
Healey/Kellas
Kidland
Kielder
Kyloe
Raylees
Sefton
Slaley/Dukesfield
Thirlmere
Uswayford
Whinfell
Whinlatter
Widdale
Number of Tetrads
Re
serv
es
Red only
Both species
Grey only
No squirrels detected
14
Fig. 4. Standardised monitoring results within the seven stronghold complexes in 2018,
illustrating the number of sites and results within each complex.
Fig. 4 highlights the results and the number of tetrads surveyed within each of the seven
stronghold complexes. The number of survey sites within each complex varied,
reflecting the difference in size of these areas. There were high levels of red squirrel
detection across sites in the Yorkshire Dales (71.4%), the North Lakes (74.2%) and
Sefton (70%). Following a significant increase in grey squirrel detection in the North
Lakes stronghold between 2016 (22.2%) to 2017 (41.6%), grey squirrel detection
increased by a small margin in 2018 (42.8%). Detection of grey squirrels in the
Yorkshire Dales was particularly low with greys observed in only 4.8% of sites
surveyed. Red squirrel detection results within the Kielder complex were lower (25%)
than grey detection (46.1%) across 52 total survey sites. Grey detection was highest
within the Slaley complex in 77.2% of sites surveyed and red detection was lowest
(9.1%) in comparison to other strongholds.
Strongholds over time 2012 to 2018
Table 5 details red and grey detection results over time within each stronghold
complex. Detection of red squirrels remained consistently high over time within the
Kyloe, Sefton, North Lakes and Yorkshire Dales complexes. The overall monitoring
results (a minor decrease in red detection and an increase in grey) are reflected in both
Harwood and Kielder this year, in comparison to results in 2017. Grey squirrel
detection over time within the Slaley complex remains high.
0 10 20 30 40 50 60
Sefton
North Lakes complex
Yorkshire Dales complex
Kielder complex
Harwood complex
Slaley Complex
Kyloe
Number of Tetrads
Stro
ngh
old
s
Red only
Both species
Grey only
No squirrels detected
15
Table 5. Red and grey results in stronghold complexes for all spring surveys, 2012-2018.
Detection is shown as a percentage of the total number of surveys completed each year.
3.8 Community involvement
Delivery of the annual monitoring programme would not be possible without the help of
volunteers. This year the number of participants was similar to 2017, with over 160
people involved in the delivery of surveys, analysis of results, and arranging access or
delivering survey equipment. Local red squirrel community groups sustained their
contribution to the programme, accounting for 110 (38%) surveys delivered. The
remaining 145 (49%) surveys were delivered by a number of different groups,
including individual volunteers, private estates and other conservation organisations
(Fig. 5).
Fig 5. Delivery by different groups of the 2018 monitoring programme out of 290 total
surveys.
110 (38%)
38 (13%)
145 (49%)
Local RSGs
RSNE staff
Other volunteers
16
4. Discussion
The annual monitoring programme continues to aim for longevity, building a
standardised, long-term dataset evidencing changes that may occur to red and grey
squirrel range over time. The programme this year continued to document fluctuations
in red and grey squirrel site occupancy across northern England. The detection and
non-detection of both species through standardised monitoring contributes towards an
understanding of red and grey distribution in areas where grey squirrels are managed
as a conservation intervention measure; this helps to gauge the success of red squirrel
conservation activity across the project area. The completion of the 7th round of this
programme in 2018 and the number of people involved is a considerable achievement.
87% of surveys were carried out by volunteers, representing a significant collaborative
effort and an extensive contribution towards programme sustainability.
One of the key messages to take from this year’s results is that red squirrels are still
widely distributed across northern England. Red squirrel site occupancy has decreased
in comparison to 2017 results; however this is a minor overall decrease (by 3%) across
the whole project area. Grey squirrel site occupancy has increased for another
consecutive year, returning to levels documented in 2015. This increase could be
natural fluctuation similar to results documented in previous years. The trend in grey
squirrel range results between 2013 and 2015 is similar to results between 2016 and
2018. There are a number of factors that may influence these fluctuations and provide
context to the monitoring results. These include human conservation intervention
(control of grey squirrel numbers) and environmental variation (including weather and
natural food supply).
Spring monitoring results 2012 to 2018
Comparison of site occupancy results, or detection, over time supports the identification
of trends (see Fig.2.). In 2013 there was a small increase in red squirrel site occupancy,
with reds detected in 50.3% of surveys whereas grey squirrel site occupancy decreased,
with detection in 30.3% of surveys. However, the overall number of surveys in 2013
increased by 35, which may have influenced these percentage changes. The increase in
grey squirrel site occupancy documented in 2014 continued in 2015, rising to 46.5%,
following reports of abundant broadleaved seed crop and a mild winter. These
environmental factors may provide some context to the increase in grey squirrel
detection in 2015. During the 2018 monitoring programme there were no significant
changes in the number of sites surveyed and no reports of an abundance of natural food
sources to aid interpretation of the increase in grey squirrel detection.
A level of stability, or maintenance, in red squirrel range was reported from 2015 to
2017. In 2018 reds were detected widely across the project area, however overall
detection decreased by a small proportion (42.4%) compared to results in 2017
(45.2%).
17
A potential concern is the increasing trend in grey squirrel detection. However, it is
worth emphasising that a similar level of grey squirrel detection occurred in 2015 and,
despite the threat posed by grey squirrels, reds remain present across much of northern
England. The results from the annual monitoring programme demonstrate that where
there is a collective will, red squirrels can be successfully conserved.
County and national park results
In a departure from previous annual monitoring programme reports, analyses of results
per county and per national park have been included. Overall results across different
counties varied considerably. Across Cumbria results for reds were positive, with
detection in 57.1% of surveys within the county. Red squirrels were widely present in
west Cumbria, the central and northern Lake District and in the Eden Valley. Grey
squirrel detection overall in Cumbria was also relatively high (47.8%), highlighting that
this is a key interface county where continued red squirrel conservation intervention is
required.
Northumberland contained the highest total of tetrads surveyed yet red squirrel
detection across the county as a whole was low, at 26.8% in comparison to 50% grey
squirrel detection. Detection of greys on the western and southern fringes of Kielder
Forest remains a concern, despite sustained and ongoing grey squirrel management in
this area. High grey squirrel detection around Haydon Bridge, Corbridge and Hexham
also represents a significant conservation challenge, with no immediate solution in
areas where there is no effective landscape-scale grey squirrel management. Red
squirrels were the only species detected in a number of areas within Northumberland in
survey sites at Kielder, North Tyne, Redesdale, Harwood, Wallington and further north
in Kyloe. The poor overall county result may be influenced by the high density of survey
sites around the Hexham/Slaley area where, despite significant conservation
investment in the last five years, grey densities and distribution remain high.
In Northumberland National Park (NNP) results were more positive with red squirrel
detection considerably higher (42.3%) than grey squirrel detection (15.3%). Detection
of red squirrels was also high in the Yorkshire Dales National Park (YDNP) with reds
detected in 61.5% of surveys. The same numbers of sites were surveyed in both YDNP
and NNP, with the same low level of grey detection (15.3%). Landscape characteristics
are considerably different in the Lake District National Park (LDNP) with higher density
and connectivity of woodlands in comparison to both NNP and YDNP. As a consequence,
there were a higher number of survey sites within the LDNP. This suitability for
squirrels and connectivity of woodland habitat is reflected in the results with a
relatively high percentage of both red and grey detection, with reds detected in 61.4%
and greys in 50.8% of sites. Red squirrels are well distributed within the LDNP overall
and therefore are in need of further acknowledgement and significant conservation
investment.
18
A number of caveats exist with regard to analysing results by county and national park.
The number of surveyed tetrads differed per county and per national park and as such
comparisons are not statistically sound. Surveyed tetrads are located within current
known red squirrel range, however in some counties red squirrel range is extremely
limited and geographically restricted, for example in Lancashire, Merseyside and North
Yorkshire. Therefore results do not reflect squirrel density and distribution across these
counties as a whole, where it is assumed that grey squirrels are widespread. The
difference in results between Cumbria and Northumberland may be due to areas of
more clustered tetrads in Cumbria compared to areas of more scattered tetrads in
Northumberland. These variations in geography, landscape and habitat may have a
bearing on results. Results per county and national park may simply detect fluctuations
in red and grey squirrel range. As the monitoring programme continues, results over
time per county and per national park may be able to document real changes or
highlight emerging trends. It might also be possible, in future reports, to provide
retrospective analysis of results for counties and national parks.
Compiled records
The strength of the annual monitoring programme is in the standardised
documentation of red and grey range fluctuation over time. However these results do
not reflect the complete distribution of both squirrel species across the project area. A
more detailed picture is possible through the collation and analysis of records from a
variety of sources, culminating in additional distribution maps (Figs 6 and 7). It should
be noted that grey squirrel distribution represented is within feasible red squirrel range
only; the assumption is that grey squirrels are widely present in other areas of northern
England.
Red squirrels were documented in a total of 350 tetrads and greys in 510 over a three
month period from submitted records. The majority of grey squirrel distribution data
comes from records of grey squirrel control activity and therefore represents spatial
documentation of greys culled. These figures are likely to be an underestimate of red
and grey squirrel range and grey squirrel control effort due to data that was either not
captured or not submitted to RSNE. Equally it is a snapshot in time, captured over a
three month period. However, these distribution maps help to highlight the scale of the
conservation effort, and associated data collection across northern England.
Additional records help to demonstrate red squirrel presence in areas where reds were
not detected during standardised monitoring. For example, reds were picked up from
additional records in Northumberland at Derwent reservoir, Wark, Morpeth, Chatton,
Greenhead and Cragside (Rothbury). The number of red squirrels recorded in south
east Northumberland paints a positive picture for that area. In Cumbria around
Windermere and Grizedale, standardised results detected either grey squirrels or no
squirrels, yet additional records confirmed red squirrels were present around
Ambleside, Rusland and Newby Bridge. Mapping these additional records highlights
19
where further conservation activity may be needed. Additional records also helped to
map red squirrel distribution in areas where there are no existing standardised survey
sites: around south east Northumberland in Cramlington and Bedlington, to the north of
Newcastle at Hazelrigg, the west coast of Cumbria around Whitehaven, east of Carlisle,
and in Sedbergh.
Community Involvement
Community involvement in the monitoring programme remained high in 2018 with
over 160 people involved. This extent of community participation enabled the
programme to be delivered by an extensive range of different interest groups including
community red squirrel groups, independent volunteers, private landowners and
managers, and volunteers or staff from other conservation organisations. The number
of surveys delivered by RSNE staff decreased from 77 surveys in 2016 to just 38 surveys
in 2017, with an identical figure in 2018. This level of community involvement is
essential to the delivery and sustainability of the programme. One of the critical
challenges will be maintaining project resources in order to manage this volunteer
workforce and the subsequent delivery of the programme. These evidence based results
can aid informed decisions and help to provide a focus for future red squirrel
conservation efforts.
Red squirrel reserves and strongholds
In 2006 17 red squirrel reserves in England were selected by the government for
protection. These red squirrel reserves consist of largely coniferous forestry plantations
where red squirrels were assumed to be at less of a competitive disadvantage to grey
squirrels in comparison to the surrounding landscape. Around these reserves, the
Forestry Commission designated 5km area buffer zones in which landowners were able
to apply for English Woodland Grant Scheme (EWGS) funding to carry out control of
grey squirrels. The reserve and buffer zones are collectively referred to as strongholds.
EWGS closed in 2014 and has now been replaced by Countryside Stewardship offering
incentives to landowners who are keen to undertake red squirrel conservation within
both these designated areas and across red squirrel range in northern England.
Strongholds continue to be recognised as significant areas for red squirrels and still
warrant analysis as they present consistent units, with a high percentage of annual
monitoring sites located within them. 2018 results for many of the reserves and
strongholds are similar to those detailed in 2017 and it is clear that the status of some of
these designated areas remain questionable. Grey squirrels were detected in the
majority of sites within the Slaley stronghold, reflecting both the halt in conservation
work, due to the lack of funding, and limited community effort in the area. However, red
squirrels were also detected in a small number of surveys, perhaps as a result of
historical conservation effort and resources invested in and around the Slaley
stronghold. A significant challenge remains in finding resources to continue a
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programme of grey squirrel management in this area with extensive woodland
connectivity, close proximity to urban areas and little community conservation effort.
Higher detection of reds amongst some strongholds such as Kyloe and Sefton must be
taken in the context of the relatively low number of sites surveyed within these
strongholds. As such, minor changes in detection percentages can appear more
pronounced. The most pronounced difference in detection percentages was in the
Yorkshire Dales stronghold, with extremely low grey detection (4.8%) compared to high
red detection (71.4%). Reds were also detected in a high percentage of sites in the
North Lakes stronghold, although the number of sites in which greys were detected was
also relatively high at 42.8%. This was no significant increase in grey squirrel detection
within the North Lakes from results in 2017; however grey only sites in areas to the
south of this complex remain a potential concern.
Comparison of red and grey squirrel detection within stronghold complexes over time
highlights both fluctuations in squirrel range and consistent detection results. Detection
of reds remains high over time in the Kyloe, North Lakes, Sefton and Yorkshire Dales
complexes. There was a decrease in red detection within the Yorkshire Dales complex
this year (71.4%) in comparison to 2017 (86.9%). However, there was a significant
decrease in grey detection within the same complex from 17.3% in 2017 to a low of
4.8% in 2018. This may reflect the conservation work undertaken in the area, but may
also be due to an increase in sites surveyed within the stronghold this year. Results over
time in Slaley demonstrate no great fluctuations, with grey detection consistently high.
The highest red detection result within Slaley in 2014 (24%) was during the midst of a
programme of grey control in the area. Results since 2014 demonstrate that this work
has had little lasting impact, yet red squirrels have still been detected each year.
Red squirrel detection was higher than grey squirrel detection within all designated red
squirrel reserves emphasising the continued importance of a number of these forests
for red squirrel populations. Red squirrels only were detected in nine out of 15 reserves
surveyed. Thirlmere reserve returned mixed results, however a RSNE programme of
quarterly monitoring and grey squirrel management around Thirlmere reservoir
continues. Results around Whinfell Forest (where no reds were detected during
standardised monitoring) were to be expected as the red squirrel population in this
reserve continues to recover from a squirrel pox virus outbreak in 2017. However,
additional records did detect red squirrels within the Whinfell reserve and surrounding
area.
Kielder, the largest red squirrel reserve in England, remains a concern. Red squirrel
detection results in the reserve itself were higher than red results within the stronghold
as a whole. Within the Kielder stronghold, greys were detected in more sites than reds
in each of the last four survey programmes (2015-2018). This continues to highlight the
need for sustained conservation effort in and around Kielder in order to protect the red
squirrel population. RSNE is currently delivering an early warning quarterly monitoring
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system in order to detect grey squirrels around the fringes of Kielder Forest as part of
the Red Squirrels United project. Two rangers, one located in the north Tyne area and
one in Kershope Forest in Cumbria, deliver grey squirrel management around the forest
borders, working proactively and in response to quarterly monitoring results. Grey
squirrels continue to follow established incursion routes from the south, using major
river corridors such as the Irthing and Liddle in Cumbria and the North Tyne in
Northumberland. Further exploration is needed in order to understand more about the
red squirrel population deeper into Kielder Forest, where there is an assumption that
the extensive monoculture (dominated by Sitka spruce) is an effective barrier to grey
incursion and colonisation.
Conclusion
The completion of the 2018 annual monitoring programme across 290 sites in three
months is a significant logistical challenge. The successful delivery of the programme
highlights the collective commitment of more than 160 people, over 80% of which are
volunteers. The programme this year has continued to document wide spread red
squirrel distribution across northern England; this continued detection of red squirrels
over the project area is due to the extensive red squirrel conservation effort across the
north. A decrease in the detection of reds in some survey sites and an increase in grey
detection amongst others is a pattern that has been observed in previous annual
monitoring results. However, the increasing trend in grey squirrel site occupancy since
2016 is a potential concern and it is crucial that there is no subsequent decrease in
conservation effort across the north of England. Delivery of this conservation work is
relentless and long-term and the most significant challenge remains in sustaining this
effort, particularly as funding sources decrease and become more difficult to access.
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Appendix: Additional maps
Fig. 6. Distribution of red squirrels recorded March – May 2018 in tetrads across
northern England. Records compiled form standardised monitoring, conservation
activity records and public sightings submitted to RSNE directly or via NRS groups.
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Fig. 7. Distribution of grey squirrels recorded March – May 2018 in tetrads across
northern England. Records compiled form standardised monitoring, conservation
activity records and public sightings submitted to RSNE directly or via NRS groups.
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Fig. 8. Map of the seven stronghold complexes: The 17 strongholds are grouped together
where there is geographical connectivity forming seven stronghold complexes.