Technical annex – Assessing change in England, Scotland and UK Butterfly
Indicators
Tom Brereton, Butterfly Conservation
David Roy, Centre for Ecology and Hydrology
May 2009 update
Introduction
Long time series of species abundance data such as those collected through the UK
Butterfly Monitoring Scheme and used to compile UK and England Biodiversity
Strategy (EBS) Butterfly Indicators can not always be summarised adequately by
linear trend lines. These long time series may show alternating periods of increase
and decrease, and it can be difficult to separate patterns of genuine change from
annual fluctuations. Consequently, methods that model smoothed trend lines through
abundance data are becoming increasingly popular. An extension of the linear trend
approach is the application of a smoothing technique that describes the pattern by
assigning a trend level (= modelled abundance) to each year in the time series
(similar to a moving average). There are several smoothing methods available such
as polynomial regression, splines and Loess estimators. These models may be
summarised as ‘flexible trend models’. The most popular flexible trend models for the
analysis of wildlife populations are General Additive Models (GAMs) and these, for
example, are used to produce the EBS Bird Indicators. However, GAMs do not
present the complete time series and do not account for serial correlation which limits
their applicability to butterfly data.
Another flexible trend method from the class of structural time series analysis has
recently been developed (Visser, 2005) and applied to European birds (Gregory et al.
2007) and European butterflies (Brereton et al. in press) using TrendSpotter software
(Visser, 2004). This is the approach used to describe and assess changes in the UK
and EBS Butterfly Indicator updates published in April 2008. Unlike the GAM
approach, the confidence interval of the trend line is not calculated by a
bootstrapping method but by application of a time series analysis and the Kalman
filter (Visser 2004). This approach uses one observation per time point (e.g. year or
month) and therefore the uncertainty in the estimate of yearly index values (e.g.
confidence intervals around each year index) is modelled indirectly in the annual
fluctuations. The main advantage of the TrendSpotter analysis however is the
calculation of confidence intervals for the differences between the trend level of the
last year and each of the preceding years, taking into account serial correlation which
is unique for flexible trend methods. This allows short-term trends to be usefully
assessed.
TrendSpotter estimates smoothed population numbers µ1, µ2, . . . , µt, . . . , µN, for a
time series with N equidistant measurements over time (y1, y2, . . . , yt, . . . , yN). The
expectations of these smoothed population numbers are denoted as m 1, m2, . . . , mt,
. . . , mN. TrendSpotter also estimates the standard deviations of the smoothed
population numbers: SD1, SD2, . . . , SDt, . . . , SDN. Finally, it estimates the standard
deviations of the differences µN–µt, denoted here as SDN–t. The estimation of
confidence intervals is based on the deviations of time point values from the
smoothed line. This emphasises temporal variation as the main source of error,
although measurement errors and errors due to imputation are implicitly incorporated
in the yearly measurements.
In TrendSpotter, the flexibility of a trend is set by the value of a standard deviation of
a noise process. This standard deviation (parameter) can be chosen by hand, or can
be optimised by maximum likelihood optimisation (the default choice). If the
parameter is set to zero, the estimated trend equals the well-known regression trend
line (straight line). If the parameter is set to a very large number, the trend will go
through all measurements y1, y2, . . . , yt, . . . , yN. All values for mI, SDI, and SDN–t
are estimated by use of the Kalman filter. This filter is attractive, because it gives
estimates with optimal statistical properties. Although normally distributed residuals
are not a necessary condition for the proper use of the Kalman filter, it still is a
desirable property. For example, all confidence limits assessed by ±1.96 X standard
error can be interpreted as 95% confidence limits. Normality of residuals can be
tested by a so-called normality plot.
In TrendSpotter, a statistical test is performed to compare the difference in the Index
in the latest year versus other years in the series.
Yearly Change Rates and confidence intervals produced in the TrendSpotter output
are used to classify the trends per year. The trend classification applied (see Soldaat
et al. 2007) is given in Table 1.
Table 1: Classification of trends on the basis of the 95% confidence intervals of the
yearly change rate in TrendSpotter smoothed indices. CL = confidence limit; CI =
confidence interval (see Soldaat et al. for explanation).
trend class
criteria
description
strong increase
lower CL > 1,05
> 5% increase / year (≈ doubling in 15 years)
moderate increase
1,00 < lower CL ≤ 1,05
increase, but unsure whether > 5% / year
stable
confidence interval contains 1,00
AND lower CL ≥ 0,95
AND upper CL ≤ 1,05
population changes less than 5% / year
moderate decline
0,95 ≤ upper CL < 1,00
decrease, but unsure whether > 5% / year
steep decline
upper CL < 0,95
> 5% decrease / year (≈ halving in 15 years)
uncertain
confidence interval contains 1,00
AND (lower CL < 0,95 OR upper CL > 1,05)
CI too large for reliable trend classification
In summary structural time series models are essentially regression models in which
the explanatory variables are functions of time and the parameters are time-varying.
The Kalman filter is an efficient recursive filter that estimates the state of a dynamic
system from a series of incomplete and noisy measurements. For mathematical
details about structural time-series analysis and the Kalman filter please refer to
Harvey (1989).
TrendSpotter is currently considered the best-available technique in the assessment
of Governmental Butterfly Indicators. Regular reviews of methods to assess changes
in butterfly indicators are needed however; techniques to model trends are an active
area of statistical development.
Example of TrendSpotter outputs
For the EBS Populations of Butterflies Indicator H1(b) generalist and specialist
indices and the corresponding smoothed trend for the period 1976-2006 are given in
Figure 1. Tests for changes in smoothed indices between 2006 and previous years
are given in Table 2. Plots of the test results comparing years are given in Figure 2.
Table 2: Indices and trend classification for specialist and generalist species of the
EBS Populations of Butterflies Indicator (H1b)
Specialist species
Year
Index
1976
100
1977
58
1978
47
1979
34
1980
33
1981
18
1982
28
1983
1984
1985
Smoothed Index
Generalist species
Trend class
Index
Smoothed Index
Trend class
74.79
moderate decline
100
78.45
stable
63.47
moderate decline
48
80.32
stable
53.06
moderate decline
76
82.22
stable
44.26
moderate decline
88
84.14
stable
37.57
stable
74
86.05
stable
33.11
stable
60
87.95
stable
30.85
stable
115
89.78
stable
28
30.22
stable
106
91.50
stable
46
30.54
stable
140
93.06
stable
35
31.05
stable
86
94.45
stable
1986
33
31.57
stable
81
95.71
stable
1987
36
32.01
stable
66
96.87
stable
1988
29
32.38
stable
70
97.95
stable
1989
31
32.80
stable
109
98.92
stable
1990
34
33.28
stable
111
99.72
stable
1991
30
33.77
stable
123
100.30
stable
1992
41
34.23
stable
140
100.63
stable
1993
30
34.51
stable
76
100.70
stable
1994
33
34.68
stable
83
100.56
stable
1995
38
34.65
stable
109
100.22
stable
1996
37
34.29
stable
118
99.68
stable
1997
42
33.57
stable
126
98.93
stable
1998
29
32.57
stable
91
98.00
stable
1999
29
31.65
uncertain
82
96.95
stable
2000
29
31.06
uncertain
87
95.84
stable
2001
26
30.96
uncertain
80
94.70
stable
2002
26
31.42
uncertain
83
93.54
stable
2003
35
32.34
uncertain
102
92.38
stable
2004
38
33.44
uncertain
97
91.20
stable
2005
37
34.52
uncertain
91
89.99
uncertain
2006
34
35.54
81
88.78
140
120
120
Combined Index
Combined Index
100
80
60
40
20
100
80
60
40
20
0
1975
1985
1995
0
1975
2005
1985
1995
Year
Year
Specialists
Generalists
Figure 1: Time series analysis of the EBS Populations of Butterflies Indicator (H1b).
The black dots indicate the observed index; the black line is the smoothed trend line
estimated by TrendSpotter. The dashed black lines indicate the upper and lower
boundary of the 95% confidence limits of the smoothed trend line.
20
Trend difference
(plus 95% CL of test tesults)
10
0
1975
1980
1985
1990
1995
2000
2005
-10
-20
-30
-40
-50
Year
Figure 2: Test result for the EBS Populations of Butterflies Indicator (H1b) comparing
the difference in the all species index in the latest year with previous years in the
series. The solid dots represent the difference in previous year index values
compared with the latest year, whilst dashed black lines indicate the upper and lower
boundary of the 95% confidence limits of the test results. Previous year indices are
different to the latest year, if both 95% confidence interval lines do not cross 0. In this
example, 1976-1978 are different (significantly lower than) to 2006.
2005
Trend assessment based on the TrendSpotter approach suggest that the 2006
specialist index was significantly lower than over the period 1976-1978, though the
trend since 2000 is uncertain. No significant change has occurred in the generalist
butterfly index, which is classed as stable over all years except 2005, where there is
uncertainty.
References
Brereton, T, van Swaay C and van Strien A (in press) Developing a butterfly indicator
to assess changes in Europe’s biodiversity. Conference Proceedings of the
European Bird Census Council Bird Numbers 2007 Conference. Chiavenna, Italy.
Gregory, RD, Vorisek, P, van Strien AJ, Gmelig Meyling AW, Jiguet F, Fornasari, L,
Jiri R, Chylarecki P, Burfield, IJ (2007) Population trends of widespread woodland
birds in Europe. Ibis: 149 (Suppl. 2), 78–97.
Harvey AC (1989) Forecasting structural time series models and the Kalman filter.
Cambridge University Press, London.
Soldaat, LL, Visser, P, van Roomen, M, van Strien, A (2007) Smoothing and trend
detection in waterbird monitoring data using structural time-series analysis and the
Kalman filter. Journal of Ornithology. Vol. 148 suppl. 2. Dec. 2007.
Visser H (2004) Estimation and detection of flexible trends. Atm Environment 38:
4135-4145.
Visser H (2005) The significance of climate change in the Netherlands. An analysis of
historical and future trends (1901-2020). MNP report 550002007.
Appendix Trend results for England, Scotland and UK Butterfly Indicators 1976-2007
Indicator
Year
Index
Smoothed
Index (SI)
SI
Lower
CL.
SI
Upper
CL.
Trend
Difference
(TD)
TD
Lower
CL.
TD
Upper
CL.
TREND
CLASSIFICATION
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Specialists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
100
51.1
40.8
34.9
35.8
18.9
29.6
29.7
48.4
35.7
34.6
37.5
31
33.5
39.5
30.3
44
32.2
37.1
41.9
38.4
44
29.6
30.3
29.1
29.6
28.3
37.2
38.9
38.1
36.8
23.9
100
46
74.1
88.1
74.1
62.9
112
100
129
79.2
75.1
63.5
66
100
100
110
127
69.5
75.8
97.7
104
113
82
75.1
79
70.9
69.72
60.07
51.27
43.93
38.35
34.60
32.65
32.06
32.31
32.80
33.38
33.98
34.56
35.18
35.81
36.36
36.84
37.12
37.23
37.09
36.62
35.84
34.86
33.98
33.38
33.13
33.19
33.39
33.47
33.25
32.69
31.92
79.09
80.25
81.44
82.64
83.83
85.00
86.11
87.12
88.01
88.78
89.45
90.05
90.60
91.06
91.40
91.59
91.60
91.43
91.10
90.62
89.99
89.20
88.26
87.23
86.12
84.95
63.37
55.15
47.13
40.08
34.57
30.82
28.87
28.30
28.57
29.07
29.66
30.27
30.85
31.48
32.10
32.65
33.14
33.41
33.53
33.39
32.91
32.12
31.13
30.23
29.62
29.36
29.41
29.61
29.62
29.09
27.75
25.51
62.91
65.97
68.73
71.19
73.32
75.16
76.72
78.00
79.04
79.87
80.55
81.15
81.67
82.11
82.44
82.62
82.63
82.47
82.15
81.69
81.08
80.30
79.35
78.25
76.99
75.55
76.07
64.98
55.42
47.78
42.13
38.37
36.42
35.83
36.06
36.53
37.10
37.69
38.26
38.88
39.51
40.06
40.55
40.82
40.93
40.80
40.33
39.56
38.58
37.72
37.15
36.91
36.96
37.18
37.33
37.40
37.64
38.33
95.26
94.54
94.16
94.10
94.34
94.83
95.50
96.24
96.99
97.69
98.35
98.96
99.52
100.01
100.36
100.56
100.57
100.39
100.04
99.55
98.89
98.09
97.18
96.20
95.24
94.35
-37.80
-28.15
-19.36
-12.01
-6.44
-2.68
-0.73
-0.15
-0.40
-0.89
-1.46
-2.06
-2.64
-3.26
-3.89
-4.44
-4.93
-5.20
-5.31
-5.18
-4.70
-3.92
-2.94
-2.06
-1.47
-1.22
-1.27
-1.48
-1.55
-1.33
-0.78
0
-2.09
-3.26
-4.45
-5.65
-6.84
-8.00
-9.11
-10.12
-11.02
-11.78
-12.45
-13.06
-13.60
-14.06
-14.40
-14.59
-14.60
-14.43
-14.10
-13.62
-12.99
-12.20
-11.27
-10.23
-9.12
-7.95
-46.83
-36.23
-26.99
-19.49
-13.88
-10.12
-8.17
-7.57
-7.81
-8.29
-8.86
-9.45
-10.03
-10.65
-11.29
-11.85
-12.36
-12.66
-12.82
-12.74
-12.33
-11.62
-10.69
-9.84
-9.20
-8.80
-8.53
-8.17
-7.34
-5.77
-3.33
0
-25.01
-24.97
-25.25
-25.80
-26.56
-27.46
-28.44
-29.41
-30.32
-31.13
-31.86
-32.51
-33.08
-33.54
-33.85
-33.96
-33.83
-33.46
-32.84
-31.98
-30.86
-29.45
-27.76
-25.79
-23.57
-21.09
-28.78
-20.07
-11.72
-4.54
1.01
4.76
6.71
7.28
7.02
6.52
5.93
5.33
4.75
4.13
3.51
2.97
2.51
2.26
2.19
2.39
2.93
3.77
4.81
5.71
6.27
6.36
5.99
5.22
4.23
3.11
1.78
0
20.84
18.46
16.36
14.51
12.89
11.47
10.22
9.17
8.29
7.57
6.95
6.39
5.88
5.42
5.05
4.78
4.63
4.60
4.65
4.74
4.89
5.06
5.23
5.34
5.34
5.18
moderate decline
uncertain
moderate decline
moderate decline
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
stable
uncertain
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
Indicator
Year
Index
Smoothed
Index (SI)
SI
Lower
CL.
SI
Upper
CL.
Trend
Difference
(TD)
TD
Lower
CL.
TD
Upper
CL.
TREND
CLASSIFICATION
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-Generalists
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-All species
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Specialists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
2002
2003
2004
2005
2006
2007
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1990
1991
1992
1993
1994
77.4
93.5
92.4
85.3
78.5
58
100
48.5
62
65.3
60.2
41
68.8
64.5
93.3
62.5
59.8
57.1
53
68.3
74.1
68.3
87.9
55.5
62.3
75.1
74.4
83.1
57.9
56.1
56.3
53.8
55
69.3
70.6
66.9
63.1
43.7
100
64.5
100
83.9
90.3
105
94.6
98.4
73.1
82.6
77.4
72.1
64.1
87.5
77.2
92.6
75.1
47.4
100
121
126
73.7
87.9
83.74
82.49
81.18
79.82
78.42
77.00
68.12
67.92
67.71
67.51
67.30
67.10
66.89
66.69
66.48
66.28
66.07
65.87
65.66
65.46
65.26
65.05
64.85
64.64
64.44
64.23
64.03
63.82
63.62
63.41
63.21
63.00
62.80
62.59
62.39
62
62
62
94.69
93.26
91.83
90.40
88.98
87.55
86.12
84.69
83.26
81.83
80.41
78.98
77.55
76.12
74.69
73.27
71.84
70.41
109.30
108.45
107.58
106.69
105.83
73.89
71.96
69.69
67.07
64.09
60.77
61.16
61.28
61.40
61.51
61.61
61.70
61.78
61.84
61.89
61.92
61.92
61.90
61.85
61.76
61.64
61.48
61.27
61.02
60.74
60.41
60.06
59.67
59.25
58.81
58.36
57.88
57.39
56.89
56.38
56
55
55
83.02
82.58
82.09
81.55
80.93
80.21
79.37
78.36
77.15
75.71
74.07
72.22
70.20
68.06
65.82
63.50
61.13
58.72
96.66
97.56
98.06
98.16
97.97
93.59
93.01
92.66
92.56
92.75
93.22
75.09
74.55
74.03
73.51
73.00
72.50
72.01
71.54
71.08
70.64
70.23
69.84
69.48
69.16
68.87
68.62
68.42
68.26
68.13
68.05
68.00
67.98
67.98
68.01
68.06
68.12
68.20
68.30
68.40
69
69
69
106.35
103.94
101.57
99.26
97.02
94.88
92.87
91.02
89.38
87.95
86.75
85.74
84.90
84.18
83.57
83.03
82.54
82.09
121.94
119.34
117.10
115.21
113.69
-6.74
-5.49
-4.18
-2.82
-1.42
0
-6.35
-6.14
-5.94
-5.73
-5.53
-5.32
-5.12
-4.91
-4.71
-4.50
-4.30
-4.09
-3.89
-3.69
-3.48
-3.28
-3.07
-2.87
-2.66
-2.46
-2.25
-2.05
-1.84
-1.64
-1.43
-1.23
-1.02
-0.82
-0.61
-0.41
-0.21
0
-24.28
-22.85
-21.42
-19.99
-18.57
-17.14
-15.71
-14.28
-12.85
-11.43
-10.00
-8.57
-7.14
-5.71
-4.28
-2.86
-1.43
0.00
-23.16
-22.30
-21.43
-20.54
-19.69
-18.34
-15.30
-11.95
-8.29
-4.31
0
-18.32
-17.73
-17.14
-16.55
-15.96
-15.36
-14.77
-14.18
-13.59
-13.00
-12.41
-11.82
-11.23
-10.64
-10.05
-9.46
-8.86
-8.27
-7.68
-7.09
-6.50
-5.91
-5.32
-4.73
-4.14
-3.54
-2.95
-2.36
-1.77
-1.18
-0.59
0
-44.20
-41.60
-39.00
-36.40
-33.80
-31.20
-28.60
-26.00
-23.40
-20.80
-18.20
-15.60
-13.00
-10.40
-7.80
-5.20
-2.60
0.00
-42.47
-40.37
-38.55
-36.96
-35.56
4.85
4.32
3.59
2.65
1.47
0
5.63
5.45
5.26
5.08
4.90
4.72
4.54
4.36
4.17
3.99
3.81
3.63
3.45
3.27
3.09
2.90
2.72
2.54
2.36
2.18
2.00
1.82
1.63
1.45
1.27
1.09
0.91
0.73
0.54
0.36
0.18
0
-4.36
-4.10
-3.84
-3.59
-3.33
-3.08
-2.82
-2.56
-2.31
-2.05
-1.79
-1.54
-1.28
-1.02
-0.77
-0.51
-0.26
0.00
-3.84
-4.23
-4.31
-4.13
-3.81
stable
stable
uncertain
uncertain
uncertain
stable
uncertain
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
moderate decline
uncertain
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
uncertain
moderate decline
moderate decline
moderate decline
Indicator
Year
Index
Smoothed
Index (SI)
SI
Lower
CL.
SI
Upper
CL.
Trend
Difference
(TD)
TD
Lower
CL.
TD
Upper
CL.
TREND
CLASSIFICATION
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland Generalists
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Farmland All species
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Specialists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
107
116
133
100
90.5
98.6
88.3
88.7
113
101
95.5
93.1
63.1
100
89.3
112
78.8
89.3
107
105
114
85.9
86.7
87.5
79.9
75.6
99.7
88.9
94.1
83.9
54.9
100
82.7
99.3
55.5
60.9
76.9
76.3
99.7
55.2
50.9
51.1
71.2
59.2
79.8
84.9
74.3
36.9
26.8
100
91.2
111
56.7
63.1
82.9
87.7
85.3
56.8
53
52.1
47.4
104.98
104.07
103.04
101.83
100.50
99.07
97.55
95.93
94.21
92.36
90.37
88.29
86.15
101.22
100.13
99.04
97.94
96.83
95.69
94.50
93.26
91.94
90.58
89.18
87.75
86.28
84.78
83.24
81.66
80.04
78.39
98.35
89.51
82.42
68.34
66.03
73.33
79.71
80.45
65.26
55.27
55.21
62.64
68.43
77.44
79.44
68.07
45.88
25.62
99.25
96.28
99.56
65.33
64.21
80.57
87.67
82.03
60.55
52.74
50.65
48.93
97.52
96.82
95.88
94.72
93.39
91.92
90.29
88.46
86.34
83.81
80.82
77.36
73.45
89.37
89.60
89.63
89.46
89.08
88.49
87.69
86.68
85.49
84.13
82.61
80.93
79.07
77.02
74.74
72.23
69.48
66.52
82.46
77.18
70.13
56.15
53.89
61.20
67.58
68.32
53.13
43.14
43.08
50.51
56.30
65.30
67.24
55.74
33.55
9.25
94.87
92.31
95.62
61.39
60.27
76.63
83.73
78.09
56.61
48.80
46.71
44.99
112.45
111.33
110.19
108.95
107.62
106.23
104.80
103.40
102.09
100.90
99.92
99.21
98.84
113.06
110.66
108.44
106.42
104.58
102.89
101.31
99.83
98.40
97.04
95.76
94.57
93.49
92.55
91.74
91.08
90.59
90.27
114.24
101.83
94.71
80.52
78.16
85.46
91.84
92.58
77.39
67.40
67.34
74.77
80.56
89.57
91.63
80.39
58.21
41.99
103.63
100.25
103.51
69.27
68.15
84.51
91.61
85.97
64.49
56.68
54.59
52.87
-18.84
-17.93
-16.89
-15.69
-14.36
-12.93
-11.40
-9.79
-8.07
-6.21
-4.22
-2.14
0.00
-22.82
-21.74
-20.65
-19.54
-18.43
-17.29
-16.11
-14.86
-13.55
-12.19
-10.79
-9.36
-7.89
-6.39
-4.85
-3.26
-1.64
0.00
-72.73
-63.89
-56.80
-42.71
-40.41
-47.71
-54.09
-54.83
-39.64
-29.65
-29.59
-37.02
-42.81
-51.82
-53.82
-42.44
-20.26
0
-64.39
-61.42
-64.70
-30.47
-29.35
-45.71
-52.81
-47.18
-25.69
-17.88
-15.79
-14.07
-34.28
-32.96
-31.50
-29.79
-27.83
-25.61
-23.10
-20.27
-17.08
-13.45
-9.39
-4.91
0.00
-41.95
-39.70
-37.58
-35.55
-33.60
-31.69
-29.75
-27.74
-25.65
-23.44
-21.11
-18.64
-16.01
-13.22
-10.22
-7.02
-3.62
0.00
-95.54
-84.38
-77.27
-63.12
-60.78
-68.09
-74.47
-75.20
-60.01
-50.01
-49.94
-57.41
-63.35
-72.65
-74.90
-62.77
-36.08
0
-70.68
-67.44
-70.70
-36.46
-35.35
-51.71
-58.80
-53.17
-31.69
-23.88
-21.78
-20.07
-3.39
-2.89
-2.28
-1.59
-0.89
-0.24
0.29
0.69
0.94
1.03
0.94
0.63
0.00
-3.70
-3.77
-3.71
-3.53
-3.26
-2.90
-2.47
-1.98
-1.46
-0.94
-0.47
-0.07
0.24
0.44
0.53
0.50
0.33
0.00
-49.91
-43.39
-36.33
-22.31
-20.03
-27.34
-33.72
-34.46
-19.27
-9.29
-9.23
-16.62
-22.27
-30.98
-32.73
-22.12
-4.44
0
-58.10
-55.41
-58.70
-24.47
-23.36
-39.72
-46.81
-41.18
-19.70
-11.89
-9.79
-8.08
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
stable
stable
stable
uncertain
uncertain
uncertain
moderate decline
uncertain
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
stable
stable
stable
stable
stable
moderate decline
uncertain
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
steep decline
moderate decline
moderate decline
moderate decline
steep decline
steep decline
steep decline
steep decline
steep decline
steep decline
steep decline
uncertain
steep decline
moderate decline
moderate decline
steep decline
steep decline
steep decline
moderate decline
moderate decline
moderate decline
moderate decline
Indicator
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland Generalists
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
England-Woodland All species
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Specialists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Year
2002
2003
2004
2005
2006
2007
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1979
1980
1981
1982
1983
1984
1985
1986
Index
Smoothed
Index (SI)
55.9
69.9
68.2
59.2
49.6
34.5
100
87.7
106
56.2
62.2
80.5
82.7
90.9
56.2
52.1
51.6
55.9
57.2
73.7
74.4
64.8
44
31.1
100
48.8
37.2
93.1
90.7
109
76.5
33.8
29.3
29.1
30.7
53.4
65.1
74.4
39.2
23.5
47.3
34.9
72.2
48.8
34.9
54
33.5
22.7
27.9
40.3
44.6
47.8
51.8
100
69.9
71.4
145
181
179
101
81.1
56.78
68.08
67.99
59.85
49.14
34.86
98.89
92.93
95.37
64.07
63.12
77.95
84.70
85.09
60.86
51.88
51.43
54.97
59.66
72.03
73.92
63.95
45.56
30.74
76.56
74.08
71.64
69.22
66.78
64.31
61.83
59.40
57.11
55.01
53.13
51.45
49.93
48.55
47.29
46.16
45.17
44.29
43.51
42.80
42.16
41.59
41.11
40.73
40.46
40.29
40.18
40.10
40.04
109.91
111.09
112.26
113.44
114.62
115.80
116.98
118.16
SI
Lower
CL.
SI
Upper
CL.
52.84
64.14
64.05
55.90
45.15
30.34
93.73
88.24
90.72
59.42
58.48
73.30
80.05
80.44
56.21
47.24
46.78
50.32
55.02
67.38
69.27
59.29
40.85
25.41
61.61
60.94
59.99
58.74
57.17
55.30
53.20
50.98
48.79
46.73
44.85
43.15
41.62
40.22
38.96
37.83
36.85
36.00
35.23
34.52
33.84
33.17
32.47
31.71
30.84
29.79
28.50
26.92
25.05
76.27
79.20
82.10
84.94
87.73
90.46
93.10
95.66
60.71
72.02
71.93
63.80
53.14
39.38
104.06
97.61
100.03
68.72
67.77
82.59
89.34
89.73
65.50
56.53
56.07
59.61
64.31
76.67
78.56
68.60
50.27
36.07
91.51
87.22
83.28
79.69
76.39
73.33
70.46
67.82
65.43
63.29
61.41
59.74
58.25
56.88
55.63
54.49
53.49
52.59
51.80
51.08
50.47
50.02
49.75
49.76
50.09
50.78
51.85
53.28
55.04
143.54
142.97
142.43
141.95
141.51
141.14
140.86
140.66
Trend
Difference
(TD)
-21.92
-33.22
-33.13
-24.99
-14.28
0.00
-68.15
-62.18
-64.63
-33.33
-32.38
-47.20
-53.95
-54.35
-30.12
-21.14
-20.69
-24.22
-28.92
-41.28
-43.17
-33.20
-14.81
0
-36.52
-34.04
-31.59
-29.17
-26.74
-24.27
-21.79
-19.36
-17.07
-14.97
-13.08
-11.40
-9.89
-8.51
-7.25
-6.12
-5.13
-4.25
-3.47
-2.76
-2.11
-1.55
-1.07
-0.69
-0.42
-0.24
-0.13
-0.06
0.00
33.00
31.82
30.65
29.47
28.29
27.11
25.93
24.75
TD
Lower
CL.
TD
Upper
CL.
-27.91
-39.23
-39.18
-31.11
-19.88
0.00
-75.57
-69.28
-71.71
-40.40
-39.45
-54.27
-61.03
-61.42
-37.19
-28.21
-27.76
-31.29
-35.99
-48.36
-50.31
-40.42
-21.41
0
-57.86
-54.23
-50.93
-47.91
-45.08
-42.39
-39.80
-37.34
-35.05
-32.97
-31.11
-29.42
-27.86
-26.39
-24.98
-23.62
-22.31
-21.02
-19.70
-18.31
-16.83
-15.25
-13.56
-11.75
-9.80
-7.69
-5.39
-2.84
0.00
-24.76
-23.88
-22.99
-22.11
-21.22
-20.34
-19.45
-18.57
-15.92
-27.22
-27.08
-18.87
-8.69
0.00
-60.73
-55.09
-57.55
-26.26
-25.31
-40.13
-46.88
-47.27
-23.05
-14.07
-13.62
-17.15
-21.85
-34.20
-36.03
-25.98
-8.22
0
-15.18
-13.85
-12.26
-10.44
-8.39
-6.15
-3.78
-1.38
0.92
3.04
4.94
6.61
8.08
9.37
10.48
11.38
12.06
12.52
12.76
12.80
12.61
12.15
11.42
10.36
8.96
7.21
5.12
2.72
0.00
90.77
87.53
84.28
81.04
77.80
74.56
71.32
68.07
TREND
CLASSIFICATION
steep decline
steep decline
steep decline
steep decline
steep decline
steep decline
uncertain
steep decline
moderate decline
moderate decline
steep decline
steep decline
steep decline
steep decline
moderate decline
moderate decline
steep decline
steep decline
steep decline
steep decline
steep decline
steep decline
moderate decline
uncertain
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
moderate decline
stable
stable
stable
stable
stable
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
stable
uncertain
stable
stable
stable
stable
stable
stable
Indicator
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-Generalists
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
Scotland-All species
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
Year
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
Index
Smoothed
Index (SI)
SI
Lower
CL.
SI
Upper
CL.
Trend
Difference
(TD)
TD
Lower
CL.
TD
Upper
CL.
TREND
CLASSIFICATION
56.6
68.2
145
149
221
184
92.4
66.3
120
102
151
241
103
87.1
101
100
154
163
150
171
112
100
63.5
59.8
128
125
133
73.7
52.6
43.8
45.1
95.9
107
140
160
74.4
50.8
109
80.5
121
157
82.9
78.3
74.8
74.6
114
116
114
137
99.3
100
58.3
53.3
38.9
37.5
22.3
39.4
38.1
57.4
41.5
38.3
119.34
120.52
121.69
122.87
124.05
125.23
126.41
127.59
128.77
129.94
131.12
132.30
133.48
134.66
135.84
137.02
138.20
139.37
140.55
141.73
142.91
85.52
86.34
87.15
87.97
88.78
89.60
90.42
91.23
92.05
92.86
93.68
94.49
95.31
96.13
96.94
97.76
98.57
99.39
100.21
101.02
101.84
102.65
103.47
104.28
105.10
105.92
106.73
107.55
108.36
72.86
64.49
56.75
50.12
45.00
41.54
39.72
39.08
39.17
39.49
39.98
98.10
100.41
102.56
104.53
106.30
107.84
109.13
110.19
111.00
111.59
111.97
112.17
112.22
112.13
111.93
111.64
111.27
110.84
110.35
109.81
109.24
62.50
64.52
66.51
68.46
70.38
72.26
74.08
75.83
77.51
79.10
80.58
81.94
83.16
84.22
85.12
85.85
86.42
86.83
87.10
87.25
87.29
87.24
87.11
86.92
86.68
86.39
86.06
85.71
85.32
65.89
59.05
52.16
45.89
40.87
37.42
35.60
34.98
35.08
35.42
35.92
140.57
140.62
140.83
141.21
141.81
142.63
143.68
144.99
146.53
148.30
150.28
152.43
154.74
157.19
159.74
162.39
165.12
167.91
170.76
173.65
176.58
108.54
108.15
107.80
107.47
107.18
106.94
106.75
106.63
106.58
106.62
106.77
107.05
107.46
108.03
108.76
109.67
110.73
111.95
113.31
114.80
116.39
118.07
119.83
121.65
123.52
125.44
127.40
129.39
131.40
79.83
69.93
61.33
54.34
49.12
45.65
43.83
43.19
43.25
43.56
44.03
23.57
22.40
21.22
20.04
18.86
17.68
16.50
15.32
14.14
12.97
11.79
10.61
9.43
8.25
7.07
5.89
4.72
3.54
2.36
1.18
0.00
22.84
22.03
21.21
20.40
19.58
18.76
17.95
17.13
16.32
15.50
14.69
13.87
13.05
12.24
11.42
10.61
9.79
8.97
8.16
7.34
6.53
5.71
4.90
4.08
3.26
2.45
1.63
0.82
0.00
-33.83
-25.46
-17.72
-11.09
-5.97
-2.51
-0.69
-0.05
-0.14
-0.46
-0.95
-17.69
-16.80
-15.92
-15.03
-14.15
-13.26
-12.38
-11.50
-10.61
-9.73
-8.84
-7.96
-7.07
-6.19
-5.31
-4.42
-3.54
-2.65
-1.77
-0.88
0.00
-16.68
-16.09
-15.49
-14.90
-14.30
-13.71
-13.11
-12.51
-11.92
-11.32
-10.72
-10.13
-9.53
-8.94
-8.34
-7.75
-7.15
-6.56
-5.96
-5.36
-4.77
-4.17
-3.57
-2.98
-2.38
-1.79
-1.19
-0.60
0.00
-43.73
-34.35
-26.11
-19.29
-14.12
-10.65
-8.83
-8.18
-8.26
-8.57
-9.05
64.83
61.59
58.35
55.11
51.87
48.62
45.38
42.14
38.90
35.66
32.42
29.18
25.93
22.69
19.45
16.21
12.97
9.73
6.48
3.24
0.00
62.37
60.14
57.91
55.69
53.46
51.23
49.00
46.78
44.55
42.32
40.09
37.87
35.64
33.41
31.18
28.96
26.73
24.50
22.27
20.05
17.82
15.59
13.36
11.14
8.91
6.68
4.45
2.23
0.00
-23.93
-16.57
-9.33
-2.89
2.18
5.63
7.45
8.08
7.98
7.64
7.15
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
uncertain
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
moderate decline
uncertain
moderate decline
moderate decline
stable
stable
stable
stable
stable
stable
stable
Indicator
Year
Index
Smoothed
Index (SI)
SI
Lower
CL.
SI
Upper
CL.
Trend
Difference
(TD)
TD
Lower
CL.
TD
Upper
CL.
TREND
CLASSIFICATION
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Specialists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-Generalists
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1976
1977
1978
1979
1980
1981
1982
1983
43.8
37.8
40
46.7
37.5
54.2
39.4
45
48.4
44.8
50.5
34.3
35.8
37.1
36.4
32.8
44
44.9
45.6
45.1
30.1
100
49.4
70.9
78.1
69.5
61.3
106
95.2
123
79.4
75.3
65.7
66.3
96.1
93.9
106
120
68.3
76.2
94.4
100
106
78.5
72.1
76.3
69.3
74.9
90.1
88.7
80.9
73.9
54.7
100
52.9
66.5
62.3
57.6
42.3
73.7
68.2
40.60
41.29
42.06
42.84
43.51
44.03
44.24
44.21
43.88
43.23
42.33
41.30
40.42
39.84
39.58
39.61
39.84
39.99
39.93
39.58
39.03
76.18
77.31
78.48
79.67
80.87
82.08
83.24
84.31
85.26
86.07
86.78
87.41
87.97
88.45
88.79
88.97
88.96
88.74
88.35
87.80
87.08
86.19
85.14
83.99
82.75
81.46
80.12
78.73
77.27
75.74
74.17
72.57
69.21
69.08
68.96
68.85
68.75
68.66
68.58
68.51
36.55
37.25
38.03
38.81
39.47
39.99
40.21
40.17
39.84
39.19
38.28
37.23
36.34
35.73
35.46
35.50
35.71
35.76
35.33
34.10
32.00
61.49
64.44
67.10
69.45
71.50
73.28
74.81
76.09
77.13
77.98
78.68
79.30
79.84
80.31
80.65
80.82
80.81
80.59
80.21
79.68
78.97
78.10
77.05
75.86
74.52
73.03
71.32
69.35
67.03
64.33
61.26
57.83
61.59
62.06
62.47
62.83
63.14
63.40
63.61
63.77
44.64
45.33
46.10
46.87
47.54
48.06
48.27
48.24
47.92
47.27
46.39
45.37
44.51
43.94
43.69
43.73
43.96
44.22
44.52
45.05
46.06
90.87
90.18
89.86
89.89
90.24
90.87
91.67
92.54
93.39
94.17
94.87
95.51
96.09
96.58
96.94
97.12
97.11
96.88
96.49
95.92
95.19
94.28
93.24
92.12
90.98
89.90
88.92
88.11
87.51
87.16
87.08
87.32
76.84
76.11
75.46
74.87
74.36
73.92
73.56
73.25
-1.57
-2.26
-3.03
-3.81
-4.48
-5.00
-5.21
-5.18
-4.85
-4.20
-3.31
-2.27
-1.40
-0.81
-0.55
-0.58
-0.81
-0.97
-0.90
-0.55
-9.66
-10.35
-11.13
-11.92
-12.61
-13.16
-13.41
-13.43
-13.17
-12.59
-11.76
-10.78
-9.90
-9.23
-8.77
-8.41
-7.97
-7.11
-5.58
-3.23
6.52
5.83
5.06
4.30
3.65
3.16
2.99
3.08
3.47
4.19
5.15
6.23
7.11
7.61
7.67
7.24
6.35
5.18
3.78
2.13
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
uncertain
uncertain
uncertain
uncertain
-3.61
-4.74
-5.90
-7.09
-8.30
-9.50
-10.67
-11.74
-12.69
-13.50
-14.20
-14.83
-15.39
-15.87
-16.22
-16.40
-16.38
-16.16
-15.78
-15.23
-14.51
-13.61
-12.57
-11.41
-10.18
-8.89
-7.55
-6.16
-4.70
-3.17
-1.60
0
-6.59
-6.46
-6.34
-6.23
-6.13
-6.04
-5.96
-5.89
-24.33
-24.28
-24.58
-25.17
-25.99
-26.98
-28.06
-29.12
-30.10
-30.98
-31.75
-32.45
-33.06
-33.57
-33.93
-34.07
-33.98
-33.63
-33.03
-32.20
-31.09
-29.69
-28.00
-26.04
-23.82
-21.35
-18.60
-15.55
-12.17
-8.45
-4.40
0
-18.36
-17.80
-17.29
-16.84
-16.44
-16.09
-15.79
-15.52
17.11
14.81
12.77
10.98
9.39
7.98
6.72
5.64
4.73
3.98
3.35
2.79
2.28
1.83
1.49
1.28
1.21
1.30
1.48
1.74
2.08
2.46
2.86
3.22
3.47
3.57
3.50
3.24
2.78
2.11
1.20
0
5.19
4.88
4.61
4.39
4.19
4.02
3.87
3.74
stable
uncertain
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
uncertain
uncertain
uncertain
uncertain
uncertain
stable
uncertain
stable
stable
stable
stable
stable
stable
Indicator
Year
Index
Smoothed
Index (SI)
SI
Lower
CL.
SI
Upper
CL.
Trend
Difference
(TD)
TD
Lower
CL.
TD
Upper
CL.
TREND
CLASSIFICATION
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-All species
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
UK-Migrants
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
95.2
65
60.8
60.6
56.7
70.3
74.9
71.4
90.9
58.7
66.3
76.3
76
82.9
58.6
57.4
60.2
56.8
55.9
71.2
71.4
68.7
65.4
45.9
100
35.8
15.6
24.4
158
40.9
234
302
38
33.2
40.1
30.4
17.8
119
156
47.3
394
21
261
39.9
1870
42.2
198
73.9
645
76.5
299
835
229
172
732
263
68.44
68.37
68.29
68.21
68.12
68.02
67.90
67.76
67.60
67.40
67.19
66.94
66.66
66.36
66.04
65.69
65.34
64.97
64.60
64.22
63.83
63.43
63.03
62.62
13.08
27.45
41.82
56.19
70.56
84.93
99.30
113.67
128.04
142.41
156.78
171.15
185.52
199.89
214.26
228.63
243.00
257.37
271.74
286.11
300.48
314.85
329.22
343.59
357.96
372.33
386.70
401.07
415.44
429.81
444.18
458.55
63.89
63.95
63.98
63.97
63.93
63.87
63.77
63.64
63.48
63.27
63.03
62.75
62.43
62.05
61.62
61.13
60.59
59.99
59.33
58.60
57.80
56.93
55.99
54.98
-255.32
-228.28
-201.50
-175.01
-148.85
-123.09
-97.80
-73.06
-48.96
-25.62
-3.16
18.28
38.54
57.49
74.98
90.94
105.29
118.04
129.25
139.02
147.47
154.75
161.01
166.39
171.02
175.00
178.44
181.41
183.99
186.23
188.18
189.88
73.00
72.78
72.60
72.44
72.30
72.16
72.03
71.88
71.72
71.53
71.34
71.12
70.90
70.68
70.45
70.25
70.08
69.95
69.87
69.84
69.86
69.94
70.07
70.26
281.49
283.19
285.14
287.39
289.97
292.96
296.41
300.40
305.04
310.44
316.72
324.03
332.51
342.30
353.54
366.33
380.72
396.70
414.23
433.21
453.50
474.96
497.43
520.79
544.91
569.66
594.97
620.73
646.89
673.40
700.19
727.23
-5.82
-5.75
-5.67
-5.58
-5.49
-5.39
-5.27
-5.14
-4.97
-4.78
-4.56
-4.32
-4.04
-3.74
-3.41
-3.07
-2.71
-2.35
-1.97
-1.59
-1.20
-0.81
-0.41
0
445.47
431.10
416.73
402.36
387.99
373.62
359.25
344.88
330.51
316.14
301.77
287.40
273.03
258.66
244.29
229.92
215.55
201.18
186.81
172.44
158.07
143.70
129.33
114.96
100.59
86.22
71.85
57.48
43.11
28.74
14.37
0.00
-15.27
-15.03
-14.80
-14.56
-14.31
-14.04
-13.74
-13.40
-13.01
-12.57
-12.08
-11.52
-10.90
-10.22
-9.47
-8.66
-7.78
-6.85
-5.86
-4.81
-3.70
-2.53
-1.30
0
-15.86
-15.34
-14.83
-14.32
-13.81
-13.30
-12.79
-12.28
-11.76
-11.25
-10.74
-10.23
-9.72
-9.21
-8.70
-8.18
-7.67
-7.16
-6.65
-6.14
-5.63
-5.11
-4.60
-4.09
-3.58
-3.07
-2.56
-2.05
-1.53
-1.02
-0.51
0.00
3.63
3.54
3.46
3.39
3.32
3.25
3.19
3.13
3.07
3.01
2.95
2.89
2.82
2.74
2.64
2.52
2.36
2.16
1.92
1.63
1.29
0.91
0.48
0
906.80
877.55
848.30
819.05
789.79
760.54
731.29
702.04
672.79
643.54
614.28
585.03
555.78
526.53
497.28
468.03
438.77
409.52
380.27
351.02
321.77
292.52
263.27
234.01
204.76
175.51
146.26
117.01
87.75
58.50
29.25
0.00
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
stable
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain
uncertain