Butterflies

Context

Sites of Special Scientific Interest (SSSIs) can be notified if they include qualifying features under the butterfly criteria outlined in section 2 of Chapter 18 'Butterflies' of the Guidelines for Selection of Biological SSSIs.  In Northern Ireland, ASSIs are selected on a very similar basis – the Guidelines for the Selection of Biological ASSIs in Northern Ireland is an addendum to the SSSI guidelines rather than an alternative.  The criteria include: nationally rare species, endemic races, nationally scarce species, and species which have experienced substantial local declines.

 
Sites can be notified for species listed in the SSSI guidelines, including for:
 
  • the re-establishment or introduction of species extinct in Great Britain e.g. large blue Maculinea arion and large copper Lycaena dispar;
  • Red Data Book endangered species e.g. large tortoiseshell Nymphalis polychloros;
  • vulnerable species e.g. heath fritillary Melitaea athalia, high brown fritillary Argynnis adippe and swallowtail Papilio machaon; and
  • rare species, e.g. Glanville fritillary Melitaea cinxia and silver-spotted skipper Hesperia comma.
 
Endemic races which qualify are grayling Hipparchia semele thyone and silver-studded blue Plebejus argus caernensis, as well as nationally scarce species (those which currently occupy 16-100 10km squares), such as adonis blue Polyommatus bellargus and purple emperor Apatura iris.  15 other species merit consideration for site notification in regions where substantial declines have taken place, but wherever possible, site notification should be made where colonies of some nationally rare and scarce species are also present.
 
The sole UK butterfly species listed on Annex II of the EC Habitats Directive which qualifies as a feature for the selection of Special Areas of Conservation (SACs) is the Marsh fritillary Euphydryas (Eurodryas, Hypodryas) aurinia.
 

Summary statistics

  SAC A/SSSI Total
Favourable condition 30% 66% 58%
Main monitoring coverage E, W E, S  
Reported assessments 20 71 91
Completeness of assessments 59% unknown  
Distribution of features     UK
 

Number of assessments reported by country and site type

Country SAC SSSI/ASSI
England 9 52
Scotland 5 19
Wales 6 0
Northern Ireland 0 0
United Kingdom 20 71
 

Natura features

List of Natura 2000 interest features within this reporting category

Interest feature name  
Formal name Informal name No. of assessments reported Total no. of features % assessed
Euphydryas (Eurodryas, Hypodryas) aurinia Marsh fritillary 20 34 59%
 
Natura 2000 comprises Special Protection Areas (under the Birds Directive) and Special Areas for Conservation (under the Habitats and Species Directive). The list presented here includes all of the qualifying interest features under these Directives, and shows the proportion of these features for which a condition assessment has been made.
 

SSSI features

List of SSSI and ASSI interest features in this reporting category

Interest feature name  
Formal name Informal name No. of assessments reported
Apatura iris Purple emperor 3
Argynnis adippe High brown fritillary 2
Argynnis aglaja Dark green fritillary 1
Aricia artaxerxes Northern brown argus 1
Boloria euphrosyne Pearl-bordered fritillary 1
Callophrys rubi Green hairstreak 2
Carterocephalus palaemo Chequered skipper 5
Clossiana euphrosyne Pearl-bordered fritillary 5
Clossiana selene Small pearl-bordered fritillary 1
Cupido minimus Small blue 1
Cupido minimus Small blue butterfly 2
Erebia epiphron Small mountain ringlet butterfly 1
Euphydryas aurinia Marsh fritillary 8
Eurodryas aurinia Marsh fritillary 7
Hamearis lucina Duke of Burgundy 6
Hesperia comma Silver-spotted skipper 1
Hipparchia semele Grayling 1
Leptidea sinapis Wood white 2
Limenitis camilla White admiral 1
Lysandra bellargus Adonis blue 6
Lysandra coridon Chalkhill blue 1
Maculinea arion Large blue 1
Melanargia galathea Marbled white 1
Mellicta athalia Heath fritillary 1
Quercusia quercus Purple hairstreak 1
Satyrium pruni Black hairstreak 4
Satyrium w-album White-letter hairstreak 3
Thecla betulae Brown hairstreak 2
 
This list has not been fully standardised at a UK level yet. It is intended to show the principal constituent "feature types" for this reporting category.
 

Maps - distribution

UK distibution of reported interest features

Distribution of reported interest features.

Map showing the locations of the 10km squares in which at least one condition assessment has been reported. It does not show features that have not yet been assessed.

 

Maps - Natura

Distribution of SAC features showing assessments of favourability Condition of SAC features, with those currently reported as unfavourable-recovering shown as favourable
Current condition of SAC features
Distribution of SAC features showing assessments of favourability (where unfavourable-recovering is counted as unfavourable).
Condition of SAC features, with those currently reported as unfavourable-recovering shown as favourable
The implication of the unfavourable-recovering condition assessments is that at some point in the future these features should become favourable. This map shows the effect of that recovery by counting the favourable and unfavourable-recovering assessments together.

 

IMPORTANT NOTE: we do not have information on the timescale of the predicted recovery, which may be influenced by many past, natural and human related factors. A sustained sympathetic management regime is more likely to result in favourable condition being attained.

Key: Proportion of assessed features on 10km squares that are favourable:

Natura map legend - Key: proportion of assessed features on 10km squares that are favourable

 

Details of how these maps were produced

 

Maps - SSSI

Current condition of SSSI/ASSI features Condition of SSSI/ASSI features, with those currently reported as unfavourable-recovering shown as favourable
Current condition of SSSI/ASSI features
Distribution of SSSI/ASSI features showing assessments of favourability (where unfavourable-recovering is counted as unfavourable).
Condition of SSSI/ASSI features, with those currently reported as unfavourable-recovering shown as favourable
The implication of the unfavourable-recovering condition assessments is that at some point in the future these features should become favourable. This map shows the effect of that recovery by counting the favourable and unfavourable-recovering assessments together.

 

IMPORTANT NOTE: we do not have information on the timescale of the predicted recovery, which may be influenced by many past, natural and human related factors. A sustained sympathetic management regime is more likely to result in favourable condition being attained.

Key: Proportion of assessed features on 10km squares that are favourable:

SSSI map legend - Proportion of assessed features on 10km squares that are favourable

 

Details of how these maps were produced

 

Condition summary

Reporting category condition summary on Natura 2000 sites and SSSI

This lists the 10 different condition assessments and presents a bar chart showing the number of features within the SSSI series and the Natura 2000 series (either SPA for bird features or SAC for features other than birds). Note that for Natura 2000 we are able to estimate the number of features that have not been assessed during the 6 year reporting period - we are unable to do this for SSSI/ASSI because we do not have an overall list of notified interest features for these designations.

 

NB favourable unclassified and unfavourable unclassified have been used in this first six year cycle to get around difficulties in identifying trends in condition as common standards monitoring is implemented. It is expected that these categories will not be used for subsequent assessments of a feature.

 

Condition assessment - Natura 2000 features

The number and proportion of assessments for Natura 2000 (SAC and SPA) interest features falling into each of the condition categories
The number and proportion of assessments for Natura 2000 (SAC and SPA) interest features falling into each of the condition categories. Note that the �unfavourable� category includes all reports of unfavourable condition except �unfavourable recovering� which is shown as a separate segment.
 

Condition assessment - SSSI features

The number and proportion of assessments for SSSI/ASSI interest features falling into each of the condition categories
The number and proportion of assessments for SSSI/ASSI interest features falling into each of the condition categories. Note that the �unfavourable� category includes all reports of unfavourable condition except �unfavourable recovering� which is shown as a separate segment.
 

Adverse activities

The number of interest features where an activity has been reported as being implicated in the "unfavourable" condition of a feature
The number of interest features where an activity has been reported as being implicated in the "unfavourable" condition of a feature. More than one adverse activity may be reported for each feature.
 

Management measures

The measures summary bar chart lists the management measures relevant to the reporting category
For each "measure" the chart shows the number of interest features where that measure has been taken on a site to improve or maintain the condition of an interest feature. More than one measure may be reported for each feature assessed.
 

Interpretation

58% of butterfly features reported are in favourable condition.  This is below the average for species features, but about the average for all features combined.  66% of A/SSSI and 30% of SAC features reported are favourable; a further 7% of A/SSSI and 20% of SAC features are in unfavourable-recovering condition. 
 
Within these figures, browns (Satyridae) were all favourable (100%), hairstreaks, coppers and blues (Lycaenidae) 63% favourable, and emperors, vanessids and fritillaries (Nymphalidae) 44% favourable.  The last of these groups includes the marsh fritillary Euphydryas aurinia.  59% of assessments required for SACs were reported for this species, of which 30% are favourable.  It is further notified on 15 A/SSSI sites, of which 46% are favourable. 
 
The main factor reported as causing unfavourable condition is under-grazing – this relates to the management of the grassland habitats upon which many of these butterflies are dependent.  Many of the sites in favourable condition have management agreements in place.  Care is needed in interpreting these assessments, as guidance on setting conservation objectives for butterfly features had not been fully developed at the time the assessments were made.