Area selection for the conservation of butterflies in the Iberian Peninsula and Balearic Islands

Coverage provided by the network of protected areas in the Iberian Peninsula and Balearic Islands was tested by measuring the coincidence between the squares protected by the network and the butterfly species recorded for such UTM grid squares. Five species were found to be absent in the network. The protected areas with the highest numbers of butterfly species were Ordesa National Park and Monte Perdido and the Posets-Maladeta Natural Park. Priority areas were selected using WORLDMAP software and showed that the all species of butterflies in the Iberian Peninsula and Balearic Islands can be found within 16 squares of 10×10 km (nine of them not within the network of protected areas). More specific area selections were also carried out: eight squares supported the total number of threatened species, five hosted all the Iberian endemisms and 13 harboured the rare butterfly species. This study detected 16 squares that are not currently protected but are important for butterfly conservation in the Iberian Peninsula and Balearic Islands

Changes in host ant communities of Alcon Blue butterflies in abandoned mountain hay meadows

1. Land use intensification is a general threat to biodiversity, but many species depend on low-intensity agricultural ecosystems. One example is European mountain meadow ecosystems, traditionally managed by hay harvesting or livestock grazing. Abandoning management often causes population declines, local extinctions and biotic homogenisation in these meadows. 2. We studied changes in the Myrmica host ant communities of the xerophilic form of the ant-parasitic Alcon Blue butterfly (Maculinea alcon) in four hay meadows in the Bükk mountains of Hungary between 2000–2007 and 2018. Abandonment started in this region in the 1970s, accelerated in the 1980s, and culminated in the 1990s. 3. We found that the Myrmica ant community has changed substantially in less than two decades. Diversity of the ant community always decreased, and species composition became more homogeneous at two sites. Habitat suitability for Maculinea butterflies decreased at three sites and increased at only one site, where management was restarted 20 years after abandonment. 4. The number of M. alcon caterpillars and pupae, the rate of infestation of ant nests and the mean number of caterpillars and pupae per ant nest decreased between the two periods, whereas host ant specificity did not differ from random in either period. 5. We conclude that the unfavourable changes in the host ant community due to abandonment have negative consequences for the persistence of Maculinea populations. Our study highlights the need for detailed monitoring, and the maintenance of low-intensity management by mowing or grazing to avoid the decline of biodiversity dependent on low-intensity agriculture

Butterfly diversity, richness, and density patterns in Sierra Nevada (SE Spain): Conservation implications under a global change scenario

Understanding factors that regulate the patterns of diversity, richness, and density of organisms is of enormous importance to manage biodiversity in a global change context. We investigate the importance of environmental factors in regulating the patterns of diversity, richness, and density of diurnal butterflies in the Sierra Nevada mountain range (SE Spain). Diversity, richness, and density seem to be strongly correlated, being mainly defined by land-use and topographic-related variables. The sites with the highest values correspond to areas of dense scrubland, near patches of forest, oriented to the west and with a high rate of solar radiation but not excessively exposed from the topographical point of view. Topographic wetness index seems to be also important but with a positive relation in the case of density and negative in the case of diversity and richness. Our results show a pattern of mid-elevation maxima, with highest values between 1600 and 2000 masl and lower in the summits and the piedmont (<1400 masl). This brings us the possibility to identify a series of areas of high value for the conservation of butterflies in this protected area, with important applications towards the conservation and management of this group of insects. Finally, a series of management recommendations to improve the conservation status of the butterfly communities in the Sierra Nevada protected area are inferred. One of the main recommendations is based on the maintenance of spatial heterogeneity, taking into account traditional land uses that enhance biodiversity

European Butterfly Monitoring Scheme (eBMS): network development. Technical report

1. The ABLE EU Pilot Project was initiated in 2018 to collate butterfly monitoring data across Europe, to facilitate the start of new schemes in the EU, and to develop indicators to help policy evaluation. This report summarises the work on developing the monitoring network (Task 2). 2. There are some 451 butterfly species occurring in the Member States of the EU(27), breeding in a wide range of habitats. Butterflies react quickly to change and are considered to be good biological indicators, especially other insects and pollinators. Monitoring butterflies can help shed light on changes in these important groups. 3. Standard methods of monitoring butterflies are well established, based on fixed routes (transects), which allow citizen scientists to estimate the relative abundance of butterflies. 4. Prior to ABLE, several countries contributed butterfly monitoring data to the European Butterfly Monitoring Scheme (eBMS), but they were concentrated in central and western Europe. Large parts of southern and eastern Europe had no regular scheme. Three groups were prioritised for action: six to eight EU countries which had a good probability of establishing a scheme; recently started schemes that required further support; and countries where longer term activities were needed to develop monitoring. 5. As a result of the two-year project, ten EU(27) countries have started new citizen Science Butterfly Monitoring Schemes - Italy, Portugal, Hungary, Austria, Cyprus in 2019 and Poland, Bulgaria, Malta, Czech and Croatia in 2020; seven of these have joined the eBMS data network. Further details are in Annex 2. 6. A suite of support materials has been produced, including a Butterfly Transect Manual, which has been translated into six languages and a series of regional butterfly identification guides. Videos have been made explaining how to count butterflies on a transect and PowerPoint presentations have been made available in several languages. 7. More than 20 workshops and training seminars were held in ten different countries involving more than 750 people. During the Covid pandemic, these were held online. 8. To help monitor rare butterflies and those that occur in remote areas, a new ButterflyCount app was developed, based on standard 15-min counts. The app has an identification guide and lists of butterflies customised to each country to facilitate recording. This data will be assimilated into the eBMS to help extend coverage and make a more representative scheme. 9. Butterfly monitoring was promoted via social media as well as by articles in magazines and in EU level meetings. The eBMS website was used to host all materials and reports. A meeting was held of all coordinators in late 2019, attended by 59 people from 29 countries. A technical workshop was held online in March 2020, attended by 35 people, with a final meeting in October 2020. 10. Lessons learnt include the value of sharing knowledge from established schemes, ensuring broad involvement of citizens/stakeholders, and promoting the value of a Europe-wide scheme. 11. The eBMS provides an invaluable resource to inform EU policy development and evaluate the effectiveness of measures such as the CAP, Habitats Directive, Natura 2000, and the EU Pollinators Initiative. However, continuing financial support is needed from each Member State to develop capacity in existing schemes and start new schemes in countries which do not have one. This will help make a more complete scheme that accurately represents changes across Europe

The EU Butterfly Indicator for Grassland species: 1990-2017. Technical report

The EU Grassland Butterfly Indicator is one of the indicators of the status of biodiversity in the European Union. It is an abundance indicator based on data recording the population trends of seventeen butterfly species in 16 (see below) EU countries. This report presents the seventh version of this indicator now covering 28 years. At the Convention on Biological Diversity meeting in Nagoya (Japan) the Strategic Plan for Biodiversity 2011– 2020 was adopted. It proposed five goals and 20 “Aichi” biodiversity targets. In line with this plan a new EU biodiversity strategy was adopted by the European Commission in May 2011. This provided a framework for the EU to meet its own biodiversity objectives and its global commitments as a party to the CBD. The Headline Target is to halt the loss of biodiversity and the degradation of ecosystem services in the EU by 2020, and restore them, in so far as feasible, while stepping up the EU contribution to averting global biodiversity loss. Under Target 3A the EU is committed to increase the contribution of agriculture to biodiversity recovery. Europe now has one year left to intensify action to achieve this. The EU biodiversity strategy includes the development of a coherent framework for monitoring, assessing and reporting on progress in implementing actions. Such a framework is needed to link existing biodiversity data and knowledge systems with the strategy, to help assess achievement of the goals and to streamline EU and global monitoring, reporting and review obligations. Some of the EU biodiversity indicators provide specific measurements and trends on genetic, species and ecosystem/landscape diversity, but many have a more indirect link to biodiversity. Very few have been established specifically to assess biodiversity. The status indicators on species only cover birds, bats and butterflies, since these are the only taxa/species groups for which harmonized European monitoring data are available (EEA, 2012). For the EU Grassland Butterfly Indicator the trends of seventeen widespread and characteristic grassland butterflies were assessed in 16 countries in the European Union. This technical report gives an overview of the method and results, and presents the indicator

Butterfly indicators 1990-2018. Technical report

There is mounting evidence of widespread declines in the diversity and abundance of insects from across the globe (Sanchez-Bayo and Wyckhuys 2019, Seibold et al. 2019, van Klink et al. 2020, Wagner 2020). This gives a stark warning for the perilous state of biodiversity (Diaz et al. 2019), and demonstrates that addressing the gap in knowledge of the status of insects is vital (Cardoso et al. 2020, Samways et al. 2020). Insects are estimated to comprise more than half of all described species and are a dominant component of biodiversity in most ecosystems (Bar-On et al. 2018). Insects also provide a crucial role in the functioning of ecosystems. They are not only related to the supply of many ecosystem services such as pollination, biological control, soil fertility regulation and diverse cultural ecosystem services but also to disservices such as damage to crops and spread of diseases to livestock and humans (Gutierrez-Arellano and Mulligan 2018, Noriega et al. 2018). There is a pressing need to assess the status of insects to set and evaluate conservation targets. At the Convention on Biological Diversity (CBD) meeting in Nagoya (Japan), the Strategic Plan for Biodiversity 2011-2020 was adopted. It proposed five goals and 20 "Aichi" biodiversity targets. In line with this plan, a new EU biodiversity strategy was adopted by the European Commission in May 2011. This strategy provided a framework for the EU to meet its biodiversity targets and global commitments as a party to the CBD. The Headline Target in the existing EU Biodiversity Strategy 2020 is to halt the loss of biodiversity and the degradation of ecosystem services in the EU by 2020, and restore them, in so far as feasible, while stepping up the EU contribution to averting global biodiversity loss. Under Target 3A the EU is committed to increasing the contribution of agriculture to biodiversity recovery. Further, the EU Biodiversity Strategy 2030 includes the development of a coherent framework for monitoring, assessing and reporting on progress in implementing actions. Such a framework is needed to link existing biodiversity data and knowledge systems with the strategy, to help assess achievement of the goals and to streamline EU and global monitoring, reporting and review obligations. Some of the EU biodiversity indicators provide specific measurements and trends on genetic, species and ecosystem/landscape diversity, but many have a more indirect link to biodiversity. Very few have been explicitly established to assess biodiversity. The status indicators on species only cover birds, bats and butterflies, since these are the only taxa/species groups for which reasonably harmonized European monitoring data are available (EEA, 2012). This technical report builds upon previous technical reports for the EU Grassland Butterfly Indicator (e.g. van Swaay et al., 2019) to: 1. Describe a new approach for assessing butterfly trends and developing indicators of European butterflies; 2. Give an overview of the main results, and present a range of butterfly indicators; 3. Discuss the next steps to improve butterfly indicators for Europe. Butterflies are ideal biological indicators: they are well-documented, measurable, sensitive to environmental change, occur in a wide range of habitat types, represent many other insects, and are popular with the public because of their beauty. Field monitoring is essential to assess changes in their abundance. Indicators based on butterfly monitoring data are valuable to understand the state of the environment and help evaluate policy and implementation. Trained volunteers are a cost-effective way of gathering robust data on butterflies, more so when supported by informative materials and efficient online recording