Butterflies of Siena

The Italian region of Tuscany is known for its high culture, history and landscapes. The birthplace of the Renaissance, Tuscany boasts great artistic masterpieces such as Florence Cathedral, perhaps most renowned for Filippo Brunelleschi’s dome, its bronze baptistry doors and frescoes, Michelangelo’s statue of the biblical David (Florence) that slew Goliath (France), Botticelli’s painting The Birth of Venus, the Adoration of the Magi by Leonardo da Vinci. Piazza dei Miracoli in Pisa with its magnificent cathedral and tower are more icons of the great age of art while the gentle rolling hills with vineyards, olive groves and hilltop woods, towering Apennine mountains and plains are pleasing to the eye. The cuisine is another feature of interest, being simple yet satisfying. Legumes, bread, cheese, vegetables, mushrooms, and fresh fruit are used. Wild Boar is a staple on menus.

Florence Cathedral.

Life seems easy there, and little wonder why. There are four seasons, and while the summer months are hot, autumn and spring temperatures are mild-warm. It rains, sometimes heavily, but summer is generally dry. November is the wettest month, but rainy periods occur in spring. Overall, the temperatures outside the summer months are not extreme, making for a pleasant experience.

The environs of Siena in April 2022. This photograph was taken at the edge of the city.

I visited the university town, Siena, twice, in September 2021 and April 2022, with similar maximum daytime temperatures in these months. A walled redbrick Medieval city, in the south of Tuscany, Siena is known for its enormous square, the Piazzo del Campo, with its showpiece town hall, The Palazzo Pubblico, much of it built between 1297 and 1310, and its steep narrow streets, for this city is constructed on three hills. The city is without the despoilation wrought by cheap contemporary architecture. Despite the dominance of clay brick and travertine stone, the city contains relieving green spaces and is compact, not sprawling, with greenery beyond the walls easily reached on foot.

The Palazzo Pubblico, in the Piazza del Campo, Siena.

On arrival on April 12th, I began to search for the best habitats, hoping to see butterflies new to me. As April is quite early for butterflies and I was not looking in habitats of special character, I felt my chances of seeing rarities and species I had yet to see were limited.

Tuesday 12th was blue-skied and warm, so I checked a steep grassy embankment overlooking the heavily wooded valley in Siena that I searched last September. Back then, Wall Browns Lasiommata megera, Meadow Browns Maniola jurtina and Small Heaths Coenonympha pamphilus were present, and two of these were there in April-the odd one out being Meadow Brown, a single-brooded butterfly not yet in flight.

Speckled Wood Pararge aegeria aegeria, Siena.

These were joined by Brimstones Gonepteryx rhamni, Large Whites Pieris brassicae and Small Whites Artogoeia rapae, Orange-tips Anthocharis cardamines, Holly Blues Celestrina argiolus, Small Coppers Lycaena phlaeas, Speckled Woods Pararge aegeria and Common Swallowtails Papilio machaon (not present in Ireland). In Ireland, one does not see the Brimstone in built-up areas; indeed, I saw one in the Piazza della Signoria, the main square in Florence. The avoidance of built environments in Ireland extends to the Small Copper, Wall Brown, and Small Heath, all strictly countryside species here.

This grassy embankment in the town holds a range of species, including Common Swallowtail, Small Copper, Wall Brown, and Small Heath.
Common Swallowtail, first generation, Siena.

A closer look at the Brimstone and Small Copper confirmed the differences between the Irish race and their Italian conspecifics; the Irish Brimstone has larger underside blotches while the male is paler than his Italian cousin. The Irish Small Copper has grey, not beige underside colouring, and a redder hindwing band. Their Speckled Woods are strikingly different to ours: we have the subspecies tircis, with cream dappling on chocolate brown wings replaced with orange on aegeria, the colour form found in Siena and most of Europe.

Irish Small Copper. Note the grey undersides (hindwing and forewing apex and margin) and crimson band compared with the paler specimens from Siena below.
Small Coppers mating in Siena, female on the left.

Exiting the town via Porta Tufi or Tufi Gate, I quickly found patches of uncultivated land containing light woodland, scrub, hedges and open grassland, some of it containing colonies of the Green-winged Orchid Orchis morio, a rare plant in Ireland. Just a ten-minute walk from Siena, it felt like a world away. In addition to the butterflies already seen, I happily discovered more. In a grassy field dominated by buttercups, I found Green Hairstreak Callophry rubi, Sooty Copper Lycaena tityrus, Green-underside Glaucopsyche alexis, and Scarce Swallowtail Iphiclides podalirius.

Grassy field containing Scarce Swallowtail, Green-underside Blue, Sooty Copper…

A reminder of home, the Green Hairstreak was found in a habitat I have never seen it use in Ireland. It was flying in a grassy field, which was quite well vegetated but with fairly dry soil. In Ireland, it is strongly associated with wet places, especially bogs and wet heath. Unlike most Irish specimens, the example I saw had almost no white markings on its undersides.

Green Hairstreak, Siena.

The same small grassy field yielded two more gems; a Sooty Copper and a Green-underside Blue, neither of which I’d seen before. The Sooty Copper is around the same size as the Small Copper but rather darker on its uppersides. It behaves quite similarly too, and the one I saw was a female, and she posed often, making photographing her quite easy, although she perched with angled wings, like the Small Copper so a full image of outstretched wings is rarely possible.

Sooty Copper upperside, Siena.
Sooty Copper, underside, Siena.

The Green-underside Blue is one of the easiest continental blues to identify and as the photograph shows, it lives up to its vernacular name. A spring and early summer species, it is a delightful creature. I wish I managed a photograph of the uppersides, a deep blue in the male that is unforgettable.

Green-underside Blue, Siena.

Two lovely Scarce Swallowtails fluttered around high scrub before departing, not landing low for a photo! The spring generation usually feeds on tree blossom, as the nectar-rich grassland flora is not available to it in spring. But just to see these large, exotic butterflies fluttering delicately in the warming air brought pleasure!

An adjoining field with herb-rich vegetation added a female wood white (not identified at species level), Clouded Yellow Colias crocea, and Grizzled Skipper Pyrgus malvae (busy laying her eggs, singly, on the underneath of leaves of a potentilla species, possibly Creeping Cinquefoil Potentilla reptans). This was the first sighting of this dizzyingly difficult flyer for me. Its sharp chequered pattern adds to its dizzying flight pattern, making tracking it tricky. Later, I saw it in a park in the city, on similar grassy vegetation. This little spring butterfly, single-brooded or double brooded depending on locality and latitude, also occurs as a scarce butterfly in the south of England but it is not present in Ireland.

Grizzled Skipper female, Siena.

Nearby, another skipper, another first, the Mallow Skipper Carcharodus alceae. Larger, and much duller, this breeds on Mallow Malva sylvestris. Males have a strange habit of lowering their wings below their thorax and elevating their abdomens, in low light and low temperature. Captive males kept in darkness retain their bizarre-looking posture for hours.  The males I saw were not put in this situation and did not perch in any spot for long.

Mallow Skipper male, Siena.

Further out in the field while observing a male Common Blue Polyommatus icarus I spotted a fidgety copper butterfly looking for a place to lay her eggs. I was delighted to see another species for the first time, the Lesser Fiery Copper Lycaena thersamon. The butterfly is absent from most of Europe, being found in Italy and the Balkans. It breeds on a fairly common plant, Common Knotweed Polygonum aviculare. While she would not sit still, I managed a half-decent photo, enough to identify her!

Lesser Fiery Copper, Siena.

While chasing her up the steep slope a Clouded Yellow crossed my path, one of several I saw including some seen from the train window on route to Siena, along with the occasional Geranium Bronze Cacyreus marshalli, a curious little butterfly now established in southern Europe from South Africa. It is described as a “pest on Pelargonium cultivars” but it rarely if ever destroys these ornamental plants. The walk back to the city yielded a fleeting glimpse of a male Cleopatra Gonepteryx cleopatra, a Brimstone with a deep orange splash on the forewing upperside. Alas, he did not pause for a photo!

A female Brimstone on a Green-winged Orchid.

This April, I recorded 23 butterfly species in and around Siena. The area is not known for its biodiversity but to a person from Ireland or Britain, it offers plenty of excitement. Interestingly, the city is divided into contradas, or districts, each with a symbol. One contrade is named Bruco, the caterpillar. Its insignia is a rather aggressive green caterpillar on a rose. While the origin of the name is unclear, Bruco’s residents worked in the silk trade, offering a likely background to the title. The contrada is famous for leading a rebellion in 1371, to overthrow the Sienese council and establish a people’s government. This great change alludes, fancifully at least, to a caterpillar’s metamorphosis via the chrysalis, a symbol of change.

Hopefully, the presence of butterflies in and around Siena will continue, a feature that adds to the charm of the area for the travelling naturalist.

The Small Heath is abundant in Siena, and flies in at least two generations, while in Ireland it has one brood.

All photographs © J. Harding

Conservation of Butterflies Across the European Union

Europe’s butterflies are in crisis, especially populations in Northern Europe, and especially grassland butterflies. There has been a 75% decline in insect biomass in reserves in western Germany over 27 years Hallman et al. (2017). In northern Germany, the populations of Marsh Fritillary are being supported by importing caterpillars from Denmark.  Denmark has lost the Swallowtail Papilio machaon. The declines are not confined to northern Europe. According to Laszio Rakosy, a Romanian expert, the Apollo Parnassius apollo has been lost from the Romanian Carpathians over the past 25 years. Malta has, it seems, lost the Brown Argus Aricia agestis and Small Copper Lycaena phlaeas and may lose their endemic Meadow Brown Maniola jurtina hyperhispulla.

Apollo upperside and underside. It is a montane species that is declining in many areas. The IUCN Red List of Threatened Species classifies the Apollo as ‘near threatened’ in Austria. In other countries, it is critically endangered (e.g. in Poland), or extinct (e.g. in the Czech Republic). Photo Michael Friel

The EU Biodiversity Strategy 2030 offers some hope for habitats in the EU. Member states must send in pledges to the European Commission to protect 30% of the land and sea area of the EU. Protected Area Pledges are needed to contribute to EU level targets for well-managed and protected areas across 30% of EU land. The situation across the EU for grassland butterflies is deteriorating. In the Article 17 Reports 2013-2018, the conservation status of the various grassland types protected under the Habitats’ Directive, such as calcareous grassland, Nardus grassland, Molinia grassland, lowland and upland hay meadows was recorded as unfavourable in most regions.

What are Article 17 Reports?

Article 11 of the Habitats Directive 1992 requires EU member states to monitor the habitats and species listed in the annexes (habitats in Annex I and species in Annexes II, IV and V of the Habitats’ Directive), and Article 17 requires a report to be sent to the European Commission every 6 years following an agreed format. The core of the ‘Article 17’ report is the assessment of the conservation status of the habitats and species targeted by the directive.

Article 17 reporting covers the habitats and species in the whole territory of the Member State concerned, not only those within Natura 2000 sites.

Conservation status is assessed using a standard methodology as being either ‘favourable’, ‘unfavourable-inadequate’ and ‘unfavourable-bad’, based on four parameters as defined in Article I of the Directive. The parameters for habitats are range, area, structure and functions, and future prospects. For species, the parameters are range, population, habitat of species and future prospects. The conservation status of each habitat and species is assessed separately for each biogeographical or marine region in which it occurs (https://www.eionet.europa.eu/etcs/etc-bd/activities/reporting/article-17).

Why is Action Needed?

The main problem lies with the condition of habitats. The prevalence of threats to grasslands described in the Article 17 reports show that abandonment of grassland management (no grazing or cutting of vegetation) is the chief threat, with 385 mentions in the reports. The second most prevalent is mowing or cutting of grasslands at 254 mentions, followed by overgrazing (240), natural succession resulting in change in the species present (148), use of chemicals to protect certain agricultural plants (111), afforestation (110), conversion from one type of farming use to another (87), conversion from other land uses to housing, settlement and recreational use (78), use of synthetic fertiliser on farmland (76), collection of wild plants and animals (72) and conversion to other forest types including monocultures (70). This information is derived from EU member state reports, so the causes of decline and the improvement steps needed are known. This needs to start in protected areas and in the new protected areas.

Solutions to be tailored to Species’ Habits

Simona Bonelli, from the University of Turin, believes that butterfly experts across the continent have the data and scientific knowledge to identify new areas that require protection under the EU Biodiversity Strategy 2030 which aims to protect 30% of the land area of the EU. Often the current protected areas are too small, and not well managed. Such distribution data and knowledge of the needs of specialised butterflies (specialised butterflies are those with highly specific habitat needs) can be applied to expand protected areas for species like the Scarce Large Blue Phengaris teleius in northern Italy.

What about species that move in a landscape, such as the Southern Swallowtail Papilio alexanor, which is expected to move due to climate change? Bonelli suggests mapping likely future habitat and stepping stones likely to be used to reach this future habitat to ensure these areas are safeguarded.

For protected habitat specialist butterflies such as the Apollo Parnassius apollo that is currently well distributed in alpine areas in Italy, the approach being used is to calculate the Favourable Reference Value for the population to judge how many sites must be placed under protection. To calculate Favourable Reference Value, required viable population size or species-specific or habitat type-specific features such as habitat suitability or required area for proper functioning are considered. Such an approach has been described to protect the Apollo in the Italian Alps (Bonelli et al. 2021).

For rare endemic species, such as Sardinian Chalkhill Blue Polyommatus gennargenti, specific action plans are needed to cover issues such as monitoring population size, high-resolution distribution data and management of protected areas.

A further approach that can be applied in Ireland is the umbrella approach. Some habitats regarded as priority habitats under the EU Habitats’ Directive such as semi-natural dry grasslands (EU Habitat Code 6210) are species-rich. By identifying areas of this habitat containing endangered butterflies protected under the EU Habitats’ Directive, such as the Marsh Fritillary, a case can be made for including such areas within the enlarged protected areas required under the EU Biodiversity Strategy 2030. Protecting habitats for the Marsh Fritillary protects many other species, making the Marsh Fritillary an umbrella species.

For species that appear to have adequate protected areas but which are suffering from changes occurring in these areas, such as changing farming practices, we need to work to persuade farmers to adopt measures to protect the habitat. Beautiful, charismatic species like the Large Copper Lycaena dispar should be used to promote the protective practice, using funding from the CAP and other sources. Agricultural intensification is a great threat to this and many butterflies.

Large Copper, a beautiful species that can be used to publicise the need for conservation practices. Photo J. Harding.

The False Ringlet Coenonympha oedippus, a species in decline across the EU needs another approach. This species breeds in Molinia grasslands, and the larval foodplants are winter greens. The larva needs structured vegetation with leaf litter.  Populations are being lost from protected sites because of natural succession. Action plans need to be written with a clear management prescription.

Overall, Bonelli believes that management and monitoring (especially the use of citizen science), as well as protection from damaging activities are key to butterfly recovery. The approach she suggests is integrating the Butterfly Monitoring Scheme with specific guidelines for monitoring species listed in the Habitats’ Directive (in Ireland’s case, the Marsh Fritillary, currently under-monitored here). This approach requires working with citizen scientists and experts.

Conclusion

While Butterfly Conservation Ireland, the Irish Peatland Conservation Council and the National Biodiversity Data Centre monitor the Marsh Fritillary, we simply do not have enough transects (fixed-route walks carried out annually) to monitor this butterfly. A serious effort to apply the Favourable Reference Value to assess the Marsh Fritillary’s populations in important landscapes, like the Burren, Sheskinmore and Ballydermot in County Kildare, should be used by the state to increase the protected areas that Ireland needs to pledge to the EU by the end of 2022 to help to address the biodiversity crisis afflicting our world.

While the measures proposed by Simona Bonelli would be very welcome if applied these are not adequate to protect butterflies and biodiversity across the European landscape. Most of our landscapes will not be strictly protected and even strictly protected areas will not necessarily benefit from these measures in the absence of much wider changes in how society operates. Pollution is playing a major role in biodiversity loss. The harm caused by atmospheric nitrogen deposition, raised CO2 levels, is now being studied.

Of interest are the findings in a German study by Habel et al. (2015) entitled Butterfly community shifts over two centuries. This looked at the impact of atmospheric nitrogen loads and climate change over the period 1840-2013. The study found that high rates of atmospheric nitrogen deposition (from exhaust emissions, the burning of fossil fuels, wood, industrial incineration and the application of nitrate fertilisers) change nutrient-poor ecosystems, resulting in the replacement of plants in nutrient-poor habitats with plants that enjoy soils enriched with nitrogen. This results in butterflies that depend on nutrient-poor habitats, such as limestone grassland and heathland, disappearing, leaving a smaller number of butterfly and moth species that are adapted to plants containing high nitrogen levels.

The study further suggests that while habitat generalists (like the Peacock) have benefited from increasing temperatures, habitat specialists have been negatively affected by increasing temperatures and rainfall. These effects may be explained by increased vegetation growth rates triggered by the combination of increased moisture, temperature, and atmospheric nitrogen. Greatly increased vegetation growth may also explain the apparently paradoxical situation that heat-loving species are declining in response to increased temperatures. However, higher vegetation growth rates, fostered by the combination of increasing plant nutrients, precipitation, and higher temperatures may produce a cooler and more humid microclimate close to the soil. The environment just above the soil is of particular importance in the development of the larvae of many butterfly species, including the Small Heath and Wall Brown. Eeles (2019) reports elevated levels of carbon dioxide which increases larval development times as another possible reason for the decline in the Small Heath.

The Small Heath is a widespread butterfly across Europe and attention is mostly focused on much less widespread species that are judged to require special protection. However, the decline in widespread grassland butterflies should set the alarm ringing, the proverbial canary in the mine. Unless the drivers of climate change are tackled, no amount of site protection will save our biodiversity.

The full Butterfly Conservation Europe event held on 29th March 2022 to discuss butterfly conservation across the European Union can be accessed at https://www.youtube.com/watch?v=D1PUk__cO_o&t=2175s

References:

Eeles, P. (2019) Life Cycles of British & Irish Butterflies. Pisces Publications, Berkshire.

Bonelli, S.,  Barbero, F.,  Zampollo, A.,  Cerrato, C., Genovesi, P.,  La Morgia, V., (2021) Scaling-up targets for a threatened butterfly: A method to define Favourable Reference Values, Ecological Indicators, Volume 133, 2021, 108356, ISSN 1470-160X, https://doi.org/10.1016/j.ecolind.2021.108356

Habel, J., Segerer, A., Ulrich, W., Torchyk, O., Weisser, W., and Schmitt, T., (2015). Butterfly community shifts over two centuries. Conservation Biology, Volume 30, No. 4, 754–762, accessed 28 December 2020, https://conbio-onlinelibrary-wiley-com.jproxy.nuim.ie/doi/epdf/10.1111/cobi.12656

Hallmann CA., Sorg M., Jongejans E., Siepel H., Hofland N., Schwan H., et al. (2017) More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLoS ONE 12(10): e0185809. https://doi.org/10.1371/journal.pone.0185809