cynthiaBulletin of the Catalan Butterfly Monitoring Scheme 2017/2018 - no. 15

Cover fer open areas such as meadows and pastures. to help improve our understanding of the ten- Yet, our long-term monitoring reveals that dencies in butterfly populations throughout Detail of the under side of the upper-wing of over 70% of the CBMS itineraries are being Catalonia, Andorra and the Balearic Islands. Striped Grayling, Hipparchia fidia (photo: Jordi affected by scrub encroachment, chiefly due The available annual series are shown in fig- Jubany) to the abandoning of grazing, which is having ure 3. Of the 154 stations that in one year or severe effects on our butterfly numbers. Due another have been active, there are 60 (39%) Black-veined White, Aporia crataegi, resting on to this process, almost 5% of the butterflies that have generated 10 or more years of data, Field Scabious Knautia arvensis (photo: Oriol monitored along our itineraries have become and 31 with 15 or more years of results. To Massana) extinct locally. Moreover, this problem affects date, during the 25 years of the project, we both protected and unprotected areas, which have gathered data on butterfly populations suggests that our nature reserves are not being from 36 Catalan counties, eight sites in Andor- managed correctly even though, supposedly, ra and seven in Menorca, Mallorca and Eivissa. Editorial the conservation of the biodiversity is one of their fundamental objectives. It is thus urgent New stations The closing-up of habitats and the to change current management strategies in Besòs-Montcada (CBMS-148, Vallès Occiden- loss of butterflies in Catalonia many of our landscapes to prevent the decline tal, 39 m). An itinerary 1522 m in length with of our butterfly communities and of those of eight sections that runs partially alongside the his fresh edition of Cynthia once again cor- other insects from becoming even more severe. river Besòs in the municipality of Montcada Tresponds to the results from two CBMS i Reixac. Despite being a fairly heavily de- seasons, namely 2017 and 2018. And, once graded area near the Barcelona conurbation, again, we are in a position to award ourselves a it possesses a notably diverse community of pat on the back since our network of butterfly The CBMS and BMSAnd network butterflies. During the first two years of walks, walks is still growing and counts are currently a total of 54 species were observed, some of being made at over 90 sites. To a large extent Situation of the Butterfly which are abundant and well established this increase is due to the incorporation of Monitoring Scheme in Catalonia, (e.g. Southern Gatekeeper (Pyronia cecilia), the so-called ‘low-effort’ stations that has en- Andorra and the Balearic Islands in Spanish Gatekeeper (P. bathseba) and Iberian abled us to include areas of difficult access and the years 2017 and 2018 Marbled White (Melanargia lachesis)). Other spread the network of stations further into the highlights include scarcer species found here Pyrenees. During the twenty-forth and twenty-fifth at surprisingly low altitude and so near Bar- During these two years interest has also years there were, respectively, 94 and celona: Green-underside (Glaucopsyche alex- grown in butterfly communities and their 93 active stations in the CBMS-BMSAnd is) and Escher’s (Polyommatus escheri) Blues, tendencies in areas where ecologically sustain- networks, the highest number ever. In Provence Hairstreak (Tomares ballus), Black- able agriculture is practiced. Thus, we now all, 13 new stations were established, two veined White (Aporia crataegi), Peacock (Aglais have three stations in vineyards in the Penedès in El Ripollès and three in Alt Penedès, io), Marsh Fritillary (Euphydryas aurinia) and wine-growing region where the producers are two counties that up to 2017 were not Small (Coenonympha pamphilus) and Dusky interested in ensuring that their viticulture is represented in the network. During (C. dorus) Heaths. Another interesting species compatible with the maintenance of a rich and these two seasons, 346,409 butterflies that has appeared in the counts is Mediterra- varied biodiversity. As well, at Sincrotró Alba belonging to 175 species were counted. nean Skipper (Gegenes nostrodamus), a migrant in the Parc de l’Alba technological centre in skipper that has increased in number signifi- Vallès Occidental, butterfly counts are used to n 2017, counts were made at 94 stations, cantly in Catalonia in recent years. The counts test whether or not site management benefits Iwhilst in 2018 there were 93 active itin- are carried out voluntarily by Juli Mauri and insect communities. This concern for guaran- eraries (fig. 1). The number of stations has Albert Lleal. teeing that agricultural practices are compat- increased significantly over these two seasons Sant Quintí de Mediona (CBMS-149, Alt ible with the conservation of the biodiversity (fig. 2) and there are now 10 more butterfly Penedès, 431 m). A low-effort itinerary that is fruit of a long series of studies that indicate walks than in 2016. This increase is largely was walked monthly in 2017 but in 2018 was that recently there has been an alarming de- due to the incorporation of low-effort stations, walked fortnightly. This itinerary and that of crease in faunal abundances (including polli- where counts are made fortnightly rather than Torrelavit are funded by Caves Recaredo as nators) in European agricultural habitats, in every week. The development of a more robust part of a project to analyse the biodiversity particular in intensive systems. methodology for estimating species abun- of its terrains and vineyards. At Sant Quintí Other, very different changes at landscape dances2 encouraged us to incorporate into the vines are managed biodynamically in or- scale are also negatively affecting Catalan but- the network these easier to fulfil itineraries. der to preserve the biodiversity and conserve terfly populations. In the section Habitat man- As a result, we have been able to cover areas the traditional landscape mosaic that consists agement and conservation, we present a study in counties such as El Ripollès, Alt Penedès of semi-natural fragments of habitat mixed in that was recently published in the journal In- and Anoia that to date had been very poorly with the vineyards. The itinerary is 1230 m sect Conservation and Diversity that quantifies prospected, and also to recover certain stations in length and has 10 sections, which include for the first time the impact of forest and scrub with poor access (e.g. Turó de l’Home on the vineyards (a young and mature one), margin- encroachment. Thanks to the vegetation data summit of the mountains of El Montseny). al land (along field edges and tracks), olive collected along our itineraries, we have been Thus, we have exceeded the threshold of 90 groves and semi-natural habitats (thyme scrub able to show that 90% of our butterflies pre- stations and so can count on more robust data and patches of grassland). The sampling effort, II Cynthia

initially monthly but subsequently fortnight- itinerary in the county of Anoia. It is located and de Prunner’s (E. triaria)), along with other ly, has detected 60 species to date. The itin- in an area that previous prospections had indi- upland species that are poorly represented in erary’s butterflies are dominated by generalist cated that there would be a notable diversity the CBMS network such as Chestnut Heath species such as Small (Pieris rapae) and Bath of butterflies. The monthly sampling in 2017 (Coenonympha glycerion), Purple-edged Cop- (Pontia daplidice) Whites, Common Blue (Pol- gave a total of 56 species and the greater effort per (Lycaena hippothoe), Turquoise (Polyomma- yommatus icarus) and Clouded Yellow (Colias in 2018 increased the number of species de- tus dorylas) and Mazarine (Cyaniris semiargus) crocea). Nevertheless, a number of interesting tected to 65. This itinerary is 1700 m long and Blues, and Olive Skipper (Pyrgus serratulae). butterflies have appeared that indicate that the has eight sections. It mainly runs through an The counts are carried out by Mike Lockwood area and its biodiversity are worthy of con- agricultural mosaic with fragments of wood- and Jordi Artola, and are backed financially by servation. Examples of these species include land mixed in with grassland and arable land. the owner of the Catllar Estate. Berger’s Clouded Yellow (Colias alfacarien- Worthy of note is the abundance of ‘Blues’, Raixa (CBMS – 155, Mallorca, 150 m). sis), Black-veined White (Aporia crataegi), including Escher’s (Polyommatus escheri), This itinerary is situated in the mountains Provence Chalkhill (Lysandra hispana), Pano- Small (Cupido osiris), Adonis (Lysandra bellar- of Serra de Tramuntana on Mallorca and is ptes (Pseudophilotes panoptes) and Chapman’s gus), Provence Chalkhill (Lysandra hispana), the first CBMS walk on this island. It was (Polyommatus thersites) Blues, Spotted Fritil- Green-underside (Glaucopsyche alexis) and begun in 2012 and although it was not offi- lary (Melitaea cinxia), Gatekeeper (Pyronia ti- Black-eyed (G. melanops) Blues, and Provence cially incorporated into the CBMS network thonus), Dingy (Erynnis tages), Small (Thymel- Hairstreak (Tomares ballus), amongst others. until 2018, the data from the initial seven icus sylvestris) and Mediterranean (Gegenes Rare species such as Marbled (Carcharodus lav- years of counts have been entered into the nostrodamus) Skippers. Of particular interest is atherae) and Mediterranean (Gegenes nostroda- CBMS database. In all, 22 of the 25 species the presence of species that are more central mus) Skippers have also appeared. The counts of butterfly known from Mallorca have been European in character, normally very scarce are carried out by José Manuel Sesma. detected, which is a similar figure to the or absent from Mediterranean environments, Setcases (CBMS-153, Ripollès, 1434 m). counts performed on the island of Menorca. such as Gatekeeper, Small Skipper and Black- Along with the Tregurà itinerary, this butterfly Small Heath (Coenonympha pamphilus) and veined White. The counts are carried out by walk is the first CBMS station to be active in Cleopatra (Gonepteryx cleopatra) fly in large Andreu Ubach. El Ripollès, one of the most diverse counties numbers, and are accompanied by the African Torrelavit (CBMS-150, Alt Penedès, 269 for butterflies in the whole of Catalonia. The Common Blue (Polyommatus celina), which m). This itinerary is very close to that of Sant itinerary, with 10 sections, runs through the replaces the more familiar Common Blue on Quintí in the Caves Recaredo estate. It is like- bottom of the valley of the Ribera del Catllar, a the Balearic Islands. Speckled Wood (Pararge wise managed biodynamically but in terms of private estate in the environs of the Capçaleres aegeria) is the commonest species and in sum- its biodiversity it is clearly poorer than Sant del Ter i del Freser Natural Park. This itinerary mer Southern Gatekeeper (Pyronia cecilia) is Quintí due to the type of agriculture that is is part of a project monitoring different taxo- particularly abundant. The counts are carried practiced there, the landscape and the fact that nomic groups in the estate and runs through out by Matilde Martínez. it lies at less altitude and so enjoys a hotter pasture, small partially forgotten hay meadows La Manresana (CBMS – 156, Anoia, 649 microclimate. It is a short itinerary, just 1003 and stretches of riparian and deciduous wood- m). This itinerary lies in the municipality of m, and has seven sections. It includes mature land. It has been walked fortnightly since it Prats de Rei in an area of the Central Cata- vines, more or less vegetated waysides, and started in 2017 and in total 67 species were lan Depression that has been poorly surveyed Aleppo pinewoods. In two years of counts counted in the first two years. The microcli- to date and so fills in a territorial gap in the only 36 species have been recorded. General- mate of this valley is very humid and certain CBMS network. In 2018 it was walked fort- ist species are predominant – e.g. Small (Pieris species that are particularly associated with nightly and in all 48 species were recorded rapae) and Large (Pieris brassicae) Whites and wet central European climates are here highly in a mixture of habitats including Mediter- Wall Brown (Lasiommata megera) – but there abundant. The most obvious example is the ranean grassland, evergreen and deciduous are also typical Mediterranean species such as exceedingly abundant The Ringlet (Aphan- woodland, and rocky limestone outcrops. Striped Grayling (Hipparchia fidia), Spanish topus hyperantus), which flies alongside good Holm-oak formations are common, along Gatekeeper (Pyronia bathseba), Cleopatra (Go- numbers of Green-veined White (Pieris napi), with open grassland with annual plants. Small nepteryx cleopatra), and Spanish Brown Argus Speckled Wood (Pararge aegeria), Pearly Heath White (Pieris rapae) is highly abundant along (Aricia cramera). Unlike Sant Quintí, at Tor- (Coenonympha arcania), Comma (Polygonia with Green-veined White (P. napi). Here relavit there are very few local or scarce species, c-album) and Scarce Copper (Lycaena virgau- too fly species that are typical of both Med- although Black-veined White (Aporia cratae- reae). Otherwise, there are many of the but- iterranean areas and the Central Depression gi), Woodland Grayling (Hipparchia fagi) and terflies found commonly in the Eastern Pyre- such as Provence Chalkhill Blue (Lysandra Panoptes Blue (Pseudophilotes panoptes) are all nees that are poorly represented in the CBMS hispana) and Large Tortoiseshell (Nymphalis present. The counts are carried out by Andreu network: False Heath (Melitaea diamina) and polychloros). Also of note are the populations Ubach. Pearl-bordered (Boloria euphrosyne) Fritillaries, of Lesser Spotted Fritillary (Melitaea trivia) Castelltallat (CBMS-151, Bages, 780 m). Turquoise Blue (Polyommatus dorylas), Duke and Woodland Grayling (Hipparchia fagi), as A low-effort itinerary in the county of Bag- of Burgundy (Hamearis lucina), Tufted Mar- well as the scarce Marbled Skipper (Carcharo- es within the Serra de Castelltallat protect- bled Skipper (Carcharodus floccifera) and Pur- dus lavatherae). The counts are carried out by ed area. This long itinerary runs for 2062 m ple Emperor (Apatura iris), amongst others. Quim Muñoz. and has nine sections. It runs through, above The counts are carried out by Mike Lockwood Conca del Bitlles (CBMS – 157, Alt Pe­ all, a forested landscape including a series of and Jordi Artola, and are backed financially by nedès, 202 m). This walk is situated in the open spaces that guarantee greater diversity. the owner of the Catllar Estate. municipality of Torrelavit in the heart of the In 2017, irregular sampling gave 52 species, a Tregurà (CBMS-154, Ripollès, 1842 m). Penedès wine-growing country. It has eight number that increased to 69 in 2018 with the This second itinerary in the valley of El Catllar sections that run through marginal land, Med- beginning of the fortnightly walks. Two very samples a subalpine environment. Apart from iterranean grassland, scrub and Aleppo pine- common species here are Provence Chalkhill the Andorran itineraries, this is the highest but- woods on the edge of the vineyards owned by Blue (Lysandra hispana) and Marsh Fritillary terfly walk in Catalonia, which confers added Segura i Viudas. It samples somewhat differ- (Euphydryas aurinia) but there are also good value to its data. The walk is 1286 m in length ent environments from the other local walk numbers of local species that are declining and has 12 sections that run along the edge of (Torrelavit; CBMS-150) that takes its name in Catalonia such as Berger’s Clouded Yellow a pine plantation and the basal part of a large from the municipality. At Conca del Bitlles (Colias alfacariensis), Dingy Skipper (Erynnis area of subalpine pasture. The final section also the walk passes through tall grassland, thickets tages) and Ripart’s Anomalous Blue (Polyom- crosses a steep gully. A total of 65 species have with Mediterranean coraria, and open pastures matus ripartii). The counts are carried out by been detected in the two years that it has been dominated by the grass Oryzopsis paradoxa. In Josep Planes. walked, with a very complete representation of 2018 48 species were recorded, which situated Conca d’Òdena (CBMS-152, Anoia, 393 subalpine species including five ringlets (Large this itinerary midway between those of Sant m). This low-effort itinerary is located in the (Erebia euryale), Piedmont (E. meolans), Pyrene- Quintí de Mediona and Torrelavit. The typi- municipality of Òdena and is the first CBMS an Brassy (E. rondoui), Mountain (E. epiphron) cal ‘Whites’ found in agricultural areas such as Cynthia III

Large (Pieris brassicae), Small (Pieris rapae) and cies it is also worth highlighting Mediterrane- been recorded very occasionally in Catalonia Bath (Pontia daplidice) Whites are common, an Skipper (Gegenes nostrodamus). The counts and as such do not maintain stable popula- while the Aleppo pinewoods boast important are carried out by Andreu Ubach. tions here. populations of Striped (Hipparchia fidia) and Els Foquers (CBMS – 160, Osona, 541 In the past two years a single new species, even Tree (Hipparchia statilinus) Graylings. m). This itinerary in the municipality of Tav- Alpine Grizzled Skipper (Pyrgus cacaliae), re- The presence of Panoptes Blue (Pseudophilotes èrnoles, walked and organized by the Osona corded on the Pessons itinerary in Andorra at panoptes) in the thyme scrub contrasts with Naturalists Group, is of great interest. It runs an altitude of 2,280 m, has been added to the the population of Comma (Polygonia c-album) through a series of different montane habi- CBMS list. in the woodland along the stream. Other no- tats in eight sections. The vegetation consists table species include the more Central Euro- of a great abundance of Mediterranean and Constantí Stefanescu and Andreu Ubach pean Glanville Fritillary (Melitaea cinxia) and more upland open spaces with abundances of the here rare Blue-spot Hairstreak (Satyrium blue aphyllanthes and grasses, dry and more For references, see the original Catalan version. spini). The counts are carried out by Ricard humid field margins, thickets with Mediter- Pintado. ranean coraria, downy oak woodland, and Fig. 1. Geographical situation of all the stations Sant Miquel del Fai (CBMS –158, Vallès arable fields. In the first year 82 species were that have ever participated in the CBMS (1994-2018) network, with their official number and name. Also Oriental, 544 m). This low-effort itinerary in registered, which makes it the second most shown are the generally accepted boundaries of the the municipality of Sant Quirze Safaja lies in species-rich itinerary in the CBMS network. biogeographical regions present in Catalonia.1 an estate belonging to the Barcelona Provin- Mediterranean and upland species are found cial Council at the confluence of the rivers alongside each other and there are significant Fig. 2. Evolution in 1994–2018 of the number of active Rossinyol and Fai in a protected area known populations of both Pearly Heath (Coenonym- stations in the CBMS network. as Els Cingles de Bertí. It runs through an pha arcania), the walk’s most abundant spe- Fig. 3. Distribution of the complete annual upland Mediterranean landscape in the Cat- cies, and Small Heath (C. pamphilus). Here series available for all the stations that have ever alan Pre-Littoral mountains and samples open too we find the CBMS’s largest population of participated in the project. Also included are data rocky areas, scrub dominated by honeysuck- Berger’s Clouded Yellow (Colias alfacariensis) from the stations of Rubina and Vilaüt, active in 1988 le, thyme and rosemary, and taller formations and abundant Adonis Blue (Lysandra bellar- and 1989, respectively before the official start of the with abundant strawberry-trees. In total, there gus). The ecological contrasts present in the CBMS counts. are eight sections that possess a great diversity area are reflected by the populations of both Fig. 4. Number of species of butterfly detected in each of butterflies as shown by the 77 species re- Panoptes Blues (Pseudophilotes panoptes) and year of the CBMS counts. corded in the first year, 2018, alone. Of note one the CBMS’s best populations of Spanish are the high indices of declining species such Festoon (Zerynthia rumina), but also species Table 1. All the butterfly species recorded from any of as Provence Chalkhill Blue (Lysandra hispana). with very different ecological requirements the CBMS stations in the 10-year period 2009–2018. The Mediterranean environment and the such as Autumn Ringlet (Erebia neoridas) and Also indicated is the number of stations at which plants that grow there help sustain good pop- Map Butterfly (Araschnia levana). Up to four the species was recorded each year. Taxonomic order follows the criteria suggested by Fauna Europaea ulations of Marsh Fritillary (Euphydryas aurin- species belonging to the genus Satyrium fly (www.fauna-eu.org). ia), while the abundance of strawberry-trees here due to the plant diversity that is present. ensures good numbers of Two-tailed Pasha Other rare species found here include Brown Photo 1. Vineyards are an important part of the (Charaxes jasius) and the probably under-de- Hairstreak (Thecla betulae), Marbled Skip- landscape of the Torrelavit, Sant Quintí de Mediona tected Chapman’s Green Hairstreak (Callo- per (Carcharodus lavatherae), Tufted Marbled and Conca del Bitlles itineraries. Here fly many Pieridae throughout the season, with Bath White phrys avis). Section 1 passes along the bed of Skipper (Carcharodus flocciferus), Marbled Fri- especially common in its autumn generation. The the river Rossinyol and is territory for various tillary (Brenthis daphne) and Duke of Burgun- photo shows section 1 of the Torrelavit itinerary with Nymphalidae including Large Tortoiseshell dy (Hamearis lucina). The counts are carried mature vines (Photo: A. Ubach). (Nymphalis polychloros), Comma (Polygonia out by Martí Franch, Alba Puntí, Carles Mar- c-album), Southern White Admiral (Limenitis torell and Jordi Faus. Photo 2. The bed of the river Rossinyol at Sant reducta) and Lesser Purple Emperor (Apatura Miquel del Fai is perfect habitat for the males of many Nymphalidae, including Speckled Wood ilia). Some of the rarer species observed in (Pararge aegeria), Southern White Admiral (Limenitis 2018 included Marbled Skipper (Carcharo- Species present reducta), Marsh Fritillary (Euphydryas aurinia), dus lavatherae), associated with woundworts In the 2017 season 168,336 butterflies were Large Tortoiseshell (Nymphalis polychloros), Stachys sp., and Blue-spot Hairstreak (Satyri- counted belonging to 173 species, whilst in Comma (Polygonia c-album) and Camberwell Beauty um spini). The counts are carried out by An- 2018 178,073 butterflies were counted be- (Nymphalis antiopa), amongst others (Photo: A. Ubach). dreu Ubach. longing to 164 species. The number of species Sincrotró Alba (CBMS – 159, Vallès Oc- detected in these two years is above the year- Photo 3. The Foquers itinerary is full of ecological cidental, 109 m). This low-effort itinerary is ly average of 163.2 species for 2006–2016, contrasts and while the more Mediterranean areas are walked in the Parc de l’Alba as part of project which corresponds to the years that the An- home to Panoptes Blue (Pseudophilotes panoptes) and designed to monitor the biodiversity of this dorran stations were fully operational and in Spanish Festoon (Zerynthia rumina), in other parts of industrial estate in Cerdanyola del Vallès. It the itinerary fly Autumn Ringlet (Erebia neoridas) and which most of the upland Pyrenean species Map Butterfly (Araschnia levana) (Photo: J. Faus). is a lowland Mediterranean area dominated have been recorded. The 173 species detected by waste ground, scrub and Mediterranean in 2017 is the highest ever annual total for the Photo 4. Large Ringlet (Erebia euryale) only appears grassland surrounded by a large area of cere- CBMS network in its 25 years of history (fig. in eight itineraries, all of them in the Pyrenees. The al crops. It has nine sections and in 2018 41 4). This was made possible by the incorpora- Tregurà itinerary has the highest annual indices for species appeared, including good populations tion of the low-effort stations, as commented this species and its counts have revealed that this of generalist species found in these ruderal en- ringlet has a biennial life cycle; in 2017 it was frequent on above but in 2018 none were observed (Photo: J. Corbera). vironment such as Spanish Brown Argus (Ari- The list of butterflies detected over the past cia cramera) and a number of other generalist 10 years is given in Table 1. Up to 2016, 188 Drawing 1. The new itineraries in El Ripollès provide Lycaenidae. However, there are also popula- species had been recorded in the CBMS net- very valuable data on the Duke of Burgundy (Hamearis tions of Green-underside (Glaucopsyche alexis) work out of a total of 201 species known from lucina), an uncommon species with very strong and Black-eyed (Glaucopsyche melanops) Blues, Catalonia. This figures represents 93.5% of populations in El Catllar. This butterfly is a true habitat specialist, establishing a close association while a plantation of mixed scrub species en- all Catalan species, which gives some idea of with the plants in the genus Primula (Drawing: M. courages the presence of Black-veined White how exhaustive this network is. Currently, it is Franch). (Aporia crataegi) due to the hawthorns that no exaggeration to say that the CBMS counts grow there. Also of note along the stream that gather data on over 80% of Catalan butterflies. coincides with sections 2–4 is the presence of The few species that have not yet appeared Lesser Purple Emperor (Apatura ilia), a species in the CBMS counts are essentially very local that is becoming commoner in this part of species that fly only in the very highest areas Catalonia. Amongst the rare but present spe- of the Pyrenees, or ones which have only ever IV Cynthia

the Ebro valley and, in August, the coast and Changes in abundance: Twenty-fourth and twenty-fifth years pre-coastal areas. There were remarkable hot fluctuations in populations of the CBMS spells in January, a short but intense heat wave The 20 commonest species at the network’s in April, heat throughout all of July, a true heat counting stations in the 2017 and 2018 sea- Balance of the 2017 and 2018 wave in August, and abnormally high temper- sons are shown in Table 1. After many years seasons atures in September. of low numbers, the False Ilex Hairstreak (Sat- Yet, the most remarkable aspect of the 2018 yrium esculi) in 2018 once again became the The year 2017 saw a notable recovery weather was the rainfall: more than half of dominant butterfly in the counts. At some in Catalan butterfly populations after Catalonia’s counties registered over 1000 mm stations there were spectacular increases in its the historically poor year of 2016. In of rain and in some normally dry areas the to- numbers, to the extent that in total 22,144 general, numbers remained constant in tal annual rainfall was the highest since records individuals were counted, almost double the 2018, although this was not due to stable began. Almost nowhere was spared and only number of the second commonest species, the populations but, rather, to a combination the Ebro Delta and the Alt Empordà plain Small White (Pieris rapae). These demograph- of significant increases in inland and failed to exceed the average rainfall for the ic explosions are related to the exceptional montane areas and declines in coastal period 1961–1990. The wettest months were sprouting of holm oaks in spring when the lar- and Pyrenean zones. The high rainfall January and February, and, particularly, Octo- vae are feeding, a phenomenon that has been in 2018 benefitted species such as False ber–November, all outside the CBMS count- observed in previous years when this hairstreak Ilex Hairstreak (Satyrium esculi) and ing period. The areas that received most rain was also the commonest species in the CBMS Meadow Brown (Maniola jurtina) but, were inland in the northeast, the western Pyr- network. The Purple Hairstreak (Favonius exceptionally, the heavy rains in the enees and the mountains of Ports de Tortosa. quercus), another Lycaenidae with a similar Pyrenees were too abundant to allow In 2017 and 2018 6.35 and 6.22 counts, biological cycle that also feeds on oaks, under- most species to complete their life cycles respectively, were lost on average per station, went a similar increase in 2018 and reached its uninterruptedly. Even so, despite the although these figures include the ‘low-effort’ second-highest ever annual total. Nevertheless, improvement compared to 2016, both stations where transects are only walked every as a species that is much harder to detect, only 2017 and 2018 are still amongst the six fortnight (figs. 1a,b). If these stations are ex- 1542 of this latter hairstreak were recorded. worst years for butterfly abundances cluded, the averages were 4.06 and 4.51, re- The abundant spring rain also favoured since the CBMS counts began. spectively, that is, 13–15% of the possible many Satyrinae, whose larvae depend on counts. Due to the adverse weather conditions, spring grasses. After a number of years in Weather and counts more counts were lost at the stations with which this group had declined notably, there weekly counts, above all in spring when rain- The year 2017 was hot and dry reflecting the were high counts of Meadow Brown (Maniola fall spread across much of the country (figs. climate change affecting our country since the jurtina), which reached its second-highest ever 2a,b). Particularly significant was the rain that 1980s. Indeed, this year ended with a ther- numbers, Great Banded Grayling (Brintesia fell during the last week of April 2017 (week mal anomaly of over 0.5ºC compared to the circe), and a recovery in the numbers of both 9), when counts were lost at almost 50% of average for 1961–90 in practically the whole Iberian Marbled White (Melanargia lachesis) all stations. country (see www.meteocat.com). It was espe- and Pearly Heath (Coenonympha arcania), cially marked in montane areas of the northern whose numbers had declined enormously in half of Catalonia and on the coast of Tarragona Changes in abundance: overview recent years (Table 2). (e.g. Baix Ebre), where positive anomalies ex- The 2017 and 2018 seasons were poor in terms It is also worth noting that these were re- ceeded 1.5ºC. Seasonally, the months of June of the commonest butterflies and both can be markable years for two species, Nettle-tree (exceptionally so), February and March were included amongst the six worst-ever seasons Butterfly Libythea( celtis) and Cleopatra (Go- very hot, as were, to a lesser extent, August of the 25 years of the CBMS (fig. 3). Even nepteryx cleopatra), that were commoner than and October. Heat waves were associated with so, these two years were an improvement on in any other year since the CBMS counts be- the entry of winds from Africa, for example 2016, the worst-ever year of counts. In all, gan. Curiously, both hibernate as adults and on March 9–11, May 24–28 and June 10–28 counts were performed at 78 stations in both so it is possible that the significant increases in (with only June 2003 hotter), odd days in July 2016 and 2017, with a significant increase their numbers was due to especially propitious and, above all, the extreme heat of August 1–5, in the number of butterflies per station from winter conditions for hibernating adult butter- comparable to the exceptional temperatures of 1471.1 ± 1132.0 (mean ± standard deviation) flies. On the other hand, these increases could July 2015. Thus, most of the CBMS stations to 1859.7 ± 1392.3 (Student t-test for paired simply be the reflection of a steady increase in were affected by abnormally high temperatures samples, P < 0.001). This increase also oc- numbers, as the significant positive tendencies in 2017. curred amongst the number of species per sta- in their populations during the study period In terms of rainfall, 2017 was dry, the only tion, with values that rose from 44.14 ± 17.5 would seem to indicate (Table 2). exception being certain areas of the Pyrenees to 45.41 ± 17.19 (P = 0.031). Finally, another exceptional year was that of (e.g. Pallars Sobirà and Vall d’Aran). The It is worth remarking that the similar val- the Red Admiral (Vanessa atalanta) in 2017, drought hit hardest in the Ebro Delta and part ues for 2017 and 2018 are not a reflection of when one of the strongest autumn migrations of the Costa Daurada, although much of the the stability of butterfly populations in the of this Nymphalidae since counts began was pre-Pyrenees and the whole north-east of the latter year but, rather, the overall outcome of recorded. Most of the migrant population ar- country saw 50–70% less rain than the average a series of rises and falls in numbers, in some rived in October, outside the official CBMS for 1961–90. After a fairly rainy March every- cases well-marked, with a clear geographical counting period, which lessened its impact where, the rest of the year was dry, above all bias. Thus, in many stations in low-lying and on the counts of this species. Even so, the in November and December. The drought also montane areas there were notable increases in annual index for Red Admirals in 2017 was became very apparent in April, May and June. numbers in 2018, in part due to demographic the third-highest ever in the past 25 years. All in all, this lack of rainfall and the high explosions of False Ilex Hairstreak (Satyrium However, the situation was reversed in 2018 temperatures gave rise to a serious drought, in esculi) and Meadow Brown (Maniola jurtina), and its numbers fell to the third-lowest ever particular in the spring. possibly due to the optimum state of their food since counts began. The other typical migrant The year 2018 was very different and, -de plants after the abundant rains. By contrast, in Nymphalidae, the Painted Lady (Vanessa car- spite being characterized by significant rain- the county of Alt Empordà, along the coast dui), flew in average numbers in both 2017 fall, was still one of the seven hottest years of Tarragona and in many Pyrenean stations and 2018. since 1950. Temperature-wise, only February, there was a serious fall in butterfly numbers. Constantí Stefanescu March and May (in the CBMS season) were As mentioned above, the heavy rainfall failed cold, the remaining months being hot or even in many cases to reach coastal areas, while in For references, see the original Catalan version. very hot, for example in January along parts of the Pyrenees the rainfall was so abundant that the central coastline, western regions of Cat- the daily activity of butterflies was disturbed alonia, the southern pre-littoral mountains, and numbers were lower. Cynthia V

Fig. 1. Coverage of the counts at the different CBMS the tendencies at population level for butter- stations in (a) 2017 and (b) 2018. The ‘low-effort’ Habitat management and conservation flies preferring closed habitats were more pos- stations, which due to their fortnightly cycle (or itive or more stable than for those preferring monthly in initial trial years) lose a large number of Habitat loss due to vegetation the possible 30 counts, are also included. open habitats. Although such a species-based encroachment leads to changes analysis is useful for understanding how spe- Fig. 2. Distribution of the lost counts during the and local extinctions in butterfly cies are responding individually, a communi- official 30 weeks (1 March–26 September) of counts in communities ty-based analysis is even more useful for ex- (a) 2017 and (b) 2018. ploring changes occurring in the composition The abandoning of traditional of butterfly populations in the long term, and Fig. 3. Ranking of the CBMS seasons in terms of the general abundance of the 66 commonest butterflies in agricultural practices and the consequent for examining whether or not there are match- the CBMS network. The best season was 2002 (closely increase in forest mass is an important ing patterns occurring in landscape changes followed by 1995) and worst (in descending order) element in landscape change in the operating at a local scale.12-13 The objective 2016, 2015 and 2012. Calculations were carried out Mediterranean basin. CBMS data have thus is to provide conservation managers with using the methodology described by Greatorex-Davies been used to quantify the degree of a tool that will be useful for showing how rap- & Roy (2001) using species’ annual indices calculated with the TRIM programme. preference of 147 butterfly species for idly butterfly communities are responding to open or closed habitats, with most species forest encroachment. Table 1. Sum of the annual indices and ranking of the showing a very clear preference for open Currently, insects are declining in general abundance of the 20 commonest species in the CBMS habitats. We also recorded a process of world over and monitoring programmes per- network in the 2017 and 2018 seasons. encroachment in more than 70% of long- formed throughout Europe have revealed neg- monitored transects, which had strong ative tendencies that show that butterflies are Table 2. Evolution of the overall annual indices for 107 14 butterflies recorded in the CBMS network based on an effects on the composition of butterfly excellent grassland indicator species. Chang- arbitrary value of 1 for 1994. The annual indices were communities. 5% of the monitored es in land use linked to overgrazing and vegeta- calculated using the TRIM programme.2 Also indicated butterfly populations went extinct in tion encroachment have been linked to butter- are the number of stations that provided data for each the same period, with a significant fly declines and extinctions.11,15 Our intention species and the population trends detected by the bias towards the species preferring was thus to analyse whether or not butterfly programme. open habitats. This study thus confirms species that show a preference for open areas Photo 1. As seems to be usual in rainy springs, in the threat that this process poses for are more likely to undergo local extinctions, 2018 the False Ilex Hairstreak (Satyrium esculi) was butterfly diversity. and whether or not the degree of preference again the most abundant butterfly in Catalonia. Huge for open or closed habitats is a predictor of concentrations of this butterfly were recorded on population tendencies at local scale. flowering brambles and other preferred nectar sources in many itineraries (photo: J. Corbera). Introduction Material and methods Drawing 1. In 2018, many populations of the Nettle- Forest and scrub encroachment consists of the tree Butterfly, Libythea celtis, showed a spectacular invasion of open areas by woody plant species Study area and datasets 1 increase. Dozens of larvae and pupae were located on in the form of scrub and forest. Although For this study data from all CBMS stations up the nettle trees, and hundreds of adult butterflies of this is a worldwide phenomenon, it is taking the new generation were recorded at some pre-littoral to 2017 (154 stations) were used to develop place, above all, in developed countries where a specific index of preference in butterfly spe- sites (drawing: M. Franch). in recent decades it has become a key element 2-3 cies for open or closed habitats. For changes in Drawing 2. The two-tailed Pasha, Charaxes jasius, in habitat transformation. Its causes are populations, we used data from stations that showed opposite extreme counts in 2017 and well known and are principally related to the in the period 1997–2017 had generated data 2018. After reaching the highest levels ever in abandoning of traditional agricultural and ex- series of 10 or more years. 2017, populations collapsed in 2018, probably as tensive stock-raising activities but can also be a consequence of massive larval mortality during Preferences for open and closed habitats attributed to an increase in atmospheric CO2 abnormally cold February and March months (drawing: 1,4 Botanical characterization. The botanical char- M. Franch). levels and the suppression of forest fires. In the Mediterranean basin thousands of years of acterization of the CBMS transects carried anthropic pressure has encouraged a rich mo- out by Cèsar Gutiérrez since 2000 were used. saic of semi-natural grassland, agricultural land These characterizations take into account the and pastures that has drastically diminished in cover of each plant community as defined by recently years as the vegetation encroaches.5 the CORINE habitat classification16 along the Specifically, forest cover in Catalonia increased 5-m-wide butterfly transect. As well, a binary at a rate of 3,300 ha/year in 1987–2012, while classification was established assigning values in the same period the amount of agricultural to closed (-1) and open (+1) plant commu- land decreased by 6,300 ha/year.6 nities. All forests were classified as closed and Vegetation encroachment threatens biodi- grassland as open, whilst scrub and other types versity due to the fact that the conservation of of plant communities were classified accord- many species depends strictly on the survival ing to their height. Then, an average value for of open habitats.7 It causes declines in plant each individual section of the transect was cal- biodiversity and affects the composition of culated by multiplying the percentage of each plant communities, and leads to the fragmen- habitat type by its assigned score (-1 or +1). tation of semi-natural grasslands.1,8 The iden- Only indices with a total value over 0.1 were tification of biological indicators that respond taken into account in subsequent analyses to rapidly to this phenomenon is essential if we avoid using sections with a balance between are to understand these processes8, and the open and closed habitats. Annual butterfly close ecological links between butterflies and data were associated with the nearest year for their habitats makes them a highly relevant which a botanical characterization was avail- group for studying changes in habitat caused able. Botanical characterizations started in by the abandoning of traditional agricultural 2000 and are repeated every six years in each practices and vegetation encroachment.9-10 The transect to record changes along the monitor- CBMS database is thus an ideal tool for stud- ing route. ying changes in habitat structure occurring in The TAO index. A TAO (TAncat-Obert; Catalonia in recent decades. in Catalan tancat = closed, obert = open) A previous study11 determined habitat pref- index, developed using a formula described erences along a gradient of closed to open hab- in a previous article,17 allowed us to establish itats for butterflies and birds, and showed that a gradient of preference between -1 i +1 for VI Cynthia

open and closed habitats. To calculate the in- species suffering local extinctions had a prefer- this tendency can be seen by comparing trends dex of a species for a particular transect the ence for open habitats. in Speckled Wood (Pararge aegeria) and Mal- average densities (examples/100m) in open Finally, population tendencies at local level low Skipper (Carcharodus alceae) (fig. 3). sections and the average densities in closed were modelled in terms of the degree of vege- sections were calculated. The final index for tation encroachment in each transect and but- Discussion and conclusions each species is the average value of all the terfly species’ preferences for open or closed indices calculated for each transect in which habitats. A mixed model was constructed In this work we used data from both the the species in question has appeared. Only using 2,484 butterfly populations including CBMS and BMSAnd networks, a dataset that species flying in at least five transects with these two factors, as well as their interaction, is long enough to establish stable values for the sections classified either as open or closed with ‘itinerary’ and ‘species’ as random factors. habitat preferences of 147 species of butterfly, were used. the majority of which show a clear preference for open habitats. This preference indicates Results that they are highly sensitive to changes in Changes in habitat and tendencies in habitat caused by vegetation encroachment. In Preference for open or closed habitats butterfly communities the Mediterranean region the increase in forest We obtained the I index for a total of 147 Vegetation encroachment. The percentage change TAO cover has been described as one of the main occurring between the first and most recent bo- species of butterflies (fig. 1), with an average elements determining landscape change in re- tanical characterization for each transect was of 50 sites used to calculate this index. The cent decades.2,18 used to investigate changes in the vegetation mean value of the index was 0.408, with ex- Over 70% of the studied transects have along the monitoring route. Thus, the time treme values of -0.419 for Speckled Wood experienced some degree of vegetation en- scale of the study corresponds to 6, 12 or 18 (Pararge aegeria), whose preference was clearly croachment in the past two decades, which is years, depending on how many characteriza- for closed habitats (nº sites=117), and of 1 for illustrative of the importance of this phenom- tions have been conducted in the transect in Olive Skipper (Pyrgus serratulae), which was enon. This was matched by a parallel shift in question. An average closed/open value describ- only recorded in open habitats (nº sites=7). the TAO community index (TAOc) given that ing vegetation change was calculated for the The mean value for the group of species as a 76% of the analysed butterfly communities whole transect. The final values lie on a gradi- whole was highly positively skewed and in to- have tended to become dominated over time ent between -100 (a change towards complete tal 91% of the species had positive values on by species preferring more closed habitats. encroachment) and +100 (maximum change the gradient, thereby indicating a preference Statistical models confirm that vegetation towards open habitats). for open habitats. encroachment is a key factor in the observed Community index. A community index Changes and tendencies in butterfly com- changes in butterfly communities. (TAOc) was developed for a total of 54 tran- munities The observed changes in the vegetation sects with 10 or more years of data. This in- Of the 54 studied sites, 41 (76%) showed were only measured via local monitoring and dex takes into account the contribution of the changes towards vegetation encroachment. not on a landscape scale; nevertheless, in the whole community of species in a particular The degree of change varied in the range of past two decades the increase in forest cover year by calculating the average values of the 0.1–31.7% between the first and most recent has also been observed in buffer areas around TAO indices of all the species that appear, botanical characterizations. The TAOc values many transects.11 Our results complement multiplied by their abundances. Given that show a similar pattern, as in 39 sites (71%) those obtained in 2015, which showed that an this index was calculated every year for each changes have occurred towards domination by increase in forest cover has an impact on both transect, the annual progression can be moni- species preferring closed habitats (fig. 2). butterfly and bird populations, as revealed by tored to determine whether the tendency is to The relationship between the degree of a multi-species indicator. move towards communities more dominated change in communities and vegetation en- The degree of change in butterfly commu- by butterfly species with preferences for open croachment is statistically highly significant. nities was greater in transects with less plant or for closed habitats. The Shannon-Wiener index was also signif- diversity (as measured by the Shannon-Wiener Modelling. The relationship between chang- icant, as was the thermal region. The initial index). This is owing to the fact that heteroge- es occurring in butterfly communities and the TAOc value and the length of the monitor- neous landscapes promote stable populations degree of vegetation encroachment was stud- ing series were not significantly related to the by offering a greater diversity of resources and ied using a generalized linear model incorpo- degree of change. There were also significant microclimates.19 The effects of the thermal re- rating a series of possible explanatory factors: differences in the four categories of thermal gion show that butterflies in more arid regions the Shannon-Wiener diversity index for the di- regions, with greater effects being noted in are more affected by this phenomenon, which versity of CORINE habitats at the initial time hotter areas. reflects the extensive vegetation encroachment of the series, with the hypothesis that a buffer occurring in the Mediterranean that is fre- effect would help stabilize a community; the Species loss and population declines quently linked to socio-economic factors such initial TAOc value, which determines wheth- A total of 126 extinctions were found to have as rural-urban drift.6 er or not the initial community structure will occurred in 40 of the 54 studied transects. The lack of relationship with the length of influence the changes occurring; the time During the study period, 5% of the monitored the time-series illustrates how quickly vegeta- elapsed (i.e. the length of the annual series), populations became locally extinct. In 12 cases tion encroachment occurs, which would thus and the thermal region to which the transect the species subsequently re-colonized, which seem not to be time-dependent. This effect belongs (a categorical variable). An ANOVA gives a total of 114 (4.53%) cases in which has been detected in other insect groups and test was also performed to determine in which a population of a species was never recorded demonstrates that their precise habitat re- region the degree of change and vegetation en- again at the site in question. The average TAO quirements and short generation time makes croachment is most severe. value for extinct populations was 0.393, while butterflies highly valuable as indicators of Species loss and population declines. A local for the surviving populations was 0.330. A environmental change.10 Neither was there extinction was defined as the absence of a spe- paired t-test showed significant differences be- any relationship with the initial TAOc value, cies from a transect in four successive years tween these values. which indicates that this phenomenon has an after four successive years of appearance; thus, A mixed model was created for tran- effect that is independent of community com- an eight-year series was needed to detect an sect-scale tendencies but showed no significant position. extinction. For each butterfly community two relationship between the gradient of change The results obtained from the analysis of values were calculated: the average TAO index and either the TAO index or vegetation en- local extinctions are worrying: 4.53% of our for species that have become locally extinct croachment. Nevertheless, there was a highly butterfly populations have become extinct, and the average TAO index for species that significant relationship in the interaction be- generally in cases of species with higher TAO have not become extinct. These averages were tween these factors, which indicates that spe- values, a finding that shows how vegetation calculated for 54 transects and a total of 2,515 cies with a preference for closed habitats tend encroachment poses a threat for species with a populations and then values were compared to have negative tendencies when habitats are preference for open areas. To appreciate further using a paired t-test under the hypothesis that opened up and vice versa. A good example of why declines are leading to local extinctions it Cynthia VII

is necessary to take into account the climatic The butterflies framework since Mediterranean areas are more The station 54 species with an annual average of 47, and 21-22 exposed to extreme climatic events. Thus, 9224 individuals (annual average of 4612) the interaction between climatic and land- Besòs-Montcada, a metropolitan have been recorded in 2017 and 2018. Abun- scape factors is the essential cause behind these river of butterflies dance and species diversity begins to rise no- negative tendencies, a problem that must be ticeably in May but peaks in June. From the taken seriously in the context of global change. Situated in the lower reaches of the beginning of June to mid-July a density of We believe that the TAO index and the way Besòs valley and on the slopes of Serra 200 ex./1000 m is sustained, which can rise as in which it serves as an approximation to the de Marina, the Besòs-Montcada CBMS high as 400 ex./1000 m in mid-June. After the butterfly community is a potentially very use- itinerary runs along the final stretch of summer drought, there is a secondary peak in ful tool for conservation managers aiming to a gully, Torrent de la Vallençana, as it species diversity in September due to the ap- preserve biodiversity, above all in light of the joins the main river Besòs and then along pearance of the second generations of bivoltine importance of butterflies as bioindicators for the river itself. It is highly variable in species, the appearance of individuals belong- insect communities. Insect conservation is es- terms of the habitats it crosses, many of ing to polyvoltine species, and the arrival of sential for guaranteeing ecosystem processes which are degraded and fragmented, and the migrant species. Looking at these figures, and services at many different levels and in this in some cases constantly under threat it is obvious that, even if the species richness sense the protection of open landscapes is key. and prone to disturbance. Nevertheless, is not particularly high, the total abundance We feel that the reversion to more traditional the butterflies that are recorded remind of butterflies is fairly generous. This is due to styles of agriculture and extensive animal hus- us of the ecological importance of open the good numbers of generalist species that bandry would help mitigate some of the prob- periurban spaces in the heart of the fly here (fig. 1): Southern Gatekeeper Pyronia lems outlined in this article. Barcelona Metropolitan Area. cecilia is very common, and there are always Andreu Ubach good numbers of Small White Pieris rapae and, to a lesser extent, Iberian Marbled White Mel- The itinerary anargia lachesis. Somewhat less common are Southern Brown Argus Aricia cramera, Mead- For references, see the original Catalan version. The Besòs-Montcada CBMS station, the 148th ow Brown Maniola jurtina, Speckled Wood in the network, has been active since 2016, Pararge aegeria, Spanish Gatekeeper Pyronia although its records only started to be evalu- Fig. 1. The TAO index calculated for all 147 species bathseba and Wall Brown Lasiommata megera, present in the CBMS network. In all, 91% of the ated in 2017. This butterfly walk is situated all generalist species. It is also worth highlight- species appear on the positive axis of the graph in the municipality of Montcada i Reixac, and ing the presence – albeit in small numbers – of indicating their preference for open habitats. runs from the slopes of Puig Castellar (Serra specialist species with a variety of habitat re- de Marina) down to Torrent de la Vallençana Fig. 2. The Vallgrassa transect (El Garraf) is a quirements such as Peacock Aglais io, Provence and on to the river Besòs to the south-west of good example of changes produced by vegetation Hairstreak Tomares ballus, and Black-eyed the town. It is 1,552 m in length and is divid- encroachment. The TAO community index has Glaucopsyche melanops and Green-underside decreased over the years due to the changes occurring ed into eight sections (average length: 190 m) G. alexis Blues. in the butterfly communities. at an altitude ranging from 59 to 28 m a.s.l. The climate is Mediterranean with average an- Fig. 3. The Mallow Skipper (Carcharodus alceae) prefers Open spaces in metropolitan areas and open environments and is undergoing population nual rainfall of 568 mm and average annual declines wherever vegetation encroachment is temperature of 16ºC. Summers are hot (max. their butterflies occurring. By contrast, the Speckled Wood (Pararge 29ºC in July) and winters relatively cool – de- A bird’s-eye view of the Besòs-Montcada aegeria) is one of the few butterflies preferring closed spite the proximity of the sea – owing to the itinerary and its surroundings does not offer environments and it shows positive tendencies where marked thermal inversion that occurs in the much promise as a site for biodiversity, in gen- these habitats increase. river valley and affects the itinerary. Most of eral, or butterflies, in particular. If you walk Photo 1. The phenomenon of vegetation the sections cross alluvial soils in the Torrent or the itinerary it becomes even less welcoming: encroachment is causing biodiversity loss in subalpine run alongside the main river Besòs, although continuous human impact and presence have meadows, where butterfly communities are especially section 8 crosses open grassland lying on old helped mould a landscape that is biologically diverse. In El Catllar (Ripollès), for example, the clay workings that are testimony to the former impoverished, very fragile, highly fragmented current grazing pressure has proven not enough to industrial activity in this area. prevent vegetation encorachment in some areas of the and threatened. Open spaces in metropoli- valley, where old pastures are becoming invaded by The itinerary passes through a number of tan areas have been largely transformed and broom (photo: A. Ubach). different environments including, above all, in some cases heavily degraded, and are of- open dry grassland, thistle-packed fields, dry ten visibly fragmented by ecological barriers Photo 2. The Cleopatra, Gonepteryx cleopatra, has and damp riverside grassland, forest tracks and including large infrastructures and other dis- been one of the few butterflies favoured by the the artificial reed beds in the Besòs water puri- turbances that isolate the ecological functions increase of forest and scrub in Catalonian landscapes fication plant (fed by water from the treatment (photo: A. Miralles). of spaces and habitats and prevent their con- plant in Montcada). In the highest part, the nectivity. Nevertheless, this and other similar Photo 3. The Dingy Skipper, Erynnis tages, has itinerary also passes through the ecotone be- transects demonstrate that a significant abun- experienced a strong decline in Catalonia in the last tween market gardens and thickets, on the one dance of butterflies can exist in these areas 25 years due to habitat encroachment (photo: J. side, and poorly structured scrub, on the other. with a reasonably wide diversity of species. Corbera). Thickets dominate the margins of section 5, This suggests that butterflies and other species which is the richest in butterflies. The most are capable of taking advantage of the resourc- natural and varied vegetation is found along es that are on offer and do not necessarily need the gully, where there are natural stands of idyllic pristine habitats in which to survive –– holm oak with deciduous oaks, a magnificent biodiversity flourishes wherever and however stand of southern nettle-trees and an extension it can. This metropolitan itinerary is perhaps of chaste trees that has managed to survive a paradigm of the great ability that butterflies years of transformation and degradation. All have to act as bioindicators, and shows the in all, the overriding feature of the walk is the importance of these open spaces lacking any fragmentation of its habitats due to ecological specific type of protection as refuges for bio- barriers such as the road, the river’s retaining diversity and as reservoirs for species and their walls, the sheds and fences in the allotments, ecological functions in an urban and periur- fly-tipping, and the water-treatment plant, ban context. The predominance of generalist amongst others, that break up their continuity. species probably indicates a simplification of habitats that will lead to a progressive loss of biodiversity. VIII Cynthia

This itinerary reveals the degree of connec- fly. The higher Tregurà itinerary is not one of regimes and the maintenance of open spaces tivity between the two ridges of Serra de Coll- the network’s most species-rich butterflies walks and their biodiversity. The aim is to determine serola and Serra Marina (each with a different but still harbours interesting butterflies due, which periods of the year are most favoura- type of protection) that converge on either side above all, to certain species’ dependence on ble for certain animal groups found in open of the river Besòs in the Parc Fluvial (anoth- subalpine habitats. Of the 65 species detected, spaces, and to decide whether or not to restrict er type of protected area). As such, like other 10 here have the best populations in the whole temporally the entry of the cows into certain periurban itineraries it is important as it pro- Catalan CBMS (fig. 1): Large Erebia euryale, sensitive spaces and what the optimum density vides data on the key role of butterflies in our Piedmont E. meolans and Spanish Brassy E. of cows should be. much-degraded periurban landscapes. rondoui Ringlets, False Heath Melitaea diamina and Meadow M. parthenoides Fritillaries, Tur- Jordi Artola and Mike Lockwood Juli Mauri i de los Rios quoise Blue Polyommatus dorylas, Purple-edged Fig. 1. Average abundance (average of the annual Copper Lycaena hippothoe, Olive Skipper Pyrgus indices during the period 2017-2018) of the 15 Fig. 1. Average abundance (average of the annual commonest butterflies at the Besòs-Montcada station. serratulae, and Chestnut Heath Coenonympha indices during the period 2017-2018) of the 15 glycerion. Thanks too to these counts, the bien- commonest butterflies at the Tregurà station. Photo. The itinerary passes through different kind of nial life cycle of Erebia euryale – with a high meadows, artificial reed beds and scrub on the slopes annual index one year followed by an index of Photo 1. The itinerary encompasses a variety of of Serra de Marina (photo: J. Mauri). subalpine landscape, such as meadows, scrub and zero the following year – has become clear. stands of mountain pine (photo: M. Lockwood). Most of the first butterflies to fly at this Aerial photo.The CBMS transect at Besòs-Montcada, in a highly degraded and fragmented habitat, always altitude are widespread species or those that Photo 2. The Turquoise Blue , Polyommatus dorylas, prone to disturbance. only fly in spring or that have an initial spring is a Pyrenean species underrepresented in the CBMS generation such as Orange-tip Anthocharis car- network but with a strong population in the Tregurà itinerary (foto: J. Jubany). damines, Large White Pieris brassicae, Small Copper Lycaena phlaeas, Holly Blue Celastrina Aerial photo. The CBMS transect at Tregurà, at 1800 m argiolus and Small Tortoiseshell Aglais urticae, a.s.l., in the Catllar valley, samples typical subalpine The station or more specialized species such as Marsh Fri- habitats in the Eastern Pyrenees. tillary Euphydryas aurinia, Duke of Burgundy Tregurà, a subalpine transect in the Hamearis lucina and De Prunner’s Ringlet Catllar valley, in the heart of the Erebia triaria. Nevertheless, the rigours of the Eastern Pyreness climate at this altitude ensure that most species are summer flying. Article review Until these two stations were Other high-level species, typical of the Carnicer, J., Stefanescu, C., Vives-Ingla, M., incorporated into the network, there Catalan Pyrenees, that fly at Tregurà include López, C., Cortizas, S., Wheat, C. W., Vila, R., were no CBMS stations in the Gironan Lycaena virgaureae L. Scarce and Purple-shot Llusià, J. & Peñuelas, J., 2019 Pyrenees. The monitoring of butterfly alciphron Coppers, Mazarine Cyaniris semiar- populations in montane, subalpine and gus and Idas Plebejus idas Blues, Pearl-bordered alpine habitats is essential for detecting, Boloria euphrosyne, Small-Pearl-bordered B. Phenotypic biomarkers of climatic observing and studying the loss of open selene and Dark Green Argynnis aglaja Fritil- impacts on declining insect spaces and the management of grazing laries, Mountain Ringlet Erebia epiphron and populations: A key role for decadal regimes, above all in a region in which the spectacular Apollo Parnassius apollo. drought, thermal buffering and the effects of climate change will become amplification effects and host plant ever more marked. Management of open spaces dynamics. in upland areas Journal of Animal Ecology, 88: 376–391. The itinerary Since time immemorial, upland areas have https://doi.org/10.1111/1365- been transformed to extract natural resources The station of Tregurà is located at 1,800 m 2656.12933. a.s.l., in the Catllar valley. The climate of the such as wood and minerals, and forests have valley is subalpine, with winter averages below been cut to create grazing and arable areas. In freezing and summer averages around 20ºC; the past century, many of the cultivated areas he analysis over time of the data series that annual rainfall varies between 1,100 mm in in the Catllar valley (where three CBMS tran- Tthe CBMS network generates has enabled the lower part of the valley and 1,200 mm in sects have been established) were abandoned, us to calculate that 70% of Catalan butter- the higher pastures along the Tregurà itinerary. which led to rapid forest encroachment. In the flies have declined in number over the past This transect is one of the highest in the higher parts, open spaces, however, support a two decades. Previous studies have attributed CBMS network and consists of 12 sections large herd of cows that spend the winter in the these demographic tendencies to the negative covering a total of 1,286 m (107 m/section). Empordà lowlands, most of who return to the effects induced by recent changes in land use It runs through a mosaic of acid subalpine pas- valley on foot every spring. and global warming. Nevertheless, the popula- tures with juniper (Juniperus communis subsp. Today, despite the animal husbandry that tions of a single species may exhibit contrasting alpina) and alpenrose (Rhododendron ferrug- continues to flourish, the higher pastures are tendencies that give rise overall to a mosaic of ineum) scrub, as well as stands of mountain gradually being invaded by scrub and lower dissimilar trends. This is the case of the Green- pine (Pinus uncinata) planted in the 1950s. down the forests continue to encroach on the veined White (Pieris napi), which has declined A herd of over 250 cows grazes freely few open spaces that remain. Moreover, the in lowland areas (e.g. El Cortalet in the Aigua- throughout the valley from June to mid-No- last few open areas in the valley bottom are in- molls de l’Empordà Natural Park and Cal Tet in vember and, to greater or lesser extent, affects tensely but briefly grazed when the herds arrive the Delta del Llobregat protected area; CBMS the butterfly populations, above all in the open or leave the valley. Consequently, for the last itineraries 1 and 4, respectively) but in upland spaces. few years attempts have been made to improve areas has remained stable (e.g. El Puig in El the overall biodiversity of the open spaces by Montseny Natural Park; itinerary 12) or even increasing the size of the pastures and mead- moderately increased (Can Jordà in the La Gar- The butterflies ows via campaigns to eliminate the broom rotxa Volcanic Zone Natural Park; itinerary 9). During the two years of counts, at Tregurà, scrub in higher areas and the hazel woodland In this study published in the Journal of An- 2,111 butterflies and 65 species at a density of in the lower parts of the valley. imal Ecology we identified a series of elements 82,01 ex./100m have been noted. At the same time as the CBMS itineraries operating at local scale that modulate by mag- The phenology is characterized by a single are walked, the effect of grazing pressure on a nifying or mitigating the regional pressures that large peak that drops off sharply from mid-Au- diverse community of animals is being studied these four populations are under. After creating a gust onwards. It is not until around week 13 in order to improve management and make model incorporating monthly rainfall and tem- (end of May) that the first butterflies begin to it more compatible with traditional grazing perature data, as well as changes in land use, we Cynthia IX

observed that the dynamics displayed by these lack of fresh, good-quality host plants. As many In the Iberian Peninsula it is widespread, al- four populations are strongly driven by summer experiments have previously demonstrated, the though it has never been recorded from the weather conditions. Specifically, we noted that interaction between these two factors will prob- Balearic Islands.1 It is common in the north- the generalized decline in June rainfall in 1997– ably negatively affect larval development and ern half of Catalonia but more local in upland 2007 was accompanied by a severe fall in Green- even have consequences for the overall demo- areas of the province of Tarragona;2,3 outside veined White numbers in lowland areas (by graphics of this butterfly’s populations. the highest areas, it is also fairly common in over an order of magnitude in the Aiguamolls Finally, this variation in the degree of ther- Andorra. Its altitudinal range is broad, rang- de l’Empordà). By contrast, this intensification mal exposure experienced by different popu- ing from sea level to 1900 m a.s.l.,4 with clear of the summer drought had no observable ef- lations may be reflected in contrasting pheno- maximum abundances between 600 and 1400 fects on population dynamics in upland areas typical characteristics that vary in terms of the m a.s.l. (e.g. Can Jordà and El Montseny), where in fact specific conditions under which butterflies -de In the CBMS network it has been detect- Green-veined White abundances increased as velop (biomarkers). In our study, the wing size ed in nearly 90 stations, almost 60% of the rainfall returned to its previous levels. of lowland Green-veined Whites diminished as whole network (fig. 1). Nevertheless, in some As previous studies have noted, the re- summer temperatures rose, whilst that of up- stations only dispersing wintering butterflies sponses of organisms to the impact of climate land populations remained the same. When appear. It is absent from stations in the Ebro change are influenced by a complex series of upland butterflies were raised in captivity un- Depression, from many coastal sites and near- interactions between a set of processes that op- der lowland temperatures, their wing size was by inland areas, and from high-level transects erate simultaneously. Thus, more studies will smaller. This demonstrates that under natural in the Pyrenees. be required integrating concurrently many conditions upland populations benefit from elements affecting population dynamics if we protection against thermal exposure. As we have are to develop a more complete vision of the seen, to explain how organisms are affected by Habitats and food plants situation. We set out to evaluate how habitat the impact of climate change we need data re- The Large Tortoiseshell is essentially a general- structure, host plant characteristics, phenotyp- garding all the numerous different factors that ist species as the fact that it has been recorded ical behaviour in the Green-veined White, and operate simultaneously and how they interact. from 17 of 19 habitat categories included in this butterfly’s response to thermal stress can the CBMS network indicates. The only two provide information regarding the degree of Maria Vives-Ingla, Jofre Carnicer and Javi Sala habitats from which it has never been record- climatic vulnerability of its populations. ed are at altitudinal extremes: beaches and 5 At each of the study sites we installed sen- Fig 1. Upland Green-veined White populations alpine meadows. This degree of generalism sors around stands of the butterfly’s host plant, benefit from the shade offered by woods. In summer, is explained in part by this species’ dispersive in both open (in fields and pastures) and closed temperatures in woodland are up to 5ºC lower than capacity and the appearance of individual but- (in the shade of trees in woods and copses) outside (Photo: J. Carnicer). terflies – above all, hibernators that have just habitats, that recorded the temperature every emerged from diapause – in a series of varied Fig 2. In summer, at lowland sites the host plants of hour. We compared the results from these sen- the Green-veined White are scarce and of low quality. habitats. Breeding areas, however, are more sors with data from the nearest weather station Moreover, there are strong temperature amplifications localized and are restricted, above all, to eco- in the Catalan Meteorological Service’s net- and the butterfly’s thermal tolerance thresholds are tones of montane forests and agricultural are- work and calculated that, due to tree cover, in exceeded (Photo: M. Vives-Ingla). as, often in the vicinity of farmhouses where its upland woodland the maximum June temper- food plants are common and males establish Drawing. Green-veined White (Pieris napi) on garlic atures were 5.2 ± 0.17ºC lower than those re- mustard, Alliaria petiolata, one of the preferred their territories. Its ties to forested areas are corded by the nearby weather stations. By con- food plants of upland populations. This same food patent, as shown by its TAO Index of 0.022, trast, the declining lowland populations had plant is widely used by Large White (Pieris brassicae) well below the average for most Catalan but- no access to any efficient thermal micro-refug- populations (Drawing: Martí Franch). terflies, which reflects its preference for envi- es. In lowland populations, thermal mitigation ronments with ample forest and shrub cover.6 was up to six times less (0.79 ± 0.32ºC) than Its association with forested areas or, at in upland areas. Moreover, most host plants least, with places with stands of trees, can be were located in open areas where temperatures put down to the fact that it uses a variety of increased by a further 2ºC. The butterfly different trees as food plants.1,7,8 Specifically, in Thus, the temperatures in open habitats in Catalonia egg-laying or caterpillar nests have lowland areas exceed the critical thermal thresh- Why is the Large Tortoiseshell been recorded from nine different tree species: olds for larval survival in this species, which we Nymphalis polychloros known as the southern nettle-tree (Celtis australis), field elm calculated via a series of thermal death time ex- Sleeping Beauty in Catalan? (Ulmus minor), wych elm (Ulmus glabra), wild periments. Nevertheless, these thresholds (min- cherry (Prunus avium), black poplar (Populus imum exposure of 6 hours at 34.5ºC during Despite being a reasonably widespread nigra), aspen (P. tremula), grey willow (Salix the three weeks of larval growth) were not ex- and spectacular species, the Large atrocinerea), weeping willow (S. babilonica) ceeded on 90% of days. Consequently, it is un- Tortoiseshell is often overlooked. This and hawthorn (Crataegus monogyna). In addi- likely that this thermal regime alone can have is due largely to its curious phenology: tion, pre-egg-laying behaviour has been noted such serious effects on the lowland populations despite living for up to 10 months on white poplar (Populus alba).7 Despite lack- of the Green-veined White. and so being one of our longest-lived ing confirmatory oviposition trials, eggs seem Indeed, thermal stress was not the only factor of all butterflies, adults of the Large to be laid preferentially on wild cherry, south- that affects this butterfly’s populations. In our Tortoiseshell enter into diapause ern nettle-tree or field elm. Laboratory exper- monitoring of the host plant, we noted that almost immediately after emerging at iments indicate that larval development time whilst in upland populations there were always the beginning of summer and do not varies greatly depending on the food plant: garlic mustard (Alliaria petiolata) plants present, reappear until the following season. for example, development takes almost 30% in lowlands the species’ two food plants, hoary They spend this long period of inactivity longer on hawthorn (35 days) than on field cress (Lepidium draba) and black mustard (Bras- hidden in dark spots in abandoned elm (28 days) and southern nettle-tree (25 sica nigra), entered into a state of senescence houses, garages and storerooms, often in days) owing to the difference in the nitrogen from June onwards after fruiting. At the same company with the Peacock. and water content of the leaves.8 The fact that, time, during the period of greatest hydric stress despite these differences in development time, the conductance of these latter plants’ leaves polyphagy occurs at local level could be related was significantly reduced, which aggravated to the lack of any correlation between larval the thermal amplification they experienced (in Geographical distribution mortality and the length of development time; June leaf temperatures reached 38ºC, 14ºC and situation in the CBMS this is an evident possibility given the high and higher than in May). Thus, in summer lowland The Large Tortoiseshell is a Palaearctic species very heterogeneous larval mortality rates (i.e. Green-veined Whites are not only affected by that flies in North Africa – it is particularly not dependent on the food plant) found in the dearth of shade but also have to cope with a common in the Rif – and much of Europe. natural populations.7 X Cynthia

Phenology and biological cycle wards the end of the gregarious phase, due to forested habitats. Most observations take place As occurs in many other species of butterfly of the accumulation of defoliated branches cov- at the end of winter and beginning of spring the tribe Nymphalini, the Large Tortoiseshell ered in silk and numerous excrements, larval when males are establishing and defending is univoltine and hibernates as an adult. Its nests become very visible. territories: territorial activity takes place above common name in Catalan – Nimfa Dorment Once fully grown, the larvae generally all at midday and at the beginning of the af- (i.e. Sleeping Beauty) – is a reflection of the abandon the food plant and enter a wandering ternoon, for example, in forest clearings, along 11 long period of time every year that the adult phase that may involve long journeys until tracks, and around trees that produce sap that is inactive. The first Large Tortoiseshells leave they find an appropriate place to pupate. In attract females. As occurs in all territorial hibernation very early in the year and can be the Large Tortoiseshell, an average distance of Nymphalidae, interactions between males are seen on sunny days in February and, above 17.1 m (max. 25 m) has been recorded for a obvious and easy to detect, whilst interactions all, March. By contrast, the fresh butterflies group of seven larvae located near the elm on between males and females – above all, mating 7 that emerge as the single annual generation which they had fed ; nevertheless, movements – are very hard to spot. between mid-May and mid-July, enter very of over 50 m, documented in the Camberwell Data on the trophic resources used by adults 12 7 quickly into diapause and remain there until Beauty, are probably not rare. The chrysalis are relatively scarce. In spring when there are the end of winter or beginning of spring of the is well camouflaged whether hidden amongst few mature fruit, hibernating adults often feed following year. the vegetation or at the base of tree trunk near on the male catkins of grey willow, on the sap The cryptic colouration of the underside ground level or higher up (up to 2 m or more) exuded by trees such as evergreen and decidu- of the wings acts as camouflage during the on rocky outcrops, under the eaves of farm ous oaks and aspen, or on honeydew produced adult butterfly’s long period of diapause. To buildings or in other similar sites (Photo d). by aphids covering branches and leaves. Oc- hibernate, butterflies typically choose a dark, This final phase is short, lasting only around casionally, adults visit the flowers of trees and well-hidden site in abandoned or non-perma- two weeks. shrubs such as almond (Prunus amygdalus), nently inhabited buildings such as farmhous- wild cherry, plum (P. domestica), blackthorn es, garages and storerooms.7,9 They are often Natural enemies (P. spinosa) and even those of box (Buxus sem- found alongside the Peacock (Aglais io) and pervirens) and tree heath (Erica arborea). The Attacks by predators and parasitoids have been importance of tree sap in spring is reinforced are also found regularly in nest boxes placed documented throughout the life cycle of the for edible dormouse (Glis glis) in oak and 7 by the fact that males have been repeatedly ob- Large Tortoiseshell. Of the parasitoids, a spe- served to establish territories on the trees they beech forests in the mountains of Montnegre, cies of Hymenoptera (family Scelionidae) has Montseny and Guilleries. These wooden boxes visit in an attempt to mate with the females been reported as attacking the eggs (Photo that also come to feed. measuring 30x15x15 cm (Photo f) are placed e)7 and various Diptera (family Taquinidae) at heights of 2.5–3 m directly on the trunks of During the brief time in which the adults parasitize the larvae; depending on the spe- of the fresh generation are active, Large Tor- sessile oaks (Quercus petraea) or beeches (Fagus cies in question, they will kill the caterpillar sylvatica).7 Data show that Large Tortoiseshells toiseshells rarely visit flowers. Records of nec- or chrysalis (e.g. Sturmia bella, whose larva taring include butterflies on bramble Rubus( hibernate in both Mediterranean environ- leave behind a characteristic thread when they ments (e.g. the Vallesana Plain at altitudes 7,13 sp.), elderberry (Sambucus ebulus) and, most leave the pupa; Photo h). The Hymenop- frequently, large-leaved lime (Tilia platyphyl- of 150–300 m a.s.l.) and in the more upland tera (family Chalcididae) Pteromalus puparum areas (700–1200 m a.s.l.) where the species is los). By contrast, in one particular part of the parasitizes the chrysalis when the cuticle is still mountains of El Montseny, Large Tortoise- most abundant. soft.7,14 We lack sufficient data to be able to A remarkable aspect of the phenology of shells are regularly noted feeding on mature calculate the impact of these parasitoids but it fruit, specifically on wild cherries. This pref- the Large Tortoiseshell, which is shared by is likely that attacks by both Taquinidae and the Camberwell Beauty (Nymphalis antiopa), erence for mature or rotten fruit is corrobo- Pteromalidae species cause great mortality in rated by the regularity with which adults are is how difficult it is to spot a fresh butterfly this species of butterfly. belonging to the annual emergence in spring attracted to traps baited, for example, with Insectivorous birds are most likely amongst semi-rotten bananas.17 In the eastern Pyrenees or summer. This is most noticeable in Med- the commonest predators whose attacks ex- iterranean environments10 and so, ostensibly, adults have also been observed visiting the sap plain the sudden disappearance of nests of produced as a result of attacks by the weevil its annual flight curve falsely indicates that the gregarious larvae.7 In the final two stages, the old individuals from the previous year appear- (family Curculionidae) Larinus sturnus on the larvae have very obvious spines that protect flowerheads of the woolly thistleCirsium erio- ing after hibernation are commoner than those them – despite their conspicuous behaviour of the current year (fig. 2). This also reflects the 15 phorum. Adults will also occasionally feed on – from attack by visual predators (Photo c). carnivore excrements. short period of time in which the majority of Nevertheless, the spines on the earliest stages Large Tortoiseshells are active after emergence, Finally, it is worth noting that adults are of the larvae are softer and act as no protection regularly observed on the ground taking hu- as shown by the large number of observations against birds, which justifies their more retir- that exist of butterflies already in diapause in midity or salts from the soil or wet leaves. This 7 ing behaviour. Indeed, it has been shown that behaviour is exhibited by both old hibernat- July. at dusk groups of larvae move onto the under- Once they leave hibernation at the end of ing individuals and freshly emerged butterflies side of the leaves, where they remain hidden about to enter into diapause. Both females winter or beginning of spring, the Large Tor- until the following day, thereby reducing the toiseshells mate and the females very quickly 7 and males have been reported as feeding in chances of being detected by visual predators. this way, which suggests that, apart from be- begin to look for egg-laying sites. Egg-batches The prepupal and pupal stages also suffer consist of groups of 100–200 eggs, general- ing simply a male-type behaviour designed to from great mortality rates due to attacks by 18 ly placed carefully around the end of a thin extract salts, it also occurs as part of active ants, possibly by small mammals, or by the searching for water. branch (2–3 mm in diameter) (Photo a). Ob- parasitoid Pteromalus puparum.7 servations of egg-laying or females exhibiting Finally, overwintering adults are preyed Population trends egg-laying behaviour take place above all in upon by small mammals including the Yel- March and occasionally in April. On the other low-necked Mouse (Apodemus flavicollis) and In 1994–2018, the Large Tortoiseshell pop- hand, nests of caterpillars (in different stages) Wood Mouse (Apodemus sylvaticus).7 These ulations in Catalonia underwent serious os- are found chiefly between the second half of cillations but with no significant positive or 7 two rodents have been identified as the main April and the first half of June. predators of hibernating Large Tortoiseshells negative tendencies (fig. 3). Amongst Catalan Eggs take 2–3 weeks to hatch. The larvae in northern Europe16 and there is no reason butterflies, it is one of the 10% of species with are gregarious and live near the egg-laying to think that the situation in Catalonia is any most variable population numbers, as shown site in a simple silken cocoon on a young leaf different. by the calculation of the coefficient of varia- (Photo b). Whilst still gregarious, the larvae tion of its annual indices of relative abundance change leaves and establish a new nest with (0.868 compared to an average of 0.536 for a each moult. In the final stage after moulting Adult behaviour total of 107 species). into the fifth instar, the larvae adopt a solitary The Large Tortoiseshell is often overlooked as Its populations hit a high in the middle of lifestyle and disperse over its host plant. To- adults are not gregarious and are closely tied to the first decade of the twenty-first century, in Cynthia XI

stark contrast to the serious declines both be- HIGH-BROWN FRITILLARY fore and after this period (e.g. in 1998–2000 Identification Upperside: orange-brown, paler in female, and 2015–2017). These fluctuations are very with black markings. similar to those observed in populations of How to separate the species of the Underside: fore-wing orange, with yellowish Camberwell Beauty (the correlation between genus Argynnis (2) apex with black markings; hind-wing with orange background colour with a variable the data series of their populations is rp = 0.87, P < 0,001), which suggests that the population The other three Catalan Argynnis species diffusion of green scales, silvery spots dynamics of these two species are influenced – Dark-green A. aglaja, High-brown A. (sometimes absent), and a series of red spots. Marked with line by similar factors. However, without a more adippe and Niobe A. niobe Fritillaries – form a very homogenous group. The two series of thick androchonial scales on Cu1 targeted study we can only speculate as to i Cu2 which environmental factors lie behind these first two are the commonest and most widely spread, but all three can be more pointed wing synchronized fluctuations. The severe impact series of large red-brown spots with silvery found together at some sites and their that natural enemies seem to have on the Large pupil Tortoiseshell (and by implication the Camber- separation can be problematical, above well Beauty as well) would seem to indicate all between the latter two. NIOBE FRITILLARY that fluctuations in its populations are closely Upperside: orange-brown with black related to density-dependence responses. ll three are typically found in upland grass- markings; female with diffusion of grey scales. The Large Tortoiseshell is regarded as stable Aland areas, but they will also fly in open Underside: fore-wing orange, with yellowish in Europe, although population levels have scrubby and shrub-dominated habitats.1,2 apex with black markings; hind-wing with been very low in parts of north-west Europe in Their altitudinal optimum is fairly similar, creamy orange background, silvery spots recent years.19 Even so, in this part of the con- 1,000–1,800 m a.s.l., but they are all found (sometimes absent), and a series of red spots. tinent this butterfly undertakes irruptions and, outside these limits: A. aglaja reaches the Marked with line for instance, in the past two years observations greatest altitudes and is found in subalpine two series of thin androchonial scales on Cu1 have become frequent in both the Netherlands and alpine pastures, whilst A. adippe flies at i Cu2 and England.20 lower levels and is even found in open spac- more pointed wing series of small large red-brown spots with es in Mediterranean areas. All three fly over Constantí Stefanescu and Jordi Jubany silvery pupil much of the Pyrenees and pre-Pyrenees (other black edging to silvery spots than the eastern-most areas). In addition, both For references, see the original Catalan version. white spot, generally with black pupil A. aglaja and A. adippe fly in the mountains of the Serralada Transversal, El Montseny, the These three fritillaries can be separated Fig. 1. Relative abundance (expressed as the values of Prelittoral ranges and Els Ports, as well as the by the underside of their hind-wings. The the annual index/100 m) of the Large Tortoiseshell at uplands of the county of La Segarra.2 A. ni- CBMS and BMSAnd stations (1994–2018). Dark-green is green with silvery spots and a obe, on the other hand, is less frequent and yellowish submarginal band with no red-brown Fig. 2. Phenology of the Large Tortoiseshell (a) at 88 to the south of the Pyrenees is only found in spots. The other two are more difficult to lowland CBMS stations (Mediterranean environment, the mountains of El Montsant and Prades.2 In separate, in part because they are so variable. n = 308 individuals); (b) at 42 montane stations the CBMS network, A. aglaja and A. adippe The High-brown is bigger; its hind-wind (Eurosiberian environment, n = 412 individuals); appear in almost a third of the stations, but underside is yellow-orange in colour, with a and (c) at 19 high-mountain stations (alpine and A. niobe in only 4%. All three are univoltine, greater or lesser extension of green scales (all subalpine environments, n = 271 individuals). Data green in f. chlorodippe), with silvery spots gathered in 1994–2018 in Catalonia and Andorra. although the adults of both A. aglaja and A. adippe can be on the wing from June through or otherwise (f. cleodoxa), and a series of Fig. 3. Population fluctuations in the Large to September, with a peak in July. Where they postdiscal-submarginal red-brown spots, with Tortoiseshell in the CBMS and BMSAnd network coincide, A. niobe tends to be the earliest to or without silvery pupils. The Niobe is smaller, in 1994–2018. Its trend, calculated with the TRIM fly. All lay their eggs one-by-one on leaves or its underside is yellow-orange but has fewer green scales, silvery spots or spots with the program, is stable. twigs close to the violets that will act as the same colour as the background colour (f. eris). Photo. The Large Tortoiseshell is one of the most food plant of their larvae. They overwinter as As well, there is a postdiscal-submarginal spectacular butterflies in our fauna. The fresh formed larvae in the egg or as a first instar lar- series of red-brown spots, with or without individuals of the new annual generation (such as the va. Data from the CBMS counts suggest that pupils, and a normally white spot with a black one in the picture), which appear mostly in May-June, Catalan populations of A. aglaja and A. adippe pupil at the base of the cell. are brightly coloured, highly contrasting with the dull- are stable; tendencies in the Catalan popula- coloured butterflies coming out of the hibernation (photo: J. Jubany). tions of A. niobe, on the other hand, are still poorly known. Plate. (a) A typical egg-cluster laid around the Identification end of a thin branch of nettle-tree; (b) first instar Jordi Dantart larvae clustered on top of an elm leaf, close to the How to separate the species of the old egg-batch; (c) fifth and last instar larva with For references, see the original Catalan version. highly developed defensive spines; (d) two prepupae genus Limenitis and one pupa, in a rocky wall; (e) A newly emerged Scelionidae from a parasitized egg; (f) nest boxes for Drawings In Catalonia fly two species belonging edible dormouse (Glis glis) are regularly used by Large to the genus Limenitis, Southern White Tortoiseshell as hibernation sites; (g) an adult coming DARK-GREEN FRITILLARY Admiral, L. reducta, and White Admiral, out from hibernation, basking on a tree trunk in a Upperside: orange-brown, brighter in male Limenitis camilla. Both are essentially winter sunny day; (h) a dead pupa parasitized by the than female, with black markings. forest species, although the Southern tachinid Sturmia bella (photographs: a-g, J. Jubany; Underside: fore-wing orange, with yellowish h, J.R. Salas). White Admiral also appears in a variety wing apex with black marks; hind-wing of open habitats. They are easy to greenish with silvery spots and a yellowish separate when resting; nevertheless, in submarginal band. flight as they glide along forest edges Marked with line three series of androchonial scales on Cu1, identification is somewhat less simple. Cu2 i 1A more rounded wing he Southern White Admiral is widespread green background colour with silvery spots Tin Catalonia, being absent only from parts submarginal band without spots of the Central Depression, the Ebro Delta and alpine habitats in the high Pyrenees.1 On the other hand, the White Admiral is restricted to humid woodland in the northern half of the country, being especially common in the XII Cynthia

mountains of the Serralada Transversal, Les Admiral is bivoltine with generations flying WHITE ADMIRAL Guilleries and El Montseny. Its southern-most between April and October. Eggs are laid sin- Upperside: Very dark with matt brown limit is the Serra de Collserola near Barcelo- gly on various species of honeysuckle (above colouration. na.1 Both species are absent from the Balearic all, Mediterranean honeysuckle Lonicera im- Underside: combination of red and white Islands.2 The altitudinal range of these two plexa and Etruscan honeysuckle L. etrusca in markings, and black spots on a grey species largely coincides, with optimum alti- the Southern White Admiral, and Atlantic background. tudes in the range 400–800 m a.s.l. They rare- honeysuckle L. periclymenum in the White Marked with line ly fly above 1,600 m a.s.l.; whilst the South- Admiral).1-3 no blue iridescence; brown small white discal spot is hard to see ern White Admiral is not rare at sea level, the two lines of black submarginal spots White Admiral is only occasionally found Constantí Stefanescu below 300 m a.s.l. Both are typical species of For references, see the original Catalan version. These two ‘white admirals’ are similar in humid gullies, thickets and woodland clear- size, colouration (dark, almost black, with ings and edges, although the Southern White a broad white band crossing both wings) Admiral is also common in maquis shrubland Drawings and behaviour. The main difference is the and garrigue if its food plants, various spe- blue iridescence on the upperside of the cies of honeysuckles, are present. The males SOUTHERN WHITE ADMIRAL Southern White Admiral since its congener of both species are territorial and perch on Upperside: dark with blue iridescence. is characterized by a dull matt brown branches in patches of sun to wait for females Underside: combination of red and white background colour. The Southern also has a to arrive. Both males and females regularly markings, and black spots on a grey white discal mark on its fore-wing that is all visit flowers to nectar, above all brambles in background. but absent in its near relative. The patterning the case of the White Admiral. The two species Marked with line on the underside in both species is more are well represented in the CBMS network: for blue iridescence complex, with a red-brown and dark grey obvious white discal patch the Southern White Admiral data has been re- background colour, white markings and black a single line of black submarginal spots corded for almost 120 itineraries, whilst for its spots. However, whilst the Southern White congener more than 50 CBMS stations have Admiral has a single submarginal line of black provided data. The Southern White Admiral spots, in the White Admiral there is a double series of spots. There is no sexual dimorphism is trivoltine, with generations on the wing be- in either species. tween May and September,3 while the White

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