Large golden-ringed dragonfly Cordulegaster heros Theischinger 1979, new for the fauna of Italy (Odonata: Cordulegastridae)
Matjaž BEDJANIČ1 & Ali ŠALAMUN2
1 Kolodvorska 21/b, SI-2310 Slovenska Bistrica, Slovenia; E-mail: matjaz.bedjanic@guest.arnes.si
2 Center za kartografijo favne in flore, Podružnica Ljubljana, Zemljemerska 10, SI-1000 Ljubljana, Slovenia; E-mail: ali.salamun@ckff.si
Abstract. The species has been recorded at three localities in the extreme eastern part of the Friuli-Venezia Giulia region, north-eastern Italy, thus bringing the number of Italian dragonfly species to 89. The distribution of C. heros in Slovenia and Italy is mapped and discussed from the zoogeographical point of view. Additionally, the collected faunistic data on other dragonfly species and sympatric occurrence of endangered frog species Rana latastei Boulenger are given. Due to inclusion of C. heros and R. latastei to the Annexes II and IV of the Habitat Directive of EU, the conservation of their habitats in Italy and western Slovenia is proposed within the European network of protected areas NATURA 2000.
Keywords: dragonflies, zoogeography, Habitat Directive, Natura 2000
Izvleček. VELIKI STUDENČAR CORDULEGASTER HEROS THEISCHINGER 1979, NOVA VRSTA ZA FAVNO ITALIJE (ODONATA: CORDULEGASTRIDAE) - Vrsta je bila ugotovljena na treh lokalitetah v skrajnem vzhodnem delu Furlanije-Julijske krajine, severovzhodna Italija, kar dviguje število zabeleženih vrst kačjih pastirjev v Italiji na 89. Razširjenost vrste C. heros v Sloveniji in Italiji je prikazana na zemljevidih ter prediskutirana z zoogeografskega stališča. Dodatno so navedeni tudi zbrani favnistični podatki o drugih vrstah kačjih pastirjev ter podatki o simpatričnem pojavljanju ogrožene laške žabe Rana latastei Boulenger. Zaradi vključitve vrst C. heros in R. latastei na Dodatka II in IV Habitatne Direktive EU je predlagano, da se njuna bivališča v Italiji in zahodni Sloveniji ohranijo v okviru evropskega omrežja zavarovanih območij NATURA 2000.
Ključne besede: kačji pastirji, zoogeografija, Direktiva o habitatih, Natura 2000
Introduction
According to Utzeri (1995), altogether 88 dragonfly species occur in Italy. Despite its size, the country is odonatologically relatively well explored, and in the easternmost Italian region
NATURA SLOVENIAE 5(2): 19-29
Zveza za tehnično kulturo Slovenije, Ljubljana, 2003
20               Matjaž BEDJANIČ & Ali ŠALAMUN: Large golden-ringed dragonfly Cordulegaster heros ... / SCIENTIFIC PAPER
of Friuli-Venezia Giulia (NE Italy) some dragonfly research has also been carried out in the past. More than 30 years ago, a comprehensive overview of dragonfly fauna of the Friuli-Venezia Giulia region was made by Kiauta (1969a), following a similar study in the neighbouring Primorska region in Slovenia (Kiauta 1969a). In addition, only a few years ago Bognolo & Pecile (1995) thoroughly studied dragonfly fauna of the Trieste and Gorizia Karst in Italy and published an annotated list of species occurring in the region. As far as the genus Cordulegaster is concerned, only C. bidentata (Selys) and C. boltonii (Donovan) have been recorded from Friuli-Venezia Giulia so far (Kiauta 1969a, Bognolo & Pecile 1995). Until now, however, one of the most enigmatic European dragonfly species, Cordulegaster heros Theischinger, escaped the notice of odonatologists and has not been reported for Friuli-Venezia Giulia or for Italy as a whole yet (Utzeri 1995, Galletti & Pavesi 1985).
According to Wasscher & Bos (2000), C. heros is one of the ten dragonfly species endemic to Europe. Two additional Cordulegaster species, viz. C. trinacriae and C. helladica, are also confined to Europe, whereby the range of the first is limited to Sicily and southern Italy and that of the later to Greece. C. heros also has a relatively small range, occurring in Austria, Slovenia, Hungary, Croatia, Serbia, Macedonia, Bulgaria, Romania and Greece. Recently it was discovered in Slovakia (Blaškovič et al., in print), and the present article formally extends its distribution range to Italy.
In Slovenia, the species is quite common and it has been recorded by the members of the Slovene Odonatological Society from more than 340 localities (Fig. 1), whereas development of the species has been documented in more than 260 localities (Kotarac et al. 2003). The exceptional number is even more impressive by the fact that the number of all other known European localities of the species is by far lower. If the proportion of unsuitable habitat for C. heros in most of the Pannonian lowlands is taken into account, the speculation that Slovenia actually represents the core area of the species’ distribution range in Europe is not far from reality.
However, in western Slovenia, close to the border to Italy, where C. heros reaches the extreme north-western edge of its European range, the suitable habitat is much scarcer and limited only to few stream catchments in the wider surroundings of the Vipava valley. The distribution of the species in this part of Slovenia has been described in detail by Bedjanič & Pirnat (2000), gathering their observation with the faunistic data from Pirnat (1996), Červek (1997), Kotarac (1997), Šalamun et al. (1997) and Bedjanič (2000). Few additional localities
NATURA SLOVENIAE 5(2): 19-29
21
have been added by Pirker (2002), and a very comprehensive overview has been presented by Kotarac et al. (2003).
Since the distribution of any living species is rarely limited by the state borders, the idea that C. heros might also occur in north-eastern Italy is not new in the minds of Slovene odonatologists. Kotarac (1997) has already predicted this possibility with the following words: “We started to collect the data about C. heros in the eastern parts of Slovenia. In five years we harrowed the species to two spots about 1 km away from the national border with Italy. It is the turn of Italian odonatologists now.” In addition, Bedjanič & Pirnat (2000) stated in a similar way: “It is interesting that so far C. heros has not been found in Italy, although it goes without saying that its already mentioned north-western distribution edge probably extends also to the western side of the Soča River.”
Quite surprisingly, nobody took over the pleasant challenge for years and there was no other possibility than to finally clear the situation by ourselves.
78
90123456789012345678
Figure 1: Distribution of Cordulegaster heros in Slovenia. Members of the Slovene Odonatological Society recorded the
species from more than 340 localities and documented its development at more than 260 localities.
Slika 1: Razširjenost velikega studenčarja v Sloveniji. Člani Slovenskega odonatološkega društva so vrsto popisali na več
kot 340 lokalitetah ter potrdili razvoj na več kot 260 lokalitetah.
22               Matjaž BEDJANIČ & Ali ŠALAMUN: Large golden-ringed dragonfly Cordulegaster heros ... / SCIENTIFIC PAPER
Localities and faunistic data
On March 23rd, 2003, a number of streams between the Isonzo (Soča) and Iudrio (Idrija) rivers in the extreme eastern part of Friuli-Venezia Giulia (NE Italy) were systematically checked by the authors for the presence of dragonflies and frogs. Special interest was dedicated to the dragonfly species Cordulegaster heros Theischinger and the frog species Rana latastei Boulenger, which both are endangered and listed on the Annexes II and IV of the EU Habitat Directive.
The dragonfly fauna was sampled randomly at subjectively defined suitable places by the means of larvae collecting with a home-made water net. Larvae of C. heros were determined on the spot, checking specific characters by the help of magnifier (e.g. the presence and size of lateral spines on the ninth abdominal segment) and released afterwards. Individual frogspawns of R. latastei were visually counted at each locality at approximate stream length of 100-200 m. Although a number of streams were checked, only the ones with recorded presence of dragonflies and frogs are listed in further text. Beside exact geographical description, the UTM square and approximate altitude are given for each of the sites (Fig. 2).
The voucher material of C. heros was taken at the Rio Sniardar stream only. One dried final instar larva is deposited in the collection of the first author. The second larva from the same locality was reared in aquarium but died during the final shedding. The specimen is deposited in the second author’s collection.
LOC 1A: Stream Groina (Grojnica) NW of Gorizia, 750 m above the place where it joins the Isonzo river (Soča); Gorizia (Gorica); Friuli-Venezia Giulia; NE Italy; UTM UL 99; alt. 80 m; DRAGONFLIES: Cordulegaster heros 1 lar.
LOC 1B: Stream Groina (Grojnica) NW of Gorizia, 1 km above the place where it falls into the Isonzo river (Soča); Gorizia (Gorica); Friuli-Venezia Giulia; NE Italy; UTM UL 99; alt. 80 m; DRAGONFLIES: Somatochlora meridionalis 1 lar. FROGS: Rana latastei 25 spawns
LOC 2A: Left tributary of the stream Groina (Grojnica) close to the road to Scedina (Ščedno), 100 m above the spot where it joins the Groina; Gorizia (Gorica); Friuli-Venezia Giulia; NE Italy; UTM UL 99; alt. 80 m; DRAGONFLIES: Calopteryx virgo 1 lar. FROGS: Rana latastei 5 spawns
NATURA SLOVENIAE 5(2): 19-29
23
LOC 2B: Left tributary of the stream Groina (Grojnica) close to the road to Scedina (Ščedno), 700 m above the spot where it joins the Groina; Gorizia (Gorica); Friuli-Venezia Giulia; NE Italy; UTM UL 99; alt. 90 m; DRAGONFLIES: Cordulegaster heros 1 lar. FROGS: Rana latastei 10 spawns
LOC 2C: Left tributary of the Groina (Grojnica) at the bridge on the road to Scedina (Ščedno), 950 m
above place where it joins the Groina; Gorizia (Gorica); Friuli-Venezia Giulia; NE Italy; UTM UL 99; alt. 90
m;
DRAGONFLIES: Cordulegaster heros 1 lar.
FROGS: Rana latastei 26 spawns
LOC 3: Stream Rio Sniardar (Smjardar) NE of Brazzano (Bračan), 100 m above the place where it joins the
Rio Fidri stream (Fedrih); Brazzano; Cormons (Krmin); Friuli-Venezia Giulia, NE Italy; UTM UL 89; alt. 80
m;
DRAGONFLIES: Cordulegaster heros 13 lar., Calopteryx virgo 2 lar., Platycnemis pennipes 1 lar.
FROGS: Rana latastei 7 spawns
Figure 2: Distribution of Cordulegaster heros in western Slovenia and eastern part of Friuli-Venezia Giulia, northeastern
Italy, with numbers indicating the three new Italian localities, where the species has been recorded recently. Slika 2: Razširjenost velikega studenčarja v zahodni Sloveniji ter vzhodnem delu Furlanije-Julijske krajine, severovzhodna
Italija. Nove najdbe vrste so označene s številkami.
24               Matjaž BEDJANIČ & Ali ŠALAMUN: Large golden-ringed dragonfly Cordulegaster heros ... / SCIENTIFIC PAPER
Discussion
As already stated in the introductory part, the occurrence of Cordulegaster heros in the eastern part of Friuli-Venezia Giulia has been predicted and expected and is therefore not surprising at all. Even more, based on the experience from numerous Slovenian localities, the suitable places for C. heros were determined with the aid of a 1:50000 map in advance with great certainty and later on merely confirmed in the field. The recipe for such "map remote sensing" planning is quite simple: (1) stream in hilly to lowland landscape, (2) only gentle slope of the field, (3) altitude 100-400 m and (4) presence of forest. Such predispositions logically originate in ecological demands of the species. C. heros is essentially a dragonfly of small forest streams in the hilly country down to the flatlands. The strongest populations can be found in slow to moderate flowing agitated streams, where their bottoms consist of fine sand covered by a thin layer of fine organic detritus. These structures enable the larvae to burrow themselves in the bottom and, on the other hand, ensure a rich supply of invertebrate prey. Three new localities of C. heros in Italy are quite different in this respect. The Groina stream near Gorizia and its tributaries seem to be a suboptimal habitat for C. heros due to their stony beds and their drying up in the hot summer months (Fig. 3). Scarcity of other water invertebrates and very poor dragonfly fauna, consisting of single Calopteryx virgo and Somatochlora meridionalis larvae, could confirm the last assumption. On the other hand, the Rio Sniardar stream near Brazzano is an optimal habitat for C. heros. Its shallow water, slow current, appropriate fine substrate, rich water invertebrate fauna and natural bank vegetation agree well with the ecological demands of the species (Figs. 4, 5). Sympatric occurrence of common dragonfly species Calopteryx virgo and Platycnemis pennipes is not surprising either.
According to literature, both other Cordulegaster species, viz. C. bidenatata and C. boltonii, are rare in the Friuli-Venezia Giulia region (Kiauta 1969b, Bognolo & Pecile 1995). The latter has been recorded only in the vicinity of Pontebba in the Alpine northeastern part of Friuli-Venezia Giulia, some 60 km north of newly discovered C. heros localities. Since C. boltonii and C. heros are closely related, it would be very interesting to work out the exact limits of their range in this part of Europe. It is worth mentioning that the well established list of Slovene odonate fauna may be incomplete in this respect. Although numerous old records of C. boltonii from Slovenia have been attributed only to C. heros described in 1979 (Kotarac 1997), it is quite possible that C. boltonii occurs somewhere in northwestern Slovenia.
In any case, western Slovenia and the eastern Friuli-Venezia Giulia almost definitely constitute the extreme north-western edge of C. heros European range. Further to the west, the landscape flows into intensively farmed deforested plains, and not far to the north there are the Alps, both with almost no suitable habitat for this particular species. Although the
NATURA SLOVENIAE 5(2): 19-29
25
three new Italian localities in the surroundings of Gorizia and Cormons are certainly not the only ones, the potential habitat of C. heros in Italy is very limited and the species therefore definitely rare and endangered. South of Gorizia, there are no streams due to the area’s karst landscape, but to the north some streams around Corno di Rosazzo and east of Cividale look very promising - at least on the map. In the field, there is indeed "…the turn of Italian odonatologists now."
Figure 3: Groina Stream NW of Gorizia, 750 m above the place where it joins the Isonzo river (Loc 1a). Suitable
Cordulegaster heros microhabitat in the stream is very scarce, the bottom is too stony and at least some stream sections
probably dry up during the summer. (Photo: M. Bedjanič)
Slika 3: Potok Grojnica SZ od Gorice, 750 m nad izlivom v Sočo (Lok 1a). Za velikega studenčarja primernih
mikrohabitatov je malo, saj je struga kamnita, vsaj nekateri odseki potoka pa se poleti verjetno posušijo. (foto: Matjaž
Bedjanič)
26               Matjaž BEDJANIČ & Ali ŠALAMUN: Large golden-ringed dragonfly Cordulegaster heros ... / SCIENTIFIC PAPER
Figure 4 (left) and Figure 5 (right): Two aspects of the Rio Sniardar stream near Brazzano (Loc 3) above the place where
it joins the Rio Fidri stream. Its shallow water, slow current, appropriate fine substrate and natural bank vegetation
constitute an ideal habitat for Cordulegaster heros. (Photo: M. Bedjanič)
Slika 4 (levo) in Slika 5 (desno): Dva pogleda na potok Smjardar pri Bračanu nad izlivom v potok Fedrih (Lok 3). Plitva
voda, miren tok, droben substrat ter naravna obrežna vegetacija sestavljajo idealen habitat za velikega studenčarja.
(foto: Matjaž Bedjanič)
Nature conservation aspect
As mentioned earlier, a special attention was paid, in addition to Cordulegaster heros, to the frog species Rana latastei. Both species are endangered and listed on the Annexes II and IV of the EU Habitat Directive (The Council Directive 92/43 EEC on the Conservation of Natural Habitats and on Wild Fauna and Flora, Off. Journal of the EC, No.L.206/7). They are stenotopic and live or breed almost exclusively in primary habitats, such as smaller forest streams and rivulets. The inclusion of C. heros and R. latastei to the Annexes II of the above-mentioned directive demands conservation of their habitats and obligates all member states, including Italy and Slovenia, to ensure long-term favourable conservation status for the
NATURA SLOVENIAE 5(2): 19-29
27
species in their territories. Their sympatric occurrence can therefore be of a great nature conservation importance.
As far as the newly discovered localities of C. heros in Italy are concerned, the Rio Sniardar stream near Brazzano (LOC 3) can definitely be proposed as future SITE OF COMMUNITY IMPORTANCE (SCI), since it presents an ideal habitat for C. heros and R. latastei as well. On the other hand, additional faunistic research is needed in order to clear the status of C. heros in Italy. A study of the species’ occurrence in the streams around Corno di Rosazzo and east of Cividale should be accomplished as soon as possible. Only then an assessment of the size and stability of the Italian C. heros population as well as an evaluation of potential threats and planning of appropriate conservation measures will be possible.
According to the strict provisions of the European Habitat Directive, Italy too should provide for a long-term survival of the C. heros population in its territory and effectively protect the species’ selected habitats. Due to the fact that the eastern Friuli-Venezia Giulia constitutes the extreme north-western edge of C. heros European range, this obligation is even more important. In this respect, the sympatric occurrence of C. heros and R. latastei can serve as an additional argument. It can facilitate the designation of suitable habitats of both species as SITES OF COMMUNITY IMPORTANCE (SCI) and herewith ensure their inclusion in European NATURA 2000 network. In this respect, the action already undertaken by Slovenia can serve as a good example (Kotarac et al. 2003, Poboljšaj & Lešnik 2003).
Povzetek
Italija je z vidika favne kačjih pastirjev razmeroma dobro raziskana in tudi v njenem severovzhodnem delu - Furlaniji-Julijski krajini - je v preteklosti potekalo nekaj odonatoloških aktivnosti (npr. Kiauta 1969b, Bognolo & Pecile 1995). Iz rodu studenčarjev Cordulegaster sta bila doslej v Furlaniji-Julijski krajini zabeležena le povirni studenčar C. bidentata in prodni studenčar C. boltonii. Veliki studenčar C. heros doslej še ni bil zabeležen v omenjeni regiji in Italiji nasploh (Utzeri 1995, Galletti & Pavesi 1985).
Veliki studenčar je razširjen na razmeroma majhnem območju, ki se razteza prek Slovaške, Avstrije, Slovenije, Madžarske, Hrvaške, Srbije, Makedonije, Bolgarije, Romunije in Grčije, s pričujočim prispevkom pa se območje znane razširjenosti vrste razteza tudi v Italijo. V Sloveniji velja veliki studenčar C. heros za dokaj pogosto vrsto, saj je bil doslej zabeležen na prek 340 lokalitetah (Fig. 1), njegov razvoj pa potrjen na prek 260 lokalitetah (Kotarac et al. 2003). V zahodni Sloveniji, blizu meje z Italijo, dosega veliki studenčar C. heros skrajno severozahodno mejo območja razširjenosti in je mnogo redkejši (Kotarac et al. 2003). Kljub temu je bila najdba vrste v Italiji pričakovana in so jo napovedovali že Kotarac (1997) ter Bedjanič & Pirnat (2000).
V okviru raziskav kačjih pastirjev in dvoživk sta avtorja 23. marca 2003 pregledala nekaj potokov med rekama Idrijo (Iudrio) in Sočo (Isonzo) v skrajnem vzhodnem delu Furlanije-Julijske krajine. Posebna pozornost je bila namenjena potrditvi pojavljanja velikega studenčarja C. heros in laške žabe Rana latastei, ki sodita med evropsko ogrožene vrste in sta uvrščena na Dodatka II in IV Habitatne direktive EU. Vrsti sta bili zabeleženi na skupno treh lokalitetah v okolici Gorice (Gorizia) in Krmina (Cormons) (Fig. 2).
28               Matjaž BEDJANIČ & Ali ŠALAMUN: Large golden-ringed dragonfly Cordulegaster heros ... / SCIENTIFIC PAPER
Potok Grojnica (Groina; Lok. 1A-B in 2A-C; Fig. 3) in njegovi pritoki zaradi neustreznega kamnitega substrata ter zelo verjetne poletne izsušitve niso ocenjeni kot najustreznejši habitat velikega studenčarja C. heros. Po drugi strani je potok Smjardar (Rio Sniardar, Lok. 3; Figs. 4, 5) pri Bračanu (Brazzano) ocenjen kot optimalen habitat te vrste. Gre za razmeroma plitev in počasi tekoč nižinski potok, katerega dno je pokrito z ustreznim drobnim substratom, kar se skupaj z bogato favno vodnih nevretenčarjev ter naravno obvodno vegetacijo v celoti pokriva z ekološkimi zahtevami velikega studenčarja C. heros.
Po podatkih iz literature sta tako povirni studenčar C. bidentata kot prodni studenčar C. boltonii v Furlaniji-Julijski krajini zelo redka (Kiauta 1969b, Bognolo & Pecile 1995). Ker je slednji v taksonomskem oziru zelo soroden velikemu studenčarju C. heros, bi bilo v prihodnosti zelo zanimivo podrobneje raziskati meje območij njune razširjenosti v severovzhodni Italiji in severozahodni Sloveniji. Novo odkrite lokalitete velikega studenčarja C. heros v Italiji nedvomno ležijo na skrajnem severozahodnem robu območja njegove razširjenosti. Sicer pa bo treba razširjenost in ogroženost velikega studenčarja v Italiji ter potencialno možnost, da se pojavlja tudi še nekoliko severneje, v okolici Korena (Corno di Rosazzo) in Čedada (Cividale del Friuli), preveriti z novimi raziskavami.
Z naravovarstvenega vidika je še posebej pomembno simpatrično pojavljanje velikega studenčarja C. heros in laške žabe Rana latastei. Gre namreč za evropsko ogroženi vrsti z relativno ozko ekološko valenco, ki naseljujeta skoraj izključno naravno ohranjene nižinske gozdne potoke. Direktiva o habitatih zavezuje Italijo in Slovenijo k ustreznemu ohranjanju njunih bivališč in zagotavljanju dolgoročno ugodnega ohranitvenega stanja njunih populacij. V tem oziru avtorja predlagata, da se njuna bivališča v Italiji in zahodni Sloveniji ohranijo v okviru evropskega omrežja zavarovanih območij NATURA 2000.
Acknowledgements
The authors would like to express their sincere thanks to all members of the Slovene Odonatological Society, who submitted their faunistic data for Slovenia. Thanks are also due to Mr Mladen Kotarac (Miklavž na Dravskem polju, Slovenia) for his critical review of the manuscript, and to Mr Henrik Ciglič (Kranj, Slovenia) for kindly checking the English language.
References
Bedjanič M. (2000): Mladinski ekološki raziskovalni tabor Vogrsko 2000. Erjavecia 10: 7-10.
Bedjanič M., Pirnat A. (2000): Prispevek k poznavanju favne kačjih pastirjev (Insecta, Odonata) Vipavske doline (zahodna Slovenija). Natura Sloveniae 2(2): 29-45.
Blaškovič T., Šíbl J., Bulánková E. (2003): First record of Cordulegaster heros ssp. heros
Theischinger, 1979 (Cordulegastridae, Odonata) from Slovakia. Biologia, Bratislava: 2, in press.
Bognolo E., Pecile P. (1995): La fauna odonatologica del Carso triestino, del Carso Goriziano e di alcune localita limitrofe. Atti Mus. civ. Stor. nat. Trieste 46: 145-171.
Červek U. (1997): Poročilo odonatološke skupine. V: Kodele Krašna, I. (ured.), Raziskovalni ekološki tabor "Goče 97", str. 36-40, Zveza prijateljev mladine Ajdovščina, Ajdovščina.
NATURA SLOVENIAE 5(2): 19-29
29
Galletti P.A., Pavesi M. (1985): Ulteriori considerazioni sui Cordulegaster italiani (Odonata, Cordulegasteridae). G. it. Ent. 2: 307-326.
Kiauta B. (1969a): Zbirka kačjih pastirjev z notranjskega krasa in Primorske v tržaškem
Prirodoslovnem muzeju s seznamom in zoogeografsko analizo favne tega ozemlja. Biol. Vestn. 17: 101-111.
Kiauta B. (1969b): Survey of the Odonate Fauna of the autonomus region Friuli-Venezia Giulia (Northern Italy). Atti Mus. civ. Stor. nat. Trieste 26(6)8: 177-247.
Kotarac M. (1997): Atlas kačjih pastirjev (Odonata) Slovenije z Rdečim seznamom: projekt Slovenskega odonatološkega društva. Center za kartografijo favne in flore, Miklavž na Dravskem polju. 205 str.
Kotarac M., Šalamun A. & Weldt S. (2003): Strokovna izhodišča za vzpostavljanje omrežja Natura 2000: Kačji pastirji (Odonata) (končno poročilo). Naročnik: MOPE, ARSO, Ljubljana. Center za kartografijo favne in flore, Miklavž na Dravskem polju. 104 str., digitalne priloge.
Pirker P. (2002): Mladinski raziskovalni tabor Vogrsko 2001. Erjavecia 13: 11-14.
Pirnat, A. (1996): Hitri lepotci - Poročilo odonatološke skupine. V: I. Šinkovec (ured.), Ekološki raziskovalni tabor "Gora 96", str. 14-17, Zveza prijateljev mladine Ajdovščina, Ajdovščina.
Poboljšaj K., Lešnik A. (2003): Strokovna izhodiša za vzpostavljanje omrežja Natura 2000: Dvoživke (Amphibia) (končno poročilo). Naročnik: MOPE, ARSO, Ljubljana. Center za kartografijo favne in flore, Miklavž na Dravskem polju. 144 str., digitalne priloge.
Šalamun A., Pirnat A., Bedjanič M., Kotarac M. (1997): Prispevek k poznavanju favne kačjih pastirjev (Odonata) jugozahodne Slovenije. V: Bedjanič, M. (ured.), Raziskovalni tabor študentov biologije Podgrad '96, str. 55-74, ZOTKS - Gibanje znanost mladini, Ljubljana.
Utzeri C. (1995): Odonata. In: A. Minelli, S. Ruffo & S. La Posta (Eds.), Checklist delle specie della fauna italiana, pt 35, pp. 1-7, Calderini, Bologna.
Wasscher M.T., Bos F.G. (2000): The European dragonflies: notes on the checklist and on species diversity. Odonatologica 29(1): 31-43.