First data on the natural recovery of the Eurasian otter (Lutra l. lutra Linnaeus, 1758) in Veneto Region (north-eastern Italy)

G. De Nadai, M. Cassol, L. Lapini

 

Abstract
After a short philological review of the present knowledge on the otter <em>Lutra lutra</em> in Veneto Region (north-eastern Italy), the Authors refer the positive results of a first short otter survey in Venetian Alps, confirming the natural return of the otter in the Province of Belluno. These are the first sure data from Veneto Region in the XXI century, which opens new perspectives of research aimed at understanding the situation to promote the conservation of the species in north-eastern Italy.

Key words: Lutra lutra, Eurasian otter, preliminary otter survey, Belluno Province, Veneto Region, north-eastern Italy

Riassunto breve
Dopo una breve revisione filologica delle attuali conoscenze sulla lontra <em>Lutra lutra</em> nella Regione Veneto (Italia nord-orientale), gli Autori riferiscono i risultati di una prima breve otter survey condotta sulle Alpi venete, confermando che la lontra è tornata naturalmente nella Provincia di Belluno. Si tratta dei primi dati certi del XXI secolo, che aprono nuove prospettive per ulteriori ricerche finalizzate a comprendere la situazione e favorire la conservazione della specie nell’Italia nord-orientale.

Parole chiave: Lutra lutra, lontra eurasiatica, otter survey preliminare, Provincia di Belluno, Regione Veneto, Italia nord-orientale

Authors addresses:
–Gabriele De Nadai – Via Cal del Vento, 9b. I-32035 Santa Giustina Belluno, Italy gabridenadai@libero.it
–Michele Cassol – Via Fornaci 25a. I-32036 Sedico Belluno, Italy michelecassol@libero.it
–Luca Lapini – Sezione Zoologica del Museo Friulano di St. Naturale, Via C. Gradenigo Sabbadini, 22-32. I-33100 Udine Italy lucalapini1@gmail.com

 

Introduction

The cause of the past dramatic decline of the otter Lutra lutra all over in Western Europe is not yet fully understood, but probably was multi-factorial (Reuther & Festetics, 1980; Panzacchi et al., 2011; Hung & Law, 2016). Otter population collapse, indeed, has been due both to the high diffusion of organo-chlorinated pesticides and PCB pollutants in European trophic-chains, to habitat losses, to road kills, hunting and poaching, all independent factors which acted synergistically (Reuther & Festetics, 1980; Loy et al., 2015). The Italian status of the otter in the 50’s-70’s of the XX century mirrored the West European situation of the species, to the point that at the beginning of ‘80s only about one hundred otters survived in central-southern Italy (Macdonald & Mason, 1982, 1983; Lapini, 1985; Cassola, 1986).

In spite of a lot of questionnaire information published by Spagnesi (1980) and Pavan & Mazzoldi (1983), the extinction of Lutra lutra in Veneto Region is well documented in both specie-specific and museum papers, being apparently referred to 50’s and 70’s of the XX century (Lapini, 1985; Cassola, 1986; Rallo, 1986; De Marinis & Lapini, 1994; Meneghini et al., 2011).
The natural recovery of Lutra lutra in Italy during the XXI century, anyway, is increasingly evident both from South, North-East and North-West (Loy et al., 2015; Giovacchini et al., 2021: Fig. 1) and bodes well in the future of Italian otters, at present estimated in about 800-1000 specimens. Nevertheless, in spite of various regional camera-trapping studies (Spada et al., 2016a; Spada et al., 2016b; De Nadai et al., 2021), up to now it was never possible to verify the return of Lutra lutra in Veneto Region, despite clear data about the natural recovery of the species in the neighbouring Austria (Kranz & Poledník, 2020), Alto Adige (Righetti, 2011) and Friuli Venezia Giulia Region (Bonesi & Lapini, 2011; Iordan, 2014; Lapini et al., 2014; Pavanello et al., 2015; Lapini, 2019; Lapini et al., 2020; Giovacchini et al., 2021; Stokel et al., 2022; Lapini, 2022).

The data published by Righetti (2011) for Alto Adige/South Tyrol seem to be in good ecologic continuity with northern Veneto and one data collected by Lapini et al. (2020) is referred to the watershed between Piave and Tagliamento River-Catchments (Forni Avoltri, Udine, June, 15th, 2019: Lapini et al., 2020: 45), quite near to the regional boundary between Veneto and Friuli Venezia Giulia. The first record of XXI century on the presence of the otter in Veneto -referred to a possible sprainting site observed upstream of Sega Digon (Belluno Province) during 2019- has been communicated as a putative otter datum to various regional officers of the public Administration of Veneto Region (dr. S. Calderola) and to the Province of Belluno (dr. S. Vendrami), but it was never confirmed in the field, in spite of various attempts conducted between September and December 2020 (Stokel et al., 2022). In order to verify this putative information a preliminary bridge otter survey has been performed in the same brook-system quoted by Stokel et al. (2022) and surroundings.

 

Methods

The first attempts to find Eurasian otter have been conducted between October, 28th, 2022 and November, 15th, 2022 in the North-East alpine area of Belluno Province. A preliminary otter survey was carried out searching for otter spraints under 34 suitable bridges (the bridge suitability was evaluated according to Lapini et al., 2020). Surveyed bridges were distributed along streams of various alpine brook-systems the northern part of Belluno Province, within six cells of the ETRS LAEA 1989 10×10 km grid cartographic system (Fig. 2).
Otter spraints were determined both for their morphology and general aspect, for their contents and particularly for their diagnostic smell. This last is surely the best diagnostic character to distinguish Lutra lutra spraints from undigested bird pellets (airons, cormorants and gulls) or faecal remains of American mink, stone/beech martens, polecats and other mammals (Macdonald & Mason, 1982, 1983; Lapini, 1985; Cassola, 1986; Hung & Law, 2016).

First results, provisional remarks and perspectives

At present our preliminary survey allowed to collect otter spraints only in Val Digon (November, 12th, 2022: Figgs. 2-5). These data confirm the indication of Stokel et al. (2022), referred to one putative unpublished datum recorded by S. Filacorda on March, 19th, 2019 in the same brook-system.

This new finding seems to confirm its validity, also indicating that almost four years later Lutra lutra is still present in the same alpine brook-system. From the review of all available sure record (Lapini et al., 2020; Stokel et al., 2022; present paper) it is so possible to hypothesize that the otter is came back to Venetian Alps since about four years. It is not a trivial thing, because in oligotrophic mountain-environments is not easy neither to find otter signs (for a researcher), nor to survive for a such long time in the same alpine brook-system (for an otter).
At present is impossible to evaluate the current status of the Eurasian otter on Venetian Alps, but the autumn marking activity made by otters in the surveyed mountain-brooks seems to be low, with only one positivity on 34 surveyed bridges. A very low positivity rate (2,94/%), but surely a concrete starting point to stimulate extensive otter surveys in the whole Veneto Region. For as concerns the provenience of the otter that lives in the studied brook-systems of the high Province of Belluno at present it is only possible to hypothesize that it cames from Austria or Alto Adige/South Tyrol rather than from Friuli Venezia Giulia Region (see Righetti, 2011 and Lapini et al., 2020).

In the prosecution of further otter surveys on Venetian Alps it seems anyway appropriate to combine other techniques and methodologies, such as camera-trapping on previously identified sprainting sites and search-paths of at least 600 meters along the riverbanks, as usually recommended by the Otter Specialist Group (e. g. Lapini, 1985; Cassola, 1986; Panzacchi et al., 2011; Loy & Fusillo, 2016). The combination of several techniques, in fact, usually ensures better results in the conduction of otter-surveys (Panzacchi et al., 2011; Loy & Fusillo, 2016; Stokel et al., 2022). A particular attention is now needed for all the Alpine and Pre-alpine areas of the Veneto Region, both to increase the data about the present distribution of the otter on these mountains and for a detailed monitoring of its natural recovery in Veneto Region. On the base of the quick recovering of the species in similar neighbouring areas (Righetti, 2011; Lapini et al., 2020; Kranz & Poledník, 2020; Giovacchini et al., 2021; Stokel et al., 2022) seem to be quite probable that also in Veneto the recovery and expansion of Lutra lutra will proceed very quickly.

 

Acknowledgements

We wish to thank all the people who provided useful details to redact this first note on the otter in Veneto. Special thanks to S. Calderola, J. Ceresatto, F. Dartora, R. Deon, E. De Zolt, S. Filacorda, E. Marconato, D. Righetti, M. Semenzato, A. Spada, G. Stokel, P. Tomè, S. Triches, S. Vendrami and M. Villa for some original news and for various bibliographic, cartographic and technical field advices.

 

References

Bon M. (curatore), 2017. Nuovo Atlante dei Mammiferi del Veneto. WBA Project Monographs, 4: 1-368.
Cassola F. (curatore), 1986. La Lontra in Italia. Censimento, distribuzione e problemi di conservazione di una specie minacciata. WWF ed., Serie Atti e Studi, 5, Roma.
De Marinis A. & Lapini L., 1994. Collections of Italian Mustelidae (Mammalia, Carnivora) housed in Italian Museums. Boll. Mus Reg. Sci. Nat. Torino, 12: 255-325.
Deflorian M. C., Caldonazzi M., Zanghellini S. & Pedrini P. (curatori), 2018. Atlante dei Mammiferi della provincia di Trento. Muse ed., Monografie del Museo dele Scienze, Trento: 1-317.
De Nadai G., Deon R., Triches S. & Cassol M., 2021. Aggiornamento della distribuzione di puzzola europea (Mustela putorius L., 1758) in Provincia di Belluno. Frammenti – Conoscere e tutelare la natura bellunese, 11: 21-31, Feltre, Belluno.
Giovacchini S., Antonucci A., Bartolomei R., Bandini M., Caldarella M., De Castro G., Riso L., Di Marzio M., Fabrizio M., Fulco E., Gariano P., Gavagnin P., Lapini L., Marrese M., Mastropasqua F.,Pavanello M., Scaravelli D., Spilinga C., Sulli C., Tremolada P., Balestrieri A. & Loy A., 2021. Conservation status of European otter Lutra lutra in Italy. EOW-Eurasian otter workshop organized by IUCN/SSC Otter Specialist Group, 26-28 February 2021 (Poster).
Hung N. & Law C. J., 2016. Lutra lutra (Carnivora: Mustelidae. Mammalian Species, 48(940): 109-122.
Iordan F., 2014. The American mink and the Eurasian otter in Friuli Venezia Giulia: a study to reveal their distribution and the most sensistive areas for their expansion. University of Trieste, Progetto Sharm 2013–2014, Supervisore prof. A. Altobelli: 1–42.
Kranz A. & Poledník L., 2020. Recolonization of the Austrian Alps by otters: conflicts and management. Journal of Mountain Ecology, 13 (2020): 31–40. Lapini L., 1985. La lontra. C. Lorenzini ed., Udine.
Lapini L., 1986. La Lontra in Friuli-Venezia Giulia. In Cassola F. (curatore), 1986. La Lontra in Italia. Censimento, distribuzione e problemi di conservazione di una specie minacciata. WWF ed., Serie Atti e Studi, 5, Roma: 48-51.
Lapini L., 2019. Il ritorno della lontra (Lutra lutra) nell’Italia nord-orientale. Habitatonline, marzo 2019. https://www.habitatonline.eu/2019/03/il-ritorno-della-lontra-lutra-lutra-nellitalia-nord-orientale/
Lapini L., 2022 (in press). Teriofauna dell’Italia nord-orientale (Mammalia: Regione Friuli Venezia Giulia). Gortania. Botanica, Zoologia, 44 (2022).
Lapini L., Dorigo L., Glerean P. & Giovannelli M. M., 2014. Status di alcune specie protette dalla Direttiva Habitat 92/43 CEE nel Friuli Venezia Giulia (Invertebrati, Anfibi, Rettili, Mammiferi). Gortania. Botanica, Zoologia, 35: 61-140.
Lapini L., Pontarini R., Molinari P., Cantarutti G., Dorigo L., Pecorella S., Cesco N., Commessatti G., Comuzzo C., Da Pieve J., De Belli E., Dreon A. L., Giacomuzzi D., Luca M., Mareschi A., Picco G. & Rossi A., 2020. The return of the Eurasian otter in north- eastern Italy. New challenges for biological conservation from Friuli Venezia Giulia Region. Journal of Mountain Ecology, 13 (2020): 41–50.
Loy A., Balestrieri A., Bartolomei R., Bonesi L., Caldarella M., de Castro G., Della Salda L., Fulco E., Fusillo R., Gariano P., Imperi F., Iordan F., Lapini L., Lerone L., Marcelli M., Marrese M., Pavanello M., Prigioni C. & Righetti D., 2015. The Eurasian otter (Lutra lutra) in Italy: distribution, trend and threats. European Otter Workshop 2015, Swedish Museum of Natural History in Stockholm, Sweden 8–11 June 2015 (poster).
Loy A. & Fusillo R., 2016. Lutra lutra (Linnaeus, 1758) (Lontra eurasiatica). In: Stoch F. & Genovesi P. (curatori), 2016. Manuali per il monitoraggio di specie e habitat di interesse comunitario (Direttiva 92/43/CEE) in Italia: specie animali. ISPRA, Serie Manuali e linee guida, 141/2016: 344-345.
Macdonald S. & Mason C., 1982. A survey for otters (Lutra lutra) in Southern Italy. Unpublished report to WWF-Italy, Roma: 1-15.
Macdonald S. & Mason C., 1983. The otter Lutra lutra in Southern Italy. Biological Conservation, 25: 95-101.
Meneghini M., Gallo F. & Nicolosi P., 2011. Vertebrati del Veneto nelle collezioni del Museo di Zoologia dell’Università di Padova. In: Bon M., Mezzavilla F. & Scarton F. (curatori), 2011, Atti VI Convegno dei Faunisti Veneti, Treviso 15-16 maggio 2010. Suppl. Bollettino del Museo civico di Storia Naturale di Venezia, 61 (9): 43-47.
Panzacchi M., Genovesi P. & Loy A., 2011. Piano d’Azione Nazionale per la Conservazione della Lontra (Lutra lutra). Quad. Cons. Natura, 35, Min. Ambiente – ISPRA: 1-267.
Pavan G. & Mazzoldi P., 1983. Banca dati della distribuzione geografica di 22 specie di Mammiferi in Italia. Collana Verde – Ministero Agricoltura e Foreste ed., 66: 33-279.
Pavanello M., Lapini L., Kranz A. & Iordan F., 2015. Rediscovering the Eurasian otter (Lutra lutra) in Friuli Venezia Giulia (NE Italy) and notes on its possible expansion in northern Italy. IUCN Otter Spec. Group Bull., 32 (1): 12-20.
Rallo G., 1986. La lontra nel Veneto. In: Cassola F. (curatore), 1986 La Lontra in Italia. Censimento, distribuzione e problemi di conservazione di una specie minacciata. WWF ed., Serie Atti e Studi, 5, Roma: 45-47.
Reuthers C. & Festetics A., 1980. Der Fischotter in Europa, Verbreitung, Bedrohung, Erhaltung. Selbstverlag der Aktion Fischotterschutz e. V, Oderhaus und der Forschungsgemeinschaft für Wildtierschutz, Göttingen.
Righetti D., 2011. Return of the otter in South Tyrol (NE Italy). Proc. XI Otter Colloquium. Hystrix, The Italian Journal Of Mammalogy (N. S., supp. 2011): 122.
Spada A., Bon M., Dartora F., Romanazzi E. & Vettorazzo E., 2016 a. Progetto di fototrappolaggio dei mustelidi e del gatto selvatico, Felis silvestris silvestris Schreber, 1777, nel Parco Nazionale delle Dolomiti Bellunesi. Atti del VII Convegno dei Faunisti Veneti, Verona 15-16 novembre 2014.
Spada A., Pascotto E. & Dartora F., 2016 b. Indagine, tramite siti di attrazione, sulla distribuzione dei carnivori di media-piccola taglia nelle Prealpi orientali del Veneto: sviluppo di una metodica ripetibile. Atti del VII Convegno dei Faunisti Veneti, Verona 15-16 novembre 2014.
Spagnesi M., 1980. Das Vorkommen des Fischotters in Italien. In: Reuthers C. & Festetics A., 1980. Der Fischotter in Europa, Verbreitung, Bedrohung, Erhaltung. Selbstverlag der Aktion Fischotterschutz e. V, Oderhaus und der Forschungsgemeinschaft für Wildtierschutz, Göttingen: 211-214.
Stokel G., Franchini M., Frangini L., Pizzul E. & Filacorda S., 2022. Has the Recolonization of the Po Plain Begun? Updates regarding the Presence of the Otter (Lutra lutra) in North-Eastern Italy. IUCN Otter Spec. Group Bull. 39 (2): 90 – 101.

 

 

 

Fig. 1. Natural recovery of Lutra lutra in Italy (NE Italy data from Lapini, 2019; Lapini et al., 2014; Iordan, 2014; Pavanello et al., 2015; Lapini et al., 2020). Map redacted by Giovacchini et al. (2021) on the base of the ETRS LAEA 1989 10×10 km grid Cartographic system. The positive cells in Lombardy are referred to the release of some B-line otters previously utilized in the breeding education centre of Ticino Regional Park. In this region, however, a road kill of one four year-old male (August, 15th, 2012 Tovo di Sant’Agata, Sondrio: not represented in the map) also indicate rare presences due to the natural dispersion of Austrian otters. The recovery of Lutra lutra in the Province of Bolzano is not represented in the map too, but it has been indicated by A. Kranz and D. Righetti at least from 2008 (Righetti, 2011).

 

 

Fig. 2. Yield of a first preliminary bridge otter survey conducted in the high Province of Belluno between October, 28th, 2022 and November, 15th, 2022. Only one of the six surveyed ETRS cells turned out to be positive for otter spraints. This cell is indicated in gray in the upper left box of the map below, representing Veneto Region according to the ETRS LAEA 1989 10×10 km grid Cartographic system.
Legend: Red dots=positive data of the present survey;
             Green dots=negative data;
               Black dot=putative data quoted by Stokel et al., 2022.

 

 

Fig. 3. Multiple sprainting site discovered in Val Digon (Belluno Province) on November, 12th , 2022
(Foto by G. De Nadai). Clearly visible on the right various undigested Salmonidae eggs. In this brook
only the common brown trout (Salmo trutta trutta) has been signalled so far (E. Marconato, ex verbis).

 

 

 

Fig. 4. A brown trout (Salmo [trutta] trutta) photographed near the sprainting site (Val Digon, Belluno, November, 12th , 2022, Photo by G. De Nadai).

 

 

 

Fig. 5. Overall view of the sprainting site (Val Digon, Belluno, November, 12th , 2022, Photo by M.
Cassol).

 

Download PDF

Preliminary observation about a mixed breeding roost of Nyctalus lasiopterus and Nyctalus noctulain north-eastern Italy (Friuli Venezia Giulia Region)

Preliminary observation about a mixed breeding roost of Nyctalus lasiopterus and Nyctalus noctula in north-eastern Italy (Friuli Venezia Giulia Region)

 

 

 

di Anne Maenurm, Matteo De Luca, Marco Luca, Stefano Zanini, Sandra Bellomo & Luca Lapini

 

Abstract: The Authors present some observations on a mixed breeding roost of giant (Nyctalus lasiopterus) and common noctule (Nyctalus noctula) in a lowland wood of the Friulian flood-plain. This maternal aggregation is the only known Italian breeding roost of Nyctalus lasiopterus. After a short synthesis of the present knowledge about the local situation of this rare bat, the Authors outline a provisional list of the local bat-community. Key words: mixed breeding nursery, Nyctalus lasiopterus, Nyctalus noctula, north-eastern Italy, Friuli Venezia Giulia Region, forest management, nature conservation.

Parole chiave: nursery riproduttiva mista, Nyctalus lasiopterus, Nyctalus noctula, Italia nordorientale, Regione Friuli Venezia Giulia, gestione forestale, conservazione della natura.

 

Riassunto breve: Gli Autori segnalano una nursery riproduttiva di Nyctalus lasiopterus in un bosco planiziario della bassa pianura friulana. L’assembramento riproduttivo è misto, condiviso con molti esemplari di Nyctalus noctula, come si evince dalle misurazioni di alcuni animali e dallo studio bio-acustico della loro emergenza serale. I conteggi degli animali effettuati prima dei parti indicano la presenza di più di duecento esemplari, ma non è stato ancora possibile studiare la proporzione fra le due specie. Vista l’estrema rarità di Nyctalus lasiopterus in Italia e in Europa, gli Autori svolgono alcune considerazioni di tipo conservazionistico con particolare riferimento alla situazione italiana della specie. Limitate survey bio-acustiche e l’esame della bibliografia infine consentono di comporre un quadro complessivo della locale comunità di chirotteri.

 

Authors Addresses:

-Anne Maenurm (hereinafter A. M.), Torviscosa, I-33050, Udine – annemaenurm@gmail.com; www.annemaenurm.com

-Matteo De Luca (hereinafter M. D. L.), Via Venezuela 31, I-33100, Udine – teto8@libero.it

-Marco Luca (hereinafter M. L.), Regional Forestry Corp of the Authonomous Region Friuli Venezia Giulia, Forestry Section of Cervignano del Friuli, Via Mons. A. Ramazzotti, 16, I-33052, Cervignano del Friuli, Udine – marco.luca@regione.fvg.it

-Stefano Zanini (hereinafter S. Z.), Regional Forestry Corp of the Authonomous Region Friuli Venezia Giulia, Forestry Section of Coseano, vis Caporiacco, I-33034, Fagagna, Udine – stefano.zanini@regione.fvg.it

–Sandra Bellomo (hereinafter S. B.), ODV (Organizzazione di Volontariato) NGO “Pronto Soccorso Pipistrelli”, Via Bosco dell’Arneret 17, I-33080 Fiume Veneto, Pordenone – sannyfly68@gmail.com

-Luca Lapini (L. L.), Sezione Zoologica del Museo Friulano di Storia Naturale, via C. Gradenigo Sabbadini, 22-32, I-33100 Udine – lucalapini1@gmail.com

 

Introduction

The giant noctule bat (Nyctalus lasiopterus) is a big arboreal species very rare both in Europe (Dietz et al., 2009) and in Italy (Lanza 2012), where it has been signalled only in about 20 localities (Lapini et al., 2019; Agnelli et al., 2019; Agnelli & Lapini, in press).

The casual descovery of a mixed maternal roost of this arboreal bat in north-eastern italy is particularly interesting. The preliminary results of the studies conducted on this roost in 2021 and 2022 constitutes the matter of this paper.

The communication of georeferenced observations about this roost is a first unavoidable step to impose the legal protection of the little lowland wood used by bats. A wrong forest-management of this wood-patch, indeed, could easily harm the breeding roost studied.

 

The area of researches

The lowland-wood theatre of the observations is the so called “Bosco di Pradiziolo” (Municipality of Cervignano, Udine), a private 20 hectares relict of the ancient pristine wood named “Silva lupanica” (Sguazzin, 2004; Maenurm, 2021).

This last was a wet oak and ash forest [Asparago tenuifolii – Quercetum roboris (Lausi 1996) Marincek 1994] that once completely covered the upper Adriatic coasts between the Catchments of River Livenza and River Isonzo, today fragmented in a lot of scattered little patches of woods dispersed in the lowlands of the Region Friuli Venezia Giulia (Sguazzin, 2004). Complexively they reach an extension of about 500 hectares, at present increased by various experiences of habitat restoration up to about 700 hectares.

Botanic and floristic details about these relict woods have been gathered by a lot of authors and a complexive synthesis of their observation have been published by Sguazzin (2004).

 

The facts

During the realization of a photo-naturalistic book on the lowland woods of the Friulian flood-plain it was possible to observe and photograph a lot of big bats fly away from a tree-hole of an aspen (Populus tremula), located at about 8 meters high. These bats where then visually determined by L. L. on the base of various photos published by Maenurm (2021: 92: fig. 4).

It was therefore possible to reconstruct the first data collected on these bats:

-On April, 30th, 2021, 20:16 the phone-video recording of a part of this nursery emerging allows to count at least 88 large bats (A. M. obs.);

-On May, 1 th, 2021, 20:13 hours, evening emergence of the same bats, lasted till 20,22 (A. M. obs.);

-On May, 5th, 2021, 20:41 hours, evening emergence of bats, lasted till 20,47 (A. M. obs.) (Fig. 4);

-On May, 21 th , 2021, 20:46 hours, first bat exit from the tree hole (A. M. obs.);

-On May, 21 th, 2021, 20:49:15 Picus viridis arrives at the entrance entering in the tree hole; it flies immediately away from the hole with at least two large bats cling to the body, entangled in a short flying fight (A. M. obs.);

-On May, 21 th, 20,49,27 Picus viridis returns at the entrance of the tree hole after the short fight with the bats (A. M. obs.)

These first observations were the starting point of further observation conducted both in 2021 and 2022 particularly focused on:

1-to determine the bat-species syntopic in the same arboreal roost;

2-to determine the species of trees used as roost by these forestal bats;

3-To determine the number of trees used as maternal roosts by bats;

4-To determine the internal structure of some roosts used by bats.

 

Methods

The main objective of the field monitoring was to avoid any kind of disturbance, both in the reproductive and in any other phenetic period of the studied bats. For this reason photos of flying and resting bats have been obtained by using digital cameras with small teleobiectives, both by hands or activated by photocells with motion sensors.

Localization of the trees used by breeding bats:

-Noctules are very vociferous in their breeding aggregations, and the low-frequency calls emitted in their reproductive tree shelter can be heard by some persons also without bat-detector. The frequent inspection of the wood permits to A. M. to take a census of various trees used by breeding bats. Fifty-five (55) field sampling days (about 550 hours) were complexively employed for this census, contemporary with other various photo-naturalistic activities.

Species determination from photos:

-the visual determination of flying bats from photos allows to distinguish hairy-winged noctules (Nyctalus lasiopterus: ventral side of the wings hairy at least up to the elbow: Fig. 2) from barewinged ones (Nyctalus noctula and/or Nyctalus leisleri: almost bare ventral side of the wings).

-some specimens were photographed resting in high tree-holes, in some cases with forearms well exposed on the border of the hole (1). With the same angulation were then taken photos of the same tree-hole cavity with a physically superimposed meter (2). The overlapping of 1 and 2 allows a precise measuration of the bat-forearms well exposed on the border of the same tree-hole (Fig. 6).

Bats count:

-A provisional bat estimation numbers has been based on their count at the evening emergency, particularly performed by A. M. and S. Z. Sometimes they where video-recorded to obtain more precise numerical estimates.

Species determination of handled bats:

-The study and recovery of each specimen fell to the ground or injuried in the research zone during the years 2021 and 2022 gathers integrative data both on the studied maternal roosts and on other sympatric bats. They were determined by L. L., treated from a health point of view by the ODV (NGO) “Pronto Soccorso Pipistrelli” managed by S. B. and after released in the original recovery point of each animal. The determination of handled bats has been performed by using the canonic diagnostic characters indicated by Dietz et al. (2009), Lanza (2012), Dietz & Kiefer (2014).

Observation of the internal structure of some breeding roost

-The study of the internal structure of some breeding roost at present was very limited to avoid any disturbance to breeding bats. Up to now it has been performed only by visual inspection of the first cavity individuated by A. M. on May, 5th, 2021, observing from the same exit hole used by bats.

Bio-acoustic bat surveys

-A provisional bio-acoustic survey was performed both in the wood and in its surroundings by using the Pettersson D1000x bat-detector, after integrated by a short nigth-by nigth ultrasonic survey performed by using the Pettersson D500x bat-detector. The recorded bat sounds were then analyzed by using the software BatSound 4.2 Pettersson, as already done in the Bats 2013-2014 monitoring project recently funded by Friuli Venezia Giulia Regional Adminstration (Lapini & Dorigo, 2015).

 

Results

-Up to now it has been possible to take a census of 12 trees utilized by breeding bats.

-The photographic identification of flying bats allows a first determination of Nyctalus lasiopterus and N. noctula, after confirmed by bio-acoustic techniques. The measuration of the forearm of various specimens allowed to confirm previous photographic and bio-acoustic identifications.

-The breeding bats use at least 12 trees of various species (Populus tremula, Fraxinus angustifolia and Quercus peduncolata) originally excavated by various woodpeckers (Picus viridis, Dryocopus martius, Dendrocopos major). Nevertheless, only one of these trees appears to be dead.

-Up to now only one of the cavities used by bats, located in a Populus tremula, has been partially explored by M. L. and S. Z. This cavity seems to be particularly extended, developing for several meters inside the tree.

-The contemporary presence of Nyctalus leisleri was verified by the late-summer recovery of an injured reproductive female from a locality very near to the studied roost. This female have been collected on September, 15th, 2021 by the Forestry Service of the Friuli Venezia Giulia Public Administration [CFR-FVG] in a locality that is about 2,4 km N-NE far from to the studied nursery and then recovered from a health point of view by the NGO “Pronto Soccorso Pipistrelli”. At its release (May, 24th, 2022) this bat made two or three circular self-orientation flights around to the local highway bridge, then pointing directly towards the studied nursery which are about 300 meters away.

 

Noteworthy remarks and perspectives

-The studied nursery is the only known Italian breeding roost of Nyctalus lasiopterus. In this maternal aggregation during the summer 2022 the species gave birth on June, 13th (Fig. 7 and 8). This is the only available datum about the birth period of the giant noctule in Italy.

-Our preliminary observations confirm that also in Italy the species constitutes mixed nurseries with Nyctalus noctula. The contemporary presence of Nyctalus leisleri in the area of researches indicate the possibility that in this lowland zone Nyctalus lasiopterus, N. noctula and N. leisleri can share the same breeding roost. Further studies are needed to confirm the local breeding of Nyctalus leisleri, that in Italy up to now seems to breed only in three localities of central Italy (Ancillotto & Russo, 2015).

-The studied nursery has been settled in at least four arboreal species (Populus tremula, Fraxinus angustifolia, Quercus peduncolata), using tree holes excavated by various woodpeckers (Picus viridis, Dryocopus martius, Dendrocopos major). In one Populus tremula the original Dryocopus martius cavity seems to be vertically extended to all the trunk, being probably used by bats also in cold season. Around to this tree, anyway, there are at least other eleven trees used by breeding bats, all enclosed in a wood patch of about 150-300 meters of diameter.

-From our preliminary observations seem to be clear that breeding bats are very mobile, constantly moving from one cavity to another. On the base of these observation we hypotesize that all the trees locally used by bats may be parts of a single large mixed maternal roost of Nyctalus noctula / N. lasiopterus.

-Almost all the nursery of noctule-bats descovered in Friuli Venezia Giulia Region were located in monumental trees of parks and urban avenue (Lapini et al., 1996), as happens in many other Italian Regions (e. g. Giuntini et al., 2022). In Friuli Venezia Giulia, anyway, noctule-bats often breed also in buildings, chimneys, bridges and other anthropic structures (Lapini et al., 2019). The mixed breeding aggregation described in the present paper is the only one known located in a natural wood of the whole Friuli Venezia Giulia Region (Lapini et al, 2020). Its legal protection certainly constitutes a priority in Nature-conservation of the whole north-Adriatic hinterland.

-The ultrasound bat-detector studies performed in the study zone and surroundings has gathered various data about the local bat-assemblage. The bat community in and around to this little lowland wood seems to be composed at least by: Pipistrellus kuhlii, Pipistrellus nathusii, Myotis daubentonii/capaccinii, Myotis myotis/blythii, Nyctalus noctula, Nyctalus leisleri, Nyctalus lasiopterus, Hypsugo savii (Tab. I).

-The protection of this small lowland wood seems to be essential to preserve the studied nursery, particularly for its future conservation. At present the wood of Pradiziolo (Cervignano, Udine) is not legally protected, but its owner gathers a very high degree of tranquillity to the wood, which is a part of a bigger private hunting estate (a so called “Azienda Faunistico Venatoria”). For this reason it is protected by fences and metal gates with the aim to reduce the main anthropic pressures in the forest (generic tourists, photo-naturalists, mushroom pickers, hunters, etc.). Its legal protection, anyway, is very urgent particularly to avoid possible wrong practices of forest-management, often capable of eliminating all hollow trees. The Biodiversity Service of the Public Administration of the Region Friuli Venezia Giulia indicates that the art. 20 of the Regional Law 42/1996 could ensure the protection of this wood even by continuing the usual cynegetic and agro-silvopastoral lowimpact activities.

-Our observations confirm that the respect of dead or diseased vertical trees perforated by woodpeckers is very important in forest-management from a conservation point of view (e. g. Meschede, 2001; Marchesi et al., 2008; Jackson, 2018; Marchesi et al., 2020), allowing the reproduction of rare forestal bats (Russo et al., 2004). The noctule-bats studied, however, seem to select hollow trees still alive for their breeding activities, probably for the particularly favorable hygrothermic conditions found in their cavities.

-The field-researches will be continued with limited mist-netting sessions, handling and sampling authorized by law (Auct. 80811 released by Ital. Env. Min. for the years 2022-2024), but this paper already indicate that a correct and intensive use of photography can be an important tool to study elusive arboreal bats avoiding any disturbance.

-Considering the conservation status of Nyctalus lasiopterus both in Italy and in the whole Europe, anyway, the legal protection of the descovered roost must becames a local conservation priority (Agnelli & Lapini, in press, see below).

 

                  Global IUCN status:       Vulnerable – VU

                  Italian IUCN status:       Critically Endangered – CR

 

Protection laws and International Conventions: Berna Conv., All. II; Bonn Conv., All. II; EUROBATS Agreement; Habitat Directive 92/43 CEE, All. IV; Italian National Law on wild and game wildlife protection 157/92.

In Italy the most binding of these protection laws and International Conventions surely are the Italian National Law on wild-game and wildlife protection (L. N. 157/92) and the Habitat Directive 92/43 CEE.

 

Aknowledgements

We would like to thank the present owner of the wood of Pradiziolo which kindly granted frequent night access to the research area, to Alessandro Di Giusto and Luca Dorigo for some pictures and measurations respectively, to Michele Cassol and Emiliano Mori for various bibliographic suggestions and to Bruno Sorato and Massimo Zucco for their kind assistence in the field. Special thanks to the Wild Animal Recovery Center and to the Biodiversity Office of the Public Administration of the Region Friuli Venezia Giulia for various aids and technical suggestions.

 

References

Agnelli P., Boga R., Dondini G., Lapini L., Simoncini I. & Vergari S., 2019. Nuovi record di nottola gigante in Italia. Atti del IV Convegno Italiano sui Chirotteri, 17-18-19 ottobre 2019 organizzato dal GIRC e dall’ATit, sezione Poster: 34, Padova.

Agnelli P. & Lapini L., in press. Nyctalus lasiopterus. In: Loy A., Baisero D., Bon M., Di Febbraro M., Amori G. (Eds) Atlante dei Mammiferi in Italia. Atlas of Italian Mammals. Edizioni Belvedere (in press).

Ancillotto L., Russo D., 2015. Reassessing the breeding range limits for two long-distance migratory vespertilionid bats, Pipistrellus nathusii and Nyctalus leisleri in the Italian peninsula. Mammalia, 79(2): 245-248.

Dietz C., Nill D., Helversen G. von, Lina P. H. C. & Hutson A. M., 2009. Bats of Britain, Europe and northwest Africa. A&C Black ed., London: 1-400.

Dietz C. & Kiefer A., 2014. Pipistrelli d’Europa. Conoscerli, identificarli, tutelarli. Ricca ed., Roma: 1-399.

Giuntini S., Ancillotto L., Falaschi M. Viviano A., Palagi E. & Mori E., 2022. Alien parakeets as a threat to the common noctule. Atti XII Congresso Nazionale di Teriologia, ATit. Hystrix, supp. 33: 89.

Jackson D., 2018. Bats & Trees. Bat Conservation Trust (BCT) ed., London: 1-8.

Lanza B., 2012. Fauna d’Italia, Chiroptera. Calderini, Bologna.

Lapini L. & Dorigo L. (a cura di), 2015. I Chirotteri protetti dalla Direttiva Habitat 92/43 CEE nella Regione Autonoma Friuli Venezia Giulia. Monitoraggi 2013-2014. Relazione finale. Museo Friulano di Storia Naturale-Udine – Relazione inedita presentata all’Ufficio Studi faunistici della Regione Friuli Venezia Giulia, Udine: 1-140.

Lapini L., Dorigo L., Luca M., Lapia M., Bufo P. & Urso G., 2019. Remarks about some noteworthy bats from northeastern Italy (Friuli Venezia Giulia Region: Chiroptera: Vespertilionidae: Myotis bechsteinii, Myotis capaccinii, Myotis daubentonii, Nyctalus lasiopterus, Nyctalus noctula). Quaderni del Museo Civico di Storia Naturale di Ferrara , 7 (2019): 61-139.

Lapini L., Dorigo L., Luca M. & Pontarini R., 2020. Preliminary chorologic Atlas of the bats from Friuli Venezia Giulia Region (Mammalia, Chiroptera; north-eastern Italy). GORTANIA Botanica, Zoologia, 41 (2019), 7: 109-123.

Marchesi L., Zanin M. & Zorer P., 2008. Lunga vita ai tronchi col buco! I picchi e la biodiversità forestale: i primi 580 alberi tutelati in Trentino. Natura alpina, 59, 1: 15-26.

Marchesi L., Angeli F., Pedrini P., Pedrotti L., Rizzolli F., Tenan S. & Zorer P., 2020. La conservazione degli alberi con cavità nido realizzate dai picidi in provincia di Trento. Dendronatura, 1: 84-92.

Meschede A., 2001. Bats in Forests – Information and recommendation for forest managers “Landschft als Lebensraum”. German Association for Landcare Deitsche Vierband für Landschaftpflege (DVL), Ansbach, Germany, 4 (July 2001): 1-21.

Maenurm A., 2021. Silva Lupanica. Anima di un bosco friulano – Soul of a Friulian Forest (Edizione bilingue). Corvino ed., Fagagna, Udine.

Russo D., Cistrone L., Jones G. & Mazzoleni S., 2004. Roost selection by barbastelle bats (Barnastella barbastellus, Chiroptera: Vespertilionidae) in beech woodlands of central Italy: consequences for conservation. Biol. Cons., 117 (2004): 73-81.

Sguazzin F., 2004. I boschi di latifoglie della bassa pianura friulana. In: Bini G. (curatore), 2004. I boschi della bassa friulana. La Bassa ed. (72): 17-77.

 

Fig. 1. A pregnant female of Nyctalus lasiopterus, recovered on April, 29th, 2019 in Passons village (Udine), photographed during its release in the wild (Coda Manin wood, Muzzana del Turnano, Udine), June, 3th, 2019, photo M. L.-L. L. (from Lapini et al., 2019). The place of release of this bat is about 15 km far from the nursery studied in this paper.

 

 

Fig. 2. The hairy ventral sides of the wings of Nyctalus lasiopterus are diagnostic in the comparison with other syntopic species of Italian noctule-bats. Pregnant female, April, 30th, 2019, Passons village (Udine), photo by Alessandro Di Giusto.

 

 

Fig. 3. The area of the researches.

 

 

Fig. 4. Flying Nyctalus lasiopterus photographed in Pradiziolo wood (from Maenurm, 2021: 92). Photo A. M., Maj, 5th, 2021

 

 

Fig. 5. Flying pregnant Nyctalus -probably N. lasiopterus– photograhed in the wood of Pradiziolo (Maj, 9th, 2022); clearly visible its breasts. Photo A. M.

 

 

Fig. 6. Measurement of the forearm of a giant noctule protruding from its arboreal shelter on June, 13th , 2022. The same measuration has been performed on various specimens and photographic sessions, always indicating about 68-70 mm, diagnostic of Nyctalus lasiopterus. In the same shelter these bats often take refuge together with Nyctalus noctula, with shorter diagnostic forearm measurements. Photos and elaboration by A. M.

 

 

Fig. 7. A giant noctule devours its placenta after the parturition in its arboreal shelter. On the right is clearly visible the head of a newborn. Photo A. M., June, 13th, 2022.

 

 

Fig. 8. A newborn of Nyctalus lasiopterus and its mother in the same tree-hole. Photo A. M., June, 13th, 2022.

 

 

Fig. 9. Two Nyctalus in the same tree-hole. On the left a smaller species -probably Nyctalus noctula– on the rigth Nyctalus lasiopterus. Photo A. M., June, 13th, 2022.

 

 

Fig. 10. Almost weaned but not flying young of Nyctalus noctula (forearm 51 mm, A. M. leg.) fell to the ground on July, 11th, 2022 in the mixed roost studied, then admitted to the NGO Pronto Soccorso Pipistrelli managed by S. B., photo by L. L.

 

 

Fig. 11. Flying Nyctalus noctula photographed during the evening emergency from the mixed roost studied. Photo by S. Zanini-M. Luca, July, 12th, 2022.

 

 

Fig. 12. Nyctalus leisleri (Forearm 44,5 mm), reproductive female collected on September, 15th, 2021, P. Polesello-M. Luca leg., in the railway yard of Cervignano, Udine, about 2,4 km far from the mixed roost studied in this paper. It was heavily injuried because completely covered with lubrificating grease used for railway switches. Admitted to the NGO Pronto Soccorso Pipistrelli, was cleaned, fed and rehabilitated by S. B. At the release (May, 24th, 2022) this bat made two or three self-orientation flights around to the local highway bridge, then pointing directly towards the studied nursery, which was about 300 meters far from the release location. Photo by S. B.

 

 

 

Tab. I. Provisional overview of the bat-community studied. Bats present around to the study area:
from a 10×10 km cell of the UTM grid Cartographic System (Lapini et al., 2020; present paper);
bats present within the study area: from original bio-acoustic 2022 summer surveys conducted
by L. L., M. D. L. and M. L.

Lapini et al., 2020; present paper Bio-acoustic survey 2022
Hypsugo savvi Yes hard Yes
Myotis daubentonii/capaccinii Yes
Myotis myotis/blythii Yes
Nyctalus lasiopterus Yes hard Yes
Nyctalus leisleri Yes hard
Nyctalus noctula Yes hard Yes
Pipistrellus kuhlii Yes hard Yes social calls
Pipistrellus nathusii Yes social calls

Abbreviations: hard= hard data; social calls= recordings of diagnostic social calls

 

 

PDF Maenurm-et-al-2022 download

 

Prima documentazione di sciacallo dorato Canis aureus nel Parco Regionale della Maremma.

 

di Giada Pacini, Lorenzo Lazzeri, Francesco Ferretti

Unità di Ricerca di Ecologia comportamentale, Etologia e Gestione della fauna, Dipartimento di Scienze della Vita, Università degli Studi di Siena, Via P.A. Mattioli 4, 53100 Siena.

 

Introduzione

Lo sciacallo dorato Canis aureus è un canide di interesse conservazionistico inserito in allegato V della Direttiva Habitat 92/43 CEE. Questa specie è arrivata in Italia spontaneamente negli anni ’80 grazie alla spinta dispersiva di alcuni individui provenienti dall’area balcanica (Lapini et al., 1993).

Le prime segnalazioni e i primi nuclei riproduttivi sono stati infatti documentati nella parte nord-orientale della penisola, dove il primo dato accertato risale al 1984 (Lapini et al., 1993). In seguito, lo sciacallo si è diffuso in buona parte delle regioni a nord del fiume Po (Lapini et al., 2018), che ha probabilmente rallentato la dispersione di questo canide verso sud. Solo recentemente, infatti, la specie è stata segnalata a sud del Po in Emilia-Romagna (Lapini et al., 2021), nel Lazio (Parco Nazionale del Circeo, nel 2020-2021: Fortebraccio & Aleotti, 2022) e in Toscana.

In questa ultima regione una prima segnalazione è relativa alla provincia di Prato e risale alla fine del 2021 (Bacci & Lunghi, 2022); a marzo 2022 è stato trovato investito un altro individuo nelle vicinanze di Empoli (E. Mori & A. Viviano com. pers.). Pertanto, la segnalazione qui riportata per il Parco Regionale della Maremma rappresenta la localizzazione più meridionale nella Regione Toscana.

 

Documentazione della specie

L’Università di Siena e l’Ente Parco Regionale della Maremma stanno conducendo da diversi anni un progetto di ricerca sui rapporti ecologici tra le specie che compongono la locale comunità di mammiferi, integrando una serie di tecniche tra cui il videotrappolaggio (Ferretti et al., 2021; Rossa et al., 2021).

Questo viene effettuato impiegando una griglia di campionamento di 1km2 x 1km2 e 60 postazioni di rilevamento mantenute attive durante tutto il corso dell’anno. Ciascuna postazione viene visitata con cadenza circa mensile per sostituire le schede SD e le batterie; nel corso delle settimane successive i filmati vengono visionati e i relativi dati sono archiviati. Durante il controllo dei filmati registrati durante la stagione invernale è stata rilevata la presenza di 2 video notturni che ritraevano uno sciacallo dorato (Fig.1), registrati in una stessa postazione in data 7 gennaio 2022 (in orario 3:02 e 17:47).

Considerando l’eccezionalità dell’osservazione, nonché le potenziali difficoltà di identificazione della specie, successivi ulteriori controlli sono stati effettuati sui filmati ripresi nello stesso periodo nelle altre postazioni di rilevamento. Sono state inoltre posizionate altre tre fototrappole nelle vicinanze della postazione in cui era stato segnalato il canide. Tuttavia, non sono state ottenute ulteriori documentazioni della presenza della specie nel Parco.

I filmati sono stati condivisi con il Dr. Luca Lapini (Museo Friulano di Storia Naturale, Udine), curatore del bollettino Canis aureus NEWS, per un confronto e una validazione condivisa della segnalazione. Considerando l’elevata intensità e continuità di campionamento in corso, è ipotizzabile che la segnalazione non sia riferibile a una presenza stabile, sebbene naturalmente ulteriori risposte potranno arrivare dal proseguimento della raccolta di dati su base standardizzata.

Nell’area è da anni riscontrata la presenza stabile del lupo (Ferretti et al., 2019, 2021; Rossa et al., 2021): questo predatore è un possibile significativo competitore per lo sciacallo dorato, potenzialmente in grado di influenzarne abbondanza e distribuzione, e potrebbe pertanto rallentare un eventuale insediamento stabile dello sciacallo nell’area (Krofel et al., 2017; Mohammadi et al., 2017; Lapini et al., 2021). La continuazione della ricerca in corso potrà comunque consentire di valutare l’evoluzione dell’effettiva presenza dello sciacallo dorato nel tempo, nonché i potenziali rapporti ecologici con gli altri carnivori presenti nell’area (p.es., Ferretti et al., 2021; Rossa et al., 2021).

 

Bibliografia

Bacci F., Lunghi E. (2022). Golden jackal on Tuscan Apennine: range expansion or wandering individuals? Natural History Sciences, in press

Ferretti F., Lovari S., Mancino V., Burrini L., Rossa M. (2019). Food habits of wolves and selection of wild ungulates in a prey-rich Mediterranean coastal area. Mammalian Biology, 99: 119-127.

Ferretti F., Pacini G., Belardi I., Ten Cate B., Sensi M., Oliveira, R., Rossa M., Burrini L., Lovari S. (2021). Recolonizing wolves and opportunistic foxes: interference or facilitation?. Biological Journal of the Linnean Society, 132: 196-210.

Fortebraccio M., Aleotti S. (2022) Primi dati sullo sciacallo dorato Canis aureus in Lazio. Habitatonline.
( https://www.habitatonline.eu/2022/02/primi-dati-sullo-sciacallo-dorato-canis-aureus-in-lazio/ )

Mohammadi A., Kaboli M., López-Bao J.V. (2017). Interspecific killing between wolves and golden jackals in Iran. European Journal of Wildlife Research, 63: 1-5.

Krofel M., Giannatos G., Ćirovič D., Stoyanov S., Newsome T. M. (2017). Golden jackal expansion in Europe: a case of mesopredator release triggered by continent-wide wolf persecution? Hystrix: Italian Journal of Mammalogy, 28, 9-15.

Lapini L., Perco F., Benussi E., 1993 – Nuovi dati sullo sciacallo dorato (Canis aureus L.,1758) in Italia (Mammalia, Carnivora, Canidae). Gortania-Atti Museo Friul. Storia Nat., 14: 233- 240.

Lapini L., Dreon A.L., Caldana M., Luca M., Villa M., 2018 – Distribuzione, espansione e problemi di conservazione di Canis aureus in Italia (Carnivora: Canidae). Quaderni del Museo Civico di Storia Naturale di Ferrara, 6: 89-96.

Lapini L., Pecorella S., Ferri M. & Villa M., 2021. Panoramica aggiornata delle conoscenze su Canis aureus in Italia. Quaderni del Museo Civico di Storia Naturale di Ferrara, 9: 123-132.

Rossa M., Lovari S., Ferretti F. (2021). Spatiotemporal patterns of wolf, mesocarnivores and prey in a Mediterranean area. Behavioral Ecology and Sociobiology, 75: 1-13.

 

Figura 1. Fermo immagine tratto dalla ripresa di sciacallo dorato nel Parco Regionale della Maremma