The main purpose of bird ringing is to study birds’ migrations and their way of life. It is of great significance that ringing data are collected regularly in order to obtain information on the status of migratory bird populations over a longer period of time and to decide what appropriate protective measures should be taken. In bird migration research, collaboration among as many countries as possible is of course important, too, as birds know no borders and can migrate over very long distances. This is the reason why the majority of countries all over the globe have established national bird ringing centres. The countries are interconnected within the EURING (European Union for Bird Ringing) organization. Our organization, called Slovenian Bird Ringing Centre (SCOP), functions within the Slovenian Museum of Natural History.

Ring - the power of information

At the moment any bird is equipped with a ring on its leg, it carries information on its identity card: sex, age, date and place of ringing, etc. Young White Storks (Ciconia ciconia) are most easily ringed on the nest when not fit to fly as yet. 

Slovenian rings bear the inscription LJUBLJANA SLOVENIJA and a serial number, e.g. ZT 43.

In the autumn of 2007, a Belgian tourist e-mailed us from the Republic of South Africa that he had noted a Slovenian ring on the leg of a White Stork. We processed the data on the ringing and the bird’s recovery through the computer in our museum and sent the details to the Republic of South Africa. Hence we discovered, among other things, that the aerial distance between the place of ringing in Slovenia and the bird’s recovery in the Republic of South Africa was 7,814 km.

The first ornithologist who embarked on systematic bird ringing (in 1899) was Professor Mortensen from Denmark. He was followed in 1900 by Professor Northumberland in England, and in 1903 by the ornithologist Theinemann in Germany. Other countries also followed in intervals (Ponebšek, 1934 in Scopolia supp. 4 Gregori 2009).
In Slovenia, ringing activities have been taking place since 1926, when the “Ornithological Observatory in Ljubljana” was founded. Bird ringing officially began a year later. We have an interesting bird ringing story from 1909. Jurij Brandl, an organ maker from Maribor, held two young White Storks and equipped them with a ring carrying his home address. In mid-September 1909, the two storks escaped and one of them was shot at the end of the same month near Rocella Jonica in the Italian province of Reggio di Calabria. The aerial distance covered by it was 950 km (Reiser 1925, Ponebšek 1934 in Scopolia supp. 4 Gregori 2009).

After World War II, the Ornithological Observatory was annexed to the Slovenian Museum of Natural History, where currently functioning as the Slovenian Bird Ringing Center (SCOP) within the Museum’s Vertebrate Department.

Since the founding of the Observatory, the number of ringed birds was on constant increase. In 1927, 143 birds were ringed; presently we ring more than 100,000 of them per year. The number of ringed birds and recoveries has increased mainly owing to the development of bird trapping methodology. Based on this development, bird ringing in Slovenia can be divided into three periods:

1st period from 1927 to 1972, when bird catching or trapping was carried out with the aid of lime sticks, snares and cages, with fledglings also ringed at nest (Božič, 2009). Today, lime sticks and snares are prohibited.
2nd period from 1973 to 1982, when nylon nets were used for bird trapping (Božič, 2009).
3rd period from 1982 to the present, when sound recordings have also been used, in addition to birds, to attract birds (Šere, 2009). For this purpose, the Slovenian Museum of Natural History keeps the Slovenian Archive of Animal Sounds. Recordings of some Slovenian birds are available on the CD Forest Birds of Slovenia and Ljubljansko barje, the Secret World of Animal Vocalization.

The bird ringing activities in Slovenia were guided by:
1. from 1926 – 1935: Dr Janko Ponebšek
2. from 1935 – 1964: Božidar Ponebšek
3. from 1964 – 1967: Janez Gregori
4. from 1971 – 1983: Ivo Božič
5. from 1983 activities have been guided by Dare Šere

From the very beginning of the ornithological activities in Slovenia, bird trapping and ringing largely relied on the voluntary work by non-resident associates. In 2010, 55 persons acquired the bird ringing permit.

Recoveries of ringed birds were first reported on in 1934 in the Ornithological Observatory Reports. Later, the recoveries were published mainly in the magazine Acrocephalus, as well as in other domestic (Proteus, Svet ptic…) and foreign (Euring Newsletter) publications. The ringing activity in Slovenia was presented in greater detail in 2009 in Scopolia Supplementum 4, the publication of the Slovenian Museum of Natural History.

From 1973, birds were being trapped exclusively with nylon nets. This particular year in fact marks the beginning of a new era in the Slovenian bird ringing activities. We got to know those bird species that we had been unable to trap before. We also recorded some new species for Slovenia. A need for an ornithological station arouse, where bird migrations could be regularly monitored. Thus, in 1987, the Vrhnika Trapping Site was founded, where every year, particularly during migration (from mid-July to the end of October), bird ringing has been carried out on a regular basis.

When the Vrhnika Trapping Site began operating in 1987, we embarked on an in-depth study of the Barn Swallow (Hirundo rustica). We were interested in where Barn Swallows that breed in Slovenia spend the winter, along which route they migrate and at what time (Šere, 1980; Šere, 1998). In 1997, when we joined the “Euring Swallow Project”, coordinated by the EURING organization, we already had some information on this popular species. In 2002, we received the first award from the Ford Company for the preservation of natural and cultural heritage within the project “Where do Barn Swallows winter in Africa”.

When a bird is caught, we determine which species it belongs to, as well as its age and sex, put a ring on its leg and make some biometric measurements (e.g. wing length; Sere, 2009). In recent years, we have taken part in research on bird diseases (Račnik et al., 2008) and parasites (Trilar, 2004). After ringing and the carried out measurements, the bird is released at once. When dealing with hard-to-catch species with nets, e.g. storks, herons, birds of prey, owls, etc. we ring their young at nest. The rings of appropriate size are made of aluminium; for population surveys, coloured rings are also used.

It is of major importance that data are carefully collected in one place. From the beginning of ringing activities until 2001, data were entered and collected in special forms.

In 2000, the Slovenian Museum of Natural History created a computer program for entering and processing ringed birds, in which all data on ringed birds are collected and kept. In 2008, we set up a new program that enabled us to plot ringed bird recoveries in certain geographical areas (Europe, Africa, Middle East).

Sedge Warbler (Acrocephalus schoenobaenus) is a relatively small warbler that breeds in Slovenia as well. In the autumn in particular, bird ringers often trap birds that breed north of Slovenia and only stop here during migration. (Photo: I. Božič)

Sedge Warbler’s voice. Source: Dr Tomi Trilar, Slovenian Archives of Animal Voices, Slovenian Museum of Natural History

An overview of the number of ringed birds and recoveries in Slovenia (1926-2009) can be found in the journal Scopolia Supplementum 4 – 2009. 

What to do if you find or watch a ringed bird:

  • Try to take a photo of the bird and the ring
  • Read the inscription and the number on the ring
  • Make a note of the place and date of the recovery, observation…
  • Make a note of the state of the bird (alive, injured, dead, found skeleton, etc.)

Send the information to the e-mail address:

When trapping and ringing birds, some rare or extremely rare species can be found.

In the 1983-2008 period, the following rare species were ringed: Meadow Pipit Anthus cervinus (9), Blyth’s Reed Warbler Acrocephalus dumetorum (8), Paddyfield Warbler  Acrocephalus agricola (8), Yellow-browed Warbler Phylloscopus inornatus (7), Dusky Warbler Phylloscopus fuscatus (2), Pallas’s Warbler Phylloscopus proregulus (1), Booted Warbler Hippolais caligata, (2), Red-flanked Bluetail Tarsiger cyanurus (1), Two-barred Crossbill Loxia leucoptera (1), Pine Bunting Emberiza leucocephala (8), Rustic Bunting Emberiza rustica (3) and Chestnut Bunting Emberiza rutila (1). The question is being raised whether the Little Bunting Emberiza pusilla is still a rare species, considering that as many as 16 of them were ringed during this particular period. It is true, however, that some rare species occur very cyclically.

The following rare species have also been ringed: Bittern Botaurus stellaris, Black Stork Ciconia nigra, Merlin Falco columbarius, Black-winged Stilt Himantopus himantopus, Avocet Recurvirostra avosetta, etc.

Prior to 1993, young Lesser Kestrels (Falco naummani) had also been ringed at nest, but have no longer bred in Slovenia since then (Šere, 2008). The reason is in the first place destruction of their habitat and use of pesticides, considering that this species feeds largely on big insects. (Photo: D. Šere)

From our ringed species list, the Aquatic Warbler (Acrocephalus paludicola) has also disappeared, as the last one was ringed in 1992.

  • Božič Ivo, 1975/76. Slovenska ornitologija med leti 1926 – 1976. Proteus 38 (7): 247 – 250
  • Božič Ivo, 1980 – 1982, 1985. Poročilo o ulovu in obročkanju ptičev v Sloveniji (več). Acrocephalus.
  • Božič Ivo, 2007. Čapljica Ixobrychus minutus = little bittern. Acrocephalus 28 (133), str. 79
  • Božič Ivo, 2009. Rezultati obročkanja ptičev v Sloveniji: 1926 – 1982. Scopolia Supplementum 4 – 2009: 23 – 110
  • Gregori Janez ur., 2009. Scopolia Supplementum 4 – 2009
  • Izvestje Ornitološkega observatorija v Ljubljani, 1926 – 1933. Kuratorij Ornit. observatorija v Ljubljani
  • Šere Dare, 1980. Lov in obročkanje kmečkih lastovk v Sloveniji. Acrocephalus, št. 5: 79 – 81
  • Šere Dare, 1998. The Euring Swallow Project in Slovenia. Euring newsletter 2. Instituto nazionale per la fauna Selvatica. str. 28 – 29
  • Šere Dare, 2001. 75 years of the bird ringing scheme Ljubljana. Euring newsletter 3. Instituto nazionale per la fauna Selvatica: 70 – 71
  • Šere Dare, Ornitološke novice za obročkovalce 1997, 1998, 2000
  • Šere Dare, 2008. Obroček – moč informacije. Konservator – restavrator: povzetki strokovnega srečanja. str. 59
  • Šere Dare, 2008. Južna postovka Falco naummanni & črna štorklja Ciconia nigra = Lesser Kestrel & Black Stork. Acrocephalus 29 (137): str. 112
  • Šere Dare, 2009. Kratko poročilo o obročkanih ptičih v Sloveniji, 1983 – 2008. Scopolia Supplementum 4 – 2009: 111 – 174
  • Šere Dare, 2009. Najdbe obročkanih ptočev na zadrževalniku Medvedce in okolici (SV Slovenija). Acrocephalus 30 (141, 142, 143): 199 – 208
  • Trilar Tomi, 2004. Ticks (Acarina: Ixodidae) on birds in Slovenia = Klopi (Acarina: Ixodidae) na pticah Sloveniji. Acrocephalus 25(123): 213 – 216 Račnik J., Slavec B., Trilar T., Zadravec M., Dovč A., Krapež U., Barlič-Maganja D.,
  • Zorman-Rojs O., 2008: Evidence of avian influenza virus and paramyxovirus subtype 2 in wild-living passerine birds in Slovenia. Eur. J. Wildlife Res. 54(3): 529 – 532.
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