Acrocephalus 38 (174/175): 81–83, 2017 Pred izidom atlasa gnezdilk On the Publication of the Atlas of Breeding Birds Z atlasom gnezdilk pojmujemo celosten popis pojavljanja in razširjenosti vrst, ki ga v sodobnem času praviloma dopolnjujemo tudi s podatki o številčnosti. V povezavi z osnovnim namenom delovanja društva, torej varstvom ptic in njihovih habitatov, se je izkazalo, da je odlično znanje o pojavljanju in številčnosti ptic na različnih območjih in v različnem času tudi eno izmed najboljših sredstev njihovega varstva. Prejšnji Ornitološki atlas gnezdilk Slovenije, ki je bil ena izmed osnovnih aktivnosti društva od samega začetka, je dal kvaliteten vpogled v osnovno razširjenost vrst, sodobna spoznanja pa so narekovala, da si želimo dodati vpogled v številčnost in natančno geolo- ciranje podatkov. Podatek, kje gnezdijo naše ptice in kako številčne so, je bil torej zastavljen za glavni cilj, ki smo ga želeli uresničiti z novim atlasom. Poleg tega pa smo si zastavili še nekaj vzporednih ciljev. Pomembna je bila ureditev osrednje podatkovne zbirke gnezdilcev v Sloveniji, ki bi delovala na nivoju geolociranja vsakega posameznega podatka. Shranjevanje podatkov, kot so bili zabeleženi na terenu, ima namreč veliko vrednost. Pogosto se zgodi, da si zelo podobne podatke na podlagi novega znanja lahko interpretiramo povsem drugače. Tako na primer iz poletnega opazovanja prvoletnega planinskega orla sklepamo, da je vrsta verjetno gnezdila nekje v bližini, medtem ko nam bo enak podatek o dve- ali triletni ptici nakazoval ravno obratno, da vrsta v bližini skoraj zagotovo nima aktivnega gnezda. Gnezdeči pari namreč aktivno branijo teritorij pred prišleki, še posebej kadar se v teritoriju pojavlja mladič, ki pa se osamosvaja šele v začetku ali sredini zime. Shranjevanje podatkov v osnovni obliki je torej ključnega pomena za ustrezno interpretacijo, ki jo je samo v tem primeru možno kasneje preverjati in primerjati z drugimi popisi. Sodobno upravljanje s podatkovno zbirko nam je omogočilo, da smo natančno shranili in obdelali več kot 350.000 opazovanj, ki so zadevala skupaj 238 vrst, s katerimi smo se tako ali drugače ukvarjali v atlasu. Od teh smo jih med vsaj možne gnezdilke Slovenije uvrstili 227, ostale vrste pa se sicer pojavljajo tu v gnezdilni sezoni, a tu (več) ne gnezdijo. Seznam gnezdilk Slovenije je v novem atlasu največji doslej in je zagotovo odsev izrednega popisovalskega vložka. Nanj je uvrščenih kar 10 vrst, ki v obdobju zadnjih 250 let v Sloveniji dokumentirano niso gnezdile. To so kormoran Phalacrocorax carbo, duplinska kozarka Tadorna tadorna, mandarinka Aix galericulata, moškatna bleščavka Cairina moschata, tatarska žvižgavka Netta rufina, virginijski kolin Colinus virginianus, žerjav Grus grus, črnoglavi galeb Larus melanocephalus, bledi hudournik Apus pallidus in brkata sinica Panurus biarmicus. Nekatere izmed njih so prišle na novo, nekatere pa so lahko le posledica boljšega poznavanja terena in večjega števila obiskov. Seveda je ravno pri teh vrstah še vedno lahko precej dilem pri obravnavanju gnezditvenega statusa. Tako npr. ne moremo mimo opazovanja kopulacije žerjava in kasnejše odganjanje lisice s strani para, ki se je zadrževal v gnezditveni sezoni na Cerkniškem jezeru, kar kaže na verjetno gnezditev, a je obenem povsem mogoče, da je bil vse skupaj le 81 Uvodnik / Editorial mladostniški poskus gnezdenja mladega para. A povsem podobno se je dogajalo s podatki o pojavljanju kormoranov v času gnezditve, dokler ni ugibanj presekala jasna novica o potrjenem gnezdenju v Renških glinokopih leta 2014. Ravno podatki o možnih in verjetnih gnezdilkah so torej tisti, ki jih zaradi kasnejše interpretacije in primerjave potrebujemo shranjene v najbolj osnovni obliki. To nam je v tem atlasu uspelo s pomočjo internetne zbirke podatkov, saj je bila njena vzpostavitev nujna zaradi natančnega pregleda s strani vrstnih koordinatorjev. Tako je bil e -Atlas ptic zasnovan v prvi meri kot pregledovalnik in urejevalnik podatkov, a se je zelo kmalu izkazal kot odlično sredstvo za zbiranje opazovanj iz vse države, ne glede na ciljne popise. To kaže na predanost in entuziazem terenskih ornitologov, ki skrbno beležijo opazovanja na vsakem koraku. Zadeva je šla celo tako daleč, da so naključna opazovanja začela resno dopolnjevati sistematično zbrane podatke, predvsem pri redkih in manj zaznavnih vrstah, in vse kaže ta hip, da bo tretja sezona atlasa mogoča že kar brez ciljnega projekta, s skrbno obdelavo obstoječih zbranih podatkov, pri katerih se število vnosov iz dneva v dan bliskovito povečuje. Znanje, ki se kopiči v tej zbirki, je sprožilo resno vprašanje, kdaj potegniti črto. Za ta atlas smo jo potegnili in prepričan sem, da vam bo shranjeno znanje in spremljajoče pisanje všeč. *** The Atlas of Breeding Birds is perceived as a comprehensive survey of the presence and distribution of birds, which has in modern times been sup- plemented, as a rule, with data on their abundance. In conjunction with the principal purpose of our Association, i.e. conservation of birds and their habitats, it has turned out that solid knowledge of the occurrence and abundance of birds in different areas and at different times is one of the best means of their conservation and protection at the same time. The previous Atlas of Breeding Birds of Slovenia, which was one of the key activities of our Association from its very beginning, rendered a solid insight into the basic distribution of species, whereas the latest findings triggered a desire in us to add an insight into the abundance and accurate geolocation of data. The information as to where our birds are breeding and how abundant they are was therefore set as our main goal, which we wished to attain with the new Atlas. Apart from it, some parallel goals were set. One of the most important tasks was to set up a central database of our breeding birds, which was to function at the level of geolocation of each separate datum. Specifically, saving of data obtained in the field is highly valuable, for it often happens that on the basis of new knowledge some very similar data can be interpreted in a totally different way. For example, from the summer observation of a 1st year Golden Eagle we may conclude that the species has probably bred somewhere close by, whereas the same datum on a 2nd or 3rd year bird will indicate something totally opposite, i.e. that species has almost certainly no active nest close by. The fact is that breeding pairs actively defend their territory from newcomers, particularly when a fledgling occurs in the territory, but becomes independent only as late as 82 Acrocephalus 38 (174/175): 81–83, 2017 in the beginning or in the middle of winter. In its basic form, data saving is thus crucial for a suitable interpretation, which can only in this case be later verified and compared with other surveys. Modern database management has enables us to save and process more than 350,000 observations, encompassing a total of 238 species in one way or another dealt with in the Atlas. Of these, 277 were classified as at least possible breeders of Slovenia, while the others indeed occur here in the breeding season, but do not breed here (any longer). In the new Atlas, the list of breeding birds of Slovenia is the largest so far and certainly a reflection of the exceptional work carried out by our observers. It contains no less than 10 species that have not bred in Slovenia in the last 250 years. These are CormorantPhalacrocorax carbo, Shelduck Tadorna tadorna, Mandarin Aix galericulata, Muscovy Duck Cairina moschata, Red-crested Pochard Netta rufina, Bobwhite Colinus virginianus, Crane Grus grus, Mediterranean Gull Larus melanocephalus, Pallid SwiftApus pallidus and Bearded Tit Panurus biarmicus. Some of them came to our country anew, while others can only be the result of our better knowledge of the terrain and a higher number of visits. There may be still many dilemmas when dealing with the breeding status of these very species. We simply cannot ignore, for example, the observation of a copulating Crane and eventual chasing away of a fox by the Crane pair which frequented the area of Lake Cerknica in the breeding season. This indicates probable breeding, although it is quite possible that this was merely a breeding attempt by the juvenile pair. Very similar was the information on the presence of Cormorants in the breeding season, until all guesswork was eliminated by clear news of Cormorant's confirmed breeding in 2014 at Renče Claypits. So, the very data on possible and probable breeders are those that need to be saved for later interpretations and comparisons in the most basic form. In this Atlas we succeeded in this respect thanks to the Internet database, for its set-up was necessary owing to the accurate surveys by species coordinators. Thus, the e-Atlas was conceived primarily as a data viewer and editor, but it very soon turned out to be an excellent means of collecting observations from the entire country, irrespective of target surveys. This shows great commitment and enthusiasm of our field ornithologists, who have been carefully recording their observations at every step. The matter went even that far that random observations began to seriously supplement the systematically gathered data, especially in respect of rare and less perceptible species. And at this moment it looks that the third season of the Atlas will be possible even without a target project with a careful processing of the existing data, where the number of data inputs is increasing from day to day at lightning speed.