Izbor staništa sekundarnih dupljašica u poplavnim nizinskim šumama uz rijeku Dravu u Hrvatskoj

The correlation between secondary hole-nesters community characteristics and floristic and structural characteristics of their habitat was studied in riverine forest stands near river Drava in Croatia. Standard point count method was used for bird community sampling and circular plot method for habitat sampling. Sampling was carried out on 66 points. PCA analysis that included 28 independent habitat variables was used, followed by Spearman rank correlation between principal component scores and bird community variables (number of species and number of pairs). Tree basal area was used as an indication of stand maturity and to classify studied points into four forest types (ash, poplar, alder and mixed). Eight secondary hole-nesting species and 14 tree species were recorded. The average forest age was 59.8 ± 20.5 years, with ash and mixed stands being on average older than alder and poplar stands. Shannon-Wiener index of secondary hole-nesters diversity was highest in stands with dominant ash and was increasing with stand maturity. A significant positive correlation was found between number of bird species as well as number of pairs and older stands with lower number of tree species and lower relative number of poplar and alder. It can be concluded that diversity of secondary hole-nesting bird species as well as their abundance is correlated with structural habitat characteristics and that older stands show greater bird biodiversity and abundance.Korelacija između karakteristika zajednica sekundarnih dupljašica te florističkih i strukturalnih karakteristika staništa istražena je u nizinskim poplavnim šumama uz rijeku Dravu u Hrvatskoj. Standardna metoda prebrojavanja u točki korištena je za istraživanje zajednica ptica, a metoda kružnih ploha za istraživanje staništa. Mjerenja su provedena na ukupno 66 točaka. Korištena je analiza primarnih komponenti sa 28 varijabli staništa te Spearman rank korelacija između skorova primarnih komponenti i varijabli zajednica ptica (broj vrsta i broj parova). Bazalna površina stabala korištena je kao indikator starosti, ali i za klasifikaciju istraživanih točaka u četiri skupine (sastojine jasena, topole, johe i miješane sastojine). Zabilježeno je ukupno osam vrsta sekundarnih dupljašica i 14 vrsta drveća. Prosječna starost istraživanih točaka bila je 59,8 ± 20,5 godina. Sastojine jasena i miješane sastojine u prosjeku su bile starije od sastojina johe i topole. Shannon-Wiener indeks raznolikosti bio je veći u sastojinama s dominantnim jasenom i povećavao se sa starosti šume. Značajna pozitivna korelacija dobivena je između broja vrsta te brojnosti ptica i starijih sastojina s manjim brojem vrsta drveća i manjim relativnim brojem jedinki topole i johe. Možemo zaključiti da sastav zajednica sekundarnih dupljašica u nizinskim poplavnim šumama ovisi o strukturnim karakteristikama šuma, pri čemu stare sastojine pokazuju veću brojnost i raznolikost

Disperzija bijele rode Ciconia ciconia u Parku prirode Lonjsko polje, Hrvatska

Dispersal of the White Stork Ciconia ciconia in the Lonjsko polje Nature Park, Croatia There are two main types of dispersal: natal and reproductive. Natal dispersal is more common and individuals travel a greater distance than during reproductive dispersal. Direction and distances depend on various factors. Dispersal of the White Storks, Ciconia ciconia, was analysed using resightings of colour-ringed individuals in the Lonjsko polje Nature Park, Croatia. 36.7% observed individuals did not disperse outside the natal settlement, while only 14.3% covered a distance longer than 50 km. The median dispersal distance was 4.21 km (IQR = 0 - 8.8, n = 49); the correlation of dispersion with the number of nests in settlements and the size of the settlements was studied. Results have shown that storks are dispersing from settlements with a small number of nest to settlements with a large number of nests and that dispersal does not depend on the size of the settlement.Postoje dva tipa disperzije: natalna i reproduktivna. Natalna disperzija je češća i jedinke prelaze puno veće udaljenosti nego tijekom reprodukcijske disperzije. Smjer i udaljenost na kojoj jedinka disperzira ovisi o gustoći populacije, kvaliteti staništa, spolu, vjerojatnosti parenja u srodstvu ili dominantnosti drugih jedinki. Jedinke mnogih vrsta su vjerne mjestu gniježđenja, stoga reproduktivna disperzija nije česta i najčešće se odvija nakon slabog reprodukcijskog uspjeha ili gubitka partnera. Roda je ptica selica i redovita gnjezdarica u Hrvatskoj. Istraživana je disperzija bijele rode Ciconia ciconia u Parku prirode Lonjsko polje. Analizom nalaza roda označenih prstenovima u boji, utvrđena je koliko je zastupljena natalna disperzija u odnosu na reproduktivnu te postoji li utjecaj brojnosti gnijezda u naseljima te veličine naselja na udaljenost i smjer disperzije. 36.7% jedinki nije disperziralo izvan naselja u kojem se izleglo, dok je samo 14.3% prešlo udaljenosti veće od 50 km. Te su ptice nađene u istočnoj Hrvatskoj, Austriji i Mađarskoj. Srednja udaljenost disperzije bila je 4,21 km (IQR = 0 – 8,8, n = 49). Rezultati su pokazali da rode natalnom disperzijom odlaze iz naselja s malim u naselja s velikim brojem gnijezda što indicira da su socijalno privučene drugim jedinkama te da disperzija ne ovisi o veličini naselja (odnosno raspoloživom prostoru za gniježđenje)

Rare Birds in Croatia (2nd Report of Croatian Rarities Committee)

The second report of the Croatian Rarities Committee presents 37 records of rare birds received after 2002. Four species and one subspecies: Western Reef-egret Egretta garzetta gullaris, Bewick’s Swan Cygnus columbianus, Terek Sandpiper Xenus cinereus, Ring-billed Gull Larus delawarensis and Yellow-browed Warbler Phylloscopus inornatus were added to the list of Croatian birds and one, Arctic Redpoll Acanthis hornemanni was omitted, giving the total number of 381 bird species recorded in Croatia. Two species, White-billed Diver Gavia adamsii and Little Bustard Tetrax tetrax were observed for the first time in last 50 years. The list of rare species now includes 50 species. Checklist of bird species is given in the Appendix of this Report

Dictionary of Croatian bird names

Rječnik standardnih hrvatskih ptičjih naziva s 11.308 vrsta i podvrsta, uređen prema BirdLife 2018 taksonomiji može se preuzeti na stranici: http://info.hazu.hr/hr/oakademiji/jedinice/zavod_za_ornitologiju/nazivlje/The dictionary of Croatian bird names with 11,308 species and subspecies, following BirdLife 2018 taxonomy can be downloaded from the webpage: http://info.hazu.hr/hr/oakademiji/jedinice/zavod_za_ornitologiju/nazivlje

Application of 2D-correlation UV/VIS spectroscopy for detection of color additives in fruit juices

U radu je istražena primjena 2D-korelacijske spektroskopije za detekciju umjetnih bojila u voćnim sokovima crnog ribiza. Spektrofotometrijski su snimani uzorci soka, bojila i soka sa dodatkom bojila u području pH vrijednosti od 3,5 do 5,0 s rezolucijom od 1 nm u području valnih duljina od 400 do 700 nm. Dobiveni spektri su filtrirani Savitzky-Golayevom metodom, derivirani i korišteni za izradu sinkronih i asinkronih korelacijskih mapa. Usporedbom dobivenih korelacijskih mapa u području valnih duljina većih od 530 nm mogu se jasno detektirati spektalne promjene uzrokovane dodatkom umjetnog bojila u sok.This work explores the application of 2D-correlation spectroscopy for the detection of color additives in fruit juices of black currant. The samples of juice, azo-dyes and juice with azo-dyeswere spectroscopically examined in the pH range from 3.5 to 5.0, with a resolution of 1 nm in the wavelength range from 400 to 700 nm. Collected spectra were smoothed by the Savitzky-Golay method, numerically derived and employed for calculation of synchronous and asynchronous correlation maps. Spectral changes caused by the addition of azo-dyes to the juice can be clearly detected by comparing the obtained correlation maps in the wavelength range greater than 530 nm

Rare Birds in Croatia (2nd Report of Croatian Rarities Committee)

The second report of the Croatian Rarities Committee presents 37 records of rare birds received after 2002. Four species and one subspecies: Western Reef-egret Egretta garzetta gullaris, Bewick’s Swan Cygnus columbianus, Terek Sandpiper Xenus cinereus, Ring-billed Gull Larus delawarensis and Yellow-browed Warbler Phylloscopus inornatus were added to the list of Croatian birds and one, Arctic Redpoll Acanthis hornemanni was omitted, giving the total number of 381 bird species recorded in Croatia. Two species, White-billed Diver Gavia adamsii and Little Bustard Tetrax tetrax were observed for the first time in last 50 years. The list of rare species now includes 50 species. Checklist of bird species is given in the Appendix of this Report

Application of 2D-correlation UV/VIS spectroscopy for detection of color additives in fruit juices

U radu je istražena primjena 2D-korelacijske spektroskopije za detekciju umjetnih bojila u voćnim sokovima crnog ribiza. Spektrofotometrijski su snimani uzorci soka, bojila i soka sa dodatkom bojila u području pH vrijednosti od 3,5 do 5,0 s rezolucijom od 1 nm u području valnih duljina od 400 do 700 nm. Dobiveni spektri su filtrirani Savitzky-Golayevom metodom, derivirani i korišteni za izradu sinkronih i asinkronih korelacijskih mapa. Usporedbom dobivenih korelacijskih mapa u području valnih duljina većih od 530 nm mogu se jasno detektirati spektalne promjene uzrokovane dodatkom umjetnog bojila u sok.This work explores the application of 2D-correlation spectroscopy for the detection of color additives in fruit juices of black currant. The samples of juice, azo-dyes and juice with azo-dyeswere spectroscopically examined in the pH range from 3.5 to 5.0, with a resolution of 1 nm in the wavelength range from 400 to 700 nm. Collected spectra were smoothed by the Savitzky-Golay method, numerically derived and employed for calculation of synchronous and asynchronous correlation maps. Spectral changes caused by the addition of azo-dyes to the juice can be clearly detected by comparing the obtained correlation maps in the wavelength range greater than 530 nm

Izbor staništa i sličnosti zajednica ptica pjevica u šumama parkova prirode Medvednica i Žumberak – Samoborsko gorje

The effect of floristic and structural characteristics of vegetation on the forest songbird communities in two Nature Parks: Medvednica andŽumberak – Samoborsko gorje was studied. The point-count method was used for analyzing songbird communities and circular plot method for habitat mapping, on 101 points at both sites. Non-parametric test were used (Kruskal– Wallis and Kendal Tau). The tree basal area was used to classify studied points into five forest types (beech, oak, mixed deciduous, coniferous and mixed coniferous forests) and as indication of the stand maturity. The total of27 and 32 songbird species were recorded on Medvednica and Žumberak –Samoborsko gorje respectively. Diversity was higher on Žumberak – Samoborsko gorje due to greater habitat fragmentation, while population density of songbirds was greater on Medvednica. Among structural characteristics, those related to forest age (average tree basal area and number of the small trees) had the most pronounced effect to the total songbird density and densities of different ecological groups of birds. Sorensen index showed that in spite of the differences in floristic composition between particular forest types in two studied areas (0.475 ± 0.120), songbird communities showed high similarity (0.872 ± 0.070). The highest similarity of songbird communities between Parks was recorded in beech and oak stands. Oak stands showed the lowest similarity in tree species composition and no significant difference in structural characteristics, while beech stands had many different structural features and several differences in densities of ecological groups of birds. The greatest difference of bird densities in the particular forest type between two Parks was found in beech and mixed coniferous stands. High structural differences between these two forests were the result of the forest age; bird populations had higher densities in older stands.Istraživanja zajednica ptica pjevica šumskih staništa ukazuju da na njihovu strukturu i gustoću populacija mogu utjecati floristička i strukturalna svojstva vegetacije. U ovom istraživanju željeli smo, usporedbom zajednica ptica šumskih staništa dvaju parkova prirode, utvrditi utjecaj florističkih i strukturalnih svojstava vegetacije na zajednicu ptica gnjezdarica. Istraživanje je provedeno tijekom 2006. i 2007. u Parkovima prirode Medvednica i Žumberak – Samoborsko gorje. Šume pokrivaju oko 60 % površineu oba parka, ali su kontinuirane na Medvednici i nešto rascjepkanije na Žumberku. Istraživanje ptica provedeno je metodom prebrojavanja u točki, a uzorkovanje staništa metodom kružnih ploha. Istraživanje je provedeno na ukupno101 točki: 49 na Medvednici i 52 na Žumberku. Pri statističkoj obradi korišteni su neparametrijski testovi (Kruskal–Wallis i Kendal Tau). Udio temeljnice stabala korišten je za određivanje pripadnosti pojedinom šumskim tipu: bukovoj, hrastovoj, mješovitoj listopadnoj i mješovitoj crnogoričnoj šumi. Prosječna temeljnica stabla korištena je kao indikator starosti šume. Istraživanjem je zabilježeno ukupno 27 vrsta ptica pjevica u šumama Medvednice i32 na Žumberku (Tablica 1). Šest vrsta ptica bilo je vezano uz određeni tip šume, s više od 40 % parova zabilježenih u tom šumskom tipu. Diverzitet vrstabio je viši na Žumberku, dok je gustoća populacija ptica pjevica bila veća na Medvednici (Slika 2). Sorensenov indeks pokazao je da zajednice ptica istog tipa šume između dva područja pokazuju znatno veću sličnost nego floristički sastav (Slika 3). Najveća sličnost u zajednicama ptica između dva Parka zabilježena je u bukovim i hrastovim sastojinama. Hrastove sastojine pokazuju najmanju florističku sličnost, ali nemaju značajnih razlika u strukturalnim svojstvima niti u ekološkim skupinama ptica. Bukove sastojine naprotiv pokazuju značajne strukturalne razlike i u njima je, kao i u mješovitim crnogoričnim sastojinama, zabilježena najveća razlika među ekološkim skupinama ptica između dva Parka. Strukturalne razlike tih šuma između dva Parka su rezultat različite starosti sastojina, a ptice su imale veće gustoće u starijim šu-mama. Među strukturalnim svojstvima vegetacije, ona vezana uz starost šume (prosječna temeljnica i broj mladih stabala) bile su značajno korelirane s ukupnom gustoćom populacija pjevica i s gustoćom različitih ekoloških skupina. Zaključak je ovog istraživanja da floristički sastav šuma ima utjecaj na odabir tipa šume u kojoj će se neke vrste ptica pjevica gnijezditi, dok na odabir samog područja gniježđenja veći utjecaj imaju strukturalna svojstva šume