Possibilities for fire as a management tool on Kras (SW Slovenia): a bird's perspective

The response of birds to wildfires in sub-Mediterranean areas and the possibleuse of fire as a nature management tool in Kras (SW Slovenia) is reviewed. In recent years the limestone region called Kras was forested with Austrian Pine Pinus nigrd and became more and more overgrown by bushes and trees due to depopulation and land abandonment, which has made it more vulnerable to fire. The latter patterns in particular are occurring throughoutthe whole subMediterranean area and are affecting bird diversity drastically. Bird mortality during fires is low. For the first few years aftera fire the richness and abundance of bird species decrease, and the species composition turnover rate is very high, from open habitat species to scrubland species. However, birds will colonise the burned area only when there is a neighbouring source population. In addition, larger burned areas are colonised more quickly than smaller ones. It is assumed that many birds will emigrate, while a number of species will adapt their territory size, nesting and foraging behaviour to the changed habitat. The severity of the habitat alteration and the change in food availability affect bird population dynamics. Bird species composition changes in parallel with vegetation succession. The effects of different aspects of fire, such as the size of the burned area, fire intensity, fire frequency and burning season, are reviewed. There are still many gaps in our knowledge of bird responses to fire, such as bird emigration after fires. However the impact of fire on birds is apparentlynot always detrimental and can even have a positive effect on populations. We therefore emphasize the importance of the continuation of research into the possibilities of fire as a management tool

Nestling growth of Great Tits Parus major with comparison among altitudes

Fledgling mass can have great influence on individual’s life history and reflects the availability and quality of food in the breeding territory. Thus growth curve is used to compare the difference in the quality between different ecological conditions. The aim of the study was to fill the knowledge gap on nestling growth in Great Tit in Slovenia, to determine the influence of altitude on it and to present a tool for estimating age of nestlings and key dates in breeding phenology of Great Tit. Great Tits young were monitored using nest-boxes at three locations between years 2010 and 2012. At two locations nest-boxes were placed on three separate altitudinal belts. Weight growth curve was compared with the curves from other parts of Europe. Growth curve from Slovenia differs in growth parameters from other European populations but falls within their range. Difference in growth parameters between separate populations probably comes from the difference in ecological conditions. When comparing three altitudes weight parameters of hatchlings were similar at lower and middle but different at upper altitudes indicating that weigh growth changes with the altitude. Lower food abundance that comes with rising altitude may be offset by lower competition through lower breeding density (hence similar growth parameters in lower and middle altitude), but not past certain altitude. Weight parameters are useful when comparing different populations, but wing-length is better in determining the age of young in the nest

Waterbirds and raptors of Cerknica polje (southern Slovenia) in 2007 and 2008, with an overview of interesting observations till the end of 2010

Od konca februarja 2007 do sredine februarja 2008 je bilo na Cerkniškem polju (južna Slovenija) v desetdnevnih obdobjih (dekadah) opravljenih 73 sistematičnih popisov vodnih ptic in ujed. Cilji raziskave so bili: ugotoviti številčnost in časovno dinamiko pojavljanja vrst, opredeliti njihov status, napraviti primerjavo s preteklim obdobjem sistematičnega zbiranja podatkov v letih 1991–1992, podati ocene gnezdečih, selitvenih in prezimujočih populacij ter na njihovi osnovi naravovarstveno ovrednotiti to območje. Zbrani so bili tudi drugi ornitološki podatki, pridobljeni do konca leta 2010. Med začetkom maja in začetkom septembra leta 2007 je voda na območju raziskave presahnila, tako da se je zadržala le v strugah potokov, vodna površina pa je bila deloma ali v celoti zaledenela od sredine novembra 2007 do začetka februarja 2008. Do konca leta 2010 je bilo na Cerkniškem polju skupaj zabeleženih 129 vrst vodnih ptic in ujed, v obdobju 2007/2008 pa 83. Dinamika pojavljanja vrst z več kot devetimi opazovanji je podrobneje predstavljena v pregledu vrst. Status gnezdilke ima 27 vrst, še nadaljnjih sedem pa je prehranskih gostov, ki gnezdijo v okolici območja raziskave. Največ vrst (118) ima status preletnega gosta, medtem ko je vrst s statusom poletnega (34) oziroma zimskega gosta (40) manj. Med zabeleženimi vrstami je 34 izjemnih in 21 redkih gostov. Prezimovalcev je 16, letovalcev sedem, vse leto pa se je tukaj zadrževalo šest vrst. V vseh dekadah obdobja raziskave so bile opažene štiri vrste: mlakarica Anas plathyrhynchos, siva čaplja Ardea cinerea, kanja Buteo buteo in postovka Falco tinnunculus. V več kot 90 % dekad je bila zabeležena še velika bela čaplja Ardea alba. Dve vrsti sta bili v obdobju 2007/2008 evdominantni (mlakarica 27,2 %, kanja 10,1 %), še dve pa dominantni (reglja Anas querquedula 7,4 %, liska Fulica atra 6,4 %). Največ osebkov je bilo zabeleženih konec marca in v začetku aprila (do 1978 os.), največ vrst (48) pa sredi aprila. Število vrst in osebkov je bilo med majem in avgustom zaradi presahlega jezera majhno. Najmanjše območje pojavljanja so imeli kormoran Phalacrocorax carbo ter skupina rac iz rodov Aythya, Bucephala in Mergellus. Galebi, čaplje, pobrežniki, lunji Circus sp. in rdečenoga postovka Falco vespertinus so se pojavljali na večjem delu območja raziskave. 10 gnezdilk izpolnjuje kriterije za oznako varstveno najpomembnejše vrste, od katerih sta dve (kostanjevka Aythya nyroca, veliki škurh Numenius arquata) vrsti globalne varstvene pozornosti, sedem pa vrste evropske varstvene pozornosti. Med negnezdilkami se 14 vrst vodnih ptic in ujed pojavlja v pomembnem številu (> 0,1 % biogeografske populacije), od tega se jih pet vsaj občasno pojavlja z več kot 1 % biogeografske populacije. Dve vrsti (rjavovrati ponirek Podiceps grisegena, kozica Gallinago gallinago) v Sloveniji gnezdita samo na Cerkniškem polju, še šest vrst pa ima tukaj vsaj 40 % slovenske gnezdeče populacije.Between the end of February 2007 and mid-February in 2008, 73 systematic surveys of waterbirds and raptors were carried out during 10-day periods at Cerknica polje (Southern Slovenia). The main objectives of our research were: to ascertain the abundance and temporal dynamics of the species occurring here, to specify their status, to make a comparison with the past period of systematic data gathering in the 1991–1992 period, to present estimates of the breeding, migrating and wintering populations, as well as to make, on these bases, a nature-conservancy evaluation of the area. Other ornithological data, acquired till the end of 2010, were gathered as well. Between the beginning of May and the beginning of September 2007, the water in the area virtually ran dry (it was retained only in the channels of the streams), while the surface itself was partially or fully icebound from mid-November 2007 till the beginning of February 2008. By the end of 2010, a total of 129 waterbird and raptor species were recorded at Cerknica polje, while in the 2007–2008 period 83 were registered. Dynamics of the species occurrence with more than nine observations made in the area is presented in a greater detail in the species overview. The breeding status was held by 27 bird species, while further seven were forage guests that bred in the vicinity of the study area. Most of the species (118) had the status of passage visitor, whereas those with the status of summer visitor (34) and winter visitor (40) were fewer. Among the recorded species, 34 were accidental and 21 rare visitors. There were 16 winter and seven summer residents, while year-round residents were six. In all 10-day periods of the research period, four species were recorded: Mallard Anas plathyrhynchos, Grey Heron Ardea cinerea, Buzzard Buteo buteo and Kestrel Falco tinnunculus. In more than 90% of 10-day periods, the Great Egret Ardea alba was recorded as well. In the 2007–2008 period, two species were eudominant (Mallard 27.2%, Buzzard 10.1%), whereas another two were dominant (Garganey Anas querquedula 7.4%, Coot Fulica atra 6.4%). Most individuals were registered at the end of March and in early April (up to 1,978 ind.), whereas the greatest numbers of species (48) were recorded in mid-April. Between May and August, the numbers of individuals and species were low owing to the dried up lake. The smallest area of occurrence was occupied by the Cormorant Phalacrocorax carbo and a group of ducks of the genera Aythya, Bucephala and Mergellus. Gulls, egrets, herons, waders, harriers Circus sp. and the Red-footed Kestrel Falco vespertinus occurred in the greater part of the research area. 10 breeders fulfilled the criteria of the species of the greatest conservation importance, two of which (Ferruginous Duck Aythya nyroca and Curlew Numenius arquata) are species of global conservation concern, whereas seven are of conservation concern on a European scale. Among non breeders, 14 waterbird species and raptors occurred in significant numbers (> 0.1% biogeographical population), five of which occurred at least occasionally with more than 1% of their biographical population. Two species (Red-necked Grebe Podiceps grisegena and Snipe Gallinago gallinago) breed in Slovenia only at Cerknica polje, while further six species have here at least 40% of their Slovenian breeding population