Vodne ptice in ujede Cerkniškega polja (južna Slovenija) v letih 2007 in 2008, s pregledom zanimivejših opazovanj do konca leta 2010 / Waterbirds and raptors of Cerknica polje (southern Slovenia) in 2007 and 2008, with an overview of interesting observations till the end of 2010

Abstract

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

The MallardAnas platyrhynchosin Slovenia: a review with an estimation of its current population

“…Some studies also include birds of prey (e.g. Bordjan 2012b). For such studies, I calculated dominance to include only waterbirds according to Božič (2020).…”

Terns (Sterninae) in the collection of the Slovenian Museum of Natural History

“…2007, prep. Al Vrezec (Slika 10) Belolična čigra se v Sloveniji redno pojavlja na selitvi, čeprav nikjer ni zelo številna (Bordjan & Božič 2009, Bordjan 2012, Škornik 2012. V zbirki PMS je shranjen le en primerek odrasle ptice, ki je drugače ni bila dokazana (Vrezec 2019).…”

“…V zbirki PMS je shranjen le en primerek odrasle ptice, ki je drugače ni bila dokazana (Vrezec 2019). Vrsta se pri nas sicer redno pojavlja na selitvi (Bordjan & Božič 2009, Bordjan 2012, Škornik 2012. Večina primerkov v zbirki PMS je bila zbrana med letoma 1949 in 1965, večino pa je zbral muzejski preparator Alojz Šmuc.…”

“…1949, leg. in Črna čigra sodi med izumrle gnezdilke Slovenije (Vrezec 2019), danes pa se redno pojavlja v obdobju selitve, tudi v večjih številih (Bordjan & Božič 2009, Bordjan 2012, Škornik 2012. Zadnja sumljiva gnezdišča so bila ugotovljena v Sečoveljskih solinah, na Cerkniškem jezeru in ob reki Dravi (Geister 1995).…”

Habitat use by waterbirds at Rački ribniki, NE Slovenia

“…(Vogrin 1997) and the Mallard Anas platyrhynchos (Bordjan 2020). Also, three studies have been published in Slovenia so far, showing distribution of different wetland species within a selected wetland (Bordjan 2012, Deberšek & Bordjan 2016, Koce 2018), indicating habitat partitioning in those species/groups. While several studies on waterbirds have been carried out at Rački ribniki (Vogrin 1998, Vogrin 1999, Vogrin 2001, Vogrin 2002, Denac et al 2011, none have dealt with habitat partitioning or conservation resulting from habitat use.…”