Search Results

1 - 2 of 2 items

  • Author: Thomas Oliver Mérő x
Clear All Modify Search

Pozvetek

Objavljanje in osnovna analiza obročkovalskih podatkov sta sicer pogosti temi člankov, redko pa so objavljeni podatki iz posameznega mesta, kot je denimo Sombor v premalo raziskani regiji Srbije. Predstavljamo podatke o obročkanju in ponovnem ulovu plavčkov Cyanistes caeruleus in velikih sinic Parus major za obdobje 32 let. Dodatno smo preverili vpliv povprečne najvišje temperature jeseni (september-december) in pozimi (januar-marec) na njihovo številčnost ter pojavljanje v dveh osnovnih habitatnih tipih (parki in vrtovi) v mestu Sombor. Skupno smo obročkali 1675 plavčkov (ponovno ujeti osebki N = 407) in 8062 velikih sinic (ponovno ujeti osebki N = 1517). Pri obeh vrstah so prevladovali mladi osebki (koda EURING 3 oz. 5). Najstarejše obročkane ptice obeh vrst so bile mlajše kot zabeleženo v drugih evropskih raziskavah. Številčnost obeh vrst ni bila povezana s povprečno najvišjo jesensko oziroma zimsko temperaturo. Število obročkanih ptic v parkih in vrtovih se ni pomembno razlikovalo. Glede na ugotovitve predhodnih raziskav sklepamo, da je njihova številčnost v posameznem habitatnem tipu odvisna od razpoložljivost hrane in vremenskih razmer, ne pa drugih okoljskih dejavnikov.

Abstract

Grasslands host a high diversity of plant and animal species. In Serbia, most alkali grasslands are located in the province of Vojvodina. The majority are not subject to conservation. The aim of the study was to investigate the relationship between the proportion of croplands and (1) the number of breeding species and (2) the number of breeding pairs in the alkali grasslands of the upper Mostonga River catchment basin (NW Serbia). The size of the study area was 400 ha. Birds were surveyed along seven parallel transects eight times per breeding season. Lengths of the cross sections of both grasslands and croplands were measured. The proportion of croplands per transect was calculated by dividing the total length of cross sections of croplands by the total length of transect. The relationship between the proportion of croplands and the number of breeding pairs and the number of breeding species, respectively, was studied using simple linear regression. We recorded a total of 171 nesting pairs belonging to 23 species in the alkali grassland investigated, with breeding densities between 2.2 and 10.3 pairs per 10 ha. The number of species per transect ranged between 6 and 11. The most abundant species were Skylark Alauda arvensis, Yellow Wagtail Motacilla flava and Corn Bunting Emberiza calandra. The numbers of breeding pairs (F6 = 21.761, P < 0.0001) and of breeding species (F6 = 13.758, P = 0.001) were both influenced negatively by the proportion of croplands. These findings highlight the need for coordinated conservation measures on the alkali grasslands of Vojvodina.