Influence of starvation on willingness to risk in Great tit (\kur{Parus major}) and Blue tit (\kur{Parus caeruleus})

In this work, I investigated influence of starvation on willingness to risk for food in presence of a predator. Experiments proceeded in winter when birds are not influenced by fear about clutch or brood and therefore the food becomes their priority. I tested birds in laboratory conditions where is possible to monitor and regulate food availability. Tits were tested for stuffed model of dangerous hunting specialist sparrow hawk (Accipiter nisus), nest predator jay (Garrulus glandarius) and harmless similar-sized bird pigeon(Columbia livia f. domestica). A control experiment without a model was conducted too. Each bird was tested for given model replete and hungry and each bird was tested only for one model. We were interested in differences in reactions to individual models and the influence of repletion rate; if the behaviour was different between replete and hungry birds, or in the {\clqq}accustom`` phase and in experiment itself. We also investigated, if there are differences in behaviour between Great Tits and Blue Tits