Zbigniew Kwieciński

Zbigniew Kwieciński

Main Interest






















In evolutionary struggles for survival, victims have developed many defense mechanisms against predators that reduce or eliminate the risk of death. Predators often reproduce in specific places for many years, causing permanent threat to local populations of victims. Thus, predators can affect their condition by forming costly defensive behaviors. One of the anti-predatory behaviors popular among birds, especially vulnerable to losses during the breeding period, is the construction of well-hidden nests. For example, in an intense agricultural landscape, the choice of nesting place for birds is of fundamental importance for their reproductive success, because the nests are exposed to changes in land use and changing weather conditions. The simplified spatial structure (open space, low forest cover) of the agricultural landscape favors more intense and easier penetration of the area by predators than in other habitats, for example in forests. One can suspect that in this structurally simplified landscape even small differences in the placement of nests and even within the same shrub or tree will determine the level of predation and thus the breeding success of birds.

Come many times in the publications, it was suggested that the good hiding of nests is directly related to breeding success, however it was not examined whether the spatial location of the nest on a very small scale, e.g. the location of the nest inside a tree or bush affects the chances of survival of eggs and chicks, and thus is it's potentially an anti-drift strategy.

In the project, I intend to investigate to what extent hiding a nest can affect the breeding success of birds, and what factors determine it. The object is three model species of birds: Turdus merula, Turdus philomelos and Lanius collurio. The first two species are more associated with typical forest habitats, but are quite widespread in the agricultural landscape. In addition, in the case of the scythe and singer, predation and anti-predatory mechanisms are poorly understood in open landscapes, which is probably related to the spatial dispersion of individuals in this environment. The research will be conducted in southern Wielkopolska, near Odolanów (floodplains of the Barycz Valley SPA, Natura 2000 area), where the abundance (density) of all these species is sufficient to carry out the scientific activities described below. Despite many assumptions and meta-analyzes made by ornithologists, there is still a lack of good experimental verification and hence the idea to verify two hypotheses explaining the problem of the location of bird nests. The first hypothesis assumes that bird nests better hidden within the bush / tree (as single and rope landscape elements) are characterized by better egg survival and nesting success from nests hidden worse. To this end, the geometrical parameters of the bush/tree structure will be determined, such as the distance from the base of the element (bush/tree), the distance between the nest and the top of the element. The next stage will be to characterize the "light environment of each nest" - execution of a set of light intensity measurements (luxometric measurements), inside and outside the bush / tree, in which the nest is oriented. The analysis of the collected geometric and luxometric data is to determine the level and differences in shade of nests with successful breeding and loss of breeding. Measurements of nests will be made at the moment of finding in the nest of eggs or chicks, finding a loss in breeding at the level of eggs or chicks and those where the chicks have left the nest successfully. The second hypothesis is that the direction from which the predator attacks the nest is related to the bird's behavior at the nest and its relative position inside the bush/tree, or more strictly with the entry of birds into the element in which the host nest is located. Birds during incubation of eggs or feeding of chicks use a diagram of the nest's arrival. The entrance to the nest (eg with food for chicks) is usually longer (measured from the edge of the element to the nest), while the exit (eg with the droppings of the hatchlings) is shorter (measured from the edge of the element to the nest). Widespread predator birds of passerines nesting in the agricultural landscape are corvidae, such as jay Garrulus glandarius, magpie Pica pica or crow gray Corvus cornix. As visually impaired, corvids, prior to attack on the nest, make a kind of study, observing the activity of a pair of birds in the vicinity of the nest. Therefore, the test of the hypothesis will be based on the registration of the event - whether predators use the same approach to the nest as the parental pair - or whether the attack and entrance to the element is accidental and independent of the location of the nest in the space of the bush / tree and the way of entry and exit of the owners slot. For this purpose, photo traps will be used to register the attack, installed inside the bottom of the element so as not to interfere with the natural breeding process of the studied birds.