Egg covering in great tits and effects on pied flycatchers

This dataset contains data from experiments carried out in a woodland area and described in the paper: “T. Slagsvold, and Wiebe, K. L. (2021) “Egg covering in cavity nesting birds may prevent nest usurpation by other species.” https://doi.org/10.1007/s00265-021-03045-w

The experiments investigated a new hypothesis, namely that the cavity nesting birds, like titmice, cover their eggs when they leave the nest during the egg laying period to prevent usurpation of the cavity by other birds. We provided nest boxes in a woodland area and filmed great tit (Parus major)nests during the egg-laying period to study the behavior of the female. Then we presented prospecting male pied flycatchers (Ficedula hypoleuca) with a dyad of nest boxes, to study whether they hesitated to enter a box when the tit eggs were covered or not, depending on the size and depth of the box.

Main results of the experiments were that (1) during the egg-laying period, the female great tit spent bouts of highly variab...