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Birds may decorated their nest to exploit a fear of feathers

Cite this dataset

Slagsvold, Tore; Wiebe, Karen L. (2021). Birds may decorated their nest to exploit a fear of feathers [Dataset]. Dryad.


This dataset contains data from experiments carried out in a woodland area and described in the paper: “T. Slagsvold, and Wiebe, K. L. (2021) "Nest decoration: birds exploit a fear of feathers to guard their nest from usurpation". 

The experiments investigated a new hypothesis, namely that some cavity nesting birds, like titmice, add feathers on the top of their nest to prevent usurpation by triggering a fear response in their rivals. We presented pied flycatchers (Ficedula hypoleuca), blue tits  (Cyanistes caeruleus) and tree swallows (Tachycineta bicolor) that were prospecting for a nest site in spring with a dyad of nest boxes, to study whether they hesitated to enter a box depending on the content of feathers.

Main results of the experiments were that (1) all three species hesitated to enter boxes with white feathers. (2) A similar avoidance of white feathers was found when the alternate nest box of a dyad held black feathers. (3) However, the birds readily collected white feathers that we placed on the ground in front of their nest box, showing the fear of such feathers was context-dependent. We suggest that naive prospecting birds may perceive feathers in nests as the result of a predation event, and that owners decorate nests with bright feathers that can be seen from the opening to deter others from entering.


The dataset was collected using extensive video filming of nest boxes provided in woodland areas in Norway and Canada, as part of a project on cavity nesting birds at Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Norway, and at Department of Biology, University of Saskatchewan, Saskatoon, Canada. From the videos we recorded when a nest box was first visited and first entered.

Usage notes

The readme file contains an explanation of each of the variables in the dataset, and its measurement units. Information on how the measurements were done can be found in the associated paper referenced above. 


NSERC discovery grant, Award: 203177