Figure 3 in Lichens in the nests of European starling Sturnus vulgaris serve a mate attraction rather than insecticidal function

Figure 3. Number of events in which lichens were added to starling nests during the nesting cycle. Before: period before the start of nest building. Beginning: the first day of nest building. Middle: between the second and the last day of the nest building. After: after the starlings had complete nest building.