Figures & data
Figure 1 Annual trend of the total number(NTOT) of departing D‐pigeons observed per day in Venice, Parma and Lucca. Smoothing lines were calculated using Locally Weighted Polynomial Regression (LOWESS) with a span = 2/3.
Figure 2 Box‐and‐whisker plot of the flock size of departing D‐pigeons observed in Venice, Parma and Lucca (numbers above boxes = number of groups observed per day – NGR). Smoothing lines of the median flock size per day (MED) were calculated using LOWESS (see figure ).
Figure 3 Number of turning points(TP) of the daily trend of D‐flights recorded in each month in Venice, Parma and Lucca. Smoothing lines were calculated as in figure . Numbers refer to the hours after sunrise needed for 50%+1 of NTOT pigeons to depart from the city boundaries (T50).
Figure 4 Time course(hours after sunrise) of the number of departing pigeons (D‐pigeons) recorded in January and June (open and filled bars, respectively) in the three considered cities.
Table I. Summary of clusters identified using a cut height = 0.5. Data on rock doves are also reported for comparison (see also Baldaccini et al. Citation2000).
Figure 5 Dendrograms showing the pattern of clustering of the 12 days considered for departing flights. Note the different scales of the three plots. Broken lines indicate the cut height = 0.5.
Figure 6 Values of the index of nesting activity(NAI) recorded during the months grouped in the two (Venice) and three (Lucca) clusters identified using a cut height = 0.5. Cluster identifiers as in table .
