Table 1.
Short list of abbreviations used in the applied methodological approaches.
Figure 1.
Graphical representation of the spectrograms of the hooting of the eagle owl (A) of male (below) and female (above) calls of the eagle owl.
Parameters measured to characterize the call are: (a) parameters in the time domain: D1, D2 and D3; (b) parameters in the frequency domain: Fmax, Fmin and FDOM (see text for explanations). (B) Four spectrograms of the territorial calls uttered by different eagle owl males in south-western Spain. The high similarity among eagle owl calls is apparent even by visual inspection. Owing to the considerable overlap observed, individuals could not be discriminated on the basis of the information concerning their vocalization.
Figure 2.
Pattern of mean productivity (±95% CI) of eagle owl territories during a 10-year period.
Differences in the fecundity distribution between territories were very small, indicating a relatively homogeneous population, which is characterized by territories of similar quality.
Table 2.
Characteristics of the temporal and frequency parameters measured from recordings of eagle owl calls (N = 478).