Pr. Galeotti et al., MACRO AND MICROGEOGRAPHICAL VARIATIONS IN THE HOOT OF ITALIAN AND ENGLISH TAWNY OWLS (STRIX ALUCO), Italian journal of zoology, 63(1), 1996, pp. 57-64
We studied the geographical variation of song in tawny owls, comparing
temporal and frequency measures of the ''hoot'' in two races of the s
pecies (English and Italian) and in both adjacent and distant populati
ons within each race. We found the two races differed significantly in
five of the 13 parameters considered, duration of the second note, lo
west frequency of the first note, and frequency modulation amplitude b
eing the most important variables; Italian and English hoots were disc
riminated with a high success rate (86.7%). The seven populations also
differed significantly from each other, particularly in the lowest fr
equency, but the overall rate of correct classification was lower (78.
2%). Microgeographic variations between adjacent populations occurred
in both countries: in general, the frequency measures varied through p
opulations according to the habitat, being higher in open farmland and
lower in dense woodland or urban habitats. A mosaic pattern of cultur
ally transmitted hoot variations was therefore recognized, which might
suggest the existence of dialects in the tawny owls.