This year, in early March 2003, a pair was recorded at the same location (internally called N-HHN). However, the female part of the spectrum was not identical with the previous year’s spectrum (Fig 15b). Two weeks later, the pair was again recorded, this time the spectrum was comparable with the last year’s calls spectrum assigned to #1,16.
A comparison with previous spectra of the pair #1,1 (old male and female) showed that there are strong similarities in the female part with spectrum 15b with older spectra, indicating that the male #1 was unison calling with his previous and long-term female #1, but two weeks later, he was again unison calling with his new mate #16!
(One week later, a female with very similar frequency pattern like F1 was guard calling - presumably in turn of entering into a mating phase - with the single male M 17 observed and recorded in 2002). This story leads to the assumption that there was a true divorce between M1 and F1, and that F1 tried to get her former mate back, but F16 won this competition. F1 then turned to try mating with F17.
(b) Brandenburg
