From 1999 until 2006 large-scale investigations were conducted on the occurrence and distribution of the Eurasian Treecreeper (Certhia familiaris macrodactyla C. L. BREHM , 1831) and the Short-toed Treecreeper (Certhia b. brachydactyla C. L. BREHM , 1820) in the area of the “Mittelelbe” (former district Wittenberg, 51.50° N, 12.50° E), from the southern rim of the “Roßlau-Wittenberger Vorfläming” to the northern rim of the “Dübener Heide”, including the River Elbe valley (topographic maps 4041, 4042, 4141, 4142, 4241, 4242 and 4342). The occurrence of the species was tested by playback experiments at 781 checkpoints on 1231 days distributed over all months. A total of 2838 excursions led to 1737 records of territorial Eurasian Treecreepers and to 2372 records of territorial Short-toed Treecreepers. In 1257 cases a syntope occurrence of Eurasian and Short-toed Treecreepers was detected on 591 checkpoints. A total of 905 Eurasian and 1593 Short-toed Treecreepers were mist-netted, measured and ringed with rings of the Hiddensee bird ringing centre. 94 Eurasian and 148 Short-toed Treecreepers were re-captured once or several times at the ringing site (details in SCHÖNFELD 2007). The behaviour and the acoustic reactions of the test birds on the playback experiments were documented at each checkpoint. A total of 3036 recordings of different utterance types, songs, call series and aggressive sounds (except single calls) were taken. Analyses of acoustics and behaviour were carried out separately for checkpoints with only one species present and for those with both species, respectively. Whereas the two species responded to playback experiments with song display in late winter and spring, they mainly displayed call series from the beginning of July. Single or series of aggressive calls as well as vocalisations to be interpreted as excitement or resentment calls were recorded in the Short-toed Treecreeper year-round. At 279 checkpoints habituation and its time-dependence on the preceding capture, aversion to repeated playbacks and dominance behaviour of adult and first-year birds was investigated in the two species on 413 excursions. The behaviour and affiliation to either of the Treecreeper species was studied in a certain number of mixed singers. The results are shown in 7 tables and 4 figures and discussed in comparison to other investigations

Passeriformes, Certhiidae, Verhalten, Lautäußerungen, Deutschland