OUWENEEL GL (1980) Short announcements: Territory behavior of bitterns Botaurus stellaris. LIMOSA 53 (2): 71-71.

On 30 april 1980 the author observed two Bitterns Botaurus stel/aris above a reed bed along the Hollands Diep (NB). For a quarter of an hour both birds circled at a height of about 30 m, gradually reaching a higher level. One Bittern was pursueding the other. The bird that pursued hold its bill somewhat opened and regularly a harsh. heron like call could be heard. During the flight both birds came into conflict with each other three times. It is supposed that these Bitterns had a territorial fight.

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