Abstract:
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Animals use colours, morphological structures and behaviour to advertise their
dominance status and ability to obtain resources (Resource Holding Potential, RHP)
in agonistic contexts with conspecifics. Dominance relationships are also known
between species, although the interactions and the information used to assess the
other species' RHP remain obscure and empirical evidence of interspecific recog nition of status is hard to obtain. Using behavioural inference is particularly im portant when a species needs to assess the potential loss of fitness in terms of
reproduction or survival (e.g., risk of damage or predation) that could be inflicted by
another species acting as a predator, parasite or competitor. Our study shows for
the first time the existence of interspecific recognition of status signals: Blue tits
Cyanistes caeruleus (subordinate species) perceive Great tits Parus major (dominant
species) as threats as hole-nesting competitors, and respond differently based on
the size of the great tit's black tie stripe. Blue tits seemed to recognize the mean ing of great tits' black ties because they were bolder when defending their nests
against small-tie (less dominant) great tits than when repelling attacks by large-tie
(more dominant) great tit males. Our results stress that behavioural inference can
potentially be used to assess the meaning of status signals that presumably evolved
in an intraspecific signalling context. |