01664nas a2200133   4500008004100000245006800041210006800109520114900177653009101326100002201417700002101439700002001460856005001480       2004                        eng d00aSound production during competitive feeding in the grey gurnard0 aSound production during competitive feeding in the grey gurnard3 a<p>The acoustic repertoire of captive grey gurnard Eutrigla gurnardus during competitive feeding consisted of three types of sound: knocks, grunts and growls. Knocks were audible as a single sound, whereas grunts and growls were perceived as longer, pulsed sounds to the human ear. Typically, knocks were composed of 1&ndash;2 pulses, grunts of 4&ndash;8 pulses and growls &gt;10 pulses. Growls were longer and had shorter pulse periods than grunts. All sound types had peak frequencies of c. 500&emsp;Hz. The sequences of behaviours observed during feeding interactions suggest that grey gurnard obtain food both by scramble and contest tactics. Competing fish emitted knocks mainly while grasping a food item and also during other non‐agonistic behaviour, suggesting that knock production may reflect a state of feeding arousal but could also serve as a warning of the forager&#39;s presence to nearby competitors. Grunts were mainly emitted during frontal displays, which were the most frequent behavioural act preceding grasps, suggesting that they may play a role in deterring other fish from gaining access to disputed food items.</p>
10aagonistic behaviour; bioacoustics; calling; scramble and contest competition; teleosts1 aAmorim, M., C. P.1 aStratoudakis, Y.1 aHawkins, A., D.  uhttp://www.blackwell-synergy.com/toc/jfb/65/1