@article {57655, title = {Great tits encode contextual information in their food and mobbing calls}, year = {2019}, abstract = {

The calling behaviour of Paridae species (i.e. titmice, tits and chickadees) in a predator-related context is well-studied. Parid species are known to alter call types, note composition or call duration according to predation risk. However, how these species encode information about a non-threatening context, such as food sources, has been subject to only few studies. Studies in Carolina chickadees (Poecile carolinensis) have shown that this species alters the ratio of C and D notes to encode information about the presence of food and/or the flight behaviour of the signaller. This suggests that parids also use graded signals to encode information about non-predatory contexts. No study to date has directly compared the calls of a feeding context with those of a predation (i.e. mobbing) context. Hence, the aim of this study was to compare the calling behaviour of these two situations in great tits (Parus major). Calls uttered at a feeder were recorded, analysed and compared with calls uttered in front of taxidermy mounts of sparrowhawks (Accipiter nisus). In the food context, great tits reduced the number of D notes and increased the number of B, C and E notes compared with the mobbing context. Furthermore, tits produced calls with longer D notes and shorter intervals between D notes than in the mobbing context. This indicates that great tits use two mechanisms of graded signals (i.e. note type and acoustic structure of D calls) to inform conspecifics about the nature of a situation.

}, keywords = {food-associated vocalizations, mobbing, Parus major, social communication}, doi = {10.1098/rsos.191210}, url = {https://royalsocietypublishing.org/doi/10.1098/rsos.191210https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.191210https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.191210https://royalsocietypublishing.org/doi/full-xml/10.1098/rsos.191210}, author = {Kalb, Nadine and Anger, Fabian and Randler, Christoph} } @article {40433, title = {Sound production in primitive Orthoptera from Western Australia: sounds used in defence and social communication in Ametrus sp. and Hadrogryllacris sp. (Gryllacrididae: Orthoptera)}, journal = {Journal of Natural History}, volume = {31}, year = {1997}, month = {Jan-07-1997}, pages = {1127 - 1141}, abstract = {

Sound production in two undescribed species of Gryllacrididae belonging to the genus Ametrus sp. and Hadrogryllacris sp. takes the form of defensive stridulation and intra-specific signalling by drumming on the substrate. Defensive stridulation is produced as part of an elaborate visual display, by femoro-tergal stridulation. Two rows of spines on abdominal tergites II and III of both species are rubbed by an elongate area of tubercules on the inner femoral surface of the hind legs. Analysis showed that the motion of the leg relative to the abdomen involves a complex counter-rotation of the leg between leg and abdomen. The defensive display may be performed in day light. Social signalling in both species occurs after dark, and involves drumming on the substrate by both hind legs in loose synchrony. Drumming is rhythmic and species\&$\#$39; specific. Males respond to playback calls and females duet with males. The evolution of this calling behaviour is discussed and comparisons are made with the other primitive ensiferan family known to produce both tergo-abdominal defensive stridulation and femoral drumming behaviour, the Stenopelmatidae.

}, keywords = {defence, duetting, social communication, sound production, substrate vibration}, issn = {0022-2933}, doi = {10.1080/00222939700770591}, url = {http://www.tandfonline.com/doi/abs/10.1080/00222939700770591}, author = {Field, L.H. and Winston J. Bailey} }