@article {57655,
	title = {Great tits encode contextual information in their food and mobbing calls},
	year = {2019},
	abstract = {<p>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.</p>
},
	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 {50495,
	title = {Calling for help: dwarf mongoose recruitment calls inform receivers about context and elicit disparate responses},
	journal = {Animal Behaviour},
	volume = {127},
	year = {2017},
	month = {Jan-05-2017},
	pages = {7 - 14},
	abstract = {<p>Social complexity and communicative complexity appear to have coevolved in terrestrial vertebrates. Understanding the information conveyed within the social signals of group-living taxa can illuminate the selection pressures impacting on a species and help to identify the factors promoting sociality. Within vocal communication, recruitment calls are of great importance to many social species, helping to maintain group cohesion and facilitating cooperative behaviour. Yet recruitment vocalizations have received limited scientific attention and it is not clear whether they convey context-specific information to receivers. We investigated the recruitment calls of wild dwarf mongooses, Helogale parvula, to ascertain whether they showed context-specific acoustic differences and whether receivers displayed context-specific responses to recruitment calls in the absence of external cues. We recorded recruitment calls (from four wild groups of dwarf mongooses) from two contexts: when an individual became separated from its group and when an individual encountered a snake. Acoustic analysis revealed that calls from the two contexts differed in acoustic structure and were distinguishable with a discriminant function analysis. Playbacks of calls from both contexts successfully recruited target mongooses, but snake calls elicited a stronger reaction (with mongooses vigilant for longer and approaching the speaker more closely). More importantly, target mongooses also displayed behaviours that were unique to call context, exhibiting head bobbing, creeping and searching of the vegetation during snake call playbacks but never during isolation call playbacks. We conclude that dwarf mongoose recruitment calls refer to context and are perceived as functionally referential by receivers.</p>
},
	keywords = {acoustic analysis, context-specific, dwarf mongoose, functional reference, Helogale parvula, mobbing, recruitment calls},
	issn = {00033472},
	doi = {10.1016/j.anbehav.2017.02.018},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347217300659},
	author = {Rubow, Janneke and Cherry, Michael I. and Sharpe, Lynda L.}
}
