%0 Journal Article
%T The smell of hunger: Norway rats provision social partners based on odour cues of need
%A Gregory R£¿der
%A Karin Schneeberger
%A Michael Taborsky
%J -
%D 2020
%R 10.1371/journal.pbio.3000628
%X When individuals exchange helpful acts reciprocally, increasing the benefit of the receiver can enhance its propensity to return a favour, as pay-offs are typically correlated in iterated interactions. Therefore, reciprocally cooperating animals should consider the relative benefit for the receiver when deciding to help a conspecific. Norway rats (Rattus norvegicus) exchange food reciprocally and thereby take into account both the cost of helping and the potential benefit to the receiver. By using a variant of the sequential iterated prisoner¡¯s dilemma paradigm, we show that rats may determine the need of another individual by olfactory cues alone. In an experimental food-exchange task, test subjects were provided with odour cues from hungry or satiated conspecifics located in a different room. Our results show that wild-type Norway rats provide help to a stooge quicker when they receive odour cues from a hungry rather than from a satiated conspecific. Using chemical analysis by gas chromatography-mass spectrometry (GC-MS), we identify seven volatile organic compounds that differ in their abundance between hungry and satiated rats. Combined, this ¡°smell of hunger¡± can apparently serve as a reliable cue of need in reciprocal cooperation, which supports the hypothesis of honest signalling
%K Rats
%K Volatile organic compounds
%K Food
%K Smell
%K Acoustics
%K Butyric acids
%K Behavior
%K Sulfones
%U https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000628