BUSCADOR RECOLECTA

Digital.CSIC. Repositorio Institucional del CSIC

oai:digital.csic.es:10261/265281

In bi-parental species, reproduction is not only a crucial life-history stage where individuals must take ftness-related decisions, but these decisions also need to be adjusted to the behavioural strategies of other individuals. Hence, communication is required, which could be facilitated by informative signals. Yet, these signalling traits might have (co-)evolved in multiple contexts, as various family members usually meet and interact during reproduction. In this study, we experimentally explored for the frst time whether a colourful plumage trait in adults acts as a signal that regulates multiple intra-family interactions in a bird species, the blue tit (Cyanistes caeruleus). We expected that an experimental reduction of adults’ UV/yellow refectance (i.e. a reduction of apparent individual quality) should afect the behavioural strategies of all family members. We found evidence for this at least in adults, since the partners of UV-blocked individuals (either males or females) increased their parental investment — perhaps to compensate for the apparent lower condition of their mates. As the UV-blocked adult did not change its provisioning behaviour, the partner presumably responded to the manipulated signal and not to a behavioural change. However, the ofspring did not co-adjust their begging intensity to the experimental treatment. It is thus possible that they responded to overall parental care rather than the signal. These results suggest that UV/yellow colouration of adult blue tits may act as quality signal revealing the rearing capacity to mates., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Grants CGL2016-79390-P and PID2019-106032GB-I00 (to JM) funded by MCIN/AEI/ https://doi.org/ 10.13039/501100011033 and by “ERDF A way of making Europe”. JG-C was supported by Grant BES-2017-079750 and JM by a Ramón y Cajal contract RYC-2014-15145 funded by MCIN/AEI/ https://doi.org/ 10.13039/501100011033 and “ESF Investing in your future”., Peer reviewed