Sexual selection in genetic colour-polymorphic species: a review of experimental studies and perspectives

Sexual selection theory has primarily focussed on the role of mating preferences for the best individuals in the evolution of condition-dependent ornaments, traits that signal absolute quality. Because the most suitable mate for one individual is not always the best for others, however, we argue that non-directional mate choice can promote the evolution of alternative morphs that are not condition-dependent in their expression (i.e. genetic polymorphism). We list the different mate-choice rules (i.e. all individuals have the same preference; preference depends on the chooser's morph; individuals mate preferentially with conspecifics displaying an uncommon or the most frequent morph) and review experimental studies that investigated mate choice in natural populations of colour-polymorphic animals. Our review emphasises that although the experimental data support the idea that sexual selection plays an important role in the evolution of genetic colour polymorphism in many different ways, little is known about the adaptive value of each mate-choice strategy and about their implication in the evolutionary stability of colour polymorphism. One way of solving this problem is to determine the adaptive function of colour morphs, a worthwhile objective, because better understanding of mate-choice rules in polymorphic species should provide important insights into sexual-selection processes and, in turn, into the maintenance of genetic variatio

Selective disappearance of individuals with high levels of glycated haemoglobin in a free-living bird

This work was supported by the ANR (ANR-06-JCJC0082 to B.D.), the CNRS (PEPS INEE and PICS France–Switzerland to B.D.), the French Ministe`re de l’Enseignement Supe´rieur et de la Recherche (PhD fellowship to C.R.), the Re´gion Rhoˆne-Alpes (Explora’doc mobility grant to C.R.), the University of Aberdeen (stipend to C.R.), the L’Ore´al Foundation-UNESCO ‘For Women in Science’ program (fellowship to C.R.) and the Rectors’ Conference of the Swiss Universities (grant to C.R. and P.B.).Peer reviewedPostprin

An Experimental Test of a Causal Link between Problem-Solving Performance and Reproductive Success in Wild Great Tits

This work was supported by a NSERC grant to A.B., a PICS grant from the CNRS (INEE, n° 31520) to B.D., a PhD writing up grant from the FESP (UdM) and a scholarship from the Biological Sciences Department (UdM) to LC and a mobility grant ERASMUS to M.L. We are also grateful to the ABS, the BOU, the BES, the Frank M. Chapman from AMNH and the Fred Cooke from the SCO for awards and research grants attributed to L.C.Peer reviewedPublisher PD

Importance of melanin-based colouration and environment in shaping intracellular glutathione levels in nestling and adult tawny owls Strix aluco

Acknowledgements – We are grateful to Isabelle Henry, Arnaud Da Silva, Mélissa Noll, Sophie Cotting, Adrian Moriette and Alexandre Chausson for assistance in the field and the Swiss National Science Foundation for financial support (PPOA-102913 and 3100AO_120517 to AR). Funding – Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung.Peer reviewedPublisher PD

Correlation in telomere lengths between feathers and blood cells in pied flycatchers

We are grateful to Toni Laaksonen, Pauliina Teerikorpi, Ville Ojala, Wiebke Schuett, Corinna Adrian and Marie Hardenbicker for their help in the field, and two anonymous reviewers for constructive comments on the manuscript. This research was financially supported by the Turku Collegium for Science and Medicine (grant to AS) and Societas Pro Fauna et Flora Fennica, The Kuopio Naturalists’ Society, and Finnish Cultural Foundation Varsinais-Suomi regional fund (grants to TK). The authors declare to have no conflict of interests. Dataset used in this study will be publicly accessible on Figshare https://figshare.com/s/dffa03e1e91c2e57dc13).Peer reviewedPostprin

Beak colour dynamically signals changes in fasting status and parasite loads in king penguins

This research was funded by the French Polar Institute (IPEV–Research Program 119) and the French National Centre for Scientific Research (CNRS-INEE). Field logistic support was provided by Terres Australes et Antarctiques Françaises. Q.S. was funded by a doctoral fellowship from the Ministère Français de l’Education Supérieur et de la Recherche. We thank all over-wintering assistants: Benoit Gineste, Sylvia Pardonnet, Laureline Durand, Emilie Lefol and Hédi Saadaoui for field work and Emilio Rojas for helpful discussion on the analyses. We apologize to our stick insect (Carausius morosus) for bearing with VAV’s inquisitive curiosity during our debates on color ornaments in king penguins. We sincerely thank the editor and 2 anonymous reviewers for their helpful comments on a previous version of the paper.Peer reviewedPostprin

Variation in feather corticosterone levels in Alpine swift nestlings provides support for the hypo-responsive hypothesis

Acknowledgements: The authors would like to thank the numerous students who helped collecting data in the field and the city council of Solothurn for access the Bieltor tower. SJE would like to thank Benedetta Catitti for producing the figures and Lukas Jenni for valuable comments on the manuscript. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Peer reviewedPostprintPublisher PD

Indirect Costs of Parasitism are Shaped by Variation in the Type of Immune Challenge and Food Availability

Parasites can inflict indirect fitness costs to their hosts by eliciting costly immune responses. These costs depend on the type and amount of immunostimulants presented to the host immune system but also on the amount of resources available to fuel host immune responses. Here, we investigated how the relative costs of two different types of immune challenge are modulated by variation in food availability. We injected nestling tawny owls (Strix aluco) with either 10μg of phytohaemagglutinin (PHA) or 20μg of lipopolysaccharide (LPS), and subsequently raised them under two different food regimes (food-restricted vs. ad libitum). After controlling for food consumption, we found that LPS-injected nestlings lost more body mass than PHA-injected ones only when food-restricted. We also found that body mass gain of owlets fed ad libitum decreased with the intensity of the skin swelling response against LPS, but not PHA. These experimental and correlative results suggest that nestling tawny owls suffered greater immune costs when treated with LPS than PHA, and that variation in the costs of two different types of immune challenge can be exacerbated under conditions of low food availability. Our study highlights the importance of taking into consideration the interplay between host immunity and nutrition in the study of indirect costs of parasitis

Antioxidant capacity is repeatable across years but does not consistently correlate with a marker of peroxidation in a free-living passerine bird

Many thanks to the landowners of Gotland for access to the study sites; to Lars Gustafsson for logistics on the field; to fifteen students and field assistants for their contribution to fieldwork; to François Criscuolo for his help designing the study and his comments on this manuscript; to Holger Schielzeth and Pierre de Villemereuil for their advice on adjusting repeatability and correlation estimates for measurement error and to Alan A. Cohen, David Costantini and anonymous reviewers for their comments on previous versions of this manuscript. This work was supported by the French National Center for Scientific Research (PICS France34 Switzerland to B.D.); the French Ministry of Research (PhD fellowship to C.R.); the University of Aberdeen (stipend to C.R.); the L’Oréal Foundation-UNESCO “For Women in Science” program (fellowship to C.R.); the Région Rhône-Alpes (Explora’doc mobility grant to C.R.); the Fédération de Recherche 41 BioEnvironnement et Santé (training grant to CR); the Rectors’ Conference of the Swiss Universities (joint doctoral program grant to C.R.) and the Fondation pour l'Université de Lausanne (exchange grant to C.R.); and the Journal of Experimental Biology (travel grant to CR).Peer reviewedPostprin