Parental investment across an altitudinal gradient in blue tits (Cyanistes caeruleus) Aisha Bründl To cite this version: Aisha Bründl. Parental investment across an altitudinal gradient in blue tits (Cyanistes caeruleus). Animal biology. Université Paul Sabatier - Toulouse III, 2018. English. NNT : 2018TOU30265. tel-02379770 HAL Id: tel-02379770 https://tel.archives-ouvertes.fr/tel-02379770 Submitted on 25 Nov 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. TH È S E En vue de l'obtention du DO CT O R AT DE L’ U N I V E R SI T É DE TO U L OU S E Délivré par l'Université Toulouse III - Paul Sabatier Discipline ou spécialité : Écologie et Évolution Présentée et soutenue par AI SHA COLLEEN BR Ü NDL Le 22 Mars 2018 Titre : Investissement parental le long d'un gradient altitudinal chez la mésange bleue (Cyanistes caeruleus) JURY Philipp Heeb (rapporteur) Nick Royle (examinateur) Stuart Sharp (examinateur) Ecole doctorale : SEVAB Unité de recherche : UMR 5321 - Station d'Écologie Théorique et Expérimentale Directeur(s) de Thèse : Andrew Russell / Alexis Chaine Rapporteurs : Philipp Heeb Investissement parental le long d'un gradient altitudinal chez la mésange bleue (Cyanistes caeruleus) 1 To Helen and Philip Hull 2 Acknowledgements “When the student is ready the teacher will appear.” (Buddhist proverb) First and foremost, I would like to thank my supervisors Andy and Alexis for showing me the ways of a scientist and enabling this unique experience of a between-country PhD at two very different, stimulating academic institutes. I am immensely grateful to both of you for believing in my abilities with your relentless support and patient encouragement throughout my PhD. How would I have survived without you teaching me everything; from the practicalities of field work (including changing flat tires on muddy Sunday afternoons) to statistics, writing and presentation skills, and generally keeping my brain from being a coach potato? At times you (and perhaps Andy’s time management) pushed me to my limits, but I would have never learnt as much without these challenges. Many thanks also to Camille for your pastoral care and encouragement. I am much indebted to NERC, the Midi-Pyrénées region and the Station d'Ecologie Théorique et Expérimentale of the CNRS (UMR5321), in particular to its director Dr Jean Clobert, in ensuring the funds for this PhD. I owe my gratitude to the Universities of Exeter and Toulouse (Paul Sabatier III) and all the people involved in drawing up this first ‘Cotutelle’ agreement between the two universities leading to a joint PhD award. I thank Dalila Booth for translating this agreement. I believe these programmes are imperative in broadening the academic horizon of young scientists, particularly in the current political climate, and I hope to see more of them in the future. 3 This thesis would not have been possible without the help and enthusiasm of all the students and volunteers that participated in the collection of field and lab data and the development of the project over the past few years. The same goes to all the blue tits involuntarily involved in this study. I’m grateful to each and every one of them. I would like to thank my amazing friends, house mates and office colleagues who have all inspired me in different academic and non-academic ways, taught me to speak French (and some more English), and given me many unforgettable PhD memories; among others those swims in the river, hikes in the mountains, weddings and crazy parties in Moulis and Falmouth. You are named in no particular order: Eleri, James, Rachel, Jeff, Beth, Mat, Cat, Alexis, Elvire, Julien, Lauranne, Feargus, Andrea, Allan, Julia, Jorge, Lisa, Jérémie, Alice, Hugo, Elise, Felix, Hannah, Oli, Ellie S, Josh, Miranda, Azenor, Durian, Jenny, Louis, Lili, Dom, Anne-Sophie, Pablo, Luz, David, Claire, Olivia, Jonathan, Paula, Johannes, Nuria, Martin, Léa, Matthieu, Kirsten, Yuval, Anne, Jérôme, Anika, Vinicius, Lucie, Jarad, Emily and Anja. I wish to express my deepest gratitude to my parents for nurturing my love for nature and letting me be the Öko. The same goes to Tara for being my partner in crime over the past, turbulent years. I know you have all shared this emotional rollercoaster ride from the very uncertain start, through the extended middle, all the way to the tight end of this PhD. I would never have managed this without your endless support. 4 Keoni - I’m extremely grateful for your astonishing patience with my peaks and troughs, for sharing the PhD experience and introducing me to the full beauty of the French Pyrenees. Last but not least, thanks to Carlos – with his soft, black paws - for being the best, most distracting writing companion I could wish for. 5 List of Contents Abstract ............................................................................................................ 3 Acknowledgements ......................................................................................... 5 Contents ........................................................................................................... 8 List of Tables and Figures ............................................................................ 12 Picture of Study species …………………….……………….………….….…… 21 Chapter 1: General introduction ................................................................... 22 1.1 General framework .................................................................................. 23 1.1.1 Reproductive investment .................................................................... 23 1.1.2 Parental care ....................................................................................... 24 1.1.3 Systems of parental care .................................................................... 27 1.1.4 Environmental variation ...................................................................... 29 1.2 PhD aims ................................................................................................... 34 1.3 Study species ........................................................................................... 35 1.4 Study system ............................................................................................ 36 1.5 Thesis outline ........................................................................................... 38 Chapter Two: Extreme plasticity in breeding phenology across an altitudinal gradient: implications for understanding phenological mismatch …………………………………………………………………………… 42 2.1 Abstract …………………………………………………………………..……. 43 2.2 Introduction ………………………………………………………………...…. 44 2.3 Methods …………………………………………………………...…………… 48 6 2.3.1 Study population and habitat …………………………….………………. 48 2.3.2 Phenology, investment and success ……………………………………. 48 2.3.3 Statistical analysis ………………………………...………………………. 50 2.4 Results …………………………………………………………….…………… 53 2.4.1 Breeding phenology ……………………………………..………..………. 53 2.4.2 Contributors to reproductive success: clutch size and hatching success ………………………………………………………………………………………… 56 2.4.3 Reproductive Output ………………………………………………..…….. 62 2.4.4 Nestling mass ……………………………………………………………… 68 2.5 Discussion …………………………………………………………………….. 71 Chapter Three: Testing the use of budburst as a reliable cue to breeding phenology in a population of blue tits breeding along an altitudinal gradient …………………………………………………………………..………… 76 3.1 Abstract ………………………………………………………………………… 77 3.2 Introduction ……………………………………………………...……………. 78 3.3 Methods …………………………………………………………...…………… 83 3.3.1 Statistical analysis ………………………………………………………… 84 3.4 Results …………………………………………………………….…………… 88 3.4.1 Phenology of budburst and lay date …………………………………..… 88 3.4.2 Timing parameters post-laying ………………..…………..………….….. 92 3.4.3 Reproductive success …………………………..…….………………… 100 3.5 Discussion ……………………………………………………….……………102 7 Chapter Four: Inducing females to lay more eggs leads to increased per capita provisioning rates of nestlings in blue tits ……………….…...…… 105 4.1 Abstract ………………………………………………………….…………… 106 4.2 Introduction …………………………………………………………..……… 107 4.3 Methods …………………………………………………………...………..… 110 4.3.1. Experimental design ……………………………………………………. 110 4.3.2 Treatment effects pre-provisioning …………...……………….……..… 112 4.3.3 Provisioning behaviour ……………………………………………..…… 112 4.3.4 Statistical analysis ……………………………………………………..… 113 4.4 Results ………………………………………………………………...……… 117 4.4.1 Treatment effects pre-provisioning …………………………………..… 117 4.4.2 Provisioning behaviour ……………………………………………..…… 121 4.4.3 Nestling mass ………………………………………………..…………… 127 4.5 Discussion …………………………………………………………………… 129 8 Chapter Five: Brood size manipulations across an altitudinal gradient shed new light on investment strategies in a bi-parental care system …….……………..………………………………………………………………….. 137 5.1 Abstract ……………………………………………………………….……… 138 5.2 Introduction …………………………………………………………….……. 140 5.3 Methods …………………………………………………………...………..… 144 5.3.1 Sex differences in provisioning natural brood sizes ……………….…. 147 5.3.2 Responses to brood size manipulations ……………………………… .147 5.3.3 Treatment