Eduardo Castro Lobato Driven by the moon: the foraging behaviour of Procellariiforms at night Dissertação apresentada à Universidade de Coimbra para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Ecologia, realizada sob a orientação científica do Doutor Vítor Hugo Rodrigues Paiva (Universidade de Coimbra) e do Professor Doutor Jaime Albino Ramos (Universidade de Coimbra) Agosto/2017 Driven by the moon: the foraging behaviour of Procellariiforms at night Dissertação apresentada à Universidade de Coimbra para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Ecologia, realizada sob a orientação científica do Doutor Vítor Hugo Rodrigues Paiva (Universidade de Coimbra) e do Professor Doutor Jaime Albino Ramos (Universidade de Coimbra). Eduardo Castro Lobato Departamento de Ciências da Vida Universidade de Coimbra Coimbra|2017 ACKNOWLEDGEMENTS After completing this master thesis, I must thank all of those who in some way contributed to its realization: First, for my supervisors Dr. Vitor Paiva, Prof. Dr. Jaime Ramos, for helping me on this process, for all guidance, patience, reviews and friendship. A special thanks to Dr. Vitor Paiva for the relentless availability, perseverance and confidence deposited in me, for the sharing of knowledge and advice given and for making me believe it was possible to complete this thesis. Also thank both of you for presenting me with this theme, without your support this work would not be possible. Thank you for be such nice persons and dedicated to me. Also a thanks for team in the Lab, that receive me with open arms and help me preparing the presentation of the seminars, thanks for the tips and advices given. Also a thanks to Luis Ferreira, for the photos provided to include on this work. A special thanks to Rita, for the constant support, the relentless motivation, the advices given, the corrections and specially for the company not only in writing the thesis but in all my college journey. Thanks to Francisco and Silvia, without you the master degree wasn’t possible, a big thanks for the support and for borrowing your house when I needed to sleep in Coimbra to attend classes. Thanks also to my friends Tiago and Mykola for all the help, advices and friendship during this journey. A special thanks to my Porto friends, Gui and Pepe, for the constant motivation and friendship. A thanks to all friendships made in Coimbra, André Francisco, André Custodio, Joca, Marta, Cerca, João, Tiago, Alcides, Rafa a big thanks for help me and be my friends during my college journey. Also a thanks to the teams of Lifeguards I worked with, in “Praia de Santa Eulália, Albufeira”, this 2 years, Marco, João, Samuel, Edgar, for the support, the knowledge, company, friendship and most important keeping the beach safe. A special thanks to my parents, Lídia and Eduardo, and to my brother, Vasco, for always helping and allowing me to do this work, always giving me the strength to continue. Table of contents Abstract 1 Resumo 2 List of Tables 3 List of Figures 4 Chapter 1 – Introduction 1.1 Marine environment and Marine top predators 6 1.2 The influence of the moon on the life cycle on marine organisms 6 1.3 The influence of moonlight on the behaviour of pelagic seabirds 7 1.3.1 At-sea behavior 8 1.3.2 Colony Attendance 9 1.3.3 Migration Movements 10 1.4 Thesis objectives 11 Chapter 2 – Methods 2.1 Fieldwork and tracking. 14 2.2 At-sea activity 15 2.3 Environmental characteristics of at-sea habitats used 16 2.4 Statistical analysis 16 Chapter 3 – Results 3.1 At-sea distribution 18 3.2 The influence of moonlight on seabirds’ behavior 20 Chapter 4 - Discussion 4.1 General discussion 26 4.1.1 At-sea activity 26 4.1.2 Colony Attendance 27 4.1.3 Migratory Movements 28 4.5 Conclusion 29 References 30 Annex 39 Abstract Procellariiforms are almost exclusively pelagic marine predators, with some species exhibiting a predominately nocturnal foraging activity. The main objective of this thesis was to investigate the effect of the moonlight on three different sized procellariiform seabirds - Cory’s Shearwater, Calonectris borealis, Deserta Petrel, Pterodroma deserta and Macaronesian shearwaters, Puffinus baroli, breeding at Berlenga Island (mainland Portugal), Bugio (Madeira archipelago) and Cima and Selvagem Grande Islets (Madeira archipelago), respectively, during the breeding seasons of 2007-2017. Global Location Sensing (GLS) devices were mounted on the birds’ tarsus and location and activity data was then filtered to analyse the nocturnal foraging activity of the individuals during their breeding and non- breeding periods. Such individual tracking data was then used to investigate the effect of moonlight (full and new moon and quarters) on the (1) at-sea behaviour, (2) colony attendance while breeding and (3) migratory schedule. Overall our results indicate that the moon influenced these seabirds in the former three behaviours. Under full moonlight small sized procellariiforms (Macaronesian shearwaters and Desertas petrels) increased their at sea activity (e.g. more time spent flying), foraged in more pelagic, high depth and windier domains, decreased their colony attendance when compared to a larger sized procellariform (Cory’s shearwater). Full moon also dictated a higher number of departures in pre- and post-breeding migrations for the transequatorial migrants (Cory’s shearwaters and Desertas petrels) but not for the resident species (Macaronesian shearwater). Keywords: Moon-phase, Moonlight, At-sea, Colony Attendance, Migratory Movements Calonectris borealis, Pterodroma deserta, Puffinus baroli. 1 Resumo Os procellariiformes são aves marinhas predadoras, quase exclusivamente pelágicas, que em algumas espécies exibem atividade predominantemente noturna na alimentação e na procura de presas (atividade no mar). O principal objetivo desta tese foi investigar o efeito da lua em três aves procellariiformes de diferentes tamanhos - cagarra, Calonectris borealis, freira-do-bugio, Pterodroma deserta e o pintaínho, Puffinus baroli, que se reproduzem na Ilha das Berlengas (Portugal), Ilha do Bugio (Arquipélago da Madeira) e Ilhéu de Cima e Selvagem Grande (arquipélago da Madeira), respetivamente, durante os anos de 2007-2017. Foram colocados no tarso destas aves, dispositivos Global Location Sensing (GLS). Estes dispositivos permitem saber a localização e obter dados sobre a atividade, sobre a forma de luminosidade e salinidade, das aves. Posteriormente, os dados de atividade foram filtrados de forma a permitir analisar a atividade noturna dos indivíduos durante seus períodos de reprodução e fora da reprodução. Os dados obtidos foram então utilizados para investigar o efeito da lua (lua cheia, nova e quartos) no (1) comportamento no mar, (2) nas visitas a colónia durante a época de reprodução e (3) nos movimentos migratórios. Globalmente, os nossos resultados indicam que a lua influenciou essas aves marinhas nos três comportamentos descritos anteriormente. Sob períodos de lua cheia as espécies de pequeno porte, a freira-do-bugio e o pintaínho, aumentaram a sua atividade no mar (por exemplo, mais tempo gasto a voar), procuraram alimento em zonas mais pelágicas, de alta profundidade e com mais vento, e também diminuíram o numero de visitas à colónia quando comparados com um procellariiforme de maior porte (cagarra). A Lua cheia também ditou um maior número de partidas em migrações pré- e pós- época de reprodução para os migrantes transequatoriais (cagarra e freira-do-bugio), mas não para a espécie residente (pintaínho). Palavras-chave: Ciclo da lua, Lua, Atividade no mar, Visitas a colónia, Movimentos Migratórios, Calonectris borealis, Pterodroma deserta, Puffinus baroli 2 List of Tables Table 1– Generalized Linear Mixed Models (GLMMs) testing the effect of the interaction between species and moon phase on foraging parameters and characteristics of habitats during their breeding period 21 Table 2– Generalized Linear Mixed Models (GLMMs) testing the effect of the interaction between species and moon phase on foraging parameters and characteristics of habitats during their non-breeding period 23 3 List of Figures Figure 1 – At-sea distribution of Cory’s shearwaters Portugal), Desertas petrels and Macaronesian shearwaters during their breeding and non-breeding periods 19 Figure 2 – Percentage of time flying during the night, % number of colony visits, depth and maximum distance to colony of Cory’s shearwaters, Desertas petrels and Macaronesian shearwaters during new, quarter and full moon of breeding period 22 Figure 3 – Percentage of time flying during the night, % of departures for the pre-breeding migration, % of departures for the post-breeding migration and wind speed of Cory’s shearwaters, Desertas petrels and Macaronesian shearwaters during new, quarter and full moon of the non-breeding period of each seabird species 24 4 Chapter I - Introduction hbw.com/ibc/1054391 5 1.1 Marine environment and Marine top predators Marine environments are among the largest, most varied and complex ecosystems on Earth (Verity et al., 2002) linking multiple scales by flow of water and species movements (Levin & Lubchenco, 2008). Marine productivity tends to be heterogeneously distributed, with high productive areas located close to specific areas such as shelf edges or coastal upwellings (Ainley & Boekelheide, 1990; Bakun, 1990; Crawford, 2007). Ocean currents, winds or river influx introduce varying complexities in the interlinkages between biotic components and environmental characteristics especially