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Accueil du site → Doctorat → Australie → 2019 → The integration of spatial-ecology and animal behaviour in the unpredictable arid zone : A case study with the zebra finch

Macquarie University (2019)

The integration of spatial-ecology and animal behaviour in the unpredictable arid zone : A case study with the zebra finch

Funghi Caterina

Titre : The integration of spatial-ecology and animal behaviour in the unpredictable arid zone : A case study with the zebra finch

Die Integration von Raumökologie und Tierverhalten in das unvorhersehbare Trockengebiet : Eine Fallstudie mit dem Zebrafink

Auteur : Funghi Caterina

Université de soutenance : Macquarie University cotutelle Universität Hamburg

Grade : Doctor of Philosophy 2019

Résumé
Unpredictable environments present several challenges for animals that need to gather information to track ecological fluctuations to ensure access to resources and optimise life-history decisions. Part of the environmental unpredictability is linked to a heterogeneous distribution of resources, both temporally and spatially. Additionally, extreme climatic events (e.g. heatwaves) can prove physiologically and behaviourally challenging. In my thesis I integrated approaches from spatial and behavioural ecology to overcome current difficulties in the study of animal behaviour in the Australian arid environment. I focused research on wild zebra finches (Taeniopygia guttata) foraging behaviour. Insight into environmental heterogeneity came from classical vegetation surveys and the most up-to-date freely available remote sensing data, focusing on the spatial distribution of the primary nutritious source for the zebra finch - Enneapogon grasses. Enneapogon abundance and productivity varied at a local scale, both temporally and spatially, primarily driven by local environmental determinants. This variation was detectable using Sentinel-2A imagery, although with some limitations, validating its use in Australian arid areas, as tool for understanding primary productivity. Furthermore, I demonstrated that in arid landscape, zebra finches have to overcome the challenge of finding food in a patchy environment and cope with extreme climatic conditions. I demonstrated that over two consecutive heatwave events, zebra finch temporal, social and spatial foraging patterns were constrained by the heat. Finally, by experimentally manipulating both food availability and brood size I demonstrated variation in individual foraging behaviour, with some birds using a greater variety of food sources and more persistently checking depleted patches. This behavioural variation in foraging strategy related to reproductive success, providing empirical support for optimal foraging theory. Overall, my results promote the use of a spatial framework for the study of animal behaviour to given valuable insight to the challenges and constraints individuals face in harsh, heterogeneous and unpredictable habitat.

Mots clés  : Australian arid environment , foraging behaviour , zebra finches , spatial ecology

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Page publiée le 7 février 2020