Ecological Implications of Primary and Secondary Dispersal of Fungi by Vertebrates

Abstract

<p>Fungal consumption (mycophagy) by vertebrates has been reported for numerous species, but until this thesis, there has been no global synthesis of the topic. Through a combination of novel research and comprehensive literature reviews, I investigated the ecological implications of vertebrate mycophagy for fungal spore dispersers, fungal ecology, plant ecology, animal food choice and animal behaviour. This thesis demonstrates that vertebrate mycophagy directly impacts most terrestrial ecosystems and is especially relevant to many plants, animals and fungi. I have taken three different methodological approaches in this thesis.</p> <p>First, I systematically reviewed mycophagy among all terrestrial vertebrate taxa. This extensive global literature review yielded three chapters (and manuscripts): one on mammals, another on reptiles and a third on birds (Chapters 2, 6 and 7, respectively). These reviews of approximately 1,500 references in more than five languages report mycophagy among nearly 600 mammals, reptiles and birds. (Despite an exhaustive search, I could find no evidence of amphibian mycophagy.) These reviews lay the groundwork for and are integral parts of my thesis.</p> <p>Second, I directly studied vertebrate mycophagy through observations and/or faecal and stomach analyses (Chapter 3, 4, 5 and 8). I collected empirical dietary data through microanalysis of animal scats acquired by live-trapping animals or by examining stomach contents of preserved museum collections. I obtained observational feeding data by watching wild animals directly, or by deploying motion-activated camera traps that recorded the behaviours of mycophagists. These studies provided new dietary data for vertebrates and showcased the previously overlooked ecological services that they provide.</p> <p>Third, I used a modelling approach to determine the dispersal potential of primary and secondary mycophagy (Chapter 5 and Supplementary Material). By using a combination of passage rate data and movement patterns gathered from animals fitted with GPS tracking devices, I was able to show that some animals have the potential to disperse mycorrhizal fungal spores more than 10 km from the point of ingestion (Chapter 5). This is the first application of modelling to mycophagy research and the first direct investigation of secondary spore dispersal. </p> <p>This thesis presents novel concepts about mycophagy and an in-depth study of the ecological importance of associations between vertebrates and fungi around the world.</p>