‘Remote’ behavioural ecology: do megaherbivores consume vegetation in proportion to its presence in the landscape?
| Autor: | Matt Sponheimer, Hannah J. O'Regan, Jacqui Codron, Christopher G. Marston, David M. Wilkinson, Daryl Codron |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Wet season 010504 meteorology & atmospheric sciences Behavioural ecology lcsh:Medicine 010603 evolutionary biology 01 natural sciences Elephant General Biochemistry Genetics and Molecular Biology Grassland Ecology and Environment African elephant biology.animal Dry season Spatial and Geographic Information Science 0105 earth and related environmental sciences geography geography.geographical_feature_category biology Animal Behavior Ecology National park Isotope General Neuroscience lcsh:R General Medicine Vegetation Remote sensing Diet Habitat Biogeography Thematic Mapper Kruger National Park General Agricultural and Biological Sciences Landsat |
| Zdroj: | PeerJ PeerJ, Vol 8, p e8622 (2020) |
| ISSN: | 2167-8359 |
| Popis: | Examination of the feeding habits of mammalian species such as the African elephant (Loxodonta africana) that range over large seasonally dynamic areas is exceptionally challenging using field-based methods alone. Although much is known of their feeding preferences from field studies, conclusions, especially in relation to differing habits in wet and dry seasons, are often contradictory. Here, two remote approaches, stable carbon isotope analysis and remote sensing, were combined to investigate dietary changes in relation to tree and grass abundances to better understand elephant dietary choice in the Kruger National Park, South Africa. A composited pair of Landsat Enhanced Thematic Mapper satellite images characterising flushed and senescent vegetation states, typical of wet and dry seasons respectively, were used to generate land-cover maps focusing on the forest to grassland gradient. Stable carbon isotope analysis of elephant faecal samples identified the proportion of C3 (typically browse)/C4 (typically grass) in elephant diets in the 1–2 days prior to faecal deposition. The proportion of surrounding C4 land-cover was extracted using concentric buffers centred on faecal sample locations, and related to the faecal %C4 content. Results indicate that elephants consume C4 vegetation in proportion to its availability in the surrounding area during the dry season, but during the rainy season there was less of a relationship between C4 intake and availability, as elephants targeted grasses in these periods. This study illustrates the utility of coupling isotope and cost-free remote sensing data to conduct complementary landscape analysis at highly-detailed, biologically meaningful resolutions, offering an improved ability to monitor animal behavioural patterns at broad geographical scales. This is increasingly important due to potential impacts of climate change and woody encroachment on broad-scale landscape habitat composition, allowing the tracking of shifts in species utilisation of these changing landscapes in a way impractical using field based methods alone. |
| Databáze: | OpenAIRE |
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