Fractal analysis measures habitat use at different spatial scales: an example with American marten
Habitat selection is traditionally assessed by how much time the animal spends in each habitat type; however, one can obtain additional information by analysing the structure of the movement paths. We followed and mapped snow tracks of American marten, Martes americana (Turton, 1806). The new method...
| Published in: | Canadian Journal of Zoology |
|---|---|
| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
2004
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/z04-167 http://www.nrcresearchpress.com/doi/pdf/10.1139/z04-167 |
| Summary: | Habitat selection is traditionally assessed by how much time the animal spends in each habitat type; however, one can obtain additional information by analysing the structure of the movement paths. We followed and mapped snow tracks of American marten, Martes americana (Turton, 1806). The new method used to test the movement paths for deviations from a correlated random walk model show that these paths fail the test. This has led to an analysis of fractal dimension versus spatial scale, which showed a natural break in fractal dimension at a scale of approximately 3.5 m, suggesting that marten displayed different responses to their microenvironment in two regions of spatial scale. Marten travel was more direct at scales <3.5 m than at scales >3.5 m. Path tortuousity was affected by habitats at smaller scales but not at larger scales, indicating different responses by marten to their environment at these two ranges of scale. Multiple regression identified canopy closure and presence of conifer in the understory as variables that affect movement patterns at the 1- to 3.5-m scale. Fractal analysis of movement patterns provides a unique approach to examining habitat use, as well as a means to identify the spatial scales at which an animal responds to its habitat. |
|---|