IUCN / SSC Cat Specialist Group - Digital Cat Library |
|
||||||||||
|
||||||||||
|
|
| Nams, V.O. | |
| Detecting oriented movement of animals | |
| 2006 Animal Behaviour (72): 1197-1203 | |
To test for movement oriented towards a given goal (hereafter 'oriented' movement), it helps to understand the biological distinctions between oriented movement and other types of movement. The key issue is the scale of the movement mechanism. Some animals orient towards certain locations, some orient towards certain habitats, and some towards certain directions. All of these imply a long-distant orientation mechanism. If animals do not orient themselves towards a given goal, then the behavioural mechanisms governing movement will act at a small spatial scale (hereafter 'unoriented' movement). Some of these mechanisms may involve orientation, but they affect movement towards goals at a small scale. Some animals orient towards individual prey that they detect using their sense of smell or sound. Alternatively, these mechanisms may just involve simple movement rules. Often the behavioural mechanism itself is ignored and the movement is modelled as a correlated random walk (CRW), where an animal makes discrete steps, and at each step, the turning angle is independent of the previous turning angle. The smaller the turning angle, the straighter the overall movement path. But there are many types of unoriented movements that cannot be modelled by CRWs. Some animals alternate turns, leading to straighter paths. Some animals tend to make successive turns in the same direction, leading to shorter paths or a looping pattern. Some animals also have autocorrelated step lengths. All of these mechanisms act at a small spatial scale. We can use these behavioural differences to test for oriented versus unoriented travel. There are two types of tests, and the choice of which test to use depends on the circumstances. |
|
 |
PDF files are only accessible to Friends of the Cat Group. Joining Friends of the Cat Group gives you unlimited access and downloads in the Cat SG Library for one year, and allows you to receive our newsletter Cat News (2 regular issues per year plus special issues). More information how to join here |
(c) IUCN/SSC Cat Specialist Group ( IUCN - The World Conservation Union) |