At RIN11 Ingo Schiffner gave his presentation Mathematical Analysis of Pigeon Tracks (the characterisation of the underlying navigational process).
He analysed 167 tracks with birds navigating from four different locations and from two different directions.
His theory is that pigeons navigate using at least four different components and these components change over the course of the journey. He considered mapping data (gradient/mosaic maps) to determine the course and compass (sun/magnetic) to locate the course and determine the flight direction.
He discovered that the correlation dimension lies in the range from 3.3-4.2 which shows that navigation is of a fractal nature (fractal systems are like the weather which allows short term prediction). This is a chaotic – deterministic process.
His findings were:
- That the pigeons did not change their performance over time and experience
- The process was independent of previous experience
- There is no switch in navigation strategy
- That there are at least four independent factors involved
- Additional factors come into play close to home
- There is a simultaneous use of the Gradient and Mosaic map.
The mosaic map is a concept introduced by Wallraff it is the idea that a map can be arranged as a map of relative positions of landmarks (these may be visual landmarks, but could also be for example olfactory landmarks, like a patch of forest a patch of cornfield etc.)
The gradient map is the idea that animals know the direction of different environmental gradients and can use this information to navigate within the known area and even extrapolate these gradients beyond familiar territory. (As opposed to the mosaic map, which cant be extrapolated).
The general consensus so far is that the gradient map is used for long/mid range navigation and the mosaic map for short range navigation. According to (Ingo Schiffner’s) findings the notion of these two different forms of maps is not easy to separate and most likely they overlap almost completely.