Refine
Year of publication
Document Type
- Article (16) (remove)
Language
- English (16)
Has Fulltext
- yes (16)
Is part of the Bibliography
- no (16)
Keywords
- Magnetic compass (3)
- Cryptochrome 1a (2)
- avian magnetic compass (2)
- cryptochrome (2)
- cryptochrome 1a (2)
- inclination compass (2)
- magnetic compass (2)
- Activated Cry1a (1)
- Brieftaube ; Orientierungsverhalten ; Flugdatenregistriergerät ; GPS <Satellitengeodäsie> (1)
- FAD (1)
- Flavin cycle (1)
- Geomagnetic field (1)
- Larmor frequency (1)
- Magnetic conditioning (1)
- Magnetic map (1)
- Magnetic ‘map’ component (1)
- Magnetite-based receptors (1)
- Photoreduction (1)
- Pulse treatment (1)
- Radical Pair model (1)
- Radical pair mechanisms (1)
- Sign posts (1)
- Trigeminal nerve (1)
- UV/V cones (1)
- asymmetry (1)
- commissures (1)
- compass orientation (1)
- conformational change (1)
- flavin cycle (1)
- flavin redox cycle (1)
- lateralization (1)
- light-activation (1)
- magnetoreception (1)
- maturation process (1)
- migratory orientation (1)
- photocycle (1)
- photoreceptor (1)
- plasticity (1)
- radical pair model (1)
- radical pairs (1)
- right eye/left brain system (1)
- ‘Fixed direction’ responses (1)
Institute
Animals use the geomagnetic field and astronomical cues to obtain compass information. The magnetic compass is not a uniform mechanism, as several functional modes have been described in different animal groups. The Sun compass requires the internal clock to interpret the position of the Sun. For star compass orientation, night-migrating birds seem to use the star pattern as a whole, without involving the internal clock. Both the astronomical compass mechanisms are based on learning processes to adapt them to the geographic latitude where the animals live and, in long-living animals, to compensate for the seasonal changes. Several mechanisms are used to determine the compass course to a goal. Using information collected during the outward journey is mostly done by path integration: recording the direction with a compass and integrating its twists and turns. Migratory animals have innate programs to guide them to their still unknown goal. Highly mobile animals with large ranges develop a so-called navigational ‘map’, a mental representation of the spatial distribution of navigational factors within their home region and their migration route. The nature of the factors involved is not yet entirely clear; magnetic intensity and inclination are the ones best supported so far.
The GPS recorder consists of a GPS receiver board, a logging facility, an antenna, a power supply, a DC-DC converter and a casing. Currently, it has a weight of 33 g. The recorder works reliably with a sampling rate of 1/s and with an operation time of about 3 h, providing time-indexed data on geographic positions and ground speed. The data are downloaded when the animal is recaptured. Prototypes were tested on homing pigeons. The records of complete flight paths with surprising details illustrate the potential of this new method that can be used on a variety of medium-sized and large vertebrates.