 |
| Titel |
Ratios among atmospheric trace gases together with winds imply exploitable information for bird navigation: a model elucidating experimental results |
| VerfasserIn |
H. G. Wallraff |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 11 ; Nr. 10, no. 11 (2013-11-04), S.6929-6943 |
| Datensatznummer |
250085392
|
| Publikation (Nr.) |
 copernicus.org/bg-10-6929-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| A model of avian goal-oriented navigation is described
that is based on two empirical findings building a bridge from ornithology
to atmospheric chemistry. (1) To orient their courses homeward from distant
unfamiliar areas, homing pigeons require long-term exposure to undisturbed
winds at the home site and olfactory access to the environmental air at home
and abroad. (2) Above Germany, ratios among some atmospheric trace gases
vary along differently oriented spatial gradients as well as depending on
wind direction. The model emulates finding (1) by utilising the analysed air
samples on which finding (2) is based. Starting with an available set of 46 omnipresent
compounds, virtual pigeons determine the profile of relative
weights among them at each of 96 sites regularly distributed around a
central home site within a radius of 200 km and compare this profile with
corresponding profiles determined at home under varying wind conditions.
Referring to particular similarities and dissimilarities depending on
home-wind direction, they try to estimate, at each site, the compass
direction they should fly in order to approach home. To make the model work,
an iterative algorithm imitates evolution by modifying sensitivity to the
individual compounds stepwise at random. In the course of thousands of
trial-and-error steps it gradually improves homeward orientation by
selecting smaller sets of most useful and optimally weighted substances from
whose proportional configurations at home and abroad it finally derives
navigational performances similar to those accomplished by real pigeons. It
is concluded that the dynamic chemical atmosphere most likely contains
sufficient spatial information for home-finding over hundreds of kilometres
of unfamiliar terrain. The underlying chemo-atmospheric processes remain to
be clarified. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|