ISSN:
1432-1351
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary 16 releases, centrally symmetrical by pairs and involving distances of displacement from 25 to 172 km, were conducted with homing pigeons pre-treated in different ways: FIL birds were, until few minutes before release, confined to containers ventilated with ambient air that had passed through filters consisting of activated charcoal. NOFIL birds were confined to containers ventilated with unfiltered air, either from departure at the loft onwards (4 experiments) or for at least 4 h at the release site (after transport under FIL conditions; 12 experiments). The olfactory epithelia of XYL birds were locally anaesthetized a few minutes before release, while NOXYL birds were not treated with xylocain. FIL/NOFIL conditions were combined with XYL/NOXYL conditions, resulting in 4 types of experimental treatment. On average, the untreated pigeons (NOFILNOXYL) were best homeward oriented and the double-treated pigeons (FIL-XYL) poorest. More importantly, the effect of olfactory deprivation during initial flight alone (NOFIL-XYL) was small, whereas long-term filtration of environmental air was quite effective even if the pigeons could smell during release time (FIL-NOXYL) (Fig. 5). These findings indicate that pigeons usually need to be exposed to local odorous air for more than only few minutes in order to utilize information extricated from this air for site localization. Additional experiments showed that homeward orientation is also prevented, if the pigeons, although breathing natural air, are ventilated with restricted volumes of fresh air. Our results are discussed with regard to the homing mechanism of pigeons as well as to their methodological consequences.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00612632
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