Investigating the impact of weak geomagnetic fluctuations on pigeon races

Petr Jandačka,Jiří Ščučka,Hynek Burda

doi:10.1007/s00359-021-01534-x

Abstract

The existence of avian magnetic orientation has been proved by many experimental studies, however, evidence for the use of magnetic cues by homing pigeons remains controversial. To investigate magnetic orientation by homing pigeons, we analyzed the results of pigeon races relative to weak fluctuations in the geomagnetic field, assuming that such disturbances could impact navigational efficiency if based on magnetoreception. Whereas most of the previous studies recorded and analyzed vanishing bearing of individually released pigeons, we evaluated relative duration of the homeward flight (homing speed, as a proxy of navigational efficiency) and its dependence on specific geomagnetic indices in racing pigeons released collectively. Our analysis of orientation efficiency of about 289 pigeon races over 15 years suggested slight negative correlations between geomagnetic fluctuations and homing time. Although the interpretation of this finding is manifold and not clear, it suggests that natural magnetic variations or disturbances can affect the homing orientation performance of pigeons. We suggest that studying pigeon races may have a heuristic potential and since these races are regularly and frequently organized in many countries all over the globe, examining homing performance relative to a suite of environmental variables may be useful for exploring hypotheses about pigeon navigation.

Highlights

Domestic pigeons (Columba livia domestica) are notable for their excellent long-distance homing abilities
The magnetite structures were observed in many organisms and some of them were designated as magnetoreceptors (Shaw et al 2015)
Hypothesis The main hypothesis was that magnetic field fluctuations affect the magnetic orientation of pigeons, prolonging their homeward flight time, consistent with the previous reports (Kowalski et al 1988; Schiffner and Wiltschko 2011)

Summary

Introduction

Domestic pigeons (Columba livia domestica) are notable for their excellent long-distance homing abilities. They are opportunistic navigators able to use different types of sensory tools according to available cues (Walcott 1996; Wiltschko and Wiltschko 2017). Experiments with homing pigeons or migratory birds are typically based on analysis of initial orientation: vanishing bearings of released birds in the field, or displayed preferred escape directions in Emlen’s funnel in the laboratory (Emlen and Emlen 1966). In the case of magnetite structures observed in the avian upper beak (Fleissner et al 2003; Hanzlik et al 2000) that had been proposed

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Conclusion