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Celestial polarized light patterns as a calibration reference for sun compass of homing pigeons

1988; Elsevier BV; Volume: 131; Issue: 1 Linguagem: Inglês

10.1016/s0022-5193(88)80120-6

1095-8541

John B. Phillips, Jerry A. Waldvogel,

Animal Behavior and Reproduction

Homing pigeons (Columba livia) housed as short-term residents in "deflector lofts" which generate clockwise or counterclockwise rotations of both light cues and wind-borne odors exhibit a corresponding clockwise or counterclockwise bias in homeward orientation upon release from a distant site. Although the biased orientation of deflector loft birds has been cited as evidence that the deflector lofts are rotating an olfactory "map" derived from wind-borne odors, recent experiments using altered deflector panels have shown instead that light cues and not odors are responsible for the deflector loft effect. This paper examines the relationship between behavioral evidence obtained in deflector loft experiments and measurements of the effect that deflector panels have on the distribution of celestial polarization cues visible within these lofts. The measurements show that the deflector panels' influence on the distribution of near-u.v. polarized light patterns which are present at sunrise and sunset matches the orientation bias observed for short-term residents. Furthermore, seasonal changes in the deflector lofts' effect on these polarization patterns parallel seasonal changes in the orientation behavior of deflector loft birds. These results therefore provide support for a theoretical model in which the pigeon's sun compass is calibrated with respect to celestial polarization patterns, and furthermore implicate a near-u.v. sensitive visual receptor in the perception of polarized light by the homing pigeon. The hypothesized compass reference system derived from celestial polarization patterns is also discussed in the light of an alternative model for calibration of the avian sun compass using magnetic cues.