QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online January 25, 2005
Journal of Experimental Biology 208, 469-478 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01383

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gagliardo, A. Articles by Ioalè, P. Search for Related Content PubMed PubMed Citation Articles by Gagliardo, A. Articles by Ioalè, P.

Factors reducing the expected deflection in initial orientation in clock-shifted homing pigeons

Anna Gagliardo^*, Francesca Odetti and Paolo Ioalè

Dipartimento di Etologia, Ecologia ed Evoluzione, Via Volta 6, I-56126 Pisa, Italy

View larger version (31K): [in a new window]   Fig. 1. Orientation distributions of pigeons released in the unshifted condition at the three experimental sites. C, control (intact) pigeons; A, anosmic pigeons. The inner diagrams (open circles) indicate the orientation of the pigeons while exiting from the circular arena; the outer diagrams (black circles) show the orientation at vanishing. Each symbol within a diagram represents a single pigeon. Inner arrows represent the distributions' mean vectors; white and black arrows are relative to arena and vanishing distributions respectively. The vector length can be read using the scale in the first diagram. The outer grey arrows indicate the home directions (H). Other details are reported in Tables 1 and 2.

View larger version (29K): [in a new window]   Fig. 2. Orientation distributions of pigeons released after 6 h fast clock-shift. White and black outer arrows represent the expected mean directions after the clock-shift treatment, for arena and vanishing distributions, respectively. Other explanations are given in Fig. 1.

View larger version (40K): [in a new window]   Fig. 3. Individual mean vector distributions relative to the orientation in the arena, in the No-Shift and Clock-Shift conditions. C, control (intact) pigeons; A, anosmic pigeons. All directions are calculated with respect to the home direction, which is set at 360°. Each inner line-and-circle represents the orientation mean vector with respect to home, calculated for a single pigeon. The outer circles indicate the mean vector directions. The inner white arrows represent the second order mean vectors. Confidence ellipses at 95%, 99% and 99.9%, according to the Hotelling one-sample test for vector distributions, are also reported.

View larger version (27K): [in a new window]   Fig. 4. Individual mean vector distributions relative to the orientation at vanishing, in the No-Shift and Clock-Shift conditions. The outer black arrows represent the expected second order mean directions after the clock shift treatment. Other explanations are given in Fig. 3.

View larger version (13K): [in a new window]   Fig. 5. Orientation at vanishing of pigeons unfamiliar with the release sites. Open and black circles represent the vanishing bearings of pigeons released without or after phase-shift manipulation respectively. The outer black arrows indicate the expected mean direction of the clock-shifted pigeons. Other explanations as in Fig. 1.

View larger version (21K): [in a new window]   Fig. 6. Comparison between the mean vectors and their 95% confidence limits of pigeons with different experience and treatment. The diagrams of the upper row (N-S, No-Shift) and the lower row (C-S, Clock-Shift) refer to the orientation of pigeons released without or after clock-shift treatment, respectively. White sectors correspond to pigeons unfamiliar with the release site; grey and black sectors correspond to pigeons familiar with the release site, intact and anosmic, respectively.