The relationships between the head orientation of domestic chicks and their trajectory of locomotion were examined in three tasks: jumping over gaps of different depths and widths; walking on surfaces of different slopes; and walking on a level transparent surface above a slope. Head orientation was measured as the angle between the horizontal and a line joining the centre of the eye to the beak tip. At the initiation of a jump, head angle increased with increasing depth of the gap but was not affected by gap width. During walking, head angle increased with increasing downwards slope of the walking surface and decreased with increasing upwards slope. The same effect of a downwards slope was observed when chicks walked on a level transparent surface above a slope, indicating that the effect does not depend on kinaesthetic information. The findings are discussed together with measurements of pigeon head orientation during landing flight. Explanations in terms of specialised retinal areas, binocular visual fields and lower visual field myopia are considered and rejected. It is proposed that the results instead reflect a general role of head orientation as a component in the visual control of locomotion in birds.

Bilo, D. (1994) Course control during flight. In Perception and Motor Control in Birds (ed. by M.N.O. Davies and P.R. Green), Springer, Berlin, pp. 227–247.
Collett, T.S., and L.I.K. Harkness (1982) Depth vision in animals. In Analysis of Visual Behaviour (ed. by D.J. Ingle, M.A. Goodale, and R.J.W. Mansfield), MIT Press, Cambridge, Mass., pp. 111–176.
Ehrlich, D. (1981) Regional specialization of the chick retina as revealed by the size and density of neurons in the ganglion cell layer. J. Comp. Neurol., 195: 643–657.
Erichsen, J.T., W. Hodos, C. Evinger, B.B. Bessette, and S.J. Phillips (1989) Head orientation in pigeons: postural, locomotor and visual determinants. Brain Behav. Evol., 33: 268–278.
Fitzke, F.W., B.P. Hayes, W. Hodos, and A.L. Holden (1985) Refractive sectors in the visual field of the pigeon eye. J. Physiol., 369: 33–44.
Frost, B.J. (1978) The optokinetic basis of head-bobbing in the pigeon. J. Exp. Biol., 74: 187–195.
Gioanni, H. (1988) Stabilizing gaze reflexes in the pigeon (Columba livia). I. Horizontal and vertical optokinetic eye (OKN) and head (OCR) reflexes. Exp. Brain Res., 69: 567–582.
Goodale, M.A. (1983) Visually guided pecking in the pigeon (Columba livia). Brain Behav. Evol., 22: 22–41.
Green, P.R., I.B. Davies, and M.N.O. Davies (1994b) Interaction of visual and tactile information in the control of chicks’ locomotion in the visual cliff. Perception, 22: 1319–1331.
Green, P.R., M.N.O. Davies, and P.H. Thorpe (1992) Head orientation in pigeons during landing flight. Vision Res., 32: 2229–2234.
Green, P.R., M.N.O. Davies, and P.H. Thorpe (1994a) Head-bobbing and head orientation during landing flights of pigeons. J. Comp. Physiol., 174: 249–256.
Guiton, P. (1959) Socialisation and imprinting in brown leghorn chicks. Anim. Behav., 7: 26–34.
Hayes, B.P., W. Hodos, A.L. Holden, and J.L. Low (1987) The projection of the visual field upon the retina of the pigeon. Vision Res., 27: 31–40.
Hodos, W., and J.T. Erichsen (1990) Lower-field myopia in birds: an adaptation that keeps the ground in focus. Vision Res., 30: 653–658.
Hollands, M.A., D.E. Marple-Horvat, S. Henkes, and A.K. Rowan (1995) Human eye movements during visually guided stepping. J. Motor Behav., 27: 155–163.
Land, M.F., and D.N. Lee (1994) Where we look when we steer. Nature, 369: 742–744.
Lappe, M., and J.P. Rauschecker (1994) Heading detection from optic flow. Nature, 369: 712–713.
Martin, G.R., and S.R. Young (1983) The retinal binocular field of the pigeon (Columba livia: English Racing Homer). Vision Res., 23: 911–915.
Ministry of Agriculture, Fisheries and Food [1987] Codes of Recommendations for the Welfare of Livestock: Domestic Fowls. HMSO, London.
Nalbach, H.O., F. Wolf-Oberhollenzer, and K. Kirschfeld (1990) The pigeon’s eye viewed through an ophthalmoscopic microscope: orientation of retinal landmarks and significance of eye movements. Vision Res., 30: 529–540.
Perrone, J.A., and L.S. Stone (1994) A model of self-motion estimation within primate extrastriate cortex. Vision Res., 34: 2917–2938.
Schaeffel, F. (1994) Functional accommodation in birds. In Perception and Motor Control in Birds (ed. by M.N.O. Davies and P.R. Green), Springer, Berlin, pp. 35–53.
Sun, H.-J., D.P. Carey, and M.A. Goodale (1992) A mammalian model of optic-flow utilization in the control of locomotion. Exp. Brain Res., 91: 171–175.
Walk, R.D., and E.J. Gibson (1961) A comparative and analytical study of visual depth perception. Psychol. Monogr., 75 no. 15.
Wallman, J., and J.-C. Letelier (1993) Eye movements, head movements and gaze stabilization in birds. In Vision, Brain and Behaviour in Birds (ed. by H.P. Zeigler and H.-J. Bischof), MIT Press, Cambridge, Mass., pp. 243–263.
Wohlschläger, A., R. Jäger, and J.D. Delius (1993) Head and eye movements in unrestrained pigeons (Columba livia). J. Comp. Psychol., 107: 313–319.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.