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.

1.
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.
2.
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.
3.
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.
4.
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.
5.
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.
6.
Frost, B.J. (1978) The optokinetic basis of head-bobbing in the pigeon. J. Exp. Biol., 74: 187–195.
7.
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.
8.
Goodale, M.A. (1983) Visually guided pecking in the pigeon (Columba livia). Brain Behav. Evol., 22: 22–41.
9.
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.
10.
Green, P.R., M.N.O. Davies, and P.H. Thorpe (1992) Head orientation in pigeons during landing flight. Vision Res., 32: 2229–2234.
11.
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.
12.
Guiton, P. (1959) Socialisation and imprinting in brown leghorn chicks. Anim. Behav., 7: 26–34.
13.
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.
14.
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.
15.
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.
16.
Land, M.F., and D.N. Lee (1994) Where we look when we steer. Nature, 369: 742–744.
17.
Lappe, M., and J.P. Rauschecker (1994) Heading detection from optic flow. Nature, 369: 712–713.
18.
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.
19.
Ministry of Agriculture, Fisheries and Food [1987] Codes of Recommendations for the Welfare of Livestock: Domestic Fowls. HMSO, London.
20.
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.
21.
Perrone, J.A., and L.S. Stone (1994) A model of self-motion estimation within primate extrastriate cortex. Vision Res., 34: 2917–2938.
22.
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.
23.
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.
24.
Walk, R.D., and E.J. Gibson (1961) A comparative and analytical study of visual depth perception. Psychol. Monogr., 75 no. 15.
25.
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.
26.
Wohlschläger, A., R. Jäger, and J.D. Delius (1993) Head and eye movements in unrestrained pigeons (Columba livia). J. Comp. Psychol., 107: 313–319.
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