Head movements and eye functions of birds.

Dunlap, Knight; Mowrer, O. Hobart

doi:10.1037/h0075905

Cited by 195 publications

(41 citation statements)

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“…The bird may have altered the direction of its gaze during this short thrust phase. This pattern has previously been reported for chickens and starlings (scientific names not given) (Dunlap & Mowrer 1930).…”

Section: Discussionmentioning

confidence: 54%

Head-bobbing patterns, while walking, of Black-winged Stilts Himantopus himantopus and various herons

Fujita

Kawakami

2003

Ornithol. Sci.

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Section: Discussionmentioning

confidence: 54%

Head-bobbing patterns, while walking, of Black-winged Stilts Himantopus himantopus and various herons

Fujita

Kawakami

2003

Ornithol. Sci.

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“…In slow motion however, it can be seen that the backwards motion is illusory. Instead of moving their heads backwards, pigeons thrust them forwards and then hold them almost perfectly stationary as the rest of their body catches up (Davies and Green, 1988;Dunlap and Mowrer, 1930;Friedman, 1975;Necker, 2007;Troje and Frost, 2000). In this way, during walking, a pigeon's head undergoes a series of rapid forward movements (thrust phases) and stationary phases (hold phases), while the body moves with a relatively homogenous speed.…”

Section: Introductionmentioning

confidence: 99%

Pigeons use distinct stop phases to control pecking

Theunissen

Reid

Troje

2016

Journal of Experimental Biology

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Pecking at small targets requires accurate spatial coordination of the head. Planning of the peck has been proposed to occur in two distinct stop phases, but although this idea has now been around for a long time, the specific functional roles of these stop phases remain unsolved. Here, we investigated the characteristics of the two stop phases using high-speed motion capture and examined their functions with two experiments. In experiment 1, we tested the hypothesis that the second stop phase is used to pre-program the final approach to a target and analyzed head movements while pigeons (Columba livia) pecked at targets of different size. Our results show that the duration of both stop phases significantly increased as stimulus size decreased. We also found significant positive correlations between stimulus size and the distances of the beaks to the stimulus during both stop phases. In experiment 2, we used a two-alternative forced choice task with different levels of difficulty to test the hypothesis that the first stop phase is used to decide between targets. The results indicate that the characteristics of the stop phases do not change with an increasing difficulty between the two choices. Therefore, we conclude that the first stop phase is not exclusively used to decide upon a target to peck at, but also contributes to the function of the second stop phase, which is improving pecking accuracy and planning the final approach to the target.

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“…These are mostly reflexive and countervail changes of the body position [head bobbing in birds (Necker, 2007)] and orientation in space. Thereby they stabilize gaze to enable, for instance, precise object fixation during locomotion (Dunlap and Mowrer, 1930;Land, 1973;Pozzo et al, 1990;Miles, 1997;van Hateren and Schilstra, 1999b).…”

Section: Introductionmentioning

confidence: 99%

Head and body stabilization in blowflies walking on differently structured substrates

Kress

Egelhaaf

2012

Journal of Experimental Biology

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SUMMARYVisually guided animals depend heavily on the quality of visual signals in order to obtain functionally relevant information about their environment. To support visual information processing, nature has evolved a large variety of physiological adaptations and behavioral strategies such as compensatory head movements. During self-movement, head rotations compensate for changes in body attitude in order to stabilize gaze. However, how walking animals cope with uneven structured substrates, which may affect body and gaze orientation, is still unknown. We used stereo high-speed video to analyze compensatory head movements of blowflies walking freely on differently structured substrates. We found that even a pronounced asperity of the ground structure, with bumps of almost the size of the animal, was largely compensated by the walking apparatus of the blowfly, which leads to body roll and pitch movements only marginally larger than those on flat substrate. Pitch and roll fluctuations of the head were smaller compared with body fluctuations on all tested substrates, emphasizing the significance of gaze stabilization during walking on structured substrates. Furthermore, we found no impairment in head and body stabilization during walks in darkness, which indicates that the control system mediating compensatory head movements works well without any visual input. Interestingly, blowflies changed their walking style in the dark and seemed to use their forelegs as tactile probes. Supplementary material available online at

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Head movements and eye functions of birds.

Abstract: Catching up with the world. Collier's, January 15, 1927. Dodge has expressed in conversation the same opinion regarding the pigeon. Mickesh's opinion that other domestic fowls show the same phenomenon does not hold for ducks and geese.

Cited by 195 publications

References 0 publications

Head-bobbing patterns, while walking, of Black-winged Stilts Himantopus himantopus and various herons

Head-bobbing patterns, while walking, of Black-winged Stilts Himantopus himantopus and various herons

Pigeons use distinct stop phases to control pecking

Head and body stabilization in blowflies walking on differently structured substrates

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