Figure 1.
The 3D pecking trajectory during woodpecker's pecking.
(a) 3D schematic diagram; (b) Pecking trajectory on the sagittal plane; (c) Pecking trajectory on the transverse plane; (d) Pecking trajectory on the coronal plane.
Table 1.
Definitions of various micro-structural parameters analyzed in this study.
Figure 2.
Micro-morphology of cranial bone.
(a) The micro-CT scanning images of Great Spotted woodpecker's head on the coronal plane; (b) The micro-CT scanning images of Eurasian hoopoe's head on the coronal plane; (c) The SEM image of Great Spotted woodpecker's cranial bone; (d) The SEM image of Eurasian hoopoe's cranial bone.
Table 2.
The peak linear and angular impact velocities, decelerations of Great Spotted woodpecker and Eurasian hoopoe.
Table 3.
Micro-structural parameters of the occiput of Great Spotted Woodpecker and Eurasian Hoopoe.
Figure 3.
Anatomical structures of head and hyoid bone.
(a) Great Spotted woodpecker's head; (b) Great Spotted Woodpecker's hyoid bone; (c) Eurasian hoopoe's hyoid bone.
Figure 4.
Micro-CT image and the FE models of Great Spotted Woodpecker' head.
(a) Micro-CT image of Great Spotted Woodpecker' head; (b) BeakLower>BeakUpper FE model; (c) BeakLower = BeakUpper FE model; (d) BeakLower<BeakUpper FE model.
Figure 5.
The pecking force-time histories at the initial velocity of 1 m/s for both the FE analysis and pecking circle-maximal pecking force in the experiment.
Table 4.
The material properties of woodpecker's skull, beak, hyoid bone and brain.
Figure 6.
The time histories of effective stress at the selected points on beak, orbit and skull.
(BeakU-the point on the tip of upper beak; BeakL-the point on the tip of lower beak; Orbit-the point on the orbit; SkullA-the point on the anterior part of skull; SkullP-the point on the posterior part of skull).
Figure 7.
The effective stress distribution of woodpecker's head during pecking.
Figure 8.
The effective stress distribution of the hyoid bone during pecking.
Table 5.
The predicted peak strain at the selected points on brain during pecking.