Raptors-inroads to multifingered grasping

Ramos, A.M.; Walker, Ian D.

doi:10.1109/iros.1998.724663

Cited by 14 publications

(11 citation statements)

References 6 publications

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“…The friction coefficient for the proximal contacts (0.36) is within the range of many experimental results (0.2–0.7) and similar to what has been used in other simulations. We reasoned that the greater friction coefficient for the talon tip is assumed because the talon can dig into the grasped object, substantially increasing the shear force that it can resist (after Ramos & Walker [ 38 ]). However, instead of representing coulomb friction this corresponds to the talon tip shearing through the grasped object and the value may depend more on the material properties of the object and the shear forces it can resist.…”

Section: Methodsmentioning

confidence: 99%

Mechanical analysis of avian feet: multiarticular muscles in grasping and perching

et al. 2015

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The grasping capability of birds' feet is a hallmark of their evolution, but the mechanics of avian foot function are not well understood. Two evolutionary trends that contribute to the mechanical complexity of the avian foot are the variation in the relative lengths of the phalanges and the subdivision and variation of the digital flexor musculature observed among taxa. We modelled the grasping behaviour of a simplified bird foot in response to the downward and upward forces imparted by carrying and perching tasks, respectively. Specifically, we compared the performance of various foot geometries performing these tasks when actuated by distally inserted flexors only, versus by both distally inserted and proximally inserted flexors. Our analysis demonstrates that most species possess relative phalanx lengths that are conducive to grasps actuated only by a single distally inserted tendon per digit. Furthermore, proximally inserted flexors are often required during perching, but the distally inserted flexors are sufficient when grasping and carrying objects. These results are reflected in differences in the relative development of proximally and distally inserted digital flexor musculature among ‘perching’ and ‘grasping’ taxa. Thus, our results shed light on the relative roles of variation in phalanx length and digit flexor muscle distribution in an integrative, mechanical context.

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Section: Methodsmentioning

confidence: 99%

Mechanical analysis of avian feet: multiarticular muscles in grasping and perching

et al. 2015

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“…Even within these broad functional groups, taxa can be distinguished along various metrics of claw shape (Csermely & Rossi, 2006). Although the biomechanical consequences of claw shape and size variation have yet to be tested explicitly, the correlations with locomotor and feeding behaviour are strongly suggestive of their roles in grasping by enhancing traction (Ramos & Walker, 1998;Fowler et al, 2009Fowler et al, , 2011, and/or the probability of contact with prey items (Csermely, Bertè & Camoni, 1998). Although the biomechanical consequences of claw shape and size variation have yet to be tested explicitly, the correlations with locomotor and feeding behaviour are strongly suggestive of their roles in grasping by enhancing traction (Ramos & Walker, 1998;Fowler et al, 2009Fowler et al, , 2011, and/or the probability of contact with prey items (Csermely, Bertè & Camoni, 1998).…”

Section: (2) the Ecomorphology Of Avian Graspingmentioning

confidence: 99%

“…Furthermore, claw curvature (Fowler, Freedman & Scannella, 2009;Fowler et al, 2011) and size (Einoder & Richardson, 2007a) have been associated with predatory behaviour and prey-type specialization, respectively. Although the biomechanical consequences of claw shape and size variation have yet to be tested explicitly, the correlations with locomotor and feeding behaviour are strongly suggestive of their roles in grasping by enhancing traction (Ramos & Walker, 1998;Fowler et al, 2009Fowler et al, , 2011, and/or the probability of contact with prey items (Csermely, Bertè & Camoni, 1998). Further investigation into how these claw characteristics interact with grasping performance (below) should yield important insights.…”

Section: Grasping In Birdsmentioning

confidence: 99%

“…Outside the realm of vertebrate biology, avian grasping performance has been a source of bioinspiration and biomimicry, as mechanical engineers have explored the efficacy of the avian foot 'design' for robotics applications (e.g. Ramos & Walker, 1998;Doyle et al, 2011). In turn, guiding principles of robotics, such as coupled and underactuated mechanisms (e.g.…”

Section: (3) the Role Of Grasping In Tetrapod Evolutionmentioning

confidence: 99%

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Getting a grip on tetrapod grasping: form, function, and evolution

Pouydebat²,

et al. 2013

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Human beings have been credited with unparalleled capabilities for digital prehension grasping. However, grasping behaviour is widespread among tetrapods. The propensity to grasp, and the anatomical characteristics that underlie it, appear in all of the major groups of tetrapods with the possible exception of terrestrial turtles. Although some features are synapomorphic to the tetrapod clade, such as well-defined digits and digital musculature, other features, such as opposable digits and tendon configurations, appear to have evolved independently in many lineages. Here we examine the incidence, functional morphology, and evolution of grasping across four major tetrapod clades. Our review suggests that the ability to grasp with the manus and pes is considerably more widespread, and ecologically and evolutionarily important, than previously thought. The morphological bases and ecological factors that govern grasping abilities may differ among tetrapods, yet the selective forces shaping them are likely similar. We suggest that further investigation into grasping form and function within and among these clades may expose a greater role for grasping ability in the evolutionary success of many tetrapod lineages.

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“…This ability is afforded by their unique pedal anatomy, compared to other birds of prey. Among these attributes is the ability to rotate the fourth toe (digit IV) antero-posteriorly, and toggle between anisodactyl (digits II-IV face anteriorly; digit I posteriorly) and zygodactyl (digits II and III face anteriorly; digits I and IV face posteriorly) toe arrangements (Shufeldt, 1909;Jollie, 1976Jollie, , 1977Raikow, 1985;Polson, 1993;Ramos and Walker, 1998;Tsang and McDonald, 2018) (Fig. 1F).…”

Section: Introductionmentioning

confidence: 99%

Peer Review #1 of "Behavioral correlates of semi-zygodactyly in Ospreys (Pandion haliaetus) based on analysis of internet images (v0.1)"

Carril¹

2019

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Ospreys are renowned for their fishing abilities, which have largely been attributed to their specialized talon morphology and semi-zygodactyly−the ability to rotate the fourth toe to accompany the first toe in opposition of toes II and III. Anecdotal observations indicate that zygodactyly in Ospreys is associated with prey capture, although to our knowledge this has not been rigorously tested. As a first pass toward understanding the functional significance of semi-zygodactyly in Ospreys, we scoured the internet for images of Osprey feet in a variety of circumstances. From these we cross-tabulated the number of times each of three toe configurations (anisodactylous, zygodactylous, and an intermediate condition between these) was associated with different grasping scenarios (e.g., grasping prey or perched), contact conditions (e.g., fish, other objects, or substrate), object sizes (relative to foot size), and grasping behaviors (e.g., using one or both feet). Our analysis confirms an association between zygodactyly and grasping behavior; the odds that an osprey exhibited zygodactyly while grasping objects in flight were 5.7 times greater than whilst perched. Furthermore, the odds of zygodactyly during single-foot grasps were 4.1 times greater when pictured grasping fish compared to other objects. This suggests a functional association between predatory behavior and zygodactyly and has implications for the selective role of predatory performance in the evolution of zygodactyly more generally.

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Raptors-inroads to multifingered grasping

Cited by 14 publications

References 6 publications

Mechanical analysis of avian feet: multiarticular muscles in grasping and perching

Mechanical analysis of avian feet: multiarticular muscles in grasping and perching

Getting a grip on tetrapod grasping: form, function, and evolution

Peer Review #1 of "Behavioral correlates of semi-zygodactyly in Ospreys (Pandion haliaetus) based on analysis of internet images (v0.1)"

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