Experimental Analysis of Perching in the European Starling (Sturnus vulgaris: Passeriformes; Passeres), and the Automatic Perching Mechanism of Birds
ABSTRACT
The avian automatic perching mechanism (APM) involves the automatic digital flexor mechanism (ADFM) and the digital tendon‐locking mechanism (DTLM). When birds squat on a perch to sleep, the increased tendon travel distance due to flexion of the knee and ankle supposedly causes the toes to grip the perch (ADFM) and engage the DTLM so perching while sleeping involves no muscular effort. However, the knees and ankles of sleeping European starlings (Sturnus vulgaris) are only slightly flexed and, except for occasional balancing adjustments, the distal two‐thirds of the toes are not flexed to grip a 6‐mm‐diameter perch. The cranial ankle angle (CAA) is ∼120° and the foot forms an inverted “U” that, with the mostly unflexed toes, provides a saddle‐like structure so the bird balances its weight over the central pad of the foot (during day weight further back and digits actively grasp perch). In the region of the pad, the tendon sheath of many birds is unribbed, or only very slightly so, and it is always separated from the tendon of the M. flexor digitorum longus by tendons of the other toe flexor muscles. Passive leg flexion produces no toe flexion in anesthetized Starlings and only after 15–20 min, at the onset of rigor mortis, in freshly sacrificed Starlings. Anesthetized Starlings could not remain perched upon becoming unconscious (ADFM, DTLM intact). Birds whose digital flexor tendons were severed or the locking mechanism eliminated surgically (no ADFM or DTLM), so without ability to flex their toes, slept on the perch in a manner similar to unoperated Starlings (except CAA ∼90°–110°). Consequently, there is no APM or ADFM and the DTLM, although involved in lots of other activities, only acts in perching with active contraction of the digital flexor muscles. J. Exp. Zool. (c) Wiley‐Liss, Inc. How to cite this article: Galton PM, Shepherd JD. 2010. Experimental analysis of perching in the European starling (Sturnus vulgaris: Passeriformes; Passeres), and the automatic perching mechanism of birds. J. Exp. Zool. 317:205–215, 2012. © 2012 Wiley Periodicals, Inc.
Number of times cited: 9
- William R. T. Roderick, Mark R. Cutkosky and David Lentink, Touchdown to take-off: at the interface of flight and surface locomotion, Interface Focus, 7, 1, (20160094), (2017).
- Young-Hui Chang and Lena H. Ting, Mechanical evidence that flamingos can support their body on one leg with little active muscular force, Biology Letters, 13, 5, (20160948), (2017).
- , Scientific Opinion on welfare aspects of the use of perches for laying hens, EFSA Journal, 13, 6, (2015). AIAA Atmospheric Flight Mechanics Conference Kissimmee, Florida AIAA Atmospheric Flight Mechanics Conference American Institute of Aeronautics and Astronautics Reston, Virginia , (2015). , (2015). 978-1-62410-340-7 10.2514/MAFM15 , 10.2514/MAFM15 2016101702270300039 http://arc.aiaa.org/doi/book/10.2514/MAFM15 Pu Xie, Ou Ma, Zhen Zhao and Lin Zhang A Bio-inspired UAV Leg-Foot Mechanism for Landing, Grasping and Perching Tasks , (2015). , (2015). 10.2514/6.2015-1689 , 10.2514/6.2015-1689 2016101702270300039 http://arc.aiaa.org/doi/10.2514/6.2015-1689
- S. B. Backus, D. Sustaita, L. U. Odhner and A. M. Dollar, Mechanical analysis of avian feet: multiarticular muscles in grasping and perching, Royal Society Open Science, 2, 2, (140350), (2015). 2014 IEEE International Conference on Robotics and Automation (ICRA) Hong Kong, China 2014 IEEE International Conference on Robotics and Automation (ICRA) IEEE , (2014). 978-1-4799-3685-4 Wanchao Chi, K. H. Low, K. H. Hoon and Johnson Tang An optimized perching mechanism for autonomous perching with a quadrotor , (2014). 3109 3115 6907306 , 10.1109/ICRA.2014.6907306 http://ieeexplore.ieee.org/document/6907306/
- Diego Sustaita, Emmanuelle Pouydebat, Adriana Manzano, Virginia Abdala, Fritz Hertel and Anthony Herrel, Getting a grip on tetrapod grasping: form, function, and evolution, Biological Reviews, 88, 2, (380-405), (2013).
- Wanchao Chi, Kin Huat Low, Kay Hiang Hoon, Johnson Tang and Tiauw Hiong Go, A Bio-Inspired Adaptive Perching Mechanism for Unmanned Aerial Vehicles, Journal of Robotics and Mechatronics, 24, 4, (642), (2012).
- Stephanie LeBlanc, Bret Tobalske, Margaret Quinton, Dwight Springthorpe, Bill Szkotnicki, Hanno Wuerbel, Alexandra Harlander-Matauschek and Sharon Swartz, Physical Health Problems and Environmental Challenges Influence Balancing Behaviour in Laying Hens, PLOS ONE, 10.1371/journal.pone.0153477, 11, 4, (e0153477), (2016).
