Suspensory behavior

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Suspensory behaviour is a form of arboreal locomotion or a feeding behavior that involves hanging or suspension of the body below or among tree branches. [1] This behavior enables faster travel while reducing path lengths to cover more ground when travelling, searching for food and avoiding predators. [2] [3] Different types of suspensory behaviour include brachiation, climbing, and bridging. These mechanisms allow larger species to distribute their weight among smaller branches rather than balancing above these weak supports. [1] Primates and sloths are most commonly seen using these behaviours, however, other animals such as bats may be seen hanging below surfaces to obtain food or when resting. [1] [4]

Contents

Biomechanics

Suspensory behavior seen in ruffed lemur (Varecia variegata) Varecia variegata suspensory posture1.jpg
Suspensory behavior seen in ruffed lemur (Varecia variegata)

In primates and sloths

Roosting behaviour in flying foxes (Pteropus conspicillatus) Pteropus conspicillatus.jpg
Roosting behaviour in flying foxes (Pteropus conspicillatus)

Animals who exhibit suspensory behaviour have similar mechanisms to perform this action and often involve many different parts of their body like the trunk, shoulders and many other features of their upper body. [5] Typically, these animals have an overall dorso-ventral flattening, a shortened lumbar region and a mediolateral expansion of the rib cage causing the scapula to be repositioned dorsally and humeral articulation to be oriented more cranially than the usual lateral placement shown in quadrupedal animals. [6] The scapula is also longer, giving these animals a particular arm and shoulder shape. [5] Combined, these morphologies allow for the infraspinatus muscle to be repositioned creating more resistance to trans articular tensile stress for suspending below a branch. These animals also have longer clavicles, creating a bigger projection of the shoulder which increases the ability to move when the forearm is raised above the head. To help with supporting their weight, the forelimbs are elongated. The humerus is longer as well and this helps with the movement of the deltoid muscles in the shoulder joint when the arm is moving away from the body. [5] The triceps branchii is small and there is a shorter distance to the elbow joint and a shorter olecranon process which allows for a greater elbow extension.

Animals, especially primates, have many different ways to position themselves during suspensory behaviour, and these positions require different bones and muscles. Below is a list of different positions and their mechanisms. [7]

In bats

Roosting is a vertical upside down behaviour seen in bats which involves the use of the feet to grasp a surface. [8] The hind limbs are very important as they provide most of the strength to support the bat. [8] The forelimbs can be used as well, having all four limbs supporting the animal. [8] The head and neck are usually kept at a 90° or 180° angle. [9]

Locomotion

Suspensory locomotion aids with reducing path lengths and covering longer distances by moving faster through branches and trees above. [2] The movements of involved in suspensory behavior can be described as being seen most often among monkeys. The swinging motion of grabbing branch after branch with alternating hands or launching the body from one support to another losing contact with the support is very common and the most popular form of locomotion among suspensory animals. [10] Some animals such as the platyrrhines, use their tails for traveling and usually never use their forelimbs for transportation, while some species use both their tails and forelimbs. [10] Suspensory behavior is advantageous for avoiding predators. The quick motions and ability to escape high above the ground enables an avoidance strategy, maintaining survival. [3] While this type of locomotion can be beneficial there can be some consequences when dealing with extreme heights as vigorously moving through the trees allows for more opportunity for injury. [3] The easiest way for animals to avoid this consequence is using their abilities to focus on uninterrupted travel, accuracy and avoiding alternative routes. [3]

Types of locomotion

Pygmy marmoset (Cebuella pygmaea) climbing tree Pygmy marmoset (Cebuella pygmaea) climbing tree.jpg
Pygmy marmoset (Cebuella pygmaea) climbing tree

Brachiation

Brachiation involves the animal swinging from branch to branch in a sequence motion above the ground in a canopy of trees. [5] [10] Typically these movements involve both arms without the aid of the legs or tail. [10] Tail and hind limb suspension can be used in different situations like feeding or escaping predators during drastic situations, however the use of the arms is preferred for this type of movement. [10]

Composite image of a juvenile proboscis monkey (Nasalis larvatus) learning to leap from one tree to another Proboscis monkey (Nasalis larvatus) composite.jpg
Composite image of a juvenile proboscis monkey (Nasalis larvatus) learning to leap from one tree to another

Climbing

Climbing consists of moving up or down a vertical surface using all four arms and legs to help move the body upward or downward. [11] There are many different ways in which an animal can climb such as using alternating arms and legs, climbing sideways, fire-pole slides and head or bottom first decline. [11] Vertical climbing is the most costly form of locomotion as the animal must defy gravity and move up the tree. [12] This is particularly harder for animals with a larger body mass, as carrying their entire weight becomes more difficult with size. [12] Also involved with climbing is a "pulling up" motion in which the animal will pull itself above a branch using both of its arms and the hind limbs launch over the branch using a swinging motion. [11]

Bridging

Animals use this type of behavior when crossing between trees and other surfaces. [2] This movement requires the use of the hind limbs to leap across extended areas. [11] Small animals have an easier time leaping between gaps, while larger animals are more cautious due to their weight and typically swing from branch to branch instead. [2]

Feeding while suspended from a rope How to peel a banana with your foot (26443349170).jpg
Feeding while suspended from a rope

Feeding

Suspensory behaviour is very important for animals in regards to feeding. It has been reported that suspensory movements make up approximately 25% of all feeding strategies shown in primates. [13] Suspension helps them reach fruits and other vegetation that might be difficult to obtain on foot, while allowing them to cover a large distance at a greater speed. [2] [13] Often in arboreal regions, flowers, fruits and other plants are located on small terminal branches and suspension enables animals to access this food while saving time and energy. [2] By suspending below the branch they avoid a greater chance at the branch breaking and are able to keep a steady balance. [14] Hanging by the tail is very common when foraging which permits the use of the hands and arms to not only grab food but to catch themselves if they were to slip or fall. [14] Suspension allows for fast travel, which is helpful when collecting food as well. Speed allows animals to minimize competition while avoiding predators to ensure they grab as much food as they can in a short period of time. [2] If an animal is in a high tree, they often eat their food then and there to avoid injury and predators. Quadrupedalism and bipedalism combined with suspensory mechanisms are crucial for providing support during feeding so the animal does not fall and risk losing the food, or risking its life. [12]

Examples

See also

Related Research Articles

<span class="mw-page-title-main">Bipedalism</span> Terrestrial locomotion using two limbs

Bipedalism is a form of terrestrial locomotion where an animal moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped, meaning 'two feet'. Types of bipedal movement include walking or running and hopping.

<span class="mw-page-title-main">Upper limb</span> Consists of the arm, forearm, and hand

The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulder, elbow, wrist and knuckle joints. In humans, each upper limb is divided into the shoulder, arm, elbow, forearm, wrist and hand, and is primarily used for climbing, lifting and manipulating objects. In anatomy, just as arm refers to the upper arm, leg refers to the lower leg.

<span class="mw-page-title-main">Brachiation</span> Form of arboreal locomotion involving swinging by the arm

Brachiation, or arm swinging, is a form of arboreal locomotion in which primates swing from tree limb to tree limb using only their arms. During brachiation, the body is alternately supported under each forelimb. This form of locomotion is the primary means of locomotion for the small gibbons and siamangs of southeast Asia. Gibbons in particular use brachiation for as much as 80% of their locomotor activities. Some New World monkeys, such as spider monkeys and muriquis, were initially classified as semibrachiators and move through the trees with a combination of leaping and brachiation. Some New World species also practice suspensory behaviors by using their prehensile tail, which acts as a fifth grasping hand. Evidence has shown that the extinct ape Proconsul from the Miocene of East Africa developed an early form of suspensory behaviour, and was therefore referred to as a probrachiator.

<span class="mw-page-title-main">Red-shanked douc</span> Species of Old World monkey

The red-shanked douc is an arboreal and diurnal Old World monkey belonging to the Colobinae subfamily. They are endemic to Laos, Vietnam, and Cambodia. They are known for their bright colors and exhibit sexual dimorphism through their body size. The species has been declared critically endangered by the International Union for Conservation of Nature, with the main threats being: hunting, habitat loss and pet trade. They are one of three species in the genus Pygathrix, the other two being the black-shanked and gray-shanked doucs.

<span class="mw-page-title-main">Animal locomotion</span> Self-propulsion by an animal

In ethology, animal locomotion is any of a variety of methods that animals use to move from one place to another. Some modes of locomotion are (initially) self-propelled, e.g., running, swimming, jumping, flying, hopping, soaring and gliding. There are also many animal species that depend on their environment for transportation, a type of mobility called passive locomotion, e.g., sailing, kiting (spiders), rolling or riding other animals (phoresis).

<span class="mw-page-title-main">Silvery gibbon</span> Species of ape

The silvery gibbon, also known as the Javan gibbon, is a primate in the gibbon family Hylobatidae. It is endemic to the Indonesian island of Java, where it inhabits undisturbed rainforests up to an altitude of 2,450 m (8,040 ft). It has been listed as Endangered on the IUCN Red List since 2008, as the wild population is estimated to comprise less than 2500 mature individuals.

<span class="mw-page-title-main">Forelimb</span> One of the paired articulated appendages attached on the cranial end of a vertebrates torso

A forelimb or front limb is one of the paired articulated appendages (limbs) attached on the cranial (anterior) end of a terrestrial tetrapod vertebrate's torso. With reference to quadrupeds, the term foreleg or front leg is often used instead. In bipedal animals with an upright posture, the term upper limb is often used.

<span class="mw-page-title-main">Knuckle-walking</span> Form of quadrupedal walking using the knuckles

Knuckle-walking is a form of quadrupedal walking in which the forelimbs hold the fingers in a partially flexed posture that allows body weight to press down on the ground through the knuckles. Gorillas and chimpanzees use this style of locomotion, as do anteaters and platypuses.

<span class="mw-page-title-main">Geoffroy's spider monkey</span> Species of spider monkey, from Central America

Geoffroy's spider monkey, also known as the black-handed spider monkey or the Central American spider monkey, is a species of spider monkey, a type of New World monkey, from Central America, parts of Mexico and possibly a small portion of Colombia. There are at least five subspecies. Some primatologists classify the black-headed spider monkey (A. fusciceps), found in Panama, Colombia, and Ecuador as the same species as Geoffroy's spider monkey.

<span class="mw-page-title-main">Terrestrial locomotion</span> Ability of animals to travel on land

Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises different problems than that in water, with reduced friction being replaced by the increased effects of gravity.

A facultative biped is an animal that is capable of walking or running on two legs (bipedal), as a response to exceptional circumstances (facultative), while normally walking or running on four limbs or more. In contrast, obligate bipedalism is where walking or running on two legs is the primary method of locomotion. Facultative bipedalism has been observed in several families of lizards and multiple species of primates, including sifakas, capuchin monkeys, baboons, gibbons, gorillas, bonobos and chimpanzees. Several dinosaur and other prehistoric archosaur species are facultative bipeds, most notably ornithopods and marginocephalians, with some recorded examples within sauropodomorpha. Different facultatively bipedal species employ different types of bipedalism corresponding to the varying reasons they have for engaging in facultative bipedalism. In primates, bipedalism is often associated with food gathering and transport. In lizards, it has been debated whether bipedal locomotion is an advantage for speed and energy conservation or whether it is governed solely by the mechanics of the acceleration and lizard's center of mass. Facultative bipedalism is often divided into high-speed (lizards) and low-speed (gibbons), but some species cannot be easily categorized into one of these two. Facultative bipedalism has also been observed in cockroaches and some desert rodents.

<span class="mw-page-title-main">Skeletal system of the horse</span>

The skeletal system of the horse is a skeletal system of a horse that has three major functions in the body. It protects vital organs, provides framework, and supports soft parts of the body. Horses typically have 205 bones. The pelvic limb typically contains 19 bones, while the thoracic limb contains 20 bones.

<span class="mw-page-title-main">Arboreal locomotion</span> Movement of animals through trees

Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose numerous mechanical challenges to animals moving through them and lead to a variety of anatomical, behavioral and ecological consequences as well as variations throughout different species. Furthermore, many of these same principles may be applied to climbing without trees, such as on rock piles or mountains.

A limb is a jointed, muscled appendage of a tetrapod vertebrate animal used for weight-bearing, terrestrial locomotion and physical interaction with other objects. The distalmost portion of a limb is known as its extremity. The limbs' bony endoskeleton, known as the appendicular skeleton, is homologous among all tetrapods, who use their limbs for walking, running and jumping, swimming, climbing, grasping, touching and striking.

<span class="mw-page-title-main">Jumping (horse)</span>

Jumping plays a major role in many equestrian sports, such as show jumping, fox hunting, steeplechasing, and eventing. The biomechanics of jumping, the influence of the rider, and the heritability of jumping prowess have all been the focus of research.

Vertical clinging and leaping (VCL) is a type of arboreal locomotion seen most commonly among the strepsirrhine primates and haplorrhine tarsiers. The animal begins at rest with its torso upright and elbows fixed, with both hands clinging to a vertical support, such as the side of a tree or bamboo stalk. To move from one support to another, it pushes off from one vertical support with its hindlimbs, landing on another vertical support after an extended period of free flight. Vertical clinging and leaping primates have evolved a specialized anatomy to compensate for the physical implications of this form of locomotion. These key morphological specializations have been identified in prosimian fossils from as early as the Eocene.

<span class="mw-page-title-main">Limbs of the horse</span> Structures made of bones, joints, muscles, tendons, and ligaments

The limbs of the horse are structures made of dozens of bones, joints, muscles, tendons, and ligaments that support the weight of the equine body. They include two apparatuses: the suspensory apparatus, which carries much of the weight, prevents overextension of the joint and absorbs shock, and the stay apparatus, which locks major joints in the limbs, allowing horses to remain standing while relaxed or asleep. The limbs play a major part in the movement of the horse, with the legs performing the functions of absorbing impact, bearing weight, and providing thrust. In general, the majority of the weight is borne by the front legs, while the rear legs provide propulsion. The hooves are also important structures, providing support, traction and shock absorption, and containing structures that provide blood flow through the lower leg. As the horse developed as a cursorial animal, with a primary defense mechanism of running over hard ground, its legs evolved to the long, sturdy, light-weight, one-toed form seen today.

<span class="mw-page-title-main">Tripod stance</span>

A tripod stance is a behaviour in which quadruped animals rear up on their hind legs and use their tail to support this position. Several animals use this behaviour to improve observation or surveillance, and during feeding, grooming, thermoregulation, or fighting.

<span class="mw-page-title-main">Stay apparatus</span>

The stay apparatus is an arrangement of muscles, tendons, and ligaments that work together so that an animal can remain standing with virtually no muscular effort. It is best known as the mechanism by which horses can enter a light sleep while still standing up. The effect is that an animal can distribute its weight on three limbs while resting a fourth in a flexed, non-weight-bearing position. The animal can periodically shift its weight to rest a different leg, and thus all limbs are able to be individually rested, reducing overall wear and tear. The relatively slim legs of certain large mammals, such as horses and cows, would be subject to dangerous levels of fatigue if not for the stay apparatus.

Danuvius guggenmosi is an extinct species of great ape that lived 11.6 million years ago during the Middle–Late Miocene in southern Germany. It is the sole member of the genus Danuvius. The area at this time was probably a woodland with a seasonal climate. A male specimen was estimated to have weighed about 31 kg (68 lb), and two females 17 and 19 kg. Both genus and species were described in November 2019.

References

  1. 1 2 3 Fleagle, John G. (1999). Primate adaptation and evolution (2nd ed.). San Diego [u.a.]: Acad. Press. ISBN   978-0-12-260341-9.
  2. 1 2 3 4 5 6 7 Youlatos, Dionisios (2002). "Positional Behavior of Black Spider Monkeys (Ateles paniscus) in French Guiana". International Journal of Primatology. 23 (5): 1071–1093. doi:10.1023/A:1019602116805. S2CID   28478677.
  3. 1 2 3 4 Primate locomotion : linking field and laboratory research. D'Août, Kristiaan., Vereecke, Evie E. New York: Springer. 2011. pp. 205–211. ISBN   9781441914194. OCLC   704395283.{{cite book}}: CS1 maint: others (link)
  4. Vandoros, Jason Demetri; Dumont, Elizabeth Rachel (2004-04-01). "Use of the wings in manipulative and suspensory behaviors during feeding by frugivorous bats". Journal of Experimental Zoology. 301A (4): 361–366. doi:10.1002/jez.a.20040. ISSN   1552-499X. PMID   15039995.
  5. 1 2 3 4 Byron, C. D.; Granatosky, M. C.; Covert, H. H. (2017-12-01). "An anatomical and mechanical analysis of the douc monkey (genus Pygathrix), and its role in understanding the evolution of brachiation". American Journal of Physical Anthropology. 164 (4): 801–820. doi: 10.1002/ajpa.23320 . ISSN   1096-8644. PMID   29023639.
  6. Selby, Michael S.; Lovejoy, C. Owen (2017-04-01). "Evolution of the hominoid scapula and its implications for earliest hominid locomotion". American Journal of Physical Anthropology. 162 (4): 682–700. doi:10.1002/ajpa.23158. ISSN   1096-8644. PMID   28128440.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Hunt, Kevin D.; Cant, John G. H.; Gebo, Daniel L.; Rose, Michael D.; Walker, Suzanne E.; Youlatos, Dionisios (1996-10-01). "Standardized descriptions of primate locomotor and postural modes". Primates. 37 (4): 363–387. doi:10.1007/bf02381373. ISSN   0032-8332. S2CID   37235291.
  8. 1 2 3 Riskin, Daniel K.; Bahlman, Joseph W.; Hubel, Tatjana Y.; Ratcliffe, John M.; Kunz, Thomas H.; Swartz, Sharon M. (2009-04-01). "Bats go head-under-heels: the biomechanics of landing on a ceiling". Journal of Experimental Biology. 212 (7): 945–953. doi: 10.1242/jeb.026161 . ISSN   0022-0949. PMID   19282491.
  9. Fenton, M. Brock; Crerar, Laura M. (1984-08-24). "Cervical Vertebrae in Relation to Roosting Posture in Bats". Journal of Mammalogy. 65 (3): 395–403. doi:10.2307/1381085. ISSN   0022-2372. JSTOR   1381085.
  10. 1 2 3 4 5 Arias-Martorell, Julia; Tallman, Melissa; Potau, Josep Maria; Bello-Hellegouarch, Gaëlle; Pérez-Pérez, Alejandro (2015-01-01). "Shape analysis of the proximal humerus in orthograde and semi-orthograde primates: Correlates of suspensory behavior". American Journal of Primatology. 77 (1): 1–19. doi: 10.1002/ajp.22306 . ISSN   1098-2345. PMID   25219580. S2CID   7159162.
  11. 1 2 3 4 Wright, Kristin A.; Stevens, Nancy J.; Covert, Herbert H.; Nadler, Tilo (2008-12-01). "Comparisons of Suspensory Behaviors Among Pygathrix cinerea, P. nemaeus, and Nomascus leucogenys in Cuc Phuong National Park, Vietnam". International Journal of Primatology. 29 (6): 1467. doi:10.1007/s10764-008-9319-9. ISSN   0164-0291. S2CID   9366197.
  12. 1 2 3 Manduell, Kirsten L.; Morrogh-Bernard, Helen C.; Thorpe, Susannah K.S. (2011-07-01). "Locomotor behavior of wild orangutans (pongo pygmaeus wurmbii) in disturbed peat swamp forest, Sabangau, Central Kalimantan, Indonesia". American Journal of Physical Anthropology. 145 (3): 348–359. doi:10.1002/ajpa.21495. ISSN   1096-8644. PMID   21469074.
  13. 1 2 Britt, Adam (2000). "Diet and Feeding Behaviour of the Black-and-White Ruffed Lemur (Varecia variegata variegata) in the Betampona Reserve, Eastern Madagascar". Folia Primatologica. 71 (3): 133–141. doi:10.1159/000021741. ISSN   0015-5713. PMID   10828690. S2CID   11002097.
  14. 1 2 Fei, Hanlan; Ma, Changyong; Bartlett, Thad Q.; Dai, Ran; Xiao, Wen; Fan, Pengfei (4 November 2015). "Feeding Postures of Cao Vit Gibbons (Nomascus nasutus) Living in a Low-Canopy Karst Forest". International Journal of Primatology. 36 (5): 1036–1054. doi:10.1007/s10764-015-9871-z. S2CID   254546412.