DOCSLIB.ORG

Locomotion, Morphology, and Habitat Use in Arboreal

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Locomotion, Morphology, and Habitat Use in Arboreal LOCOMOTION, MORPHOLOGY, AND HABITAT USE IN ARBOREAL SQUIRRELS (RODENTIA: SCIURIDAE) A dissertation presented to the faculty of the College of Arts and Sciences of Ohio University In partial fulfillment of the requirements for the degree Doctor of Philosophy Richard L. Essner, Jr. June 2003 This dissertation entitled LOCOMOTION, MORPHOLOGY, AND HABITAT USE IN ARBOREAL SQUIRRELS (RODENTIA: SCIURIDAE) BY RICHARD L. ESSNER, JR. has been approved for the Department of Biological Sciences and the College of Arts and Sciences by Stephen M. Reilly Associate Professor of Biological Sciences Leslie A. Flemming Dean, College of Arts and Sciences ESSNER, JR., RICHARD L. Ph.D. June 2003. Biological Sciences Locomotion, Morphology, and Habitat Use in Arboreal Squirrels (Rodentia: Sciuridae) (135pp.) Director of Dissertation: Stephen M. Reilly Arboreal locomotion has not been well studied in mammals outside of primates and mammalian gliding has received even less attention. While numerous studies have examined morphological variation in these forms, there is currently a lack of detailed kinematic, behavioral, and ecological data to assist in explaining the patterns. Here, I present three studies that focus on differing aspects of locomotion in arboreal squirrels. These range from 3-D kinematics (Chapters 1 & 2) to morphology, locomotor behavior, and habitat use (Chapter 3). First, kinematics were quantified and compared among leaping, parachuting, and gliding squirrels to test for differences during the launch phase. Only six out of 23 variables were found to differ significantly among the three species investigated. The six significant variables were partitioned into morphological, behavioral, and performance based differences. Remarkably, there were no differences attributable to hindlimb kinematics indicating that propulsion is the same in leaping, parachuting, and gliding squirrels. Next, the initial airborne phase was investigated. Following the launch nongliding squirrels initiated gradual and symmetrical movements of the limbs. Flying squirrels initiated highly stereotyped fluttering movements characterized by a series of rapid asymmetrical rotations of the fore and hindlimbs. This behavior is hypothesized to provide control over angular momentum and disrupt detrimental fluid dynamic effects. The kinematics of the landing phase were also investigated in flying squirrels. Landing was characterized by limb adduction, tail dorsiflexion, and billowing of the patagium which acted to increase angle of attack and slow descent. Flying squirrels reached maximum extension of their limbs and maximal flexion of the vertebral column as they contacted the landing platform. This was hypothesized as a mechanism for increasing deceleration time and reducing peak landing forces. Finally, in order to determine which aspects of morphology, behavior, and ecology define evolutionary transitions from arboreality to semiarboreality/terrestriality or gliding in squirrels I investigated each of the levels using ordination (principal components analysis and correspondence analysis) and multivariate analysis of variance. In addition, I examined causal linkages across levels by testing a number of biomechanical predictions. Flying squirrels and chipmunks occupied extreme regions of morphospace, ethospace, and ecospace, while red squirrels were generally located in intermediate positions consistent with the idea that they exhibit the ancestral condition. Biomechanical predictions were supported in some instances but not in others, reinforcing the need for further study. Approved: Stephen M. Reilly Associate Professor of Biological Sciences 5 Acknowledgments I extend my sincere gratitude to my advisor Steve Reilly. Steve initially inspired me through the book he co-edited entitled Ecological Morphology. The ragged pages of that book have provided me with a roadmap throughout my graduate career. Steve has continued to inspire me through his passion for science and his quest for “the nanosecond of discovery.” I am also deeply indebted to Clay Corbin, Pete Larson, and Lance McBrayer. I have learned more from them than they will ever know. Clay in particular made the long commutes from Lancaster bearable. I will truly miss our conversations on that long and winding road. I thank Audrone Biknevicius, Ron Heinrich, and Larry Witmer for being excellent mentors. Their guidance and encouragement through the years have been a valuable asset. In addition, Sue Bullard and Brigitte Demes were extremely helpful with their comments. I sincerely appreciate their efforts on my behalf. These outstanding individuals comprised my dissertation committee and I thank them all for their support and dedication. I thank John Scheibe for giving me the “spark” of scientific curiosity. John was the first person to introduce me to the field of ecology and evolutionary biology. In addition, he did me the great service of passing along his enthusiasm for ecomorphology and gliding locomotion. I am forever in his debt. I am also indebted to Jim Robins and A. J. Hendershott for the times spent discussing gliders ad infinitum over the years. I thank the Reilly Lab past & present especially Jason Elias, Andy Parchman, and Kristen Hickey for their help with many aspects of my research. I also thank the OU 6 Evomorph group, most notably Kay Earls and Nancy Stevens, for their welcome advice. I have never been associated with a finer group of individuals. I sincerely thank the army of undergraduates who helped with much of this research. Special thanks go to Jeremy Caudill, Tara Chapman, Kim Huber, Brian Mussio, Colin Shelton, and Jonathan Vega. Their hard work made this project possible. I thank Robert Dudley, Steve Edinger, Cliff Frohlich, Ted Goslow, Robert Hikida, and Robert Srygley for helpful comments. I thank Jerry Svendsen for expanding my background in the fields of ecology, mammalogy, and statistics and for generously allowing me to borrow traps for an extended period of time. Dave Elliott was extremely generous with his time and materials on many occasions during my time at OU. Scott Carpenter and the Lab Animal Resources Staff took excellent care of the animals used in this study. Their expertise and dedication are truly impressive. I sincerely thank my family for their construction skills, but more importantly for their love and support over all of these years. They have gone above and beyond the call of duty on countless occasions and are in large part responsible for getting me to this point. Most of all I extend my deepest gratitude to my wife Jill for her inexhaustible love and patience. I cannot count the number of weekends she gave up to assist me with data collection. She has been a partner in everything I have done. This research was supported by NSF Dissertation Improvement Grant (IBN 0076342), an Ohio University Student Enhancement Award, grants-in-aid from the Society for Integrative and Comparative Biology and the American Society of Mammalogists, and several Ohio University John Houk Memorial Research Grants. 7 Table of Contents Abstract................................................................................................................................3 Acknowledgments................................................................................................................5 List of Tables .......................................................................................................................8 List of Figures......................................................................................................................9 General Introduction ..........................................................................................................11 References................................................................................................................15 Chapter 1 Three-Dimensional Launch Kinematics in Leaping, Parachuting, and Gliding Squirrels ........................................................................................................................17 Materials and Methods ............................................................................................20 Results .....................................................................................................................25 Discussion ...............................................................................................................28 References ...............................................................................................................36 Chapter 2 Three-Dimensional Aerial Kinematics in Arboreal Squirrels..........................46 Materials and Methods ............................................................................................52 Results .....................................................................................................................57 Discussion ...............................................................................................................64 References ...............................................................................................................73 Chapter 3 Morphology, Locomotor Behavior, and Habitat Use in Arboreal Squirrels....93 Materials and Methods ............................................................................................98 Results ...................................................................................................................102 Discussion .............................................................................................................105
Load more

Recommended publications
  • Fish Locomotion: Recent Advances and New Directions
    MA07CH22-Lauder ARI 6 November 2014 13:40 Fish Locomotion: Recent Advances and New Directions George V. Lauder Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138; email: [email protected] Annu. Rev. Mar. Sci. 2015. 7:521–45 Keywords First published online as a Review in Advance on swimming, kinematics, hydrodynamics, robotics September 19, 2014 The Annual Review of Marine Science is online at Abstract marine.annualreviews.org Access provided by Harvard University on 01/07/15. For personal use only. Research on fish locomotion has expanded greatly in recent years as new This article’s doi: approaches have been brought to bear on a classical field of study. Detailed Annu. Rev. Marine. Sci. 2015.7:521-545. Downloaded from www.annualreviews.org 10.1146/annurev-marine-010814-015614 analyses of patterns of body and fin motion and the effects of these move- Copyright c 2015 by Annual Reviews. ments on water flow patterns have helped scientists understand the causes All rights reserved and effects of hydrodynamic patterns produced by swimming fish. Recent developments include the study of the center-of-mass motion of swimming fish and the use of volumetric imaging systems that allow three-dimensional instantaneous snapshots of wake flow patterns. The large numbers of swim- ming fish in the oceans and the vorticity present in fin and body wakes sup- port the hypothesis that fish contribute significantly to the mixing of ocean waters. New developments in fish robotics have enhanced understanding of the physical principles underlying aquatic propulsion and allowed intriguing biological features, such as the structure of shark skin, to be studied in detail.
    [Show full text]
  • Comparative Locomotor Performance of Marsupial and Placental Mammals
    J. Zool., Lond. (1988) 215, 505-522 Comparative locomotor performance of marsupial and placental mammals T. GARLAND,JR Department of Zoology, University of Wisconsin, Madison, WZ 53706, USA School of Biological Sciences, The Flinders University of South Australia, Bedford Park, Adelaide, 5042, South Australia (Accepted 13 October 1987) (With 6 figures in the text) Marsupials are often considered inferior to placental mammals in a number of physiological characters. Because locomotor performance is presumed to be an important component of fitness, we compared marsupials and placentals with regard to both maximal running speeds and maximal aerobic speeds (=speed at which the maximal rate of oxygen consumption, \jozmax, is attained). Maximal aerobic speed is related to an animal's maximal sustainable speed, and hence is a useful comparative index of stamina. Maximal running speeds of 1 I species of Australian marsupials, eight species of Australian murid rodents, two species of American didelphid marsupials, and two species of American rodents were measured in the laboratory and compared with data compiled from the literature. Our values are greater than, or equivalent to, those reported previously. Marsupials and placentals do not differ in maximal running speeds (nor do Australian rodents differ from non- Australian rodents). Within these groups, however, species and families may differ considerably. Some of the interspecific variation in maximal running speeds is related to differences in habitat: species inhabiting open habitats (e.g. deserts) tend to be faster than are species from habitats with more cover, or arboreal species. Maximal aerobic speeds (compiled from the literature) were higher in large species than in small species.
    [Show full text]
  • Squirrels and Allies (Sciuridae Spp.)
    Squirrels and Allies (Sciuridae Spp.) There are about 275 species of tree, ground, and flying squirrels throughout the world, ranging from the five-inch pygmy squirrel (Myosciurus pumilio) of Africa to the nearly three-foot giant squirrel (Ratufa indica) of Asia. Currently, there are five species of squirrel found in Rhode Island: The Eastern gray squirrel, the Southern flying squirrel, the red squirrel, the chipmunk, and the woodchuck. Tree squirrels are those species that nest in trees, while ground squirrels nest in underground burrows. This publication is intended to provide information on the above species found in Rhode Island. Eastern Gray Squirrel (Sciurus carolinensis) Gray squirrels are the most common species of squirrel in Rhode Island. They are a tree squirrel, however they spend much of their time on the ground, and have adapted well to human-altered environments. They are commonly found in urban and suburban habitats. Gray squirrels can be grayish-brown, gray or black, with a white or light brown underside. Adults range in size from 15 to 20 inches, and between 1 to 1 ½ pounds. Their bushy tail accounts for almost half of their length. Gray squirrels may live between four and eight years in the wild, but they have been known to live up to ten years in captivity. They are active mainly during the day and do not hibernate. In the winter they spend days at a time in their nests, leaving only to gather food. Their habitat is mainly any wooded area with mast producing trees, where they live in tree cavities or leaf nests.
    [Show full text]
  • Northwestwildlife.Com Species Reports
    A publication by: NORTHWEST WILDLIFE PRESERVATION SOCIETY Northern Flying Squirrel Glaucomys sabrinus Photo credit: US Fish and Wildlife By Renee Picard There are two species of flying squirrels that live in North America. The northern flying squirrel (with 25 sub-species) may be found in forests throughout most of Canada, except for the central prairies and the extreme North; also in the U.S. in Alaska and northern areas of the Rockies and Appalachians. The southern flying squirrel (with 10 sub-species) inhabits a broad range in the eastern and midwestern United States, but in Canada is only found in very small, scattered pockets of southeastern Ontario. The southern species is considered ‘vulnerable’ but the northern species is not at risk. It is the northern squirrel that you would be likely to encounter in the Pacific Northwest, so it is the focus of this article. Characteristics The scientific name for the northern flying squirrel is Glaucomys sabrinus. Glaucos means for silver or grey, mys means mouse, and sabrinus come from the Latin word for river-nymph. So you will notice them often in riparian areas, near streams and rivers. Their colours range from tan to cinnamon and they have greyish-white belly fur. They are about 30 cm (12 in.) long and weigh about 139 g (46 oz.) Flying squirrels have big black eyes and this characteristic helps their night vision for they are nocturnal animals. You might be surprised to find that, despite their name, flying squirrels do not really fly—they glide down from branch to branch. The front and back legs are connected with a thin fold of furry skin or membrane called a patagium.
    [Show full text]
  • The Dynamics of Pine Marten Predation on Red and Grey Squirrels
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/341099392 The dynamics of pine marten predation on red and grey squirrels Article in Mammalian Biology - Zeitschrift fur Saugetierkunde · May 2020 DOI: 10.1007/s42991-020-00031-z CITATION READS 1 246 3 authors: Joshua P Twining Ian Montgomery Queen's University Belfast Queen's University Belfast 10 PUBLICATIONS 21 CITATIONS 241 PUBLICATIONS 4,723 CITATIONS SEE PROFILE SEE PROFILE David G Tosh National Museums of Northern Ireland 30 PUBLICATIONS 375 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Northern Ireland artificial den box scheme for pine marten View project Origins of Irish mammals View project All content following this page was uploaded by Joshua P Twining on 28 September 2020. The user has requested enhancement of the downloaded file. Mammalian Biology https://doi.org/10.1007/s42991-020-00031-z ORIGINAL ARTICLE The dynamics of pine marten predation on red and grey squirrels Joshua P. Twining1 · W. Ian Montgomery1 · David G. Tosh2 Received: 12 October 2019 / Accepted: 3 April 2020 © The Author(s) 2020 Abstract Invasive alien species pose one of the greatest threats to global biodiversity. In parts of Europe, introduced eastern grey squir- rels (Sciurus carolinensis) have caused regional extinctions of the native red squirrel (Sciurus vulgaris). However, exposure to pine martens (Martes martes) has been demonstrated to reverse the competitive outcome between red and grey squirrels. The mechanism whereby this efect occurs remains unclear. It is hypothesised that direct predation, facilitated by a lack of behavioural response, is the mechanism driving this relationship.
    [Show full text]
  • Rethinking the Evolution of the Human Foot: Insights from Experimental Research Nicholas B
    © 2018. Published by The Company of Biologists Ltd | Journal of Experimental Biology (2018) 221, jeb174425. doi:10.1242/jeb.174425 REVIEW Rethinking the evolution of the human foot: insights from experimental research Nicholas B. Holowka* and Daniel E. Lieberman* ABSTRACT presumably owing to their lack of arches and mobile midfoot joints Adaptive explanations for modern human foot anatomy have long for enhanced prehensility in arboreal locomotion (see Glossary; fascinated evolutionary biologists because of the dramatic differences Fig. 1B) (DeSilva, 2010; Elftman and Manter, 1935a). Other studies between our feet and those of our closest living relatives, the great have documented how great apes use their long toes, opposable apes. Morphological features, including hallucal opposability, toe halluces and mobile ankles for grasping arboreal supports (DeSilva, length and the longitudinal arch, have traditionally been used to 2009; Holowka et al., 2017a; Morton, 1924). These observations dichotomize human and great ape feet as being adapted for bipedal underlie what has become a consensus model of human foot walking and arboreal locomotion, respectively. However, recent evolution: that selection for bipedal walking came at the expense of biomechanical models of human foot function and experimental arboreal locomotor capabilities, resulting in a dichotomy between investigations of great ape locomotion have undermined this simple human and great ape foot anatomy and function. According to this dichotomy. Here, we review this research, focusing on the way of thinking, anatomical features of the foot characteristic of biomechanics of foot strike, push-off and elastic energy storage in great apes are assumed to represent adaptations for arboreal the foot, and show that humans and great apes share some behavior, and those unique to humans are assumed to be related underappreciated, surprising similarities in foot function, such as to bipedal walking.
    [Show full text]
  • Species Factsheet: Red Squirrel (Sciurus Vulgaris) [email protected] 023 8023 7874
    Species Factsheet: Red Squirrel (Sciurus vulgaris) [email protected] www.mammal.org.uk 023 8023 7874 Quick Facts Recognition: Fur colour variable from bright ginger through to red and dark brown or black tinged with grey in winter; larger ear tufts in mid-winter which disappear by the summer; bushy tail which bleaches white by late summer in some individuals. Size: 180-240mm, tail about 175mm. Weight: Juveniles: 100-150g; Adults up to 350g. Life Span: They survive for up to six years in the wild. Distribution & Habitat Red squirrels spend about three-quarters of their active time above ground in trees and shrubs, and are at home in both conifer forests and broadleaved woodland. The distribution of red squirrels has declined drastically in the last 60 years and they are now extinct in southern England except for a few on the Isle of Wight and two small islands in Poole Harbour. Elsewhere in central Britain they are confined to rather isolated populations in Wales (notably Anglesey) and around Formby in Merseyside. Red squirrels are still widespread in the North of England and Scotland, and in Ireland, but even here their range is contracting. General Ecology Behaviour Red Squirrels are active during the daytime, though in summer it may rest for an hour or two around mid-day. Squirrel nests, or dreys, are constructed of twigs in a tree fork, above a whorl of branches close to the stem of a conifer, or, less visibly, in a hole in a tree. They are lined with soft hair, moss and dried grass.
    [Show full text]
  • Breeding Ecology of Barred Owls in the Central Appalachians
    BREEDING ECOLOGY OF BARRED OWLS IN THE CENTRAL APPALACHIANS ABSTRACT- Eight pairs of breedingBarred Owls (Strix varia) in westernMaryland were studied. Nest site habitat was sampledand quantifiedusing a modificationof theJames and Shugart(1970) technique (see Titus and Mosher1981). Statisticalcomparison to 76 randomhabitat plots showed nest sites werb in moremature forest stands and closer to forest openings.There was no apparent association of nestsites with water. Cavity dimensions were compared statistically with 41 randomlyselected cavities. Except for cavityheight, there were no statistically significant differences between them. Smallmammals comprised 65.9% of the totalnumber of prey itemsrecorded, of which81.5% were members of the familiesCricetidae and Soricidae. Birds accounted for 14.6%of theprey items and crayfish and insects 19.5%. We also recordedan apparentinstance of juvenile cannibalism. Thirteennestlings were produced in 7 nests,averaging 1.9 young per nest.Only 2 of 5 nests,where the outcome was known,fledged young. The Barred Owl (Strix varia) is a common noc- STUDY AREA AND METHODS turnal raptor in forestsof the easternUnited States, The studywas conducted in Green Ridge State Forest (GRSF), though few detailedstudies of it havebeen pub- Allegany County, Maryland. It is within the Ridge and Valley lished.Most reportsare of singlenesting occurr- physiographicregion (Stoneand Matthews 1977), characterized by narrowmountain ridges oriented northeast to southwestsepa- encesand general observations(Bolles 1890; Carter rated by steepnarrow valleys(see Titus 1980). 1925; Henderson 1933; Robertson 1959; Brown About 74% of the countyand nearly all of GRSF is forested 1962; Caldwell 1972; Hamerstrom1973; Appel- Major foresttypes were describedby Brushet al. (1980).Predom- gate 1975; Soucy 1976; Bird and Wright 1977; inant tree speciesinclude white oak (Quercusalba), red oak (Q.
    [Show full text]
  • A Bird's Eye View of the Evolution of Avialan Flight
    Chapter 12 Navigating Functional Landscapes: A Bird’s Eye View of the Evolution of Avialan Flight HANS C.E. LARSSON,1 T. ALEXANDER DECECCHI,2 MICHAEL B. HABIB3 ABSTRACT One of the major challenges in attempting to parse the ecological setting for the origin of flight in Pennaraptora is determining the minimal fluid and solid biomechanical limits of gliding and powered flight present in extant forms and how these minima can be inferred from the fossil record. This is most evident when we consider the fact that the flight apparatus in extant birds is a highly integrated system with redundancies and safety factors to permit robust performance even if one or more components of their flight system are outside their optimal range. These subsystem outliers may be due to other adaptive roles, ontogenetic trajectories, or injuries that are accommodated by a robust flight system. This means that many metrics commonly used to evaluate flight ability in extant birds are likely not going to be precise in delineating flight style, ability, and usage when applied to transitional taxa. Here we build upon existing work to create a functional landscape for flight behavior based on extant observations. The functional landscape is like an evolutionary adap- tive landscape in predicting where estimated biomechanically relevant values produce functional repertoires on the landscape. The landscape provides a quantitative evaluation of biomechanical optima, thus facilitating the testing of hypotheses for the origins of complex biomechanical func- tions. Here we develop this model to explore the functional capabilities of the earliest known avialans and their sister taxa.
    [Show full text]
  • A Comparison of Flight Potential Among Small-Bodied Paravians
    Chapter 11 High Flyer or High Fashion? A Comparison of Flight Potential among Small-Bodied Paravians T. ALEXANDER DECECCHI,1 HANS C.E. LARSSON,2 MICHAEL PITTMAN,3 AND MICHAEL B. HABIB4 ABSTRACT The origin of flight in birds and its relationship to bird origins itself has achieved something of a renaissance in recent years, driven by the discovery of a suite of small-bodied taxa with large pen- naceous feathers. As some of these specimens date back to the Middle Jurassic and predate the earli- est known birds, understanding how these potential aerofoil surfaces were used is of great importance to answering the question: which came first, the bird or the wing? Here we seek to address this question by directly comparing key members of three of the major clades of paravians: anchiorni- thines, Microraptor and Archaeopteryx across their known size classes to see how they differ in terms of major flight-related parameters (wing loading; disc loading; specific lift; glide speed; takeoff poten- tial). Using specimens with snout to vent length (SVL) ranging from around 150 mm to 400 mm and mass ranging from approximately 130 g to 2 kg, we investigated patterns of inter- and intraspe- cific changes in flight potential. We find that anchiornithines show much higher wing- and disc- loading values and correspondingly high required minimum glide and takeoff speeds, along with lower specific lift and flapping running outputs suggesting little to no flight capability in this clade. In contrast, we see good support for flight potential, either gliding or powered flight, for all size classes of both Microraptor and Archaeopteryx, though there are differing patterns of how this shifts ontogenetically.
    [Show full text]
  • Three Gray Classics on the Biomechanics of Animal Movement
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Harvard University - DASH Three Gray Classics on the Biomechanics of Animal Movement The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Lauder, G. V., Eric Tytell. 2004. Three Gray Classics on the Biomechanics of Animal Movement. Journal of Experimental Biology 207, no. 10: 1597–1599. doi:10.1242/jeb.00921. Published Version doi:10.1242/jeb.00921 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:30510313 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA JEB Classics 1597 THREE GRAY CLASSICS locomotor kinematics, muscle dynamics, JEB Classics is an occasional ON THE BIOMECHANICS and computational fluid dynamic column, featuring historic analyses of animals moving through publications from The Journal of OF ANIMAL MOVEMENT water. Virtually every recent textbook in Experimental Biology. These the field either reproduces one of Gray’s articles, written by modern experts figures directly or includes illustrations in the field, discuss each classic that derive their inspiration from his paper’s impact on the field of figures (e.g. Alexander, 2003; Biewener, biology and their own work. A 2003). PDF of the original paper accompanies each article, and can be found on the journal’s In his 1933a paper, Gray aimed to website as supplemental data.
    [Show full text]
  • Conference Main Sponsors-2018
    Anatomical variation of habitat related changes in scapular morphology C. Luziga1 and N. Wada2 1Department of Veterinary Anatomy and Pathology, College of Veterinary and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania 2Laboratory Physiology, Department of Veterinary Sciences, School of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8558, Japan E-mail: [email protected] SUMMARY The mammalian forelimb is adapted to different functions including postural, locomotor, feeding, exploratory, grooming and defense. Comparative studies on morphology of the mammalian scapula have been performed in an attempt to establish the functional differences in the use of the forelimb. In this study, a total of 102 scapulae collected from 66 species of animals, representatives of all major taxa from rodents, sirenians, marsupials, pilosa, cetaceans, carnivores, ungulates, primates and apes were analyzed. Parameters measured included scapular length, width, position, thickness, area, angles and index. Structures included supraspinous and infraspinous fossae, scapular spine, glenoid cavity, acromium and coracoid processes. Images were taken using computed tomographic (CT) scanning technology (CT-Aquarium, Toshiba and micro CT- LaTheta, Hotachi, Japan) and measurement values acquired and processed using Avizo computer software and CanvasTM 11 ACD systems. Statistical analysis was performed using Microsoft Excel 2013. Results obtained showed that there were similar morphological characteristics of scapula in mammals with arboreal locomotion and living in forest and mountainous areas but differed from those with leaping and terrestrial locomotion living in open habitat or savannah. The cause for the statistical grouping of the animals signifies presence of the close relationship between habitat and scapular morphology and in a way that corresponds to type of locomotion and speed.
    [Show full text]