MS, University of Cincinnati, 2010, Arts and Sciences : Biological Sciences
Arboreal habitats pose several challenges for locomotion resulting from narrow cylindrical surfaces, steep inclines, and branches that obstruct straight paths. I determined whether different diameters, inclines, or complexity of branches affected speed of movement and path choice for a semi-arboreal rodent (Peromyscus leucopus). We videotaped laboratory trials of locomotor performance of mice running on cylinders with diameters of 10, 16, 28, 54, and 116 mm, oriented at inclines of 0° and 45° (uphill and downhill), and a subset of diameters horizontally oriented that had secondary branches (pegs) every 10 or 20 cm. For similar branch diameters the speeds of mice were usually faster when running horizontally rather than on inclines, and pegs decreased running speed compared to unobstructed surfaces. When pegs were present, the frequency and duration of pauses increased, speed decreased with decreased distance between pegs, and larger diameters enhanced speeds by reducing the need of mice to use a convoluted trajectory to avoid the pegs. The difficulties of maintaining balance and avoiding toppling seem likely to have caused much of the decrease in speed and increased amounts of pausing. Thus, branch diameter, incline, and the presence of and spacing of secondary branches often had widespread and significant interactive effects on locomotor performance, and additional experiments revealed some of these factors significantly influenced the routes chosen by mice.
Committee: Guy Cameron PhD (Committee Chair); Bruce Jayne PhD (Committee Member); Kenneth Petren PhD (Committee Member)
Subjects: Ecology