Locomotion in the fastest rodent, the mara Dolichotis patagonum (Caviomorpha; Caviidae; Dolichotinae)

SILVA CLIMACO DAS CHAGAS KARINE; VASSALLO ALDO IVÁN; BECERRA FEDERICO; ECHEVERRÍA ALEJANDRA ISABEL; FIUZA DE CASTRO LOGUEIRO MARIANA; ROCHA-BARBOSA OSCAR

Mastozoología Neotropical

Sociedad Argentina para el Estudio de los Mamíferos

Lugar: Mendoza; Año: 2019 vol. 26 p. 65 - 79

Although rodents can move fast, they are in general considered non-cursorial mammals, with the notable exception of some species within the suborder Caviomorpha which are convergent with small-sized artiodactyls. The mara, Dolichotis patagonum (average body mass: 8 kg), is a member of the family Caviidae which occupies relatively open habitats in southern South America, and shows remarkable anatomical traits associated to fast locomotion. These include elongated limbs, especially their distal segments, a digitigrade footposture, and muscles attached near limb joints. However, its locomotor behavior is not yet well understood. Here we focus on the mara?s locomotor kinematics, especially on the gaits performed at different speeds, and providenew data and analyses. By means of high-speed video-recordings, it was observed that maras use lateral walk at low speeds and pace at moderate speeds. By implementing half bound maras reached their maximum speed at 36 km/h, i.e. 14.3 body length/s. It was also confirmed that maras are able to perform pronking, a probable alarm or fitness signal. Kinematic parameters (e.g. duty factor; stride frequency), and comparisons of running speed with other caviomorph and artiodactyl species are also provided.