Jumping ability in the arboreal locomotion of didelphid marsupials

DELCIELLOS, A.C.; VIEIRA, M.V. 2009. Jumping ability in the arboreal locomotion of didelphid marsupials. Mastozoología Neotropical 16(2):299-307.

Abstract. Didelphid marsupials are considered to cross discontinuities between arboreal supports using a cautious locomotion, using the prehensile tail as fifth limb. However, this ability was only described for Caluromys philander. We describe and compare the locomotory performance and postural behavior of seven species of didelphid marsupials crossing discontinuities between artificial supports representing arboreal gaps. Individuals were captured in areas of Atlantic Forest in Rio de Janeiro State, Brazil. Animals were stimulated to jump from a fixed horizontal support one meter above the ground to an inclined support of same diameter. We measured the maximum distance of jump (40, 60, 80 or 100 cm) and reach or distance actually reached by the jump. Arboreal species (Marmosops incanus, Gracilinanus microtarsus, Micoureus paraguayanus, and C. philander) jumped longer distances and had longer relative reach in jumps than semi-terrestrial species (Didelphis aurita, and Philander frenatus). Only the specialized terrestrial Metachirus nudicaudatus did not jump in the tests. The relation between absolute reach and body size was weak and non significant. This study did not corroborate the view that didelphid marsupials cross discontinuities between arboreal supports only through a cautious locomotion, without jumping. On the contrary, we identified patterns of jumping performance and behavior of didelphid marsupials related to their use of the vertical strata.