Energetic costs of locomotion in bears: is plantigrade locomotion energetically economical?
J Exp Biol
; 221(Pt 12)2018 06 19.
Article
em En
| MEDLINE
| ID: mdl-29921569
ABSTRACT
Ursids are the largest mammals to retain a plantigrade posture. This primitive posture has been proposed to result in reduced locomotor speed and economy relative to digitigrade and unguligrade species, particularly at high speeds. Previous energetics research on polar bears (Ursus maritimus) found locomotor costs were more than double predictions for similarly sized quadrupedal mammals, which could be a result of their plantigrade posture or due to adaptations to their Arctic marine existence. To evaluate whether polar bears are representative of terrestrial ursids or distinctly uneconomical walkers, this study measured the mass-specific metabolism, overall dynamic body acceleration, and gait kinematics of polar bears and grizzly bears (Ursus arctos) trained to rest and walk on a treadmill. At routine walking speeds, we found polar bears and grizzly bears exhibited similar costs of locomotion and gait kinematics, but differing measures of overall dynamic body acceleration. Minimum cost of transport while walking in the two species (2.21â
Jâ
kg-1 m-1) was comparable to predictions for similarly sized quadrupedal mammals, but these costs doubled (4.42â
Jâ
kg-1 m-1) at speeds ≥5.4â
kmâ
h-1 Similar to humans, another large plantigrade mammal, bears appear to exhibit a greater economy while moving at slow speeds.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Postura
/
Ursidae
/
Metabolismo Energético
/
Locomoção
Tipo de estudo:
Health_economic_evaluation
Limite:
Animals
Idioma:
En
Revista:
J Exp Biol
Ano de publicação:
2018
Tipo de documento:
Article