Abstract 282 – Metabolic rates of two co-existing Ursidae species: Asiatic black bears and sun bears

Zachary David, Megan Owen, Barbara Durrant, Vuthy Choun, Nev Broadis, Kirsty
Officer, Michael Griego, John Whiteman

Metabolic rate (MR) is a fundamental property that reflects the total energy demand for all
aspects of organismal function, from immune performance to reproduction. As a result,
understanding metabolic rate is a key aspect of bear conservation. Asiatic black bears (Ursus
thibetanus) and sun bears (Helarctos malayanus) are considered “Vulnerable”; however, little is
known about their metabolism. Resting metabolic rate (RMR) is a measurement of the total
amount of energy necessary for self-maintenance and therefore is an essential component of
field metabolic rate (FMR). We measured RMR of captive individuals at the Cambodian Bear
Sanctuary supported by Free the Bears and located within the Phnom Tamao Wildlife Rescue
Center, Cambodia. Using positive reinforcement, bears were trained to rest in a custom-built
metabolic chamber connected to sensors which continuously recorded O2, CO2, and water
vapor concentration. Measurements for sun bears in July were 0.55 – 0.78 ml O2 g-1 hr-1
(mean = 0.63) and in January/December were 0.42 - 1.24 ml O2 g-1 hr-1 (mean = 0.83). RMR for
Asiatic black bears in July ranged from 0.26 – 0.48 ml O2 g-1 hr-1 (mean = 0.35) and in
January/December ranged from 0.29 – 0.55 ml O2 g-1 hr-1 (mean = 0.35). Analysis is currently
ongoing to assess the influence of activity and nutritional state of measured individuals and
comparability to previously measured Ursidae species.