Balancing the scales: Preliminary investigation of total energy expenditure and daily metabolizable energy intake in Matschie’s tree kangaroo (Dendrolagus matschiei)

Abstract

Matschie’s tree kangaroo (Dendrolagus matschiei) is an endangered arboreal marsupial native to Papua New Guinea. Detailed field studies of its behavior and ecology are scarce due largely to its occupation of remote cloud forests and cryptic nature. Although this species has been in human care since the 1950s, much of its biology is still unknown. The current ex situ population is not sustainable due to health and reproductive problems, believed to stem largely from issues with diet and obesity. To better assess potential discrepancies between energy requirements and energy intake, we sought to 1) quantify total energy expenditure (TEE) of two zoo-housed Matschie’s tree kangaroos (body mass = 9.0–9.7 kg) on a diet composed largely of leafy browse; 2) quantify food and macronutrient intake, apparent dry matter macronutrient digestibility, and metabolizable energy (ME) intake over a 14-month period; and 3) test for seasonal changes in ME intake due to seasonal differences in the varieties of leafy browse offered. Using the doubly labeled water method, we determined TEE for the female (288 kcal day -1) and male (411 kcal day -1). Resulting mean TEE was well below the expected value for marsupials and macropods (i.e., ~60% of the expected value based on body mass). The mean calculated ME intakes for the female and male were 307 kcal day-1 and 454 kcal day-1, respectively. There were significant seasonal differences in ME intakes, driven by reduced intake in the autumn. These results demonstrate that Matschie’s tree kangaroos can be maintained at healthy body weights and conditions on fiber-rich and browse-heavy diets. Our findings contribute important insights into tree kangaroo energetics and physiology and can be applied to help reformulate the diet of Matschie’s tree kangaroos at captive facilities to improve population health and sustainability.

Effects of honey locust seed pods on the behavior and nutrient intake of zoo‐housed François langurs and prehensile‐tailed porcupines

“…One example of such practice is the provisioning of leafy or woody browse. In most facilities, browse is given as part of an enrichment regime, though some institutions now use browse as a staple diet item for various herbivorous species (Campbell et al, 2001;Dunham et al, 2022;Hatt & Clauss, 2006;Hatt et al, 2005;Nijboer & Dierenfeld, 1996;Nijboer et al, 2003).…”

Seasonal Diet Composition of Goitered Gazelle (Gazella subgutturosa) in an Arid and Semi-Arid Region of Western China

“…Understanding the ecology of herbivores is crucial for developing strategies that promote their sustainability [ 1 ]. As a fundamental aspect of ecological research, diet contributes to the substantial body size variation observed in herbivore populations [ 2 ] and provides valuable basic information for estimating environmental capacity [ 3 ], calculating energy metabolism [ 4 ], assessing habitat suitability [ 5 ], analyzing intra- and interspecific relationships [ 6 ], and formulating protection strategies [ 7 ]. Additionally, seasonal dietary changes play a significant role in the avoidance of seasonal resource bottlenecks by herbivores [ 8 , 9 , 10 ].…”