Division of Conservation and Science, Cleveland Metroparks Zoo, Cleveland, OH, United States of America.
Department of Biology, Case Western Reserve University, Cleveland, OH, United States of America.
PLoS One. 2022 Jun 27;17(6):e0270570. doi: 10.1371/journal.pone.0270570. eCollection 2022.
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.
马氏树袋鼠（Dendrolagus matschiei）是一种濒危的树栖有袋动物，原产于巴布亚新几内亚。由于其栖息地主要在偏远的云雾森林中，且具有隐蔽性，因此对其行为和生态的详细实地研究非常有限。尽管自 20 世纪 50 年代以来，这种物种就一直在人类的照料下，但它的许多生物学特性仍然未知。由于健康和生殖问题，目前的圈养种群无法维持，这些问题主要源于饮食和肥胖问题。为了更好地评估能量需求与能量摄入之间的潜在差异，我们试图：1）量化两种圈养马氏树袋鼠（体重为 9.0-9.7 公斤）在以大量树叶状饲料为主的饮食下的总能量消耗（TEE）；2）在 14 个月的时间里量化食物和宏量营养素的摄入量、表观干物质宏量营养素消化率和可代谢能量（ME）的摄入量；3）由于提供的树叶状饲料种类的季节性差异，测试 ME 摄入量的季节性变化。使用双标记水法，我们确定了雌性（288 千卡/天）和雄性（411 千卡/天）的 TEE。结果表明，马氏树袋鼠的平均 TEE 明显低于有袋动物和有袋目动物的预期值（即，基于体重的预期值的~60%）。雌性和雄性的平均计算出的 ME 摄入量分别为 307 千卡/天和 454 千卡/天。ME 摄入量存在显著的季节性差异，主要是由于秋季摄入量减少。这些结果表明，马氏树袋鼠可以在富含纤维和以树叶为主的饮食下保持健康的体重和状态。我们的研究结果为树袋鼠的能量学和生理学提供了重要的见解，并可应用于帮助重新制定圈养设施中马氏树袋鼠的饮食，以提高种群的健康和可持续性。
