Effects of food availability and climate on the activity budget of Shortridge's langur (Trachypithecus shortridgei) in the Drung Valley, Gaoligong Mountains, China

Jia-Yang Zhang; Ying-Chun Li; Yin Yang; Paul A Garber; Ke-Guo Han; Zhi-Pang Huang; Liang-Wei Cui; Wen Xiao

doi:10.1002/ajp.23467

Effects of food availability and climate on the activity budget of Shortridge's langur (Trachypithecus shortridgei) in the Drung Valley, Gaoligong Mountains, China

Am J Primatol. 2023 Apr;85(4):e23467. doi: 10.1002/ajp.23467. Epub 2023 Jan 23.

Authors

Jia-Yang Zhang^{1

2

3}, Ying-Chun Li⁴, Yin Yang^{3

5}, Paul A Garber^{3

6}, Ke-Guo Han^{1

7}, Zhi-Pang Huang^{3

8}, Liang-Wei Cui^{1

3}, Wen Xiao^{3

8}

Affiliations

¹ Key Laboratory for Conserving Wildlife with Small Populations in Yunnan, Southwest Forestry University, Kunming, Yunnan, China.
² Key Laboratory of Forest Disaster Warning and Control of Yunnan Province, Southwest Forestry University, Kunming, Yunnan, China.
³ International Center for Biodiversity and Primates Conservation, Dali, Yunnan, China.
⁴ Nujiang Administration Bureau, Gaoligongshan National Nature Reserve, Liuku, Yunnan, China.
⁵ Institute of International Rivers and Eco-security, Yunnan University, Kunming, Yunnan, China.
⁶ Department of Anthropology, Program in Ecology, Evolution, and Conservation Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
⁷ Management and Conservation Bureau of Wenshan National Nature Reserve, Wenshan, Yunnan, China.
⁸ Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, Yunnan, China.

PMID: 36688347
DOI: 10.1002/ajp.23467

Abstract

Food availability and climate represent environmental factors that affect species' social behavior, ranging patterns, diet, and activity budget. From August 2012 to September 2013, we examined the effects of seasonal changes in food availability, temperature, and rainfall on the diet and behavioral ecology of Shortridge's langur (Trachypithecus shortridgei) an Endangered primate species inhabiting moist evergreen broadleaf forests in the Eastern Himalayas. Our field site represents the northernmost latitudinal distribution of this species. Data were collected using scan sampling at 10 min intervals, and analyzed based on generalized linear models. The results indicate that the langurs experienced two feeding peaks (9:00 and 17:00) and two traveling peaks (10:00 and 19:00) during each day. Periods of rest, mainly occurred between 10:00 and 13:00, and overnight. Feeding accounted for 38.5% of the daily activity budget, followed by resting (35%), traveling (24.5%), and socializing (2%). During periods when young leaves were most available, the langurs increased feeding time on young leaves (35% vs. 4%). During periods of maximum fruit availability, the langurs decreased total time spent feeding (36.6% vs. 40.4%), devoted more time to traveling (28.1% vs. 21%), and increased time spent consuming fruit (49.1% vs. 11.8%). During the winter, the langurs increased their consumption of mature leaves (44.5%) and reduced time spent traveling (20.2% vs. 25.4%). Overall, time spent resting was greatest in the spring (47.5%), time spent feeding was greatest during the summer (51.1%), and time spent in traveling was greatest in the autumn (33.2%). The frequency of social interactions remained relatively constant throughout the year. Foraging effort was greatest in the summer, when fruits dominated the diet. Like other species of temperate langurs, T. shortridgei devoted less time to resting, more time to feeding, and was characterized by a greater year-round foraging effort than tropical/subtropical langurs.

Keywords: Trachypithecus shortridgei; activity budget; dietary strategies; foraging effort; seasonality.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
China
Diet / veterinary
Feeding Behavior
Forests
Fruit
Presbytini*
Social Behavior