Blog Two: Northern Plains Gray Langur

Blog Post 2: Geographic Range, Habitat, Locomotion, & Ecology 

Nicole Anguiano-Garcia   


                                             Northern Plains Gray Langur | BirdForum

Geographic Range & Habitat Use:

    Northern plains gray langurs inhabit Southern Asia. Native populations are found across Eastern India, south of the Himalayas. They occupy an area that spans over 1,900 km, between major rivers in India including the Tapti River, the Narmad, and the Krishna Rivers (Rahman et al., 2015). They are also found in Western Bangladesh, although this population is believed to be introduced by humans (Botting, 2019). 

Northern plains gray langur range. IUCN, 2021. 

Their natural habitat includes tropical dry and deciduous forests (Botting, 2019). These biomes are characterized by having long dry seasons that are followed by heavy rainfall and are places where trees are losing their leaves at the end of each growing season (Petruzzello, 2025). However, the majority of northern plains gray langurs are found within human-populated landscapes. Recall from the last blog that this species of langurs is considered sacred and is often left alone. This is likely why so many populations co-exist with humans. Home ranges, which do not move, are typically between 0.07 to 22 km2. Many bachelor groups tend to have larger home ranges than other groups for the purpose of finding mates (Gron, 2008). 

Example of tropical dry deciduous forests that can be found in India. Picture from Sharad Vats, Tiger Safari India.

Locomotion: 

Northern plains gray langurs partake in palmigrade quadrupedalism. This means that gray langurs walk on all four feet and place their whole palm on the ground as they walk. Due to their type of locomotion, gray langurs have substantial wrist dorsiflexion, or the ability to bend their wrist up towards the back of the hand (Patel & Carlson, 2007). They spend half of their time on the ground and the other half in arboreal settings or tall-man made structures. They also tend to run instead of walk, and are excellent climbers. 

Northern Plains Gray Langur - Facts, Diet, Habitat & Pictures on Animalia.bio
Notice how this langur's palms are on the ground. Picture from Animalia. 


Ecology: 

Due to their distribution, the diet of northern plains gray langurs varies depending on availability. For the most part however, they are mainly folivores, though they do tend to consume fruits and flowers if encountered. Feeding is usually done during the day as northern plains gray langurs are diurnal (Botting, 2019). 


To demonstrate their feeding ecology, I will highlight a 2015 study by Md Rahman, in which researchers observed 8 groups of northern plains gray langurs in Bangladesh to see what their feeding habits looked like. The study found that the langurs spent approximately 60% of their time feeding, with the majority of that time dedicated to consuming leaves (57.5%). This was followed by fruits (20.7%), buds (8.5%), flowers (3.9%), and bark (0.5%). Additionally, provisioned food items given by humans made up for 8.7% of their diet, while non-plant food sources, such as soil, water, and fungi, made up 1%. The research also revealed a significant difference in time spent feeding on natural foods between adult males and adult females, with females spending considerably more time feeding than males. 


Graph from Rahman et al. Visualization of time spent feeding on different food items based on study, total of 303 hours.  



Video of a northern plains gray langur eating :D

Ecological Role: 

Northern plains gray langurs play an ecological role in seed/food dispersal. Since fruits are a major source of their diet, gray langurs aid in seed dispersal by scattering them once they have passed through their digestive system. Any food scraps that they may drop is also a source of food for cattle and deer (Botting, 2019). 




Works Cited: 


Botting, J. (2019). Northern Plains Gray Langur: Semnopithecus entellus. New England Primate Conservancy. https://neprimateconservancy.org/northern-plains-gray-langur/


Gron, K. (2008). Primate Factsheets: Gray langur (Semnopithecus). Wisconsin National Primate Research Center. https://primate.wisc.edu/primate-info-net/pin-factsheets/pin-factsheet-gray-langur/


Patel, B. P., Carlson, K.J. (2007). Bone density spatial patterns in the

distal radius reflect habitual hand postures adopted by quadrupedal primates.

Journal of Human Evolution (2), 130-141.

https://doi.org/10.1016/j.jhevol.2006.08.007


Petruzzello, M. (2025). Tropic dry forest ecology. Britannica. https://www.britannica.com/science/tropical-dry-forest

Rahman, M. M., et al. (2015). Feeding Ecology of the Northern Plains Sacred Langur Semnopithecus entellus (Dufresne) In Jessore, Bangladesh: Dietary Composition, Season and Age-Sex Differences. Asian Primates Journal 5(1), 24-39. 

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