By Joey Lara
Rhesus macaques (Macaca mulatta) are known for their resiliency and ability to acclimatize to a wide array of landscapes, climates, and proximities to human population centers. As ecological generalists, these monkeys are able to form thriving populations even under non-ideal conditions.
Rhesus monkeys’ ability to survive despite adversity can be attributed in part to several key factors:
-They exhibit flexibility in their diets and can effectively digest tough fibers, ripe and unripe fruits, and hard nuts among other food sources.
-They form communities in which individuals protect one another, alert each other to dangers and opportunities, and transfer valuable knowledge about their environment.
-They have a high ability to solve recurring problems.
-Their varied means of using their bodies to traverse their environment allows them to compensate for acute and chronic physical limitations that arise.
-In my opinion, they are fortified by their sheer obstinance
Hanuman, or Hanu, is a prime example of rhesus macaques’ resiliency.
At 21 years old, Hanu has lived a turbulent life. Among his biggest challenges today is navigating his diabetes. Hanu requires extra care for us to manage his diet and keep his urinary glucose and ketone levels in check. While some days are better than others, Hanu persitantly presses on, often apparently unfazed by the disease. Among the complications due to diabetes that Hanu experiences is a mobility impairment due to diabetic neuropathy. This has led to some visible weakness and decreased range of motion in his legs.
Despite this limitation, and his old age, Hanu finds a way to traverse any new furniture installed in his enclosure, especially if there are leafy greens to be found by climbing on something new. Oftentimes, Hanu will climb by his own unique style, wherein he makes leaps to different furniture items by keeping his feet together and “frog-hopping” with assistance from his stronger upper body. While he may not be as graceful as our resident acrobat, Batman, Hanu still readily makes attempts to climb on new structures and has even learned how to scale the ceilings!
While some monkeys prefer to climb on familiar materials, like the scalable steel that makes up the walls of their enclosures, Hanu has grown most comfortable on natural oak branches harvested from fallen trees around the sanctuary premises. His favorite midday resting spot is now along one of these branches, on which he has learned to balance and sleep simultaneously.
It seems that the longer that Hanu is here at Primates Inc, the more comfortable and confident he becomes. When I began working at Primates Inc, Hanu was a fairly new resident who was still early on in the process of gaining trust with the human caregivers and volunteers here. If one so much as looked in his direction from afar, he would give his characteristic threat stare and head bob, telling the onlooker, “leave me alone, don’t even pay attention to me”. Over the past two years, Hanu has really grown in his trust of humans and the security of our routines at Primates Inc.
There is no doubt that part of that trust has come through providing him with new opportunities to engage with enrichment puzzles and through giving him his favorite treats. He has responded positively to being given new healthy food options (like his new favorite, jicama) as well as locally available food options like fresh grass, oak leaves, and acorns. Now, Hanu will often follow me outside and sit in his tunnel while watching me, waiting to receive some fresh grass or oak. He just waits patiently and calmly until I give him his treat and then chomps away at it.
Now, Hanu is embarking on the next chapter of his life at our sanctuary. We have just finished building him a new outdoor enclosure; our largest one yet! It is full of oak logs and branches to climb to his heart’s content, with plentiful space to forage through the budding grass, catch grasshoppers, drink fresh water from his pool, or just relax on a branch up high and watch the world around him.
Shortly after his introduction to the enclosure, Hanu was already exploring the new space, taking in the new views, and foraging for grass seed on the ground. He is now comfortable climbing on and even leaping between structures in this new addition to his home.
Despite his unique challenges and reservations, Hanu seems determined to exhibit more monkey-like behaviors at every turn. We are so happy to provide Hanuman with the opportunities to further develop his climbing abilities, musculature, trust in humans, affinity for a naturalistic diet, and a sense of tranquility.
