Like everyone else, I was familiar with "ulluk" as a swear word since my childhood.
Who knows what it means- stupid perhaps?
If so, I am sure I had seen ulluks in my life many a time, especially when I stood in front of a mirror.
But I could not care any less until I saw a real one.
Years ago, a friend and I started hiking in the jungles of the country.
During the adventures through Lawachhara National Park, we often confronted the barking deer, locally known as maya horin.
So we decided we wanted a photo of this elusive species.
But before you could aim your camera, in a blink of an eye, the deer would vanish in the dense bushes like an illusion, to justify the Bangla name given to it.
One day, after several failed attempts to take a photo in a pre-dawn-to-midday drive, we were coming out of the jungle as every fauna in the jungle fell silent.
We were almost on the outskirts of the forest when we heard a human voice calling "oi" (hey).
We turned back, but seeing no one, headed back to the direction of nearby road connecting Srimangal and Kamalganj, which cuts through the forest.
We knew there were pockets of lemon gardens inside the forest, and people worked there. We probably could not see them because of dense foliage.
Then, we heard the call again.
As we turned again, we saw the source.
An animal covered in black fur was hanging from a lower brunch of a tree, enthusiastically staring at us. It appeared like a monkey, but was clearly not one.
"Wow, is this a chimp?" we thought to ourselves.
But we knew chimpanzees are not native to Bangladesh, or even Asia.
The primate posed for our cameras for several minutes and then climbed up the tree.
It brachiated from this tree to that tree and then lost interest in us.
In the meantime, we started suspecting that it was a real life ulluk- a hoolock gibbon.
As we returned to mobile network coverage, a quick Google search confirmed our assumption.
From then on, we saw dozens of hoolock families in Lawachhara.
Although they are a bit shy, it is not difficult to find them thanks to their distinct call that can be heard from about a kilometre away.
When you locate them, just stay there, do not talk, do not disturb them, and you will get to watch them do their thing- that is the rule of thumb.
Watching wildlife always fascinated me.
Of them all, hoolocks occupy a special place in my mind.
It is not just because IUCN has declared hoolocks as Critically Endangered, they are actually very interesting.
You will always find two black and brown hoolocks close together, with babies with milky white or buff-coloured hair.
The black one with remarkable white brow is the male and the grey-brown one is female.
Young hoolock's colour changes to black after six months of age if it is a male, and the female turns grey-brown.
Hoolocks live together in monogamous pairs and they are very territorial.
They are thought to use their call to keep other hoolocks away from respective territory, and to connect to family members.
Why such a shy animal descended to a low branch and called to draw our attention that day remained a mystery.
But I believe, when you fall in love with nature and wildlife, strange things happen; and nature starts to open up to you.
From then on, I never used ulluk as a swear word.
Ulluks are just too cute for that.