The cuckoo Cuckoo

When I was living in Pune, the window of my room opened near a hedge. The hedge was lush green and had many trees. The tree closest to my window was that of a fig, (umber, उंबर in Marathi). Now throughout the day and the night, a variety of fauna visited the tree. Avians, insects, mammals all of them benefitted from the tree.
During the prime of the fruiting season, one would get an aroma of ripe fruits in the middle of the night. The closest smell I can think of is that of a very sweet and ripe apple. Nothing else comes close. I would wonder why does this smell manifest in the middle of the night. Then I discovered that there would be fruit bats munching on these delicious fruits, and the tearing of the fruits would give this aroma. During the day, various other birds including crows, cuckoos, mynahs, some times hornbills too, along with the resident squirrels. So this tree was full of life. A couple of crows used to sit on the tree for hours, caressing each other. Some love couple it was.
But the reason I am writing this post is because of a cuckoo the Asian koel (Eudynamys scolopaceus), a cuckoo who was a cuckoo. Now, as a noun, the cuckoo refers to the bird, but as an adjective, it refers to someone who is mad. Now, what does a cuckoo mean? It means a mad cuckoo. Now one would hear the cucu of the cuckoo during their mating season at the start of the summer, we find nothing odd. In fact, the call of the cuckoo signifies the season change, and for rest of the year, the cuckoo stays relatively silent.

Being familiar birds with loud calls, references to them are common in folklore, myth and poetry. It is traditionally held in high regard for its song … Wiki

And mostly one would hear the cuckoo only during the day. All this being said, I come to the protagonist of the post.
This one cuckoo was mad. I would say this because it would sit on this fig tree and sing in the harshest possible way, much higher notes than usual melodious tone, in the middle of the night. At 1 AM, at 3 AM at any time in the night. The cuckoo would sit right next to the branch of the tree which was closest to my window and sound the alarm. When I first heard it, I woke up thinking that the world is coming to an end or some epic disaster has occurred. The cuckoo from hell. I looked at it from the window, hoping that its eyes are glowing red with hellfire. I could not make sense of what was happening. The intensity and the harshness of the vocalization were like a shock given to me. Once woken, I could not sleep due to the continuous assault on my auditory senses. That night I slept, uneasily, after a few hours almost at the start of the dawn.
This event repeated over many other days.  But over many episodes, I got used to this. It was like my internal cognitive mechanisms created filters for ignoring this. Only on an occasional off day, I would be awakened by the calls. Some of my friends, who had the misfortune to visit me during those days would get the jolt to be woken in the middle of the night.
I don’t know whether this was normal behaviour of the cuckoo. I am sure avian experts would be able to put more light on this, but for me, it was cuckoo who had gone cuckoo.