In August 2021, I did a re-union cum wildlife exploration in Bhadra tiger reserve with three of my Environmentalist friends who were also my Post Graduation class mates. It was full monsoon when we visited the forest.
I came back to Bhadra again to fulfil the customary requirement of a wildlife photographer to capture the images of river terns.
Needless to say that, it was a photography boot camp. The skipper was none other than M.V. Shreeram of Darter Photography. The sharp contrast of that Bhadra trip with the previous one was not opting for a single jeep safari. In the middle of April 2022, forests of Karnataka were warned out in scorching heat and less rainfall. Gasping big mammals of Bhadra’s parched forest were drawn out from their dense foliage hideout, in search for water sources.
In spite of the news of frequent sighting of leopards and tigers, in Bhadra tiger reserve, the participants of that boot camp decided to go for all four-boat safaris in the backwater of Bhadra River, to ensure capturing their best images of river terns.
Hardly such occasion arises even in any wildlife photography boot camp, in a tiger reserve, where wildlife photographers willingly sacrifice opportunity of shooting tigers for other “less important subjects”.
There was one particular island which was emerged enough to provide sufficient nesting ground to river terns. Cacophony erupted out of the colony of river terns hit our ears, moment that islands were visible from our boat. When we were near to the edge of that island, where waves of Bhadra backwater were caressing the rocky land, flocks of thousand river terns drew our attention.
Initially it was very difficult to observe their behaviour. Numerous avifauna of yellow bill and red legs were all over the islands, snooping into water and hovering in the sky. The black cap on all of them suggested it was a huge breeding colony of one of the vulnerable (as per IUCN) birds of this subcontinent.
Our first three hours of afternoon boat safari just went past to get accustomed to align our camera movement with their erratic flying pattern and chaotic behaviour. Making sharp images of those birds turned out to be really challenging. At times, it was appeared that even two morning safaris of two hours each and two afternoon safaris of three hours each would not be adequate to learn how to make images of river terns.
In couple of hours, we all were completely overwhelmed by these abrupt and over-ornate feathered friends.
However, from the third boat safari onwards we started getting used to with their behaviour pattern. Our eyes-hands coordination synchronized with their flying, taking off and landing sequences. We started realizing what they were up to in that island surfaced out of Bhadra backwater.
The rocky surface of the island was not just the favourable nesting ground but also helped camouflage for their eggs, chicks and young ones. Being on islands, the birds were also relatively safe from the predators. Although there was occasional visit of few resident osprey and brahminy kites.
The careful watching unfolded interesting stories of courtship and parenting of these graceful birds. The backwater is paradise of nutrition reach small freshwater fishes, which are favourite of these birds. The speed at which they were fishing was hard to notice. The fishing activity was not just for their survival but was also part of their courtship ritual. The male river terns not only fish for themselves but also fish for their potential mates.
Calling this as “ritual” is quite appropriate. The males were found to wash the fish caught by them in the backwater of Bahdra before they offered them to their potential mates. They washed themselves as well before they approached the females. Once the catch was accepted by the females, it was considered as consent for sex. Feeding is just the beginning of courtship. The females were found to lower their bodies and flutter their wings as acceptance. The males on the other hand were lowering their wings and lifting their heads.
Although securing a mating partner by a male river tern does not eliminate possibility of any further challenges by other male. We saw mating between a pair lasted only for few seconds. But those few seconds were not without any trouble, as another male was still trying his luck with that same female, with a silver fish on his bill. He did everything possible to disrupt the love making of that pair.
Few nesting were also discovered as birds were found sitting on grounds or behind rocks for long time, incubating the eggs. For river terns the incubation process typically lasts for about three weeks and task is shared by both parents. Chicks are as usual curious and while venturing out towards the edge of island often they put themselves in danger of being hunted by opportunist predators, like coral or cat snakes, hiding in backwater.
Therefore, parents were found to keep watchful eyes on them. Generally, one of them goes for fishing while the other stands on guard. When the one comes back with a catch that could be for both the chicks as well as the one standing on guard. Small fishes or insects are the part of diet of chicks.
During our visit in the early summer, nesting just started and chicks were yet to hatch. Although we saw couple of chicks and one juvenile. The juveniles have a brown head, brown-marked grey upperparts, grey breast sides and white underparts. The bill is yellowish with a dark tip.
Terns also have other neighbours as we saw few wagtails, three species of cormorants, black headed ibis, darters and pratincoles.
The unpredictable monsoon and sudden water level rise leads to death of lot of river tern chicks every year, as those islands in Bhadra backwater hardly have any protection from lash of rains and get submerged quickly with rising water level. Once monsoon starts, the chicks, which hatched early, can only make it through heavy rain along with adult river terns, to come back again as grown up in next year.
Bhadra always beckons for their re-union.