Pretty Cochoas: Sparking Joy in the Himalayas

I remember being obsessed with the idea of spotting a cochoa when I began birding in class 10, ever since I came across the bird in my field guide. Two species, the green cochoa (Cochoa viridis) and the purple cochoa (Cochoa purpurea), occur in India. They are closely related to thrushes but extraordinarily coloured. I subsequently looked up their call on xeno-canto (a website that shares wildlife sounds) and found it magical. While the popular sentiment is to admire birdsong with complexity, there was something eerily beautiful about this simple, single-note call. I read Pritam Baruah’s trip report from the Mishmi Hills, where he describes coming across a pair of cochoas displaying and calling to each other in a bamboo forest. I imagined seeing these cochoas and hearing their flutey calls in a bamboo forest shrouded in mist as a truly magical experience.

Cochoas have been recorded mostly from higher altitudes (1,500 m and beyond) and are known to be “nomadic” in nature. Though their movement is not well studied, anecdotally, they are summer migrants. While rare or unrecorded in the western Himalayas, they are frequently sighted in several parts of the eastern Himalayas. To experience their magic, I would have to go to these mountains sometime.

Cut to a few years later in 2019 and I was doing field research in the rainforests of Assam’s Dehing Patkai Wildlife Sanctuary (now a national park). It was a normal day of fieldwork when Bablu da (my field collaborator), Abir (my batchmate), and I were returning to our base camp on a warm March morning. We were on the Hilikhali trail, running along the Tipam nala (small river). This trail has always been rewarding and was especially birdy as the weather had started warming up. During this time, the forest was flush with birdsong. We were particularly interested in this trail for the multitude of fruiting trees that attracted a plethora of wildlife. We have seen blue-eared barbets calling from the tall Bombax trees, flocks of brown hornbills feeding on Beilschmiedia fruits, gibbons almost peeing on me, and Malayan giant squirrels foraging. I also had many memorable experiences watching waves of mixed species flocks in the early mornings. That day, however, we were curious about the fleeting single-note flutey call I’d picked up while we were walking back. I did not believe it to be a cochoa because there was no way it would be at this altitude. But there it was, calling again. In no time, we spotted it — a beautiful purple cochoa perched on a Ficus tree not too far from us. We slipped on mud, scrambling to take out the camera from the bag and simultaneously focus our binoculars. It was messy, but the bird was patient. It flew to a different perch and sat there as we looked at it with amazement. None of us had expected to see this bird. 

Back home, a couple of years later, I decided to dig deeper into the question of whether cochoas are really high-altitude birds. Or do they come to lower elevations occasionally? What is the mystery behind them? I scoured old natural history notes, eBird records, went through the South Asian Bird Bibliography, and even wrote to the ornithology curator of the Natural History Museum, London. That’s how I discovered that the green cochoa is regularly reported from lower altitudes. Even the purple cochoa has been recorded a few times at lower altitudes, including a one-off recording of the bird from a golf course in Dhaka, Bangladesh (barely above sea level)! I also found that the bird likely makes seasonal movements across its range, probably tracking fruiting trees like Ficus, Beilschmedia, Litsea, Phoebe, etc. This was meticulously documented and published in natural history notes (this pattern of fruit tracking has been recorded for many frugivorous birds but never for birds like the cochoa). 

While ours was a one-off sighting, the cochoa (and my investigation of it) has taught me many things. Piecing together information from multiple sources (notes, records, museum specimens) also made me appreciate how important natural history information is in the field of biodiversity science. Yet, it is valued so little in the way we practice science today — as a strictly non-emotional, objective truth-seeking venture. It has also made me realise the importance of focusing on the common birds, the overlooked ones, and what answers they may hold towards comprehending biodiversity and its changes.

Additionally, the cochoa reminds me of my old spark of joy in the flutey single-note call. And I continue to build castles in my mind of seeing the bird someday in a mist-shrouded bamboo forest.