Bengaluru: A year after the Hesaraghatta Grassland on the city’s outskirts was notified as a conservation reserve, the last remaining grassland ecosystem of Bengaluru is steadily evolving into a thriving biodiversity hotspot, offering renewed hope for conservationists and naturalists.Underscoring this ecological revival is the recent sighting of the rare Eastern marsh harrier (Circus spilonotus) by city-based birdwatchers. The species, seldom recorded in southern India, is largely documented along the eastern coastline, particularly near Chennai, making its presence near Bengaluru highly unusual.The sighting was made by SNS Murthy and J Harish Kumar during their weekend exploration around Hesaraghatta Lake on March 15 and 26. What initially appeared to be a routine observation of raptors later turned into one of the rarest documented sightings in the region. Murthy said, “We started our walk around the lake at 4pm and spotted several winter migrants such as the Pallid harrier, Montagu’s harrier and Western marsh harrier, species commonly recorded in the area. But at around 6.05pm, we noticed a distinct individual that stood out for its bulkier build and different flight profile.”The duo managed to photograph the bird as it moved across the grassland before being chased away by other harriers. However, follow-up visits failed to relocate the individual.“We were unsure if it was just a variation of the Western marsh harrier or something more unusual. But experts whom we consulted and those who responded on the portal clarified it was indeed Eastern marsh harrier based on images, flight shots and consultation with raptor experts. A few even suggested the possibility of it being a hybrid with the usual Western marsh harrier, an extremely rare phenomenon with limited global documentation,” Murthy told TOI.“These raptors are known for their low, gliding hunting behaviour over marshy and grassland habitats, further highlighting the ecological suitability of Hesaraghatta’s recovering landscape,” Murthy added.A migratory species, the Eastern marsh harrier breeds across northeastern China, Mongolia, southeast Siberia and parts of Japan. “Their breeding season begins in April and is completed by the monsoon, with eggs hatching into young birds. Even though there has been news about interbreeding of Western and Eastern marsh harriers, there is very little documentation on this trend,” said a birder from south Bengaluru.The sighting not only highlights the ecological value of Hesaraghatta, but also reinforces the need to protect Bengaluru’s rapidly shrinking grassland habitats.
