Warm February and wet March hasten butterflies’ arrival in Delhi

Since February end, butterflies like Painted Lady, Blue Tiger, Asian Cabbage White, and Large Cabbage White have been seen in large numbers across Delhi-NCR

With a relatively warm February in Delhi-National Capital Region, followed by a wet March with three times the normal rainfall, butterfly enthusiasts have spotted butterfly species migrating to Delhi one to two months earlier than usual.

The Tropical Indian Fritillary, a butterfly seen in the Himalayas, is another rare sighting in Delhi-NCR, and was spotted at a roundabout near Janpath. (Chandra Bhushan Maurya)

Since the end of February, butterflies such as the Painted Lady, Blue Tiger, Asian Cabbage White, and Large Cabbage White have been seen in large numbers in several locations across Delhi-NCR. According to experts, these butterflies typically breed in the Himalayan region in April and then migrate to Delhi following some pre-monsoon showers.

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Surya Prakash, a zoologist studying butterflies in the region for more than three decades, believes this year’s climatic fluctuations have triggered early migration. “While these butterflies breed in the Himalayan region in April, we started seeing them around the end of February and are now being seen in large numbers. The Large Cabbage White and Asian Cabbage White were still missing at the same time last year, but high temperatures in February followed by a wet March has led to the early bloom of flowers, which may have also caused these butterflies to breed early, as caterpillars can sense temperature changes even in the pupa stage,” said Prakash, a retired professor from Jawaharlal Nehru University (JNU).

These observations, according to Prakash, are fairly consistent across the NCR at locations such as JNU, Sanjay Van, Asola Bhatti Wildlife Sanctuary, both Aravalli Biodiversity Parks in Gurugram and Delhi, Surajpur wetlands, Dhanauri, and Mangar.

The butterfly breeding and migration cycle coincides with flower blooming, allowing them to feed on nectar. Pollination occurs as a result. Most of these flowers bloom during the summer.

From October to December, butterflies migrate from the plains to the higher reaches and Ghats, before returning to the plains between April and June. Butterflies typically arrive in Delhi from the Himalayas, where they breed until April and May.

However, early or delayed migration can harm any butterfly species in the long run. According to Faiyaz Khudsar, a scientist in charge of the Delhi Development Authority’s biodiversity parks programme, “It’s possible that the temperatures are high, but the host plants or flowers aren’t mature enough to reproduce. Such changes in weather patterns are fine for a year or two but can impact butterflies in the long run,” he said.

The Tropical Indian Fritillary, a butterfly seen in the Himalayas, is another rare sighting in Delhi-NCR.

According to Chandra Bhushan Maurya, a birder and butterfly enthusiast, the Tropical Indian Fritillary was spotted at a roundabout near Janpath, and that early flower bloom, combined with good rain, may have facilitated early breeding this year.

“February was warm, but rains in March caused most flowers to bloom, allowing these butterflies to breed in abundance. As a result, even the resident butterfly population, such as Plain Tiger, Striped Tiger, Pioneer, and Pea Blue, is larger than usual,” he said.

According to Khudsar, the presence of butterflies indicates a healthy environment and ecosystem. “Their population is an excellent predictor of climate change. Their role in pollination is also vital,” Khudsar added.

Prakash believes that planting abundant flowers as part of the G-20 summit preparations in Delhi has also contributed to the increased population of butterflies. “Because the Tropical Indian Fritillary is drawn to ornamental flowers, it’s no surprise that it was spotted in one of these flower beds. Butterflies are also finding suitable host plants among the flowers that have been planted,” Prakash added.