One of the notable observations of this census was the first geographical record of the Blank Swift butterfly which is a species rare to the Northern Plains.Coming from the family of skipper butterflies, the Blank Swift is commonly seen in high humidity areas that are moist and damp. The species was spotted in the Aravalli Biodiversity Park, which also reported the highest number of species (65), maintaining its previous year’s record. It is closely followed by the Northern Ridge (Kamala Nehru Ridge) with 48 species.
<p><em>Clockwise from top left: Lime Butterfly, Common Mormon, Lemon Pansy, Lime Blue, Mottled Emigrant</em></p><p><em><br></em></p>
This effort to assess butterfly species, their population and habitat suitability were conducted for six days from 30 October to 4 November across all the seven Biodiversity Parks in the city. The census is conducted in joint collaboration of the Centre for Environment Management of Degraded Ecosystems (CEMDE), Delhi University and the Delhi Development Authority (DDA).
All these Biodiversity Parks lie within Delhi’s two major habitats- the Yamuna river basin, which act as an ideal habitat for the skipper group of butterflies, and the Aravalli hill ranges, whose dense canopy provides protective homes for several species of butterflies. This habitat heterogeneity facilitates high diversity of butterfly species across Delhi.
Notably, the Plain Tiger stood out as the most frequently sighted species, with a count of 1,119 individuals recorded across all seven parks. Among other species spotted in significant numbers were the Yellow Orange Tip, Lemon Pansy, Common Gull, Zebra Blue, Rounded Pierrot, Striped Tiger, Common Emigrant, and the Common Grass Yellow. Individuals of all five butterfly families of India were recorded during this survey.
The exercise was led by scientists of the biodiversity parks with assistance from students and teachers of some leading colleges and universities, and citizen volunteers of New Delhi Nature Society. Dr Aisha Sultana, Wildlife Ecologist, and Mohammad Faisal, Entomologist, Delhi Biodiversity Parks coordinated the exercise.
![<p><em>Clockwise from top left: Lime Butterfly, Common Mormon, Lemon Pansy, Lime Blue, Mottled Emigrant</em></p><p><em><br></em></p> 1000x1000-Butterfly-02](https://static.toiimg.com/thumb/imgsize-23456,msid-105011026,width-600,resizemode-4/105011026.jpg)
<p><em>Clockwise from top left: Lime Butterfly, Common Mormon, Lemon Pansy, Lime Blue, Mottled Emigrant</em></p><p><em><br></em></p>
For six days daily in the morning from 10 am to 12 noon, 15 groups of 2-5 butterfly observers walked on the pre-specified fixed transects to identify, count, enumerate and photographically document the sightings of butterflies. Mohammed Faisal says, “Due to the ongoing smog situation in Delhi, butterflies became active after 11 AM due to late sunshine and this has reduced their activity time. However, no other major changes in movement apart from this has been observed.”
He notes that despite the changing weather patterns, butterfly diversity hasn’t witnessed any significant challenges in the last few years. He adds, “Biodiversity rich habitats such as the DDA parks in Delhi are resilient to changing climate, and this is why despite this year’s inconsistent weather pattern and erratic rainfall, butterfly’s density, diversity and their activities have been fairly sustainable. The stable population indicates that the mosaic of habitats and diverse microhabitats of these biodiversity parks are acting as a safe refuge for butterfly species. If one observes, the overall AQI levels inside these biodiversity parks are much lesser than the mean AQI levels in the city.”
Dr. Aisha Sultana points out how butterflies as keystone species are extremely crucial to study the environment. She says, “As an indicator species, butterflies are sensitive towards any kind of habitat change or manipulation. This makes them very important ecological indicators crucial to conservation. Delhi’s DDA Biodiversity Parks focus on the creation of both small and large habitats to assist butterfly conservation. The census not just helps us understand which species are visiting these parks but also their habitat suitability. Long term data from the census may also help in predicting environmental changes taking place around the city.”
Delhi’s DDA parks are now living laboratories to study the ecology around the city. The annual butterfly census underscores the importance of these biodiverse havens and their role in safeguarding butterfly species.
*Data as per officials aware of census details
All Photos by special arrangement with Delhi Biodiversity Park officials.