Bird watchers experience decline in sighting of migratory birds amid temperature rise

Due to the early onset of summer coupled with above-normal temperatures being reported since the beginning of January this year, bird watchers are experiencing a decline in the sighting of migratory bird species at popular spots across the city. Birds are leaving early this year which could be associated with rising temperatures and though it cannot be established as a trend, the pattern is there, said Ranjeet Rane, a city-based bird watcher and coordinator of the Great Backyard Bird Count initiative.

“The exact impact of increasing average annual temperatures on bird migration will need to be studied over the longer term. From the available data, we see a pattern this year that both the number of species and their individual numbers seem to have gone down with the winter cut short. For a trend to emerge, we will have to look at data for a few more years. The concern however is that waiting for validation may be too late to act upon. Lack of avian diversity has been well established as a proxy for measuring habitat degradation, and the reduction in numbers seen this year must be taken seriously by citizens, urban planners and policymakers alike,” said Rane.

“The smaller migratory birds commonly found in the hills in Pune are now not seen. The Sandpiper birds that were found in large numbers at Vetal Tekdi during this winter season are now not seen anymore. Apart from that, the number of Larks has also reduced significantly in the same area,” said Rane.

Because of its location, climate and the nearby natural habitats, Pune is an attractive stopover for many migratory bird species. Every year, hundreds of migratory birds arrive in Pune during the winter season between October and February from Europe, Africa, the Himalayan region and many other places. These birds usually stay till the end of March and begin their return journey once the summer season starts. This year however, due to the rise in temperatures, the return journey of these birds has started early and bird watchers have experienced a significant decline in the sighting of migratory bird species by the end of February itself.

Even Bhigwan, which is a popular stopover for migratory birds, is now seeing an early departure of migratory bird species. Sandeep Nagare, a wildlife photographer and bird watcher, said, “Some species of migratory birds, especially ducks, were seen leaving early this year. The rise in temperature does have a crucial connection with the early departure of bird species from Ujani dam and the nearby water bodies. There is a possibility that some birds have arrived early this year and might be leaving early or may be shifting elsewhere as the water level is sufficient in other areas too. But temperature rise does impact species of migratory birds such as ducks that generally stay in this area till the end of March but are now leaving early.”

The rise in temperature is not only impacting bird species but also butterfly species. Rajat Joshi, who is actively involved in butterfly research and conservation, said, “The temperature rise is certainly impacting butterfly species. In many places, I have observed that due to the rise in temperature, butterfly activities are restricted. They play around the plants for a limited period early morning after which they find shelter in nearby places. This is impacting their egg-laying process as well. Normally 30 to 31 degrees Celsius is the ideal temperature for butterflies but in February, the temperature rose to 35 degrees Celsius which certainly impacted butterflies at various locations in Pune.”

Indeed, climate change is impacting bird species globally. “Various organisations are conducting research on the same and it is well established that migratory birds are adapting to climate change. Hence, we can see early arrival and early departure of migratory bird species,” said Tushar Chavan, deputy conservator of forests (wildlife), Pune forest department.

Photo caption: Some duck species captured by wildlife photographer and bird watcher Sandeep Nagare at Ujani dam and nearby water bodies.