This is a guest post by G. Parameswaran & R. Sivashankar, members of the Perur Lake Forum (a group of birders who systematically monitor wetlands in Coimbatore). It is a summarised version of their research paper “The Composition and Status of Waterbirds of Perur Lake in Tamil Nadu, India”, published in the Journal of Threatened Taxa (download here).
The Perur Lake Forum (PLF) came into being to conduct systematic bird surveys in the Greater Coimbatore area, Tamil Nadu in early 2014. Nine volunteers – G. Parameswaran (founder), R. Sivashankar, R. Vridhi, Sai Vivek, Dilip Joshi, Gajamohanraj, Chetankumar Joshi, Sharang Satish and Prakash G. – volunteer their time and effort over the weekends to perform these surveys.
The PLF started monthly birds counts in the Perur-Sundakamuthur Lake, called Perur Lake, in early 2014 and continues till the present day. These counts are usually performed on every second Saturday of the month from 7:00 AM – 9:30 AM by the group, with the aid of binoculars and spotting scopes. This monitoring is entirely self-funded and the group shares the cost of transportation and breakfast. It is a model that can work in any city or small town with the only requirement being the commitment to the mission.
Perur Lake covers an area of 5.768 km2 in the south-western part of the Greater Coimbatore region. It receives its water from the monsoon-fed Noyyal River, and is one in a series of wetlands constructed by the Kongu-Chola regimes in the 8th – 9th century. These congregations of about 30 wetlands in this dry region provide water for agriculture, perform functions such as flood control, water purification, and ground water recharge. Additionally, of course, they provide an important habitat for biodiversity in the region. Since the composition of birds that utilise this lake during the year shows a clear picture of its biological diversity and ecological health, it was decided to start the study at this accessible location.
The data collected from May 2014 to Apr 2016 has now been published as an open-access paper (details at the top of this article). Some of the major findings are listed here:
- 112 bird species were recorded in Perur Lake during this period, representing 44 families and 18 orders. This study focused mostly on waterbirds, of which 49 species belonging to 14 families and seven orders were recorded. Only their status is discussed in detail in the publication.
- From the data collected so far, the highest number of birds and species diversity was recorded from February to April. This underlines the need to maintain adequate water levels in these wetlands during these crucial months for the benefit of the northward-bound migrating waterbirds. This practice also allows the opportunity for additional groundwater recharge during these lean months, which benefits the community.
- During the study period, it was also found that activities such as road construction could have had a deleterious effect on the number of birds that used this wetland.
We recommend that similar studies be carried out in some of the adjoining wetlands of the area in a synchronous manner to further understand the subtlety of local avian movements within the Greater Coimbatore area
The members of Perur Lake Forum have now also started a monthly bird count in Anuvavi Subramaniarkovil located in the Thadagam area of Greater Coimbatore on the third Sunday’s of the month since Jan 2018.