By Tarun Singh
The Ahobilam corridor is a narrow strip of parallel-running hills harbouring pristine forests of high conservation significance in the Eastern Ghats Range of India. WCS India’s ‘Project Ahobilam’ is the beginning of an effort to improve the conservation status of the area as part of the contiguity with existing PAs in the Nallamala Landscape.
Presently it is a Reserve Forest (RF) south of Gundla Brahmeswaram Wildlife Sanctuary. These areas are identified as the tiger corridor connecting the Nallamala hills of Nagarjunasagar Srisailam Tiger Reserve, the country's largest tiger reserve, with Sheshachallam hills in the South. Presently, we have started surveys to assess the biodiversity profile of the area, which includes RF and areas outside it. The following account sheds some light on how wildlife uses and thrives outside PAs. It should interest anyone who works in conservation, whether it is someone who visits the field quite often and makes observations while collecting the data or someone managing projects remotely, trying to make sense of it.
Our reconnaissance* surveys began during monsoons, and for two months, we inventoried any biodiversity, from insects to mushrooms, that we could record in the field**. After that, we began surveys on getting relative abundances of various bird communities in the forest through Times-Species Counts. To represent wetland birds, we marked visible perennial water sources from a digital satellite map of our study area, where we proceeded to determine the habitat suitability. On the ground, these water sources turned out to be some of the many reservoirs formed around the Telugu Ganga project. It is a 408 Km long canal system between Andhra Pradesh and Tamil Nadu that runs along the base of forested Nallamalla hills. These reservoirs were deep, with rapid water flow and no apparent shoreline. It was disappointing to see these vast aesthetic expanses of water devoid of any bird life. With this, we learned a significant field lesson: all waters are not suitable for sustaining wildlife. Meanwhile, as we were traversing back and forth from our field station to our field sites, the paddy fields were being sown. In these fields, some interesting observations could be made each time we passed by. Visibly, there were more numbers and diversity of wetland-dependent birds here. There were Painted Stork (Mycteria leucocephala), Black-headed Ibis(Threskiornis melanocephalus), Eurasian Spoonbill (Platalea leucorodia), Red-naped Ibis (Pseudibis papillosa), Black-winged Stilt (Himantopus himantopus), Fulvous Whistling Duck (Dendrocygna bicolor), Lesser Whistling Duck (Dendrocygna javanica), and assemblages of various common egrets and herons. One evening, large flocks of small-sized ibis-like birds appeared silhouetted on the horizon and kept pouring in. It was the seasonal movement of Glossy Ibis (Plegadis falcinellus), and in the upcoming weeks, their numbers kept increasing to the point where a thousand birds could be easily counted from a single point. All this had something to do with the shallow, flooded paddy fields as birds settled in to make the most of such opportunistic foraging. These observations piqued our interest, and our curiosity led us to spend some more time here, even though these fields were slightly away from the digital grids laid down for our survey work.
We targeted small-sized village lakes or Tanks (locally called Cheruvu) surrounded by paddy fields to document the bird diversity. An unexpected spectacle unfolded at one such site. There were commotions at the edge of the lake; these turned out to be the flocks of Garganey (Anas querquedula), a wintering anatid to India. Ruffs Philomachus pugnax and Wood Sandpipers (Tringa glareola) were feeding in the tender green rows of paddy by probing their bill in the soft earth below a thin sheet of water. A Eurasian Marsh Harrier (Circus aeruginosus) was flying low, scanning the fields. Plaintive whistles of Common Redshank (Tringa totanus) could be heard. As we waded forward through slushy mud, a snipe (species unidentified) got flushed and flew up in a zig-zag flight shrieking its complaints about our intrusion from the sky. At last, we reached a point from where we could scan a congregation through binoculars and cameras and discovered a resting flock of Black-tailed Godwits (Limosa limosa) (Near Threatened, IUCN Red List). On a follow-up survey, we even recorded a pair of Greater Flamingo (Phoenicopterus roseus), a flagship species of the wetland ecosystem.
To summarise what to make of these observations: Though the many reservoirs along the Telugu - Ganga Canal are more perennial and abundant sources of water, the Village Tanks (Cheruvus), along with paddy fields with their attributes such as shallow water depth to wade, soft mud substrate to feed, and seasonal flooding, mimic the habitats preferred by wetland habitat specialists such as various sandpipers and flamingos. As the planting season coincides with the autumn migration, migratory waterbirds to India in the Central Asian-Indian Flyway use these altered or reclaimed wetlands as stop-over and refuelling sites. Thus from a conservation point of view, the irrigated paddies might sustain part of the original biodiversity and represent refugia for the fauna from affected wetlands (Fowler 2001). However, these areas are prone to heavy pesticides and other harmful chemical loads that can potentially be very dangerous to the avifauna life in this area. Sustainable agricultural practices such as organic farming and integrated pest management strategies that require fewer chemical inputs may aid in the ability of these sites to function as surrogate*** wetlands (Fowler 2001). As these spaces are not protected areas and are shared by communities and wildlife harmoniously, these could be promoted and managed through Other Effective Area-based Conservation Measures (OECM).
*Reconnaissance: A preliminary survey to gain information (especially for military purposes).
**Field: A particular area where the same information is regularly recorded.
***Surrogate: One that serves as a substitute.