AMPHIBIAN DECLINE IN PUNE CITY

A. D. Padhye¹ and Mukul Mahabaleshwarkar²

1 Department of Zoology, Abasaheb Garware College, PUNE 411 004. Email : nandudp@yahoo.com
2 Flat 15, 24 E, Paschima nagari Society, Kothrud, Pune 411 029. Email: chidanand@ip.eth.net

INTRODUCTION

Amphibians are probably the best indicators of environmental health of all vertebrates being extremely sensitive to temperature and humidity (Daniels, 1991). Their easily permeable skin makes them susceptible to environmental changes, including pollution. They are also sedentary, unlike birds that have strong dispersal ability. Thus, any change in amphibian population alarms conservationists the most. This prompted us to undertake the present investigation. Earlier studies by Yazdani and Mahabal (1976) and Paranjape and Mulherkar (1979) together record 13 amphibian species from Pune City.

METHODOLOGY

ADP has been collecting amphibian eggs for experiments and natural history studies since 1986 from Pashan, Khadaki, University, Vitthalwadi and the Mutha river banks till Khadakwasla, Hingane, Kothrud, Hadapsar, Yerawda, Nagar road and adjacent areas, besides observing habitat changes therein. These and other places around Pune city were more intensely combed during the monsoon 2000 for estimating their current status. Presence of frog species was based on siting, presence of egg clutches or the calls. In case field identity was found difficult, the specimens were collected and identified in the laboratory with the help of literature (Daniel, 1963, 1975, Daniel and Sekar, 1989). During the field visits, ecological factors like abundance, habitat, microhabitat, food preferences, human influence were also noted. We have also studied various museum collections.

RESULTS AND DISCUSSION

Our present survey reveals 14 species belonging to 7 genera and 4 families (Annexure). Nine of these today occur only outside the city while four of them are recorded only beyond 20 km from city centre. Three species such as Rana cyanophlictis inhabit all localities, three such as inhabit all or most localities except the city, while three such as Uperedon globulosus are highly localised in and around city. In fact, five of the previously reported species from could not be presently retraced in their reported localities or elsewhere and may be locally extinct. These include Rana hexadactyla, Bufo stomaticus, B. parietalis, B. microtympanum and Philatus bombayensis. This is only expected given the indications of amphibian decline by Paranjape and Mulherkar (1979) since long and by Ghate and Padhye (1996) of late.

Much of the amphibian decline can be attributed to the habitat loss due to rampant urbanisation, accompanied by quarrying and slums that have not even spared hills. Over two third of the past habitat area of amphibians is now encroached. Recent Industrial estate Pirangut has reduced the Tomopterna and Rana malabarica populations that were aplenty earlier, the latter being nearly wiped out due to loss of paddy fields, a major breeding ground. Construction of Sports City at Balewadi and the highway bypass joining it to Katraj has only stretched the habitat loss further. Resultant loss of scrub, grasslands, paddy fields; compaction and modification of the soil has ceased the formation of rainwater pools that are critical to amphibian sustenance. The important breeding grounds along the riverbed within the city had somehow survived this fringe expansion untill recently, but is not spared by the road construction. The proposed inclusion of fringe villages into corporation limits will only further intensify habitat destruction, with conversion of farms, grasslands, paddy fields, river banks and the so called barren land that harbour puddles to the urban habitation and infrastructure. Suburbs and fringe villages of Pune city that once boasted of prime amphibian habitats now barely shelter small, fragmented populations, prone to extinction with aberrations like monsoon delay or failure. Any major calamity, like scanty or irregular monsoon, will totally wipe out such fragmented populations. Recently, herpatologists have begun debating the global amphibian decline, even in low human impact area like Brazilian rainforests possibly due to the ongoing climate change. This can hardly be detected around the scientific and educational city of Pune, where not the global climate but urbanisation will spell doom for amphibians.

Fortunately, few low impact areas like scrub and grasslands within military campus such as NDA still offer some peace to amphibians despite the ever-increasing human pressures. Many hills around Pune city have become tree clad due to the efforts of the Forest Department, besides some housing societies, temple trusts and NGOs. The consequent recolonisation of these sinks from the connected source populations such as at Katraj have enabled the visitors, for instance, to chance upon tree frogs at Pachgaon. Such areas offer last vestiges for amphibian survival and even re-introduction of the lost species. Protection of the habitats especially breeding sites free from human interference is a must. Pune city that boasts of a snake park, must think ahead of even running a amphibian park, if Forest Department, Municipal Authorities and NGOs can collaborate. This park to provide also for captive breeding besides public awareness and education.

ACKNOWLEDGEMENTS

Rahul Marathe, Rahul Bahulikar, Sagar Pandit, Nilesh Dahanukar, Rupesh Raut, Sachin Ranade, helped us in the survey and field work. Vivek Gaur Broome and Sanjay Thakur shared their perceptions. Dr. H. V. Ghate guided us variously including in manuscript preparation. Dr. Milind Watwe variously encouraged us. Mrs. S. P. Modak, Head, Zoology Department and Dr. A. S. Inamdar - Principal; Abasaheb Garware College obliged by providing infrastructure like specimen preservation. Prof. Madhav Gadgil provided us unparalleled research opportunity earlier while Utkarsh Ghate persuaded us further. RANWA and Department of Science and Technology (DST) sponsored the project. We are indebted to them all.

REFERENCES

Daniel, J. C. 1963. Field guide to the amphibians of the Western India, Part 1 & 2. Jr.B.N.H.S. 60: 415-438, 690-702.

Daniel, J. C. 1975. Field guide to the amphibians of the Western India, Part 3. Jr.B.N.H.S. 72: 506-522.

Daniel, J. C. and Sekar, A. G. 1989. Field guide to the amphibians of the Western India, Part 4. Jr.B.N.H.S. 86: 194-202.

Daniels, R. J. R. 1991. The problem of conserving amphibians in the Western Ghats, India. Current Science 60 (11): 630-32.

Ghate, H. V. and Padhye, A. D. 1996. Impact of urbanisation on amphibians of Pune. Zoo’s print 11 : 14 - 16.

Paranjape, S. Y. and Mulherkar L. 1979. On the survey of amphibian fauna in and around Pune. J. Univ. Poona, Sci. & Technol. 52: 423 - 434.

Sawant, S. B. 1972. The City of Poona: A Study in Urban Geography. Ph.D. Thesis, University of Poona.

Yazdani, G. M. and Mahabal, A. 1976. Amphibians of Poona. ZSI Newsletter 2:138 - 139.

ANNEXURE : Ecological preferences and changes of amphibian species of Pune.

HABITATS :

MICROHABITATS :

AB (Abundance) : Vc- very common, C- common, O- occasional, R- rare; PC (Population changes) : D- decline, En- endangered;

REMARKS : Blw- Balewadi, Kth- Kothrud, Mst- Mastani lake, Psh- Pashan, Sgd- Sinhgad, Unv- University

CONTENTS