Reptiles of Pune Urban Area: Increase or Decline?

Sanjay Thakur

• 666/1 Bhoi Ali, Raviwar Peth, Talegaon Dabhade, Pune District, 410 506, India.

• Vivek Gour-Broome
  J. E. Farm, Marunji P.O., Taluka Mulshi, District Pune, 411 027, India.

Introduction

Reptiles, given difficulty in their detection due to cryptic nature, are less documented than other classes of vertebrates. The first records dealing exclusively with the reptiles found in and around Pune appear to have been written by Underwood (1948) who reported 26 species, including 12 species of snakes. Since then there have been few publications that have added to the list of reptiles found in the city and its suburbs. Subsequently, Chopra (1964), Khaire & Khaire (1985) and Ghatpande et al. (1990) added few records. Comprehensive review of snakes (Khaire, & Khaire, 1993) reports 23 species, double that of the Underwood (1948). Recently, Wadadekar has reported about a dozen species of snakes just from the Pune University campus www.iucaa.ernet.in/~yogesh/snake.html http://www.iucaa.ernet.in/~yogesh/snake.shtml

Methodology

Our list is based on first hand observations over the past ten years as well as reliable oral information, besides literature. We have included species reported from within a radius of 25 km from Pune centre. We have used relative encounter rates of various reptiles across various habitat types were used as an abundance index. Identifications were based on keys in Smith (1933, 1935, 1943).

Literature revealed past occurrence of species. We also gathered perceptions of several field experts, especially about ongoing population changes. Reptiles not seen by us have been attributed to the individuals who recorded them. All reptiles found by the authors were identified and released unharmed.

Results and Discussion

We report 52 reptilian species (annexure) from the area, about two third of which are snakes. We report nearly report nearly thrice as many snake species as five decades ago (Underwood, 1948) while one and half times the decade old record (Khaire and Khaire, 1993). This increase in species richness is however cosmetic, resulting neither from recent colonisation nor eco-restoration but only from more intensified combing and accumulation of knowledge amongst naturalists. Diversity reported by us is nearly twice that of Delhi while one and half times that of Bangalore (Nalavade et al, this volume). The high diversity at Pune can be primarily attributed to its mantle of rivers and hill chains that possibly serve as corridors for the dispersal of even the Western Ghats specialists like the shield tail snakes.

Table 1 depicts the distribution of species diversity across habitat types. Nearly three fourth of the total species inhabit while a fifth are confined to the low impact zone comprising of forest, scrub and grassland habitats. Above half the species inhabit the high impact zone comprising of plantations, agriculture and habitation, just two of them being exclusive. Forest is most species rich habitat type, harbouring nearly two third of the total species, seven of them being exclusive. Human habitation is most species poor, hosting just 8 species, none being exclusively so. None of the high impact habitat types harbour any exclusive species. Thus, habitat loss resulting from urbanisation poses threat to nearly half the reptilian species. Mula-Mutha river bed is an excellent foraging ground for snakes due to abundance of prey species such as rodents and frogs. However, much of this fertile breeding ground is lost due to channel walls and ongoing road along the riverbed, demolishing also crab holes that shelter snakes. Similarly, encroachment of grassland and barren lands i.e. so called wasteland along city fringes by urbanisation has affected species such as Saw scaled viper. Habitat loss includes deforestation that especially affects tree dwelling species such as Bamboo pit viper, Cat and Vine snakes. However, habitat of grassland dwellers like Racer snakes is lost due to monoculture plantations around Pune, especially on hillocks. Forest restoration along the hill chain may theoretically benefit many reptile species. However, slum dwellers and labourers if not the elite that frequent the hills variously kill most of the snakes.

Besides direct loss of habitat as above, habitat degradation also variously affects reptiles. Excessive cattle grazing and concurrent fires hold threats for Racer and Cat snakes, besides skinks. Tree snakes are affected by the fuelwood collection rampant in the hills. Saw scaled vipers are susceptible to rock excavation along hills, while soil extraction from riverbed and banks affects shield tail and worm snakes. Keelback snakes seem susceptible to chemical water pollution. Fertiliser and pesticidal effluents from agriculture affect the breeding of most species therein while domestic chemical sprays threaten house geckos. Wanton killing by humans out of fear psychosis threatens all snake species, resulting in paucity of full grown specimens, entailing very limited breeding population. Perhaps as many or more might be caught for venom extraction. These are literally killed but effectively removed from the habitat, affecting natural breeding population. Killing out of fear has ensured that hardly any snake species is found abundantly. Killing out of superstitions affects Chameleon the most. Turtle and monitor lizard are hunted for consumption as food and for medicinal purpose.

To conclude, we emphasise that notwithstanding the increase in the reported species richness due to enhanced inventory, most reptiles are gradually declining in numbers and face a bleak future. Possible corrective measures include encouraging restoration of not just hill forests but also grasslands and rocky areas from fringe villages as well as the restoring the riverbed ecology, besides public awareness to minimise the fear-borne killing.

Acknowledgement

In the first place, we are indebted to all the informants. Ashok Captain also helped in manuscript prep. Drs. M. S. Pradhan and B. D. Bastawade from Zoological Survey of India and Drs. H. V. Ghate, Anand Padhye, S. B. Nalavade provided valuable literature and suggestions. Prakash Gole provided crucial suggestions in manuscript prep. All colleagues from Kalpvriksh and friends like Kaustubh Moghe provided a congenial working environment. Utkarsh Ghate’s persuaded us no end.

References

Daniels, J. C. 1983. The Book of Indian Reptiles. Oxford.

Chopra, R. N. 1964. Notes on Some Lizards of Poona. Jr. Univ. Poona (Sci&Tech) 28: 39-42.

Das I. 1997. Checklist of the Reptiles of India with English Common Names. Hamadryd. 22(1):32-45.

Ghatpande, S. K., Joshi, S., and Khaire, A. 1990. Additional Information on the Ophiological Fauna of Pune Region. Herpeton 3: 1-2.

Khaire, A and Khaire, N., 1985. A List of Snakes in the Neighbourhood of Poona, Maharashtra with Some Observations. Geobios: 4: 112-114.

Nalavade S., Padhye A. and Utkarsh G. (this volume). Pune city wilderness: Millennium biodiversity assessment of an urban ecosystem.

Khaire A and Khaire N 1993 Occurrence of Brown Whip Snake Ahaetulla Pulverulenta (Dum. & Bibr.) in Pune, India. The Snake 25: 147-8

Smith, M. A. 1933. The Fauna of British India, Ceylon and Burma, including the whole of the Indo-Chinese subregion. Reptilia And Amphibia. Vol. I, Loricata, Testudines. Taylor & Francis, London. Pp. i-xxviii + 1-185.

Smith, M. A. 1935. The Fauna of British India, Ceylon and Burma, including the whole of the Indo-Chinese subregion. Reptilia And Amphibia. Vol. II. Sauria. Taylor & Francis, London. Pp. i-xiii + 1-440.

Smith, M. A. 1943. The Fauna of British India, Ceylon and Burma, including the whole of the Indo-Chinese subregion. Reptilia And Amphibia. Vol. III, Serpentes. Taylor & Francis, London. Pp. i-xii + 1-583.

Tikadar B. K. and Sharma, R. C. 1992. Handbook of Indian Lizards. Zoological Survey of India, Calcutta. Pp. xv, 250.

Underwood, G., 1948.- Notes on Poona Reptiles. J. Bombay nat. Hist. Soc. 47(4): 627-632.

TABLE 1

Reptile species richness across habitat types

ANNEXURE : Distribution of Reptiles in Pune Urban Area

CODES :

Localities : An- Aundh, Bm- Bhamburda, Cc- Chandani Chowk, Fc- Fergusson College, Kj- Katraj, Kw- Khadwasla, Kt- Kothrud, Mw- Malwadi, Pc- Pachgaon, Pd- Paud, Ps- Pashan, Sg- Sinhgad, Uv- University, Wj- Warje, Yw- Yerwada, Vs- Vadgaon-sheri

Habitats : F- Forest, S- Scrub, G- Grassland, P- Plantation, A- Agriculture, H- Habitation, W- Water, R-Rocky

Ab (Abundance) : A- Abundant, C- Common, O- Occasional, R- Rare

Remarks : Species recorded without our own observations are accredited to reporters:- AC-A. Captain, AK- A. Khaire, RM- R. Marathe, SN- S. Nalawade, HG- H. Ghate; besides literature as per the case.

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