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Location India, Pondicherry
Central coordinates 79o 51.32' East  12o 2.12' North
IBA criteria A4i, A4iii
Area 618 ha
Altitude 0
Year of IBA assessment 2004

Bombay Natural History Society

Site description Bahour lake is the second largest wetland in Pondicherry. It is located near the Bahour village about 20 km from Pondicherry city, north of the Pennaiyar river. It is a seasonal freshwater wetland that receives water during the monsoon between September and March. The lake is dry for about 5 months.

Key Biodiversity 

AVIFAUNA: Balachandran and Alagarrajan (1995), and Jhunjhunwala (1998) conducted surveys of the wetlands of Pondicherry and recorded over 25,000 waterfowl in Bahour, belonging to 16 species. Over 10,000 Eurasian Wigeon Anas penelope and over 3,000 Little Grebe Tachybaptus ruficollis have been recorded (Balachandran and Alagarrajan 1995). Both occur much above the 1% population threshold determined by the Wetlands International (2002). For instance, according to Wetlands International (2002), the nonbreeding population of Eurasian Wigeon wintering in South Asia is 2,50,000. This means that at least 4% of this population is found in Bahour lake. In March (outward migration period), Bahour lake provides staging and feeding sites for thousands of migratory waterfowl, waders and terns. For example, in March 1995, Balachandran and Alagarrajan (1995) counted about 25,000 waterfowl. After March, the water is drained for fishing but by that time, most of the migratory birds move out. The impact of draining of water on resident birds needs to be studied to provide management recommendations.

OTHER KEY FAUNA: As this is basically a wetland surrounded by agricultural fields and human habitation, no mammal or reptile of conservation concern is found here.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Eurasian Wigeon Mareca penelope winter  2004  present  A4i  Least Concern 
Little Grebe Tachybaptus ruficollis 2004  present  A4i  Least Concern 
A4iii Species group - waterbirds unknown  2004  20,000 individuals  unknown  A4iii   

IBA Monitoring

2003 very high not assessed not assessed
Good - based on reliable and complete / representative data

Agriculture and aquaculture annual & perennial non-timber crops - small-holder farming happening now small area/few individuals (<10%) moderate to rapid deterioration low
Agriculture and aquaculture livestock farming and ranching (includes forest grazing) - small-holder grazing, ranching or farming happening now small area/few individuals (<10%) slow but significant deterioration low
Biological resource use fishing & harvesting aquatic resources - unintentional effects: subsistence/small scale happening now small area/few individuals (<10%) slow but significant deterioration low
Biological resource use hunting & collecting terrestrial animals - intentional use (species being assessed is the target) happening now small area/few individuals (<10%) slow but significant deterioration low
Natural system modifications dams & water management/use - abstraction of surface water (agricultural use) happening now whole area/population (>90%) moderate to rapid deterioration very high
Pollution agricultural & forestry effluents - herbicides and pesticides likely in short term (within 4 years) some of area/population (10-49%) no or imperceptible deterioration low
Pollution agricultural & forestry effluents - nutrient loads likely in short term (within 4 years) some of area/population (10-49%) no or imperceptible deterioration low


IUCN habitat Habitat detail Extent (% of site)
Artificial - aquatic   -
Coastline   -

Land use

Land-use Extent (% of site)
agriculture -
Notes: Agriculture
fisheries/aquaculture -
Notes: Fisheries
rangeland/pastureland -
Notes: Livestock grazing
water management -
Notes: Water management

Acknowledgements Key contributors: Supriya Jhunjhunwala, S. Balachandran, and Priya Davidar.


Balachandran, S. and Alagarrajan, R. (1995) An ecological survey of the wetlands of Pondicherry with special reference to Ousteri lake. Institute of Restoration of Natural Environment. Nagercoil. Pp. 40.

Jhunjhunwala, S. (1998) The Ornithological importance of Ousteri lake and Bahour lake: A study of the habitat preferences of their waterfowl and waders. M.Sc. Dissertation. Salim Ali School of Ecology and Environmental Sciences, Pondicherry University.

Wetlands International (2002) Waterbirds Population Estimates: Third Edition. Wetlands International Global Series No. 12. Wageningen, the Netherlands.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Bahour Lake. Downloaded from on 27/10/2016

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