EVALUATION OF WATERBIRD COMMUNITIES IN RELATION TO PHYSICAL PARAMETERS OF URBAN LAKES OF GREATER BANGALORE METROPOLITAN CITY (GBMC), KARNATAKA, INDIA

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1 EVALUATION OF WATERBIRD COMMUNITIES IN RELATION TO PHYSICAL PARAMETERS OF URBAN LAKES OF GREATER BANGALORE METROPOLITAN CITY (GBMC), KARNATAKA, INDIA S. Rajashekara 1 and M. G. Venkatesha 2 Department of Zoology Bangalore University Jnana Bharthi Campus Bangalore Karnataka State, India 1 rajachandra3908@yahoo.co.in 2 venkatmelally@gmail.com

2 1. INTRODUCTION q Aquatic birds - very good indicators of human impact on the fresh water ecosystem. q Activities of waterbird communities (WB. C.) - considered as indicator of quality of the lake ecosystem. q Form the terminal links in many aquatic food chains, & as a result they reflect changes originating in several different ecosystem components. 2

3 v Greater Bangalore Metropolitan City (GBMC) - capital city of Karnataka state, fifth metropolitan & second fast developing city in India. v GBMC - Garden City - many beautiful parks, lakes, gardens & natural vegetations. v GBMC lakes - balancing reservoir for sustaining native flora & fauna. v An ideal habitat to local & migratory waterbird spp. 3

4 v Aquatic bird communities of the GBMC region - one - imp. bioindicators of lake ecosystems, which should be protected to conserve the biodiversity & environment. v No. of biotic & abiotic factors - may influences the distribution, abundance & interactions among the WB. spp. v As not much information is available on incidence of WB.C. with relation to physical parameters of urban lakes of GBMC region, a study - conducted to know their incidence in different lakes. 4

5 2. MATERIALS AND METHODS STUDY LAKES: Lakes - chosen based - various locations, water level & occurrence of WB. population. Surveys - conducted in the selected 15 lakes of GBMC region. 5

6 Fig. 1. Location of different study lakes in GBMC region. 6

7 Photos of Studied Lakes: 16/11/ /07/2009 Anekal Lake Chandapura Lake 19/10/ /11/2009 Gottigere Lake Hebbala Lake 7

8 06/10/ /11/2008 Hesaraghatta Lake Hoskote Lake 09/11/ /04/2009 Jakkuru Lake Kengeri Lake 8

9 17/02/ /10/2008 Lake of Lalbagh Botanical Garden 04/08/ /09/2009 Medahalli Lake Nelamangala Lake Somanahalli Lake 9

10 03/05/ /02/2009 Thippagondanahalli Lake Ulsooru Lake 23/11/2008 Varthuru Lake 10

11 2. 2. SURVEY & SAMPLING METHOD: Sampling period: v Once in fortnight from Feb to Jan Sampling method: v Lake bunds - walked at a uniform pace of about km/h. v Point counts made by the visual counting - within the visible radius at different times of the day from morning AM to evening PM when they are most active & conspicuous; v Call notes of WB. used for identifying their locations (Ali 1996). v Nomenclature & taxonomy - followed by BirdLife International (2009). 11

12 WB. Surveys: v Moreover, observations - also made on the nests, nesting sites, feeding habitat, food source, water sources & anthropogenic activities. Vegetation surveys: v v At each study lake, the various aquatic vegetation types - identified up to spps. level. No. of weed spps. present in the different lakes - determined. v Check list of weed spps. - prepared by following Ramaswamy & Razi (1973). 12

13 o Lake physical parameters - lake area, water & weed coverage, water depth; no. of islands & tree density around each lake evaluated as effective tools to assess the WB. Populations. o Anthropogenic disturbances - lakes surrounded by roads, buildings; & usage of lakes for various purposes such as washing clothes, inlet of domestic sewage, fishing & aquaculture, & recreational activities - evaluated & correlated with WB. populations. 13

14 2. 3. Biodiversity indices: Population density, species composition & diversity of WB. C. in different lakes - assessed using various biodiversity indices such as Shannon-Weiner diversity (H'), Margalef s species richness (R1), Equitability Index [J], Fisher s alpha Diversity, Mean Population density/ha. of birds Percent frequency occurrence - using BIODIVERISTY PROFESSIONAL Version 2.0 (1997) (McAleece et al. 1997) & PAST (2001) (Hammer et al. 2001) 14

15 o Correlation between WB. density & habitat factors: Pearson s Correlation Matrix (PCM) (MEGASTAT) (Orris 1999) & Hierarchical Cluster Analysis (HCA) - used to correlate WB. population density using BIODIVERSITY PROFESSIONAL Version 2.0 (McAleece et al. 1997). o Data analysis: One way ANOVA - used to assess the Shannon- Weiner & Fisher s alpha diversities, Species richness, & equitability indices using SPSS (SPSS Inc., 2008). 15

16 3. RESULTS AND DISCUSSIONS 43 spp. of WB genera - 15 families - recorded. 22 spp. commonly found in all study lakes. Bubulcus ibis (Cattle egrets) 100% & Dendrocygna javanica (Lesser whistling duck) 1.94%. 31 spp. of aquatic weeds - 27 genera - 18 families recorded. 2 spp. commonly found in all study lakes. J J Ipomea aquatica (Water Morning Glory) & Ricinus communis (Castor). 16

17 45 Number of species Ulsooru Lake Somanahalli Lake Thippagondanahalli Lake Gottigere Lake Jakkuru Lake Varthuru Lake Hoskote Lake Chandapura Lake Hebbala Lake Study lakes Hesaraghatta Lake Kengeri Lake Nelamangala Lake Anekal Lake Medahalli Lake Lake of Lalbagh Botanical Garden 17 Fig. 2. Number of Waterbird species in different lakes of GBMC region (Feb Jan. 2010).

18 Very common, 16 spp. (76-100%) Common, 8 spp. (51-75%) Rare, 12 spp. (0-25%) Uncommon, 7 spp. (26-50%) 18 Fig. 3. Occurrence status of Waterbird species at GBMC lakes.

19 Piscivore/insectivore, 2 spp. Herbivore, 4 spp. Animal matter, 1 sp. Carnivore/Insectivore, 10 spp. Insectivore, 4 spp. Piscivore, 6 spp. Carnivore, 8 spp. Omnivore, 8 spp. 19 Fig. 4. Feeding guild analysis of Waterbird species at GBMC lakes.

20 Residents 5 spp. Resident migrants 21 spp. Migrants 17 spp. 20 Fig. 5. Residential status of no. of WB. spps. of GBMC lakes.

21 Ciconiidae, 2 Motacillidae, 4 Anatidae, 7 Pelecanidae, 2 Alcedinidae, 3 Ardeidae, 9 Rallidae, 4 Phalacrocoracidae, 2 Anhingidae, 1 Podicipedidae, 1 Laridae, 1 Charadriidae, 2 Scolopacidae, 2 Jacanidae, 2 Recurvirostridae, 1 21 Fig. 6. No. of WB. spp. belonging to different families in GBMC lakes.

22 Near threatened (2 spp.) 5% Pelecanus philippensis (Rosy pelican) & Mycteria leucocephala (Painted strok) Least concerned (41 spp.) 95% 22 Fig. 7. Conservation status of WB. spp. recorded at GBMC lakes ( ).

23 Fulica atra 14.45% (Common coot) Sarkidiornis melanotos 0.03% (Comb duck) % abundance Fulica atra Bubulcus ibis Egretta Anas garzetta querquedula Phalacrocorax Ardeola carbo grayii Gallinula Ardea chloropus cinerea Motacilla Tachybaptus madaraspatensi ruficollis Charadrius Actitis dubius hypoleucos Halcyon smyrnensis Casmerodius Ardea albus purpurea Anas poecilorhyncha Phalacrocorax Motacilla niger cinerea Alcedo atthis Vanellus indicus Motacilla flava Motacilla alba Ceryle rudis Aquatic bird species Nycticorax Porphyrio nycticorax porphyrio Himantopus Amaurornis himantopus phoenicurus Anas acuta Anastomus oscitans Metopidius indicus Pelecanus onocrotalus Hydrophasianus chirurgu Pelecanus philippensis Ardea goliath Mesophoyx Mycteria intermedia leucocephala Anhinga rufa Tringa nebularia Anas clypeata Anas platyrhynchos Sterna aurantia Dendrocygna javanica Sarkidiornis melanotos Fig. 8. Rank abundance of different WB spps. recorded at GBMC lakes.

24 Scolopacidae (2.59) Alcedinidae (4.86) Recurvirostridae (0.38) Anatidae (11.40) Rallidae (18.57) Anhingidae (0.77) Podicipedidae (1.94) Phalacrocoracidae (9.25) Pelecanidae (1.48) Motacillidae (7.04) Laridae (0.08) Ardeidae (36.33) Jacanidae (0.56) Ciconiidae (1.32) Charadriidae (3.42) 24 Fig. 9. Relative abundance (%) of various WB. families at GBMC lakes.

25 Scolopacidae, 0.27 Alcedinidae, 0.50 Recurvirostridae, 0.00 Rallidae, 0.65 Podicipedidae, 0.00 Phalacrocoracidae, 0.23 Pelecanidae, 0.28 Anatidae, 1.36 Motacillidae, 0.72 Anhingidae, 0.00 Laridae, 0.00 Jacanidae, 0.32 Ciconiidae, 0.29 Charadriidae, 0.26 Ardeidae, Fig. 10. Richness index (R1) of different WB. families at GBMC lakes ( ).

26 Mean population density/ ha Anekal Lake Chandapura Lake Gottigere Lake Hebbala Lake Hesaraghatta Lake Hoskote Lake Jakkuru Lake Kengeri Lake Lake of Lalbagh Botanical Garden Study lakes Medahalli Lake Nelamangala Lake Somanahalli Lake Thippagondanahalli Lake Ulsooru Lake Varthuru Lake Sig. diff. (P<0.05) 26 Fig. 11. Mean population density per hectare of WB.C. in different lakes of GBMC region (Feb Jan. 2010).

27 4 3.5 Shannon-Weiner diversity Anekal Lake Chandapura Lake Gottigere Lake Hebbala Lake Hesaraghatta Lake Hoskote Lake Jakkuru Lake Kengeri Lake Lake of Lalbagh Botanical Garden Medahalli Lake Nelamangala Lake Somanahalli Lake Lake Thippagondanahalli Ulsooru Lake Varthuru Lake Sig. diff. (P<0.05) Study lakes 27 Fig. 12. Shannon-Weiner diversity of waterbirds in different lakes of GBMC region (Feb Jan. 2010).

28 6 5 Fisher's alpha diversity Anekal Lake Chandapura Lake Gottigere Lake Hebbala Lake Hesaraghatta Lake Hoskote Lake Jakkuru Lake Kengeri Lake Lake of Lalbagh Botanical Garden Medahalli Lake Nelamangala Lake Somanahalli Lake Thippagondanahalli Lake Ulsooru Lake Varthuru Lake Sig. diff. (P<0.05) Study lakes 28 Fig. 13. Fisher s alpha diversity of waterbird communities in different lakes of GBMC region (Feb Jan. 2010).

29 Margalef's species richness Anekal Lake Chandapura Lake Gottigere Lake Hebbala Lake Hesaraghatta Lake Hoskote Lake Jakkuru Lake Kengeri Lake Lake of Lalbagh Botanical Garden Study lakes Medahalli Lake Somanahalli Lake Nelamangala Lake Thippagondanahalli Lake Ulsooru Lake Varthuru Lake Sig. diff. (P<0.05) 29 Fig. 14. Species richness of waterbird communities in different lakes of GBMC region (Feb Jan. 2010).

30 Equitability index Anekal Lake Chandapura Lake Gottigere Lake Hebbala Lake Hesaraghatta Lake Hoskote Lake Jakkuru Lake Kengeri Lake Lake of Lalbagh Botanical Garden Medahalli Lake Nelamangala Lake Somanahalli Lake Thippagondanahalli Lake Ulsooru Lake Varthuru Lake Sig. diff. (P<0.05) Study lakes 30 Fig. 15. Species equitability index of waterbird communities in different lakes of GBMC region (Feb Jan. 2010).

31 35 30 No. of family No. of genera No. of species Percentage of total species No. of family/ genus No./ % of species Summer Monsoon Winter Common throughout the year 0 Season 31 Fig. 16. Seasonal variations of WB. C. of GBMC lakes (Feb Jan. 2010).

32 Lake area (in ha.) Weed coverage (~%) Water coverage (~%) Water depth (in m) No. of fishing boats No. of Islands No. of nesting sites No. of Weed spp. Tree density Waterbird population Density/ ha (*) (*) (**).562 (*) (**) (*).549 (*) (**) Significant at 0.01 level, (*) Significant at 0.05 level. Fig. 17. Pearsons correlation matrix (PCM) of WB. population density/ ha. in relation to habitat factors in different lakes of GBMC region. 32

33 Pearson's correlation matrix (PCM) - analyzed for all study lakes in relation to WB. population density/ ha. WB. population density showed significant positive correlation with the no. of islands (P<0.01), tree density (P<0.05) & increasing water depth (P<0.05) in different lakes of GBMC region. In contrast, WB. population density showed significant negative correlation with the decreasing lake area (P<0.05) & water coverage (P<0.01), increasing weed coverage (P<0.05), & less no. of weed species (P<0.05). Detailed PCM analysis of WB.C. indicated that lake area, no. of islands, water & weed coverage, water depth, tree density, & weed species were the dominant factors influencing the WB.C. in the urban lakes of GBMC region. 33

34 Fig. 18. Dendrogram showing similarity in GBMC lakes based on the mean WB. population density/ ha. 34

35 Highest mean population density/ ha. of WB. Lake of Lalbagh Botanical Garden - due to availability of various food sources & water depth, nesting sites, highest no. of islands, & tree density. Lowest population density/ ha. of WB. Thippagondanahalli Lake - due to low no. of nests & less no. of weed spp. in the lake. 35

36 4. CONCLUSIONS Availability of water, safe habitat & food sources for both adults & nestlings; essential nesting & roosting sites around the lakes - play an imp. role for the occurrence & abundance of WB. populations. Water depth, water quality & trophic structure imp. lake characteristics that influences the abundance & diversity of WB.C. Proper & regular maintenance of GBMC lakes further increases the WB. populations. Results of this study - help to conserve WB. populations in urban regions. 36

37 5. RECOMMENDATIONS Among 15 study lakes, only Jakkuru lake - under rejuvenation process; Hebbala lake - maintained by East India Hotels (under Public Private - Partnership policy). Privatization of Hebbala lake has been pointed out as a threat to the bio-diversity of the lakes, particularly the birdlife as the company plans to introduce recreational activities on the shore apart from draining & drying of the lake for various operations. Kengeri KFD; Lalbagh Botanical Garden & Ulsooru lakes BLDA; Hesaraghatta & Thippagondanahalli lakes maintained - BWSSB. Whereas remaining 8 lakes are not maintained properly. 37

38 Lakes - rejuvenated with 2-3 islands planted with suitable vegetations. Plants & trees - maintained around the lakes for the roosting & nesting of waterbirds. Lake areas, where there is no proper bunds are to be handed over to the Forest Department for tree planting; KFD shall work out programme for formation of tree parks/ foreshore tree planting & formation of regional parks & for implementing the programme. Operation of local fishing boats - not be permitted in less than 50 ha. 38

39 In larger & smaller lakes, the no. of fishing boats - be limited/ minimized. Boating activities - be avoided during avian breeding season in winter, because of arrival of migratory birds. Small sized gill nets - not be allowed to catch small fishes, which are main source of food of waterbirds. Recommendations shall be implemented to improve the quality of lakes which helps to conserve waterbird populations in urban regions & the city will become a paradise of avifauna. 39

40 The paper is presented in Lake2010: Wetlands, Biodiversity and Climate change Bangalore, 22 nd 24 th December 2010