An overview of Kukkarahalli Lake Birds and Butterflies
- Depending on the type of natural habitat, bird density and diversity differs. More birds frequent water-bodies, woodland, and grasslands. The Kukkarahalli Lake surrounded by CFTRI, RIE, AIISH, Chandravana, and Mysore University is a vast expanse of green patch supporting varied life forms. Mysore University campus and the Lake supports 432 species of plants spread over 85 families (Rao & Razi, 1974).
- The Lake is an Important Bird Area (IBA no. IN KA-20) prioritized for conservation as breeding of vulnerable- Spot-billed Pelican Pelecanus philippensis; near threatened Darter Anhinga melanogaster, Painted Stork Mycteria leucocephala, Oriental White Ibis Threskiornis melanocephalus exists .
- Within Kukkarahalli many habitat types occur, birds may utilize a few of these. The majority of birds strictly restrict to particular habitat where ample natural food and suitable micro habitat exist. For example, family Ardeidae(Egrets, Heron & Bittern) mostly found in shallow waters, followed by Reed beds, floating vegetation and drying water hole. The variation in the habitat usage pattern infers availability of preferred food in turn quality of water body. Incase habitat is poor in resource, resident and migratory birds will find another.
- Migratory birds fly vast distances in north – south axis from arctic and temperate regions where they reproduce to foraging sites in temperate and tropical areas, twice a year. Indian sub-continent lies within Central Asian Flyway one among known eight flyways, and is shortest of all. This flyway happens to be within the Northern Hemisphere. More than 300 species use the Central Asian Flyway. Several species undertake regular, seasonal movements within the Indian subcontinent. Kukkarahalli, being part of central-Asian Flyway hosts around 51 migratory birds out of 169 recorded so far in recent years. Greenish warblers and Paddyfield Warblers arrive from West Palaearctic; from same region comes Rosy Starlings whose population fluctuates depending on the success of monsoon in northern India. Trees in isolated breeding island is an ideal roosting ground for them. Green warblers from Caspian region; Red-breasted Flycatchers arrived from Western Palaearctic whereas Taiga Flycatchers from Eastern Palaearctic, till recently these were considered as a single species.
- Water birds utilize the wetland for day to day activities - either throughout or during certain part of their life.
- Birds forage on insects (including aquatic) and their larvae, worms, termites, wasps, bees, ants, moths, butterflies, beetles, dragonfly, grasshoppers, cicadas, frogs, tadpoles, fish, crustaceans, molluscs, shrimps, crabs, Plankton, lizards, snakes, mice, offal, carrion and garbage; grains, seeds, tender shoots, pollen, nectar and marsh plants, and fruit.
- Birds’ diet depends on the species and changes with the seasons depending on the availability of natural food. By ensuring a diversity of native plants that support insect life, fruits at different time of the year offering berries, seeds retain the bird’s density and diversity throughout the year. Smaller herbs & grass undergrowth to shrubs to trees -offering different strata of vegetation, provides supportive summer and winter cover as well supports suffice food for sustenance.
- Habitat modification or disappearance always affects residing population.
- White-bellied Drongo is usually found in dry scrub or open forests; gradual transformation to secondary woodland (closed canopy plantations) deterred birds from getting flying insect as food hawked on wing due to absence of clear visibility.
- Red Avadavat is a bird of flat plains, in places with tall grasses or crops, often near water open fields and grasslands; gradual reduction and finally absence of habitat costed Avadavat and like grainivorous species.
- Indian thick-knee used to reside in area between eastern shore and present day Kalamandir compound. Opening up of 3 walkways and surge of walkers for almost 6 hours a day causing disturbance might have driven birds away. But it is observed that one or two individuals tried to breed here, but success could not be ascertained.
- Streaked weavers primary diet is seeds and habitat - reedbeds associated with grains field. Here, lengthy grasses that were present in open grasslands off hunsur road, horticulture property has disappeared affecting granivourous birds.
- Large Grey Babblers ard birds of open scrub country, forage on or close to the ground. Habitat’s gradual transformation to Woodland with closed canopy driven babblers to possibly suitable habitat around heritage Ficus religiosa tree in University campus.
- Micro habitats mentioned below is most essential for birds presence and survival.
- Nests: floating – half submerged, reed beds,
- walking about on the grass-covered edges of Lakes
- Total area of the lake is 104 hectares and water spread area is 49 hectares when full. As most of the catchment area feeder canal is encroached upon, lake hardly gets fresh water. So, at any point of time, vegetative cover is more than half of the area. Kukkharahalli vegetation is not exposed to pesticides or harmful toxic chemicals. Birds especially those consume insects are residing perpetually (refer graphs). But same cannot be referred to water birds. Contamination through sewage and run off rainwater drastically affected aquatic life forms, soil-dwelling insect and worm populations, thus keeping away the water birds (refer graphs). Improvement of water quality can bring the variety of water birds that have stopped visiting.
- Historical records of -Lesser Adjutant, Egyptian Vulture, White-rumped Vulture, Eurasian Curlew, Zitting Cisticola, Black Winged Kite, Streaked Fantail Warbler, Plain Prinia, Rufous backed Shrike, Lesser Pied Kingfisher, Jungle bush Quail have not been listed in the checklist of birds. Roosting and foraging consistency is altogether missing in case of aquatic birds like --Shovellers. Pintals, Garganey, Lesser Whistling Teal. In addition, dwindling in population of White-bellied Drongo, Red Munia, Large Grey Babbler, Streaked Weaver Bird, and Stone Curlew have been observed mainly due to habitat modification, increased human presence and extensive growth of city dwellings around the lake.
PROBABLE REASONS AFFECTING THE DIVERSITY & DENSITY:
- Disappearance of grassland, mono-cultured plantations. The vegetation has undergone a significant change. Plantation and woodland have succeeded grassland in the northwestern part of the lake over period of 30 years. A corresponding change in bird life has been seen, with disappearance of grassland species.
- Isolated island in lake hosted colonial breeding activity of Pelicans from 1998-1999 onwards; whereas, Painted Storks & White Ibises breeding was well before 1996.
- Non-availability of favoured depths. Change in the habitat condition –water quality affecting the primary producers and consumers and intern feed to the birds
- Extensive human traffic throughout the year causing disturbance for foraging, roosting and breeding (decreases or even retards reproductive capability)
- Secluded nesting and roosting sites are exposed to the humans and stray and pet dogs.
- Construction activity like Training college, Vehicle parking area, Shops & eatery outlet, Widened walking trail, Paragola, Amusement park, and Gardens has reduced considerable size of Lake area.
- Occasionally Rangayana encroaches upon greenery on its southern boundary.
- NCC (Navy) wing boats are found sailing all around the Lake disturbing foraging birds repeatedly whenever the Lake has sufficient water. They were supposed to sail with hand roved boat adjoining Lake bund within marked zone with floats, but not beyond that.
IDEAS FOR IMPROVING BIRDS STATUS:
- Reedbeds are part of wetland land ecosystems are dynamic in nature with succession and associated drying. The older and drier parts of the reed bed support the highest overall invertebrate diversity. Invertebrate assemblages are ultimately part of wider food supporting scores of fishes, amphibians, birds & mammals. Note that all stages of reedbed succession also support invertebrate communities. Over the years, generations of reedbeds growth and drying results in considerable litter layer that rises above the water level. Thus giving way for scrubs and trees and gradually eliminating the reedbed habitat. So, management is necessary to have perpetual reed beds. Managing a range of succession stages of reedbeds will enhance their conservation value and biodiversity.
- Avoid human movement close to shores where waders are actively foraging
- Shun boating /fishing that affects open water foraging, resting, roosting birds and affecting nesting activity
- Continuous clearing of shrubs and undergrowth throughout the year.
- Augmentation of fresh water inlet
- Study floral diversity in comparison with the documentation of Raghavendra Rao & Basheer Ahmed Razi (1974).
- Online monitoring of biodiversity components like Birds, Butterflies, Spiders, Dragonflies, etc.,
CHECKLIST OF KUKKARAHALLI LAKE BIRDS:
(Index: STATUS – R Resident, M Migratory; ABUNDANCE – VC Very Common, CM Common, UC Uncommon, R Rare, VR Very Rare; HABITAT GUILD - Aq Aquatic, T Terrestrial, Ar Arboreal, Ae Aerial; FEED GUILD – I Insectivore, C Carnivore, O Omnivore, G Granivore, Herbivore, F Fruigivore, N Nectarivore)
A. Bird species according to their habitat guilds
B. Bird species according to their feed guilds
C. Abundance of Avian community
Very common (found throughout season), Common (> 75% sightings), Uncommon (< 50% sightings), Rare (< 25% sightings), Very rare (less than five sightings)
Study over a period of a Two decade has resulted in observation of 86 species representing five families. Regularly Common Sailer, Blue Tiger, Psyche and rarely Bamboo Tree Brown, Common Silverline are met with. Occasionally rare butterfly like -Chestnut streaked Sailer, Gaudy Baron and Peacock Royal have been recorded. Abundance, seasonal variation and encounter frequency have been depicted below. Repeated clearance of under herb and shrub in Lake Premises has drastically reduced the diversity and density count.
Typical Seasonal variation of density and diversity of Butterflies in Mysore
Abundance of Butterflies in Kukkarahalli Lake (first 15 species)
IDEAS FOR IMPROVING BUTTERFLY STATUS:
- Butterflies are one of the pollinators playing a very important role in the food chain. Depending on available host and nectar plants butterflies are found in variety and numbers. Each butterfly species has a specific host plants on which its caterpillar feed. Butterfly diversity of a place can be predicted by the mere presence of floral diversity and vice versa. Re-creating the natural habitat for butterflies would enumerate their diversity.
- Butterflies need supplementary diet in the form of minerals for reproduction, which they get from mud patches, soil, carcasses, salt, manure, rotten fruits & vegetables, urine, dung, standing water, tree sap etc. Habitat with such mud puddling patches will definitely allure the species, which regularly mud-puddle.
- Since butterflies are fragile, they need protection in terms of bushes, shrubs against winds and heavy rains in different tiers.
- Using of pesticides and insecticides is harmful to host and nectar plants and directly affects the butterfly life cycle and also the macro habitats of other variety insects.
- https://ebird.org/barchart?byr=2000&eyr=2018&bmo=1&emo=12&r=L2479400. Accessed on 01/5/2018.
- Islam, M.Z. & A.R. Rahmani. 2005. Important Bird Areas in India: Priority sites for conservation. Mumbai: Indian Bird Conservation Network: Bombay Natural History Society and BirdLife International (UK).
- Rao,R.R & Razi,B.A. 1974. Flowering plants of the Mysore University campus, Prasaranga, University of Mysore, Mysore.
- Rao,R.R & Razi,B.A. 1981. A synoptic flora of Mysore district, Today & Tomorrow's printers and publishers, New Delhi.
(Article prepared in May 2018)