A Survey of the Birds of Indroda Nature Park in Gujarat, India
The Asian koel calls incessantly from the folds of the neem tree outside, and I open my eyes. A house sparrow dodges the whirring fan blades and lands daintily on top of the ceiling fixture. Oblivious of my gaze, she tucks another blade of dry grass into the nest above the fan. A house sparrow worthy of its name, I think. Waking up in India is a dream.
In the summer of 2006, I spent a month in Gujarat, in western India (see Map 1), visiting family. It was the middle of June, but in India summer was coming to a close. Every living thing was waiting for the monsoon rains to arrive and put an end to the infernal heat. It was perhaps not the best time of year to study birds, but for an apartment-dwelling, sun-deprived Connecticut bird enthusiast, any time was good enough for a field trip.
I had read alarming reports (Swan, 2006) about recent precipitous declines in vulture populations across India, and I wanted to help with their conservation. The Gujarat Ecological Education and Research Foundation where I hoped to work had just completed their report on Gujarat's vultures. Unfortunately, I had arrived too late.
While talking to the director of the foundation about vultures and other potentially vulnerable bird species, he pointed out that one of the reasons the vulture crisis loomed so large and so suddenly was that in India there is a paucity of general bird surveys. Citizens' science groups or bird clubs in India are few in number, so monitoring species abundance and fluctuations is difficult. The onus of collecting even basic data falls on research institutes with big mandates and very few resources.
It was obvious; I had to put my bird identification skills to good use and conduct a field survey of my own. The director suggested I document the birds of Indroda Nature Park, and he offered me the services of a "local chap" to be my guide. He also introduced me to an ornithologist on his staff in case I needed any help. He then left me to my own devices.
My guide, Irshad Theba, was the park warden's son. He was two years older than me, and although he never finished school, he remained a student of nature. He had the quiet manner of someone whose eyes miss nothing. He spoke little English, and I little Gujarati, but we had no problem communicating. Once we set foot on a trail, we found our lingua franca: birds.
The aim of my survey was to create a comprehensive species list of the avifauna in Indroda Park, and to estimate the relative abundance and habitat preferences of each species. Because it was breeding season, I also recorded some nesting data.
The park's size was both small enough to survey with some accuracy and large enough to support many resident and migrant species. Anthropogenic pressures such as grazing, firewood collecting, farming, and land development have forced the birds of Gujarat either to adapt to the altered environments, or to survive in small habitat refuges (Islam and Rahmani, p. 377). Although not a pure wilderness, Indroda Park provides a variety of habitats for a multitude of bird species, making it an ideal location to learn about the habitat preferences and breeding habits of central Gujarat's avifauna. A survey of the park's birdlife would give an accurate picture of its summer avian population and provide insight into the breeding of resident species.
Materials and Methods Geography
Indroda Nature Park, covering 468 hectares, is situated on the outskirts of Gandhinagar, the state capital of Gujarat. The Sabarmati River bisects the park; in the summer a thin ribbon of water flows sluggishly in a wide and sandy riverbed, but in monsoon the river is heavy with water and spreads water life up onto its banks (see Fig. 1).
The park is surrounded by developed land on all sides. There are office buildings, a small zoo, and botanical gardens within the park boundary (see Map 2).
I made ambitious plans to grid off the park and walk timed transects, but the plan proved impractical. It was impossible to walk a straight line in the snake-infested ravines and thorny brush terrain; besides, the only map I could lay my hands on was hopelessly inaccurate. I wanted to start at dawn, when birds are most visible and audible, but that, too, was not to be. I lived an hour away from Indroda and had no way of getting there at sunrise. Reality always gets in the way, especially when you are 16.
Without a dependable map, it was difficult to measure and compare the relative sizes of bird habitats. After reconnaissance, I decided to divide them into four broad categories: forest, scrub, water, and human-influenced.
Forest habitats were stands of trees taller than five meters. Typically, they were plantations of Acacia nilotica, A. tortilis, and A. senegal, as well as Prosopis cineraria, Azadirachta indica, and Eucalyptus sp. Most trees were no taller than eight meters and were planted in even rows (see Fig. 2). In places the forest had a groundcover of small legumes and grasses like Cenchrus biflorus. One small stand of forest had grown in a wet ravine; it had a dense growth of broadleaved Ficus species, with an understory of other broad-leaved species. I identified 16 forest areas in all.
Scrub habitats featured small thorny bushes, less than five meters tall, of Acacia and Prosopis species, especially the invasive P. juliflora, as well as other genera such as Zizyphus and Salvadora. The growth of many scrubland species was stunted because the soil was poor and degraded. In many cases this stalled its ecological succession and prevented the land from becoming a forest. There were nine areas I identified as scrub.There were three water habitats: a small man-made lake by a lawn, a sandy bank along the stagnant Sabarmati river, and a flooded field, waterlogged because of a broken pump. Even here, there were Phragmites around the lake.
Human-influenced habitats were around the zoo, the gardens, and the buildings. There were ornamental plants, native and non-native species, a medicinal herb garden, and an arboretum. There were areas without cover such as lawns and roads, and a lot of human traffic. I counted 11 such areas.
Forest and scrub areas covered approximately 60% of the park, human-influenced habitats 30%, and water habitats 10%.
Because these habitats were of differing sizes, I used transect sampling for data collection. All of my data was collected between June 27 and July 12, 2006, for a total of nine days. I also took timed point samples on three instances: June 30, July 11, and July 12. I collected data for four hours each day, from 8:30 a.m. to 12:30 p.m.
Every morning I would meet Irshad at the gate, and we followed a predetermined route. We visited each area twice, walking the park in a crisscross pattern. I had a pair of Nikon Monarch binoculars; Irshad had his bionic eyes.
Each time I sighted a bird, I would make an identification and record the name of the species, the number of birds of that species, and the behavior of the bird in my notepad. Upon spotting a nest, I also made an identification, noted the nest's shape, the presence and number of eggs and chicks, its location, its estimated height in meters above the ground, and the tree species in which it was found. I only noted data I was able to collect; where nests were out of reach or the inhabitants not visible, I did not include that information.
I have always believed that 120 degrees of human vision isn't enough; time and again I was forced to borrow Irshad's eyes as well. Irshad's bird identification skills were surprisingly good; between the two of us I like to think we managed to note all the bird activity around us. Apart from visual identification, I also chose to include birds identified by call, excluding the abundant and very vocal peafowl, whose relentless wails came from all directions! At around noon, when most birds retreat from the oppressive midday heat, we, too, headed home for lunch. After lunch I entered the day's data in the computer.
Relative Abundance and Richness
I documented a total of 1,451 individual birds, representing 78 species, and noted further evidence of another three species by their nests.
The 16 areas classified as forest yielded a total of 647 birds of 63 different species, representing 44.6% of the total number of birds and 80.8% of all bird species found in the park (see Chart 1 and Chart 2). Nine species were exclusively documented in the forest habitat: Tickell's blue-flycatcher (Cyornis tickelliae), rufous-backed shrike (Lanius schach), painted stork (Mycteria leucocephala), common woodshrike (Tephrodornis pondicerianus), yellow-wattled lapwing (Vanellus malabaricus), black-headed cuckoo-shrike (Coracina melanoptera), black-shouldered kite (Elanus caeruleus), red-collared dove (Streptopelia tranquebarica), and plain prinia (Prinia inornata). The common hoopoe (Upupa epops) (see Fig. 3), large gray babbler (Turdoides malcolmi), and rose-ringed parakeet (Psittacula krameri), although found in other habitats, were in greatest numbers in the forest.
The nine scrub areas had the second-highest values for both species richness and abundance of birds; they supported 427 individual birds of 51 different species, representing 29.4% of the individual birds spotted and 65.4% of total species spotted. Three species were exclusively seen in the scrub: ashy prinia (Prinia socialis), Asian palm swift (Cypsiurus balasiensis), and common babbler (Turdoides caudatus), though all in low numbers. The Brahmini starling (Sturnus pagodarum), small bee-eater (Merops orientalis), and white-throated munia (Lonchura malabarica) were found in markedly higher numbers in the scrub areas.
The three water habitats attracted 239 birds representing 24 species; that is, 16.47% of the number of birds and 30.8% of all species. Birds which were exclusively or almost exclusively recorded in water habitats were: blue rock pigeon (rock dove) (Columba livia), comb duck (Sarkidiornis melanotos), gray heron (Ardea cinerea), Indian roller (Coracias benghalensis), large egrets, (Casmeroides albus), median egrets (Mesophyx intermedia), little egrets (Egretta garzetta), little grebe (Tachybaptus ruficollis), and lesser whistling duck (Dendrocyna javanica).
The 11 human-frequented areas were poorest in terms of abundance, with only 196 birds recorded. However, 39 species, or 50% of all species, were recorded in human-disturbed habitats. So, despite the low abundance, the area was still fairly high in richness. Two species, the purple-rumped sunbird (Nectarinia zeylonica) and the spotted dove (Streptopelia chinensis), were the only species noted in human-disturbed habitats that were not found in the other three habitats. Only the jungle babbler (Turdoides striatus) seemed to prefer human-influenced areas—30 out of the 44 total were seen in such habitats; every other species present on human-influenced land was more abundant in the other three habitats.
I recorded more than 110 nests, and found additional evidence of nesting in the park. A number of species built nest holes in riverbanks, ravines, and road cuts. By observing the hole for telltale signs of activity, I determined the species that inhabited them. Distinguishing between bird cavities and reptile holes was difficult at times; eroded and abandoned holes also confounded the counting. I noticed that banks shorter than four meters did not show evidence of bee-eater (Merops) nesting.
Spotted owlets (Athena brama) also built nest holes at the same height as bee-eaters. The bank myna (Acridotheres ginginianus), on the other hand, showed no pattern according to height; being a gregarious bird, its nests were in proximity to one another on the same bank. The common myna (Acridotheres tristis) was very adaptable in its nesting choice; their tree nests were more abundant and ranged from as low as three meters in a live Albezia lebbek tree, to 15 meters in a thoroughly dead tree of the same species. Where breeding sites were abundant, mynas formed colonies. One nest was stunningly situated under the tongue of a giant Tyrannosaurus rex sculpture by the zoo; there the myna had built a twig nest.
Certain species were noted at various stages of the breeding process. In June, a white-breasted water hen (Amaurornis phoenicurus) was spotted leading three fuzzy black chicks. Nearly two weeks later, another water hen was spotted incubating eggs in a freshly made nest. Similarly, the golden oriole (Oriolus oriolus) was seen both with fledglings and building nests.
Nests woven from twigs, grasses, and bark were very common, though often more difficult to locate than those in tree cavities and bank holes. The limiting factors in nesting appeared not to be nesting materials but nesting spaces. The average tree in the park is a five-meter-tall Acacia nilotica, a perfect height for species such as the black drongo (Dicrurus macrocercus) and the large gray babbler (Turdoides malcolmi); thus, their nests were relatively common. The shikra (Accipiter badius) and both species of crows (Corvus) illustrated a different trend; the sole shikra nest I surveyed was located in an Azadirachta indica tree seven meters high, while the four jungle (Corvus macrorhynchos) and house crow (C. splendens) nests were found on a tall Acacia nilotica between 7 and 10 meters high. Since neither shikra nor crow nests were found in any other sites, one may note their preference for taller trees. Bay-backed and rufous-backed shrikes (Lanius vittatus and L. schach), the white-throated munia (Lonchura malabarica), the red-vented bulbul (Pycnonotus cafer), and the large gray babbler (Turdoides malcolmi) preferred nesting in Acacia tortilis, which is a dense and thorny species.
Discussion and Conclusion
I was surprised to discover the tolerance of Indian birds to human-influenced areas, although the data does show that their numbers drop in human surroundings. Even the notoriously commensal house sparrow (Passer domesticus) was more abundant in scrub! The absence of the blue rock pigeon (Columba livia) in the human-influenced habitat was equally surprising. I sighted 80 or so individuals roosting in tall Acacia trees growing on small mounds in the artificial lake. Had the birds convened at the lake for water after feeding on grain all morning? Once the midday heat died down, would they return to nearby buildings for food? I suspected an American bias in my thinking because I know it as the only member of the Columbidae family that lives close to man in the United States. But in India, where there are more dove species to share the human niche, the blue rock pigeon appeared to have retained its original place in the ecosystem.
Forest habitats supported both arboreal as well as terrestrial species of birds. The rose-ringed parakeet (Psittacula krameri) and the black-rumped flameback (Dinopium benghalense) are purely arboreal species, while the black ibis (Pseudibilis papillosa) and the Eurasian thick-knee (Burhinus oedineus) are purely terrestrial species. All four were common in the forests but rare or absent in the scrub. I wondered why. One reason could be that for arboreal species the scrub did not provide an adequate canopy, and for terrestrial species the scrub was too dense and hard to forage in, especially for larger birds. The Acacia trees prohibited the growth of dense groundcover plants; this left the forest floor open for both terrestrial and arboreal assemblages of birds.
At any given time I saw more birds, in number and species, at the three water habitats than in the forest. However, since water habitats covered a proportionally smaller area than the other habitats, the numbers of birds there also appeared proportionally fewer. Water scarcity not only caused water-specific species to gather, but also attracted birds from other habitats—I noticed the Indian roller (Coracias benghalensis) hawking insects above the stagnant water in the flooded field.
Grouping together diverse areas into four broad categories was necessary but unfortunate. The forested areas were not the same; the composition and location of the forest determines the species present. Tickell's blue-flycatcher (Cyornis tickelliae) was seen only once, perched in the dense understory of a shady, broad-leaved forest. Only one such forest existed on the park; hence the low numbers of this bird.
The two painted storks (Mycteria leucocephala) and the single black-shouldered kite (Elanus caeruleus) were seen flying over the forest habitat and therefore were included among forest birds. However, this does not mean that these two species are forest-specific. A single plain prinia (Prinia inornata) was sighted singing in some bushes on the edge of the Eucalyptus forest and was by default included as a bird of the forest. Whether this is its preferred habitat I could not determine, though this was the only place in which it was seen during the survey.
Similarly, I only noted one individual of both ashy prinia (Prinia socialis) and Asian palm-swift (Cypsiurus balasiensis); again, the reason for only one sighting could not be determined. In fact, the Ashy prinia was heard, not seen, in an Acacia scrub. The purple-rumped sunbird (Nectarinia zeylonica) and the spotted dove (Streptopelia chinensis) were both seen on one occasion in a parking lot—the dove feeding on the dusty ground, the sunbird in Acacia nilotica blossoms. Further studies should determine the correlation between the presence of each species and their habitat. Birds nest at the highest point on a bank whenever possible, presumably for safety; the frequency and locations of bank holes are ample evidence. The shikra (Accipiter badius) was the only bird to nest in the Azadirachta indica plantation. In general, A. indica is excellent for nesting purposes, but since smaller passerines were absent from the forest, one can assume that the presence of the shikra had driven other nesters out.
Sometimes the birds themselves suggested breeding; nearly every sighting of Eurasian collared and little brown doves (Streptopelia decaocto and S. senegalensis) was of a pair. The small minivets (Pericrocotus cinnamomeus) (see Fig. 4) would warn their mates of my approach and then flee together. My survey occurred just before the monsoon; birds were passionately pairing up in anticipation of the fertile season, when dense vegetation and insect life would allow them to breed.
The lack of satellite-based map was a major hurdle. It would have allowed me to make a grid and measure area density with accuracy, and it would have allowed new comparisons between habitats. Instead, I was forced to classify each area in the field as I walked it, making for a patchwork of data.
Other factors are likely to have affected the results of the survey. Large or vocal birds were more likely to be recorded than small or reclusive species. The Oriental honey-buzzard (Pernis ptilorhynchus) was recorded in multiple locations, and my data suggested seven birds. However, since it was often seen soaring, and was spotted from long distances, it was very likely overcounted. A pair was seen in the Eucalyptus forest, so I can infer that the same pair was sighted multiple times.
A few biases affected my nesting data. Bird nests are difficult to locate, and so the larger nests in the open were more likely to be spotted and surveyed; nests of common but secretive species that nest in dense, broad-leaved shrubs, such as the common tailorbird (Orthotomus sutorius) and the prinias, may have been in greater numbers than my data suggests. Because walking transects required discipline and consistency, many nests were probably overlooked.
The richness of bird life rested upon the diversity of plants that made up the habitat. But what was the relationship between the individual bird species and plant species? Would a forest naturally regenerated from scrubland support more birds than an artificially planted forest? What other factors decided the taxa and abundances present in each habitat? What I knew for certain was that every habitat was essential to the diversity of birdlife in Indroda Park; each supported healthy populations of common species and provided habitat for less common species. Overall, none of the species I surveyed were rare or endangered.
It is so easy to take common birds for granted, especially in India, where birds are so abundant. In the past eight years, vulture populations in India have gone from tens of millions to less than 10,000 (Vanishing Vultures, 2006). Three years ago, when I came to India, they were still circling the city skies, and I did not give them a second thought. Last summer I did not see one. The survey gave me a chance to look at each and every bird with a more loving and grateful eye.
Brower, James E. Field and Laboratory Methods for General Ecology. New York: McGraw-Hill, 1997.
Grimmett, Richard, Carol Inskipp, and Tim Inskipp. Birds of India, Pakistan, Nepal, Bangladesh, Bhutan, Sri Lanka, and the Maldives. Princeton, New Jersey: Princeton University Press, 1999.
Indroda Nature Park—A Wilderness Park. Gujarat Ecological Education and Research Foundation. Retrieved from the World Wide Web on 13 March 2007. http://www.geerfoundation.gujarat.gov.in/parks_inp.htm.
Islam, Zafar-ul, and Asad Rahmani, eds. Important Bird Areas in India: Priority Sites for Conservation. Bombay, India: Indian Bird Conservation Network, Bombay Natural History Society and Birdlife International, 2004.
Rasmussen, P.C., and John C. Anderton. Birds of South Asia: The Ripley Guide. Washington, D.C. and Barcelona: Smithsonian Institution and Lynx Editions, 2005
Sahni, K.C. The Book of Indian Trees. Mumbai: Oxford University Press, 2000.
Sutherland, William J., ed. Ecological Census Techniques: A Handbook. Cambridge: Cambridge University Press, 1996.
Swan, Gerry E. Toxicity of diclofenac to Gyps vultures. Biology Letters 2 (2006): 279-282.
Vanishing Vultures. Dir, Mike Pandey. Earth Matters Foundation. DVD. 2006.
I would like to thank Irshad Theba for making data collection both a possibility and a pleasure, and to Mr. C.N. Pandey at GEER for suggesting such an interesting project. My special gratitude to Jankiben Teli and Ms. Emily Sprowls for their wisdom and encouragement.
More About This Resource...
This winning entry in the Museum's Young Naturalist Awards 2007 is from a Connecticut 11th grader. Arjun conducted a field survey of the birds of Indroda Nature Park. His essay includes:
- details about his summer trip to Gujarat, in western India, and how he came to conduct a field study;
- the materials and methods he used to create a comprehensive species list of the avifauna in Indroda Park, and to estimate the relative abundance and habitat preferences of each species; and
- the results of his field study, during which he documented 1,451 individual birds that represented 78 species.
OriginYoung Naturalist Awards