Ranade: Whiskered Terns 7

References Jha, K. K., 2012. Some breeding and ecological aspects of colonial nesting waterbirds at Anonymous. 2020a. Website URL: https://censusindia.gov.in/pca/pcadata/Houselisting- Soor Sarovar Bird Sanctuary Agra, Northern India. Asian Journal of Conservation housing-TM.html. (Accessed on 09 November 2020.) Biology 1 (1): 35–41. Anonymous. 2020b. Website URL: http://www.imdchennai.gov.in/NEM2018.pdf. Kharitonov, S. P., & Siegel-Causey, D., 1988. Colony formation in seabirds. Current [Accessed on 07 July 2020.] Ornithology 5: 223–272. Baker, R. H., 1940. Crow depredations on heron nesting colonies. The Wilson Bulletin Madden, C. E., Arroyo, B., & Amar, A., 2015. A review of the impacts of corvids on bird 52 (2): 124–125. productivity and abundance, Ibis 157: 1–16. Bibby, C. J., Burgess, N. D., Hill, D. A. & S. Mustoe, S., 2000. Bird census techniques. Nair, N. C., & Henry, A. N., 1989. Flora of Tamil Nadu, India. 3 vols. Botanical Survey Elsevier. of India, Calcutta. Dorfman, E. J., & Read, J., 1996. Nest predation by corvids on cormorants in Nathan, K. K., 1980. Droughts in Tamil Nadu: A qualitative and quantitative appraisal. Australia. Emu-Austral Ornithology 96 (2): 132–135. Drought Network News 10 (3): 3–6. Erwin, R. M., Nichols, J. D., Eyler, T. B., Stotts, D. B., & Truitt, B. R., 1998. Modeling Paulraj, S., 1985. Studies on Vedanthangal Bird Sanctuary. Project Report-Final. Parts 1 colony-site dynamics: a case study of gull-billed terns (Sterna nilotica) in coastal & 2. Report submitted to the Chief Conservator of Forests, Madras, Tamil Nadu. Virginia. The Auk 115 (4): 970–978. Roshnath, R., & Sinu, P. A., 2017a. Are the heronry birds adapting to urbanization? Zoo’s Ewins, P. J., 1991. Egg predation by corvids in gull colonies on Lake Huron. Colonial Print 32 (12): 27–33. waterbirds 14 (2): 186–189. Roshnath, R., & Sinu, P. A., 2017b. Nesting tree characteristics of heronry birds of urban Fasola, M., & Alieri, R., 1992. Conservation of heronry Ardeidae sites in North Italian ecosystems in peninsular India: implications for habitat management. Current agricultural landscapes. Biological Conservation 62 (3): 219–228. Zoology 63 (6): 599–605. Fellowes, J. R., Fang, Z., Shing, L. K., Hau, B. C., Lau, M. W., Lam, V. W., & Hafner, H., Roshnath, R., Athira, K., & Sinu, P. A., 2019. Does predation pressure drive heronry 2001. Status update on White-eared Night Heron Gorsachius magnificus in South birds to nest in the urban landscape? Journal of Asia-Pacific Biodiversity 12 (2): China. Bird Conservation International. 11 (2): 101–111. 311–315. Garg, A., 2016. Nest–plant correlation and predator preclusion in Asian Openbill Storks Santharam, V., 1990. Asian waterfowl counts 1990—a report. Blackbuck 6 (1): 7–11. (Anastomus oscitans): a case study from Nawabgunj Bird Sanctuary, India. Indian Subramanya, S., 1996. Distribution, status and conservation of Indian heronries. Forester 142 (2): 179–186. Journal of the Bombay Natural History Society 93 (3): 459–486. Gibbs, J. P., 1991. Spatial relationships between nesting colonies and foraging areas of Urfi, A. J., 2010. Using heronry birds to monitor urbanization impacts: A case study of Great Blue Herons. The Auk 108 (4): 764–770. Painted Storks Mycteria leucocephala nesting in the Delhi Zoo, India. Ambio 39 Hafner, H., 2000. Heron nest site conservation. In: Kushlan A. J., Hafner, H., (Ed). Heron (2): 190–193. conservation. San Diego (CA): Academic Press. Pp. 201–215. Vaneerden, M. R., Koffijberg, K., & Platteeuw, M., 1995. Riding on the crest of the wave— Jamgaonkar, A. V., Jacob, P. G., Rajagopal, S. N., & Bhat, H. R., 1995. Records of new possibilities and limitations for a thriving population of migratory Cormorants breeding colonies of Painted Stork Mycteria leucocephala in Karnataka. Pavo 32 Phalacrocorax carbo in man-dominated Wetlands. Ardea 83 (1): 1–9. (1&2): 59–62. Veitch, B. G., Robertson, G. J. Jones, I. L., & Bond, A. L., 2016. Great Black-backed Gull Jayson, E. A., 2001. Structure, composition and conservation of birds in Mangalavanam (Larus marinus) predation on seabird populations at two colonies in eastern Mangroves, Cochin, Kerala. Zoos’ Print Journal 16 (5): 471–478. Canada. Waterbirds 39 (Sp1): 235–245.

Breeding colonies of Whiskered Terns Chlidonias hybrida in Assam

Sachin Ranade

Ranade, S. P., 2021. Breeding colonies of Whiskered Terns Chlidonias hybrida in Assam. Indian BIRDS 17 (1): 7–9. Sachin P. Ranade, Vulture Conservation Breeding Centre, Belguri Village, Rani, Kamrup District, Assam 781131, India. E-mail: [email protected]. Manuscript received on 30 June 2020.

he Whiskered Tern Chlidonias hybrida has a wide distribution Whiskered Terns in Morigaon, Kamrup, and Sivasagar districts of range covering four continents: Africa, Asia, Europe, and Assam. The observations of breeding birds were carried out from TAustralia. In South Asia, it is known as a breeding resident a safe distance of about 200 m. I visited the site approximately in the Gangetic Plains and is likely to breed in Afghanistan. It once a week, prioritising the welfare of the species (Barve et al. is a winter visitor and passage migrant in most of parts of the 2020). Indian Subcontinent (Rasmussen & Anderton, 2012; Gochfeld I observed a nesting colony of the Whiskered Tern on the et al., 2020). Ali & Ripley (1983), mentioned that the Whiskered outskirts of Pobitora Wildlife Sanctuary (26.23°N, 92.03°E; c.52 Tern breeds in North Cachar in Assam, Kashmir, Delhi, Uttar m asl), in Morigaon District [4], about 30 km from Guwahati, Pradesh, and Bihar, and in Bangladesh. Rasmussen & Anderton Assam. The Sanctuary resides in the floodplain of the Brahmaputra (2012) expressed the need of substantiating its breeding reports River and encompasses large water bodies, grasslands, and from Assam, and Bangladesh. Hussain et al. (2018) reported woodlands. I spotted Whiskered Terns along an 80 km stretch the presence of Whiskered Terns, in their breeding plumage of the Brahmaputra, from the Sanctuary in the north to Mirza, [3], from various places in Assam. As per eBird, there were 87 Kamrup District in the south. Whiskered Terns breed in Water sight records of this species from Assam until June 2020. Here, Hyacinth Eichhornia crassipes infested lagoons, on both sides of I would like to provide the records of breeding populations of the Brahmaputra River. Their eastern-most breeding colony was 8 Indian Birds Vol. 17 No. 1 (Publ. 29 March 2021)

sighted in Sivasagar District, also on the bank of the Brahmaputra hrs through binoculars, and also photographed their activity. The (Fig. 1). nests were on an ‘island’ of Water Hyacinth growing in marshland. It was c.200 m from the road, undisturbed by the traffic. The nests were concealed in vegetation and quite far away from me to confirm the presence of eggs or chicks. I presumed the existence of nests when I saw adult terns landing frequently in the hyacinth patch, carrying either nesting material in their beaks, or food for a partner. The adults used aquatic vegetation as nest material [5], and collected this during short flights, or hovering over potential material and extracting it. The terns guarded their nests zealously. During the three months of observation, they were seen chasing away, and diving at Purple Swamphen Porphyrio poliocephalus (n=16), Yellow Bittern Ixobrychus sinensis (n=8), Pheasant- tailed Jacana Hydrophasianus chirurgus (n=2), and Bronze- winged Jacana Metopidius indicus (n=6). Their chicks were sighted in the Water Hyacinth patch in late July. On 21 July one fledgling was sighted in a bed of Water Hyacinth, on the banks of the Brahmaputra, in Guimara village, Mirza (26.11°N, 91.47°E). The month-old fledgeling had a black cap, black lores, black ear coverts, brownish-black scapula, black bill, and red tarsi. It had a white belly and vent, while the overall appearance from top view 3. A Whiskered Tern in breeding plumage. was grey. It had semipalmate feet and could swim very well [6]. It was seen bathing, and oiling and preening its feathers. All: Ranade Sachin 4. Habitat for the breeding colony at Pobitora Wildlife Sanctuary, Morigaon, Assam.

5. Adult carrying nest material to nest.

Fig. 1. Map of breeding colonies of Whiskered Tern in: 1. Kamrup, 2. Morigaon, 3. Sivasagar districts of Assam, India.

The nesting colony near Pobitora was monitored from June to August 2019 (n=8 visits). I first noticed the colony on 02 June, when I spotted 15 adult Whiskered Terns in breeding plumage. Subsequently, I visited this site once every fortnight for three months. On each visit I observed the birds from 1600 to 1800 6. Fledgling of Whiskered Tern. Ranade: Whiskered Terns 9

Table 1. Nests and adult Whiskered Terns recorded near Pobitora Wildlife Sanctuary, Morigaon District, Assam in 2019 Date Nest Whiskered Tern in flight 02 June No data 15 13 June 40 42 22 June 100 300 29 June 100 100 13 July 10 100

27 July 40 100 Sachin Ranade Both: 07 August 0 30 29 August 0 6

Food 8. Flock of Whiskered Tern. I observed the adult terns dive to catch fishes and frogs. Common prey among fishes were barbs (Ciprinidae), notopterid fishes (Notopteridae), and catfishes (Bagridae) [7]. Sometimes active nests with adult birds. The nesting colony at Mirza, Kamrup they pursued and caught flying insects. The adult terns uttered District (26.11°N, 91.47°E), was noted on 18 July 2019, but by calls when they approached the nesting area with food in their then the young birds had fledged, though I did see seven adults beaks. flying about. The breeding of Whiskered Terns has not been recorded from Assam for many years. The earliest record is Baker’s (1935), from lower Assam (Barak Valley). Birds in breeding plumage were recorded from all over Assam (Choudhury 2000; Hussain et al. 2018; eBird 2020) but nesting was never confirmed. Therefore it is interesting to document the presence of more than 100 nests in Morigaon District. The nesting in Sivasagar District appears to be the eastern-most breeding ground in India. It won’t be a surprise, if in future the birds are found nesting in Dibrugarh and Tinsukia districts, where similar habitat exist. As mentioned by Ali & Ripley (1983), it is possible that a number of nests, and offspring, get washed away in flash-floods as the birds nest on the ground or on Water Hyacinth beds, as happened on 13 July with the entire colony that I was studying. But there was a fair chance that the chicks survived in the buoyant hyacinth beds. The benefits of buoyant hyacinth beds for nesting, might be worth studying. 7. Adult carrying a fish to nest. References Nesting progress near Pobitora Wildlife Sanctuary Ali, S., & Ripley, S. D., 1983. Handbook of the birds of India and Pakistan together with those of Bangladesh, Nepal, Bhutan and Sri Lanka. Compact ed. Delhi: Oxford It seemed that breeding activities were initiated at the beginning University Press. Pp. i–xlii, 1 l., pp. 1–737, 56 ll. of June, when the birds occupied nests, and laying commenced Baker, E. C. S., 1935. The nidification of birds of the Indian empire [Pandionidae- in the second and third weeks of June. The maximum number Podicepidae]. 1st ed. London: Taylor & Francis. Vol. IV of 4 vols. Pp. i–x+2, 1–546. of adults (n=300) were sighted during my visit on 22 June 2019 Barve, S., Raman, T. R. S., Datta, A., & Jathar, G., 2020. Guidelines for conducting [8]. Towards the end of June, the monsoon had become active. research on the nesting biology of Indian birds. Indian BIRDS 16 (1): 10–11. On 13 July, the area was heavily flooded, leaving only a few Choudhury, A., 2000. The birds of Assam. 1st ed. Guwahati: Gibbon Books & World hyacinth beds intact, while most of them were washed away. Wide Fund for Nature-India. Pp. 1–240. eBirds 2020. Whiskered Tern. Website URL: https://ebird.org/species/whiter2/IN-AS The flood waters had reduced by 27 July, but by then the original Accessed on 29 June 2020. colony had been completely displaced. Gochfeld, M., Burger, J., Kirwan, G. M., & Garcia, E. F. J., 2020. Whiskered On that day, I spotted a new colony c.500 m to the south of Tern (Chlidonias hybrida), version 1.0. In Birds of the World (J. del Hoyo, the original spot. About forty nests were initiated by the adult birds A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of on some islands and hyacinth beds in the water filled marshland. Ornithology, Ithaca, NY, USA. Website URL: https://doi.org/10.2173/bow. It appeared as a second breeding attempt by these birds. whiter2.01. Hussain, M. M., Talukdar, S., Dey, T., Paul, S., & Singha, H., 2018. Whiskered Tern: On 09 August 2019, small breeding colonies of Whiskered Sightings of Whiskered Tern Chlidonias hybrida (Pallas, 1811) in Son Beel, Assam. Terns were sighted at Gorokhia Dol (27.16°N, 94.58E) and Zoos’ Print 33 (2): 30–34. Disangmukh (27.05°N, 94.58° E), both located in Sivasagar Rasmussen, P. C., & Anderton, J. C., 2012. Birds of South Asia: the Ripley guide. 2nd District. At Gorokia Dol, 15 Whiskered Terns in breeding plumage, ed. Washington, D.C. and Barcelona: Smithsonian Institution and Lynx Edicions. 2 and five active nests were observed, while Disangmukh had two vols. Pp. 1–378; 1–683.