Indian Skimmer Rynchops albicollis Scientific name definitions

38–43 cm; wingspan 102–114 cm; culmen 58–75 mm. Unmistakable within range; generally black above and white below , with broad white forehead and broad white trailing edge to secondaries and inner primaries visible in flight ; most striking feature, however, is long yellow-tipped red bill , with much longer lower mandible ; comparatively short red legs . Differs from wholly allopatric R. niger and R. flavirostris by having white collar in adult breeding plumage; tail white with inconspicuous dark centre stripe. Non-breeding adult has somewhat duller, browner upperparts, with mottled hindneck and rump (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ). Female similar to male, but somewhat smaller. Juvenile similar to non-breeding adult, but generally browner and more heavily mottled above, with buff scaling, white-fringed tertials and primaries (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ), and much shorter, duller bill.

Largely restricted to major rivers, particularly along calm stretches with sandbars ; rare or vagrant to estuaries, inshore coastal waters and freshwater tanks.

Moves upriver during season of low water, and down during period of floods. Occasionally visits lakes and estuarine mudflats in winter (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ). Movements within Indian Subcontinent poorly understood: considered only a summer visitor to most of Pakistan (although probably still resident in S Sind) and NW India, and primarily a winter visitor to SW Gujarat and N half of W coast of India, as well as Bangladesh (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ), with southernmost records in India from Tamil Nadu, singles at Chennai (Madras) before 1845, Puduchcheri (Pondicherry) in Jul 1932 and, most recently, Mudhaliarkuppam, Cheyur, in Apr 2009 (2 Madhav, N.V. and Nagarajan, D. (2010). Indian Skimmer Rynchops albicollis: a recent record from Tamil Nadu. BirdingASIA. 13: 98. Close ). Vagrant to SE China, Thailand and Vietnam. Has been listed for Iran, presumably also as vagrant, but probably in error (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ).

Fish, insect larvae (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ) and shrimps, often taken in very shallow water (just 3–4 cm deep) (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ). In one Indian study diet was dominated by the following small, surface-feeding fish: Salmophasia bacaila, Salmophasia sardinella, Systomous sarana, Pethia ticto (all Cyprinidae) and Dermogenys pusilla (Zenarchopteridae) (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ). Crepuscular and nocturnal, as well as diurnal, sometimes foraging on moonlit nights; such behaviour may be influenced by weather, e.g. strong summer winds that prevent daytime feeding, or by prey activity (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ). Food caught exclusively by skimming  the water in flight with mouth open and lower mandible submerged; prey items touched by mandible are grasped while head doubles back under body; prey swallowed in flight or after landing.

A nasal “kyap, kyap ” given by adults (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ), likened to the bark of a small dog, while chicks unable to fly give quiet cheeping notes (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close ). Adults give barking notes as an anti-predator response, to warn neighbours of potential danger, and also to display aggression at neighbours that intrude into their territory.

Generally mid Feb to Jun, with local variations dictated by water levels (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ) and colonies laying relatively synchronously, e.g. within two-week period at one Indian site (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ). Monogamous. Colonial (typically 20–40 pairs), often with terns, e.g. Little Terns (Sternula albifrons) and River Terns (Sterna aurantia), and pratincoles, e.g. Small Pratincole (Glareola lactea) (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close ). One record of a skimmer apparently laying in a nest belonging to Sterna aurantia (the egg failed to hatch) (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ). Nests on sandbanks or islands in larger rivers during season of low water; nest is an unlined scrape (in one study mean diameter c. 133 mm, depth 33 mm) (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ) in sand, with at least 10 cm between adjacent pairs (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close ), typically 4–5 m (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ). Clutch usually four eggs in NW India (exceptionally five), 2–3 eggs further E (in Uttar Pradesh, of 27 nests in which entire clutches hatched, 16 had one chick, eight had two and three had three chicks) (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close ); whitish to salmon-buff with scattered darker brown and blue-grey markings, mean size 42·8 mm × 30·1 mm, mean mass 18·7 g (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ); incubation c. 21–24 days (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ), by both sexes but mainly by female; chick has greyish or sand-coloured down with scattered dark brown spots. Predators on eggs and young include Pallas’s Fish-eagle (Haliaeetus leucoryphus), crows (Corvus spp.), kites and jackals, but goats and cattle may trample eggs and chicks, and domestic dogs have been recorded eating nestlings and possibly eggs (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close ). In one study, in India, of 200 eggs laid in 64 nests, at least 139 hatched successfully (19 were washed away) (3 Rajguru, S.K. (2017). Breeding biology of Indian Skimmer Rynchops albicollis at Mahanadi River, Odisha, India. Indian Birds. 13(1): 1–7. Close ).

VULNERABLE. Total population estimated at c. 6000–10,000 birds, or 4000–6700 mature individuals, and considered to be probably declining, but status very poorly documented throughout most of range. In India, still fairly common locally but just 18 birds recorded in midwinter counts, 1991, and appears to be generally rare away from Gujarat and Punjab (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ), although recently > 100 birds have been regular in winter at Bhitarkanika Wildlife Sanctuary, Orissa, where suitable breeding habitat also exists (5 Gopi, G.V., Jena, A.K. and Pandav, B. (2006). Bhitarkanika Wildlife Sanctuary (Orissa), a key congregation area for Indian Skimmer Rynchops albicollis. BirdingASIA. 5: 78. Close ), and the species breeds (at least 40–50 pairs reported; 92 pairs at six sites in 2013 (6 Das, D. K. (2015). Breeding status of Indian Skimmer Rynchops albicollis in the National Chambal Sanctuary, India. Indian Birds. 10(2): 53–54. Close ) ) in National Chambal Sanctuary, Uttar Pradesh, where 341 birds were counted along rivers in Jan–Feb 2002 (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close ). Present in the Son Gharial Wildlife Sanctuary, Madhya Pradesh, where newly found breeding in April 2012; 14 birds were at a colony on a sandbank (7 Dilawar, M. and Sharma, V. (2016). A new breeding location of Indian Skimmer Rynchops albicollis, and notes on other birds in Son Gharial Wildlife Sanctuary, Madhya Pradesh, India. Indian Birds. 11(2): 35–38. Close ). Local extinctions reported, e.g. in Dehra Dun Valley, Uttar Pradesh (8 Singh, A. P. (2000). Birds of lower Garhwal Himalayas: Dehra Dun valley and neighbouring hills. Forktail 16:101–123. Close ).

In Pakistan, has apparently declined over last 60–70 years; in latter part of 19th century was tolerably common all along R Indus, but by mid 1960s no birds at all seen except during monsoon season, other than one in Lahore in Dec 1973 (9 Vittery, A. (1993). The birds of Pakistan: supplementary observations from the northern Punjab and hills. Forktail 9: 143–147. Close ); main cause of decline is probably habitat loss, as result of damming of major rivers, which reduces risk of flooding, and encourages human populations to move in and cultivate river islands and sandbars.

In Nepal (and Assam) (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ), species is uncommon and irregular winter visitor or passage migrant (1 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ) near Indian border; may have bred.

In Bangladesh, no recent breeding records until 2016, when three pairs were found on R Padma (10 Kabir, M.T., Chowdhury, S.U., Tareq, O., Alam, A.B.M.S., Ahmed, S., Shahadat, O. and Foysal, M. (2016). New breeding records of riverine birds in Bangladesh. BirdingASIA. 26: 39–42. Close ); local winter visitor to coast and major rivers, where c. 3000 birds counted in 1988/89, 602 birds in 1991 and 600 birds in Jan 2013 (11 Mohsanin, S. (2014). Survey of wintering Indian Skimmer Rynchops albicollis in Bangladesh. BirdingASIA. 21: 105–106. Close ). No recent records from Bhutan or Laos (12 Thewlis, R. M., R. J. Timmins, T. D. Evans, and J. W. Duckworth (1998). The conservation status of birds in Laos: a review of key species. Bird Conservation International 8(Supplement):1–159. Close ). Formerly common locally in Myanmar, but now rare with just three known localities (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close ). Rare or merely vagrant to other parts of SE Asia, but may breed in Cambodia.

Human disturbance and habitat modification, including sand mining on sandbars, cattle grazing and burning, are probably the greatest threats throughout range, with negative effects of large-scale irrigation projects also being reported in some areas; these may reduce water levels on rivers to point where birds do not breed at all (4 Sundar, K.S.G. (2004). Observations on breeding Indian Skimmers Rynchops albicollis in the National Chambal Sanctuary, Uttar Pradesh, India. Forktail. 20: 89-90. Close , 13 Malla, G., Ray, P., Bagaria, P., Sivakumar, K., Johnson, J.A., Gopi, G.V. and Sathiyaselvam, P. (2015). Does the Indian Skimmer Rynchops albicollis have a future in East Godavari district, Andhra Pradesh? BirdingASIA. 23: 58–59. Close ).