Indian pond heron

The Indian pond heron or paddybird (Ardeola grayii) is a small heron. It is of Old World origins, breeding in southern Iran and east to the Indian subcontinent, Burma, and Sri Lanka. They are widespread and common but can be easily missed when they stalk prey at the edge of small water-bodies or even when they roost close to human habitations. They are however distinctive when they take off with bright white wings flashing in contrast to the cryptic streaked olive and brown colours of the body. Their camouflage is so excellent that they can be approached closely before they take to flight, a behaviour which has resulted in folk names and beliefs that the birds are short-sighted or blind.[2][3]

Indian pond heron
In non-breeding plumage (India)
Breeding plumage (India)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Pelecaniformes
Family: Ardeidae
Genus: Ardeola
Species:
A. grayii
Binomial name
Ardeola grayii
(Sykes, 1832)
Synonyms

Ardeola leucoptera

Description

They appear stocky with a short neck, short thick bill and buff-brown back. In summer, adults have long neck feathers. Its appearance is transformed from their dull colours when they take to flight, when the white of the wings makes them very prominent. It is very similar to the squacco heron, Ardeola ralloides, but is darker-backed. To the east of its range, it is replaced by the Chinese pond heron, Ardeola bacchus.

During the breeding season, there are records of individuals with red legs. The numbers do not suggest that this is a normal change for adults during the breeding season and some have suggested the possibility of it being genetic variants.[4][5][6][7]

Erythristic plumage has been noted.[8] The race phillipsi has been suggested for the populations found in the Maldives, however this is not always recognized.[9] It forms a superspecies with the closely related Chinese pond heron, Javan pond heron and the Madagascar pond heron.

They are usually silent but may make a harsh croak in alarm when flushed or near their nests.[9]

This bird was first described by Colonel W. H. Sykes in 1832 and given its scientific name in honour of John Edward Gray. Karyology studies indicate that pond herons have 68 chromosomes (2N).[10]

Behaviour and ecology
When flushed the contrasting white wings flash into view
Usually hunched, they appear short necked

They are very common in India, and are usually solitary foragers but numbers of them may sometimes feed in close proximity during the dry seasons[11] when small wetlands have a high concentration of prey. They are semi-colonial breeders. They may also forage at garbage heaps. During dry seasons, they sometimes take to foraging on well watered lawns or even dry grassland. When foraging, they allow close approach and flush only at close range. They sometimes form communal roosts, often in avenue trees over busy urban areas.[12]

Food and feeding

The Indian pond heron's feeding habitat is marshy wetlands. They usually feed at the edge of ponds but make extensive use of floating vegetation such as water hyacinth to access deeper water. They may also on occasion swim on water or fish from the air and land in deeper waters.[13][14][15][16] They have also been observed to fly and capture fishes leaping out of water.[17] [18] Sometimes, they fly low over water to drive frogs and fishes towards the shore before settling along the shoreline.[19] They have been noted to pick up crumbs of bread and drop them on the water surface to bait fishes.[20]

The primary food of these birds includes crustaceans, aquatic insects, fishes, tadpoles and sometimes leeches (Herpobdelloides sp.).[21] Outside wetlands, these herons feed on insects (including crickets, dragonflies[22] and bees[23]), fish (Barilius noted as important in a study in Chandigarh) and amphibians.[24]

Breeding
Pair at nest in Kolkata, West Bengal, India
Indian pond heron with bright red legs in breeding season

The breeding season begins with the onset of the monsoons. They nest in small colonies, often with other wading birds, usually on platforms of sticks in trees or shrubs. Most nests are built at a height of about 9 to 10 m in large leafy trees. The nest material is collected by the male while the female builds the nest. Three to five eggs are laid.[25] The eggs hatch asynchronously, taking 18 to 24 days to hatch. Both parents feed the young.[26] Fish are the main diet fed to young.[11] Nest sites that are not disturbed may be reused year after year.[27]

Mortality factors

They have few predators but injured birds may be taken by birds of prey.[28]

An arbovirus that causes "Balagodu", trematodes[29] and several other parasites have been isolated from the species.[30][31][32][33][34] Antibodies to Japanese encephalitis and West Nile virus has been detected in pond herons and cattle egrets from southern India.[35] Traces of heavy metals acquired from feeding in polluted waters may be particularly concentrated in the tail feathers.[36]

In culture
Large numbers in a drying pond

The habit of standing still and flushing only at the last moment has led to widespread folk beliefs that they are semi-blind and their name in many languages includes such suggestions. In Sri Lanka the bird is called kana koka which translates as "half-blind heron" in the Sinhala language.[2] The Hindustani phrase "bagla bhagat" has been used to describe a "wolf in sheep's clothing" or a hypocrite appearing like a meditating saint[37] and occurs in a Marathi proverb.[38] The paddy-bird also appears as a character in the Hitopadesha where, in one story, it takes injury to itself to save a king.[39] The bird was noted by Anglo-Indian naturalist-writers for the surprising transformation in colours. Phil Robinson described the bird as one that sits all dingy gray and flies all white.[40] It is said to have been eaten by many in India in former times.[41]

During the height of the plume trade, feathers were collected from the "paddy bird" and exported to Britain.[42]

References
  1. BirdLife International (2012). "Ardeola grayii". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.CS1 maint: ref=harv (link)
  2. Anonymous (1998). "Vernacular Names of the Birds of the Indian Subcontinent" (PDF). Buceros. 3 (1): 53–109.
  3. Yule, Henry; Burnell, A. C. (1903). Crooke, William (ed.). Hobson-Jobson: A Glossary of Colloquial Anglo-Indian Words and Phrases, and of Kindred Terms, Etymological, Historical, Geographical and Discursive. London, UK: John Murray. p. 650.
  4. Gopisundar, K. S. (2004). "Abundance and seasonality of Indian Pond Herons Ardeola grayii with red legs in Uttar Pradesh, India" (PDF). Forktail. 20. Archived from the original (PDF) on 2007-10-11.
  5. Abdulali, H. & Alexander, H. G. (1952). "Ardeidae with red legs". Ibis. 94 (2): 363. doi:10.1111/j.1474-919X.1952.tb01829.x.
  6. Wesley, H. D. (1993). "Genetics of the red tarsi and feet in the Pond Heron". Newsletter for Birdwatchers. 33 (4): 73.
  7. Sundar, Gopi KS (2005). "Distribution and extent of Pond Herons Ardeola grayii with red legs in India" (PDF). Indian Birds. 1 (5): 108–115.
  8. Parasharya, BM (1983). "An erythristic pond heron". Pavo. 21 (1&2): 107–108.
  9. Rasmussen, PC; JC Anderton (2005). Birds of South Asia:The Ripley Guide. Smithsonian Institution & Lynx Edicions.
  10. M. K. Mohanty; S. P. Bhunya (1990). "Karyological studies in four species of ardeid birds (Ardeldae, Ciconiiformes)". Genetica. 81 (3): 211–214. doi:10.1007/BF00360867.
  11. Begum, S. (2003). "Colonial nesting behavior in Indian Pond Heron (Ardeola grayii grayii) of Bangladesh" (PDF). Zoos' Print Journal. 18 (6): 1113–1116. doi:10.11609/jott.zpj.18.6.1113-6.
  12. Gadgil, Madhav; Salim Ali (1975). "Communal roosting habits of Indian birds". J. Bombay Nat. Hist. Soc. 72 (3): 716–727.
  13. Chandra-Bose, DA (1969). "The Paddybird, Ardeola grayii (Sykes) floating on water". Pavo. 7 (1&2): 74–75.
  14. Neelakantan, KK (1986). "Pond heron afloat". Newsletter for Birdwatchers. 26 (5–6): 11–13.
  15. Krishna, MB (1978). "Pond Herons". Newsletter for Birdwatchers. 18 (10): 12.
  16. Muir, G.B.F. (1916). "Paddy-birds Ardeola grayii fishing". J. Bombay Nat. Hist. Soc. 24 (2): 366–367.
  17. Grimwood, I.M .; Brocklehurst, M.J.C. (1984). "Unusual feeding behaviour in the Paddy Bird or Indian Pond Heron Ardeola grayii". J. Bombay Nat. Hist. Soc. 81 (3): 696–697.
  18. Sivasubramanian, C (1988). "Aerial feeding by Median Egret (Egretta intermedia), Little Egret (Egretta garzetta) and Pond Heron (Ardeola grayii)". J. Bombay Nat. Hist. Soc. 85 (3): 611–612.
  19. Kirkpatrick, K. M. (1953). "Feeding habit of the Indian Pond Heron (Ardeola grayii)". J. Bombay Nat. Hist. Soc. 51 (2): 507.
  20. Réglade, Michel Antoine; Dilawar, Mohammed E.; Anand, Ulhas (2015). "Active bait-fishing in Indian Pond Heron Ardeola grayii". Indian Birds. 10 (5): 124–125.
  21. Mathew, DN; Narendran, TC; Zacharias, VJ (1978). "A comparative study of the feeding habits of certain species of Indian birds affecting agriculture". J. Bombay Nat. Hist. Soc. 75 (4): 1178–1197.
  22. Santharam, V. (2003). "Indian pond-herons Ardeola grayii feeding on dragonflies". Journal of the Bombay Natural History Society. 100 (1): 108.
  23. Prasad, JN; Hemanth, J (1992). "Pond Heron Ardeola grayii (Sykes) feeding on bees". J. Bombay Nat. Hist. Soc. 89 (2): 246.
  24. Sodhi, N.S. (1986). "Feeding ecology of Indian pond heron and its comparison with that of little egret". Pavo. 24 (1&2): 97–112.
  25. Pandey, Deep Narayan (1991). "Nesting of the Pond Heron Ardeola grayii (Sykes) on Eucalyptus trees". J. Bombay Nat. Hist. Soc. 88 (2): 281.
  26. Yesmin, R.; Rahman, K. & Haque, N. (2001). "The breeding biology of the Pond Heron (Ardeola grayii Sykes) in captivity". Tigerpaper. 28 (1): 15–18.
  27. Ali, S.; S. D. Ripley (1978). Handbook of the birds of India and Pakistan. 1 (2nd ed.). New Delhi: Oxford University Press. pp. 63–64.
  28. Navarro, A (1962). "Pale Harrier taking a Pond Heron". J. Bombay Nat. Hist. Soc. 59 (2): 653.
  29. Umadevi K; R. Madhavi (2000). "Observations on the morphology and life-cycle of Procerovum varium (Onji & Nishio, 1916) (Trematoda: Heterophyidae)". Systematic Parasitology. 46 (3): 215–225. doi:10.1023/A:1006398205390. PMID 10845654.
  30. Pavri K, Sheikh BH, Singh KR, Rajagopalan PK, Casals J (1969). "Balagodu virus, a new arbovirus isolated from Ardeola grayii (Sykes) in Mysore State, South India". Indian J Med Res. 57 (4): 758–64. PMID 4979767.
  31. Pavri KM, Rajagopalan PK, Arnstein P (1968). "Isolation of Ornithosis bedsoniae from paddy birds, Ardeola grayii (Sykes), in Mysore State India". Indian J. Med. Res. 56 (11): 1592–4. PMID 5715959.
  32. Sahay S, Sahay U, Verma DK (1990). "On a new trematode of the genus Psilorchis (Psilostomidae Looss, 1900) from pond heron Ardeola grayii". Indian Journal of Parasitology. 14 (2): 203–205.
  33. Madhavi, R; Narasimha Rao, N; Rukmini, C (1989). "The life history of Echinochasmus bagulai Verma 1935 (Trematoda, Echinostomatidae)". Acta Parasitologica Polonica. 34 (3): 259–265.
  34. Deshmukh PG (1971). "On the male of Avioserpens multipapillosa Singh, 1949 from Ardeola grayii". Rivista di Parassitologia. 32 (2): 101–3. PMID 5166875.
  35. Paramasivan, R.; A.C. Mishra; D.T. Mourya (2003). "West Nile virus: the Indian scenario" (PDF). Indian J Med Res. 118: 101–108. PMID 14700342.
  36. Muralidharan, S.; Jayakumar, R.; Vishnu, G (2004). "Heavy metals in feathers of six species of birds in the district Nilgiris, India". Bulletin of Environmental Contamination and Toxicology. 73 (2): 285–291. doi:10.1007/s00128-004-0425-x. PMID 15386041.
  37. Pahwa, Munshi Thakardass (1919). The modern Hindustani scholar of the Pucca munshi. Baptist Mission Press, Calcutta.
  38. Manwaring, A. (1899). Marathi proverbs. Oxford: Clarendon Press. p. 40.
  39. Arnold, Edwin (1893). The Book of Good Counsels from the Sanskrit of the Hitopadesa. London: W.H.Allen and Co. p. 108.
  40. Dewar, Douglas (1896). Bombay Ducks. London: John Lane Company. pp. 111, 235–239.
  41. Susainathan, P. (1921). Bird friends and foes of the farmer. Bulletin NO. 81. Madras: Department of Agriculture. p. 48.
  42. Watt, George (1908). The Commercial Products of India. London: John Murray. p. 139.

Other sources
  • Lamba B.S. (1963). "Nidification of some Indian birds. No.6. The Indian Pond Heron or Paddy bird Ardeola grayii (Sykes)". Pavo. 1 (1): 35–43.
  • de Boer LEM, van Brink JM (1982). "Cytotaxonomy of the Ciconiiformes (Aves), with karyotypes of eight species new to cytology". Cytogenet Cell Genet. 34: 19–34. doi:10.1159/000131791. PMID 7151490.
  • Parasharya BM, Bhat HR (1987). "Unusual feeding strategies of the Little Egret and Pond Heron". Pavo. 25 (1–2): 13–16.
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