Reflections from Habitat of Brahminy Kite Family at Goa
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TECH VISTAS VOL. 1, NO. 1 , NOV. 2018 Reflections from habitat of Brahminy Kite family at Goa Soham Ray 1 1Department of Biotechnology, Amity University, Kolkata -700135, West Bengal. E-mail: [email protected] Abstract We report on the Brahminy Kites as observed on January 2018 in the area of Japanese Garden of Vasco da Gama, Goa, India hovering over the adjacent Grandmother’s beach. (n=4) brahminy kites (Haliastur Indus) were observed co-existing with (n=20+) black kites (Milvus migrans) and photos were shot by a camera. It illuminates the habitat and ecology of Brahminy kites. Typical kleptoparasitic behaviour of Indian house crows (Corvus splendens) upon the kites was also observed. Key Words: Brahminy Kites, habitat, coexistence, kleptoparasitism, Goa 1 Introduction The brahminy kite was described first in 1760 by French ornithologist Mathurin Jacques Brisson as l'Aigle Pondicery with a Latin binomial Aquila pondiceriana and later in 1783 Dutch naturalist Pieter Boddaert used the name Falco indus. Brahminy kites were placed in the genus Milvus by Amadon (1978), and a close relationship between that genus and Haliastur was supported by the syringeal morphology study of Griffiths (1994) and the mitochondrial cytochrome b studies of Wink and Sauer-Gürth (2000), who regarded Haliastur as a closely related sister group to Milvus. However, the molecular studies of Lerner and Mindell (2005) did not support such an arrangement, and they thought that this genus shares a sister relationship with the sea eagles, Haliaeetus. About this kite (Haliastur Indus) Salim Ali (2012) has a sketchy description as follows: “Bright rusty red above white elsewhere, immature chocolate brown. Tail rounded. Sea coast and inland waters’’ whereas their geographical range lies ``Throughout the Indian Union up to about 2000 m in the Himalayas; Pakistan (Part); Bangladesh; Sri Lanka; Myanmar’’. According to Ferguson-Lees and Christie (2001) their habitats are found in tropical and subtropical coasts, estuaries, mangroves, beaches, coral reefs, dunes, salt marshes, cliffs and village harbours. However, in India and in parts of south-east Asia, it also occurs inland, by rivers, lakes, swamps, rice paddies and other wetlands. On the demographical perspective it have been argued by them that the population is declining, especially in South-East Asia, owing to loss of habitat, persecution, over-use of pesticides and, possibly, increased human hygiene resulting in reduction of available scraps. Though their population is confirmed to be declining (Van Balen, 1993) they are assessed as Least Concern (LC) category of IUCN red list for which justification reads as follows: “This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 71 Ray: Reflections from habitat of Brahminy Kite … <20,000 sq.km combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern’’ (IUCN Red List Category & Criteria, 2017). It is to note that the Brahminy kite is the ‘National Heritage Bird’ of Republic of India. It is also known as Garuda which represents the mount of Lord Vishnu in Hindu scriptures. 2 Methodology and Geographical background We observed (n=4) Brahminy kites on 11th & 18th January 2018 as we were bird watching inside Japanese Garden at Vasco da Gama, Goa, India. The exact location of garden is at Mormugao Port Trust Colony, Mormugao, Goa (GPS coordinates: 15° 23' 9.7188'' N and 73° 50' 38.5440'' E). The garden is a small one with a beautiful flowery park along with a children's playground and sitting benches. It was around 10 am to 1 pm with temperature around 32 °C. We took a few photographs with camera (Nikon D3300, DSLR) overlooking the sea and sky as well as sea shore which is popularly known as Grandmother’s hole beach. The Mormugao region of Vasco da Gama in Goa is an industrial region which ends with undeveloped beaches along Arabian Sea and rocky hills in a peninsular fashion protruded towards west. The observed area includes the Japanese Garden at a elevated height, the Grandmother’s hole beach at depression and the western corners of Mormugao. Most of the region surrounding the coast included steep rocky slopes and hills with coastal vegetation. 72 TECH VISTAS VOL. 1, NO. 1 , NOV. 2018 Fig. 1: Geographical location 73 Ray: Reflections from habitat of Brahminy Kite … Figs. 2 & 3: Japanese garden Fig. 4: The Grandmother’s hole beach 74 TECH VISTAS VOL. 1, NO. 1 , NOV. 2018 Figs. 5, 6 & 7: Three flying Brahminy kites which are distinctive from their wings: the first one has a small rapture on the tip of right wing primaries; the second one has a small cleavage like structure on the bottom of right wing primaries; the third stretched in its full wingspan. Brahminy kites are known to be kleptoparasitic birds themselves (Kalsi and Kaul, 1992; Nayak, 1999; Ryan, 2012) but here they were the victims of kleptoparasitism exhibited by Indian house crows (Corvus splendens). Kleptoparasitism of crows is common and have been noted by the following authors Marzluff et al. (2015) and Simes et al. (2017). Typical kleptoparasitic behaviour of crows pecking alone or mobbing in groups were noticed on multiple kites. The most common attempts of the crows included pecking the primary feathers on the wings of the kites during flight. These may explain the small cleavages on different wing feathers of the kites in Figs. 5 & 6. However in most of the attempts the kites escaped through a speedy flight towards the sea. After few minutes there were no trace of crows and the kites continued gliding over the garden and beach. 75 Ray: Reflections from habitat of Brahminy Kite … 3 Discussion The brahminy kites do prefer “Sea coast and inland waters’’ (Ali, 2012) and our observation also indicates towards that trend. “Rare sighting of brahminy kite thrills birders’’ brahminy kite has been spotted in the sky of Chennai, a coastal megacity (Times of India, 2017). They were also spotted in Toranmal Reserve Forest, in the adjacent state of Maharashtra (Patil, 2011). The patterns also indicate that they reside in windy areas and as well as near large waterbodies utilizing it as stable and staple food source. Brahminy kites are commonly seen to coexist with Black kites (Milvus migrans) and White bellied sea eagle (Haliaeetus leucogaster). The adult birds can be easily distinguished from other kites by rusty red coverts which starkly contrast with white throat. The juveniles lack the reddishness and appear similar to black kites but can also be distinguished by a black cere instead of yellow cere in black kites. Their calls are distinct with a descending 'teeeh-eeh-eeh' notes resembling meowing of cats. “The Brahminy kite is normally seen alone, in pairs or occasionally in small family groups, but rarely in the large flocks formed by some kite species” (Olsen 1995). The (n=20+) black kites serve as an example of the later kite species in our observation. On the ecologica l perspective the prescription by Gause (1932, 1934) and later on by Hardin (1960), i.e. competitive exclusion principle, the observed coexistence and small family pattern it can be noted that Brahminy kites are not complete competitors of black kites and there may be variation in food resources between the two species. 4 Conclusion From our observation on Brahminy kites at Grandmother’s hole beach of Vasco da Gama, Goa we would like to specifically provide the following salient features: (1) It is mentioned that the brahminy kite is normally seen alone, in pairs or occasionally in small family groups, but rarely in the large flocks formed by some kite species (Olsen, 1995; Wells, 1999; Lutter et al., 2006). From our observations, family of (n=4) can be recorded as an example. (2) As there is a small family group comprising of at least four brahminy kites so there are possibilities of nearby habitats of these declining bird species among coastal region and mangroves in Goa which should be protected. (3) Though brahminy kites were themselves kleptoparasitic birds they were also victims of kleptoparasitism by crows. (4) As seen in many other raptor species, brahminy kites showed coexistence with black kites (Sarà et al., 2016). 5 Acknowledgement 76 TECH VISTAS VOL. 1, NO. 1 , NOV. 2018 I am grateful to my mother Mrs. Samapti Ray for her constant inspiration, father Dr. Saibal Ray for supervising to write my maiden research paper, and father’s research scholars Mr. Debabrata Deb and Mr. Sourav RoyChowdhury for their various technical helps. Reference [1] Amadon, D., (1978). Remarks on the taxonomy of some Australasian raptors, Emu, 78, 115–118. [2] Griffiths, C.S., (1994), The Condor, 96 (1), 127-140. [3] Wink, M., and Sauer-Gürth, H., (2000). Advances in the molecular systematic of African Raptors. In Raptors at Risk (R.D. Chancellor & B.-U. Mayberg, Eds), WWGBP/HancockHouse, pp 135-147. [4] Lerner, H.R.L., and Mindell, D.P., (2005), Molecular Phylogenetics and Evolution, 37, 327–346 [5] Ali, S., (2012), The book of Indian birds, Bombay Natural History Society, Oxford University Press, p.11 and 96.