INTRODUCTION CHAPTER 1 INTRODUCTION 1.1 A Introduction On the occurrence of the Indian Eagle Owl Bubo bengalensis it can be best said in the words of T. C. Jerdon (1862), 'There is not a rocky hill in the Camatic (present day Kamataka state in south India), nor a ravine in the Deccan, where this owl may not be seen on the summit of a Indian, or a ledge, till long after sunrise, and looming large against the clear sky looking more like a quadruped than a bird.' The only change unfortunately is that the owl is by no means that common today (Plate 1). Most owls are nocturnal while some species are crepuscular in habit. Though they are not easily seen, they have made a tremendous impact on human thinking. The owls have forward facing almost human like eyes, they can turn the head in almost foil circle in various planes, they have a silent flight, they are cryptically coloured and are difficulty to observe for a greater period of time and many owls utter an eerie call at night, hence they arouse a feeling of fear, awe and mystery and not surprisingly the owls are deeply shrouded in the fog of superstitions. Owls are persecuted and killed out of fear wrong beliefs. Therefore, owls are also relatively less studied birds. Rodents, shrews and other crop pests are recorded from the diet of owls and hence they are beneficial to the farmers. To throw hght on the life of one of the less studied owl species, I have undertaken the study of Indian Eagle Owl Bubo bengalensis. 1.1 B What is an owl? Owls are arboreal, chiefly nocturnal birds of prey, characterized by large, round heads, short necks, round long wings and comparatively short tail. They have large round forward facing eyes, large ears with acute hearing ability, aided by the round facial disc that helps focusing of sound in the asymmetrically placed ears. The bill is 1 short, hooked and partially covered with feathers. The tarsus and toes are feathered, outer toe is reversible and claws are strongly hooked. The plumage is cryptic in colour, the broad, rounded wings are soft, velvety and have serrated margins that impart the ability of silent and buoyant flight that is not swift. The food is principally rodents, they usually nest in hollows, the young are nidicolous and downy, and both parents attend the young (Ali and Ripley, 1969; Duncan, 2003). The word owl is derived from Middle English oule, from Old English ule, imitative in origin. So also in Sanskrit, the name Uluka for the owl is from its cry ululi. (Dave, 2007; Pande, Suruchi 2009). Owls are grouped under Order Strigiformes in the Family Strigidae and Family Tytonidae. Generally speaking the owls are nocturnal predatory birds. 1.2 Owls in the world The owls are found in almost all the habitats from tropical regions to the Arctic polar region. The owls are distributed in various zoogeographic zones of the world such as the Neotropical, the Ethiopian, Oriental and Australian zones, and also in the Palearctic and the Nearctic zones. In the analysis of 205 species of owls worldwide, there are 16 species of owls in the family Tytonidae and 189 species of owls in the family Strigidae; fiirther, the subfamily Striginae has 117 species and the tribe Bubonini has 25 species (Duncan, 2003). Since new species of owls continue to be discovered, presently, about 217 species of owls are recorded from the world (Rasmussen and Anderton, 2005). 1.3 Owls in the Indian Subcontinent About 38 species of owls (2 families and 12 genera) are recorded from the Indian Subcontinent. Further, Family Tytonidae has 5 and family Strigidae has 31 species of owls; 2 additional species {Strix seloputo from Nicobars and Strix hutleri from Mekran coast in Pakistan) are possibly recorded only once but there are no recent records. (Table 1) (Rasmussen and Anderton, 2005). 1.4 Genus Bubo Dumeril, 1806 Kingdom: Animalia, Phylum: Vertebrata, Class: Aves Order: Strigiformes, A] Family: Tytonidae (Bam, Grass and Bay owls) and B] Family: Strigidae (Owls, Owlets and allies), i) Subfamily: Striginae, Tribe: Bubonini (Eagle-Owls and dM\QS-Bubo (Table 2), Ketupa, Nyctea and Scotopelid). ii) Subfamily: Sumiinae, Tribes : Sumiini, Aaegolini, Ninoxini. iii) Subfamily: Asioninae. (The classification follows Ali and Ripley, 1969) The recent classification as per Wikipedia is as follows: Superregnum: Eukaryota Supergroup: Unikonta Cladus: Opisthokonta Regnum: Animalia Subregnum: Eumetazoa Cladus: Bilateria Cladus: Nephrozoa Cladus: Deuterostomia Phylum: Chordata Subphylum: Vertebrata Infraphylum: Gnathostomata Superclassis: Tetrapoda Classis: Aves Subclassis: Carinatae Infraclassis: Neomithes Parvclassis: Neognathae Ordo: Strigiformes Familia: Strigidae Subfamilia: Striginae Genus: Bubo The Genus Bubo is quite well distributed in the world with 23 species but the members are not represented in Australia, New Zealand and further south (Table 2). The genus has the most species diversity in Africa and Asia. Almost a fourth of all the species in the genus Bubo are represented in India (Table 2 and 3). In all, 6 species of Bubo owls are recorded from India, particularly Bubo bubo. Bubo bengalensis (Plate 1), Bubo nipalensis, Bubo coromandus, Bubo zeylonensis and Bubo flavipes. The comparative data about their distribution, status, habitat, size, plumage, call, biometry, predominant pellet contents, nest sites and eggs of each species are summarized in Table 3. 1.5 A. The Indian Eagle Owl Bubo bengalensis (Franklin, 1831) (Plate 1) 1.5 B. ETYMOLOGY Latin. Bubo, the eagle owl; Latin bengalensis, Related to Bengal, formerly denoting North-East India (Pande 2009). 1.6 NAMES 1.6 A. COMMON NAMES Indian Eagle-Owl Bubo bengalensis syn. Bubo bubo bengalensis (Franklin), is also called Indian Great Homed Owl, Eagle Owl, The Indian Homed Owl, Northem Eagle-Owl, Rock Eagle-Owl and Great Homed Owl. (Jerdon, 1862; Baker, 1922-1928; Ali and Ripley, 1969). 1.6 B. LOCAL NAMES Ghugu (Hindi); Gug (Sind); Hutom pecha (Bengal); Ghubad (Marathi); Ghuwad (Gujarati); Yerra gudla gubad (Telugu); Komban andai (Tamil); Komban munga (Malayalam). (Jerdon, 1862; Ali and Ripley, 1969). 1.6 C. SANSKRIT NAMES Uluka, Pechaka, Vayasarati, Divandha, Kausika, Ghuka, Divabhita, Nisatana Ghutkaraka, Hridilochana Naktachari, Kausi, Ghargaraka, Bhiru, Kakasatru, Pingala, Dudula, Vrksarayi, Brhadravin, Pingalaksha, Bhyankara, Tamasa, Kuvi, Ulukceti, Hikka, Kankasi, Kontha, Kakari, Harilocana, Nisadarsi, Bahusvana, Mahapakshi, Krsna, Naktaka, and Krtamalaka. (Dave, 1985; Pande, Sumchi, 2007). 1.7 A. ZOOLOGICAL NOMENCLATURE Kingdom: Animalia, Phylum: Vertebrata, Class: Aves, Order: Strigiformes, Familiy : Strigidae (Owls, Owlets and allies). Subfamily: Striginae, Tribe : Strigini. (Eagle-Owls and dMiQS-Bubo, Ketupa, Nyctea and Scotopelid). Genus: 5w6oDumeril, 1806, Zool. Ananlytique : 34. Type by tautonymy, Strix bubo Linnaeus. Bubo bubo (Linnaeus) Cf. Vaurie, C, 1963, American Mus. Novitates, No. 2132:1- 10. Bubo bubo bengalensis (Franklin) Otus bengalensis Franklin, 1831 (1830-31), Proc. Zool. Soc. London:! 15. (The Ganges between Calcutta and Benares and in the Vindhyan Hills between the latter place and Gurra Mundela) Baker FBI No. 1660, Vol. 4:414 (Ali and Ripley, 1969). 1.7 B. CHRONOLOGICAL HISTORY OF NOMENCLATURE Otus bengalensis Franklin, 1831 (1830-31) Proc, Zool. Soc. London: 115. Baker, FBI No. 1660, Vol. 4-414. P.Z.S. 1831-Sydes, Cat. 18-Grould, Cent. Him. Birds, PI. 3- Blyt, Cat. 143-Hors., Cat 88-Jerdon, Cat. 43-U. Cavearia, Hodgson. Urrua bengalensis, Franklin(Jerdon, 1862). 1.7 C. SUBSPECIES OR RACES Four subspecies are described (Ali and Ripley, 1969) on the basis of colouration and wing lengh: Bubo bubo bengalensis (Franklin) : darkest, richly coloured and wing 370-433 mm. B.b. tibetanus Bianchi: dark and browner with wing 420-465 mm. B.b. turcomanus (Eversmann): paler, grayer, feathered toes hide claws; wing 435-513 mm. B.b. hemanchalana Hume : palest, sharp streaks on hind crown, wing 433-508 mm. 1.7 D. BUBO BENGALENSIS RECOGNIZED AS A SPECIES The races Bubo bubo turcomanus (Turkestan Homed or Eagle-Owl), B.b. tibetanus (Tibetan Homed or Eagle Owl) and B. b. hemachalana (Himalayan Homed or Eagle Owl) (Plate 2) (vide AH and Ripley, 1969, Synopsis nos. 625-626a and Vaurie, 1965) are now grouped under a separate species Bubo bubo. The Eurasian Eagle-Owl and race Bubo bubo bengalensis is elevated to a species rank as Indian Eagle-Owl {B.bengalensis) (Buceros, 1988 Vol. 3, August, No.2). So also, on the basis of DNA classification, Indian Eagle-Owl Bubo bengalensis and Eurasian Eagle-Owl Bubo bubo are designated as separate species (Wink and Heidrich, 1999). 1.8 STATUS AND KNOWN DISTRIBUTION The Indian Eagle Owl Bubo bengalensis syn. Bubo bubo bengalensis, Franklin, is endemic resident of the Indian subcontinent and is found from coastal regions up to 1500 m altitude and rarely up to 2400 m altitude in Western Himalayas. From Kashmir, in India (with adjacent Punjab province and Kohat, Peshawar and Rawalpindi districts in Pakistan), it extends eastwards up to West-Central Nepal. It is not reported from Sikkim, Bhutan or North East Frontier Agency, but may be found there. It occurs from Rajasthan state in the west, across Gangetic Plain to the states of Assam, Nagaland and Manipur, through Bangladesh and also Myanmar. Southward it is found in Peninsular India up to Kanyakumari in suitable habitats. It is not recorded from Sri Lanka and Andaman and Nicobar Islands (Jerdon, 1862; Baker, 1922-1928; Ali and Ripley, 1969; Duncan, 2003). 1.9 FIELD IDENTIFICATION 1.9 A. Based on appearance: The large size with the overall height similar to the village hen, the 'horn-like' erect feather tufts on the crown, the 'cat-like' round face, the yellow iris, the vertical stance and the cryptic brown-buff plumage with streaks on the chest and belly are helpftil to identify this owl in the field. (Table 3) (Plates 1, 2) (Ali and Ripley, 1969).