A Winter Roost Count of the Short-Eared Owl Asio Flammeus (Aves: Strigiformes: Strigidae) at Porbandar, Gujarat, India
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Journal of Threatened Taxa Building evidence for conservaton globally www.threatenedtaxa.org ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) Short Communication A winter roost count of the Short-eared Owl Asio flammeus (Aves: Strigiformes: Strigidae) at Porbandar, Gujarat, India Dhavalkumar Varagiya & Anita Chakraborty 26 October 2018 | Vol. 10 | No. 11 | Pages: 12566-12570 10.11609/jot.3617.10.11.12566-12570 For Focus, Scope, Aims, Policies and Guidelines visit htp://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-0 For Artcle Submission Guidelines visit htp://threatenedtaxa.org/index.php/JoTT/about/submissions#onlineSubmissions For Policies against Scientfc Misconduct visit htp://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-2 For reprints contact <[email protected]> Publisher & Host Partners Member Threatened Taxa Journal of Threatened Taxa | www.threatenedtaxa.org | 26 October 2018 | 10(11): 12566–12570 A winter roost count of the Short-eared Owl Asio flammeus (Aves: Strigiformes: Strigidae) at Porbandar, Gujarat, India ISSN 0974-7907 (Online) 1 2 Short Communication Short Dhavalkumar Varagiya & Anita Chakraborty ISSN 0974-7893 (Print) 1 School of Pharmacy, RK University, Rajkot-Bhavnagar Highway, Kasturbadham, Rajkot, Gujarat 360020, India OPEN ACCESS 2 Department of Botany, SSLNT Mahila Mahavidlaya, Luby Circular Road, Dhanbad, Jharkhand 826001, India 1 [email protected] (corresponding author), 2 [email protected] Abstract: The Short-eared Owl Asio fammeus is a common to Museum), Rajasthan (5 January 1949 specimen: The uncommon winter visitor to Gujarat. The species roosted in bushes Field Museum; Singh 1997), Karnataka (20 January 1941 of Prosopis julifora in the grassland of Shiroda area, Odadar Village of Porbandar District. Communal roosts were identfed by foot surveys specimen: The Field Museum), Utar Pradesh (Grewal between 9–17 November 2016. A total of 20 individuals co-existed 2000), Andhra Pradesh (Kanniah & Ganesh 1993) and with grazing catle in the grassland of ca. 1km2. At present due to their restricted nestng habits and nomadic nature, the species is vulnerable other states. to habitat loss at their feeding and roostng grounds. Conversion of The Short-eared Owl has an extremely large range, open habitats to agriculture, grazing, recreaton, housing and tourism and therefore it does not approach the thresholds for development are the current threats to the species in the wetland complex. The IUCN conservaton status further confrms that though Vulnerable under the range size criterion (extent of they are assessed as Least Concern, in spite of the species populaton occurrence <20,000km2 combined with a declining constantly declining with global populaton estmated at 3,000,000 or fuctuatng range size, habitat extent/quality, or individuals which equates to 2,000,000 mature individuals. The present study is the frst systematc atempt to count a roost in Gujarat. populaton size and a small number of locatons or severe fragmentaton) as well as under the populaton Keywords: Gujarat, IUCN, Porbandar, Short-eared Owl, wetland, trend criterion (>30% decline over 10 years or three wintering roost. generatons) and populaton size criterion (<10,000 mature individuals with a contnuing decline estmated to be >10% in 10 years or three generatons, or with a The Short-eared Owl Asio fammeus is a widespread specifed populaton structure) in IUCN conservaton winter migrant to India (Blanford 1894). It prefers status evaluaton. For these reasons the species is grassland and open country (Ali & Ripley 1987). In India, designated as Least Concern. it is reported from Maharashtra (Jamdar & Shrivastava At present, due to their restricted nestng habits and 1988; Chandrasekaran 1995), Madhya Pradesh (Pasha nomadic nature, the species is vulnerable to habitat loss et al. 2004), Tamil Nadu (Thyagaraju 1933), Kerala on their feeding and roostng grounds. Conversions of (Jayson & Mathew 2002; Chandrasekhara & Nameer open habitats to agriculture, grazing, recreaton, housing 2003), Gujarat (19 November 1993 specimen: The Field and tourism development are the current threats to the DOI: htps://doi.org/10.11609/jot.3617.10.11.12566-12570 Editor: Reuven Yosef, Ben Gurion University of the Negev, Eilat, Israel. Date of publicaton: 26 October 2018 (online & print) Manuscript details: Ms # 3617 | Received 30 June 2017 | Final received 12 September 2018 | Finally accepted 02 October 2018 Citaton: Varagiya, D. & A. Chakraborty (2018). A winter roost count of the Short-eared Owl Asio fammeus (Aves: Strigiformes: Strigidae) at Porbandar, Gujarat, India. Journal of Threatened Taxa 10(11): 12566–12570; htps://doi.org/10.11609/jot.3617.10.11.12566-12570 Copyright: © Varagiya & Chakraborty 2018. Creatve Commons Atributon 4.0 Internatonal License. JoTT allows unrestricted use of this artcle in any medium, reproducton and distributon by providing adequate credit to the authors and the source of publicaton. Funding: Field work was self funded by Dhavalkumar Varagiya. Competng interests: The authors declare no competng interests. Acknowledgements: We are thankful to Kishore Joshi, Bhaskar Thankey, Vijay Jethva, Nayan Thanki, Vikrant Rana, Punit Karia, Zeel Badiyani, Konark Karia for joining us during surveys voluntarily. 12566 Winter roost count of Short-eared Owl Varagiya & Chakraborty species in the wetland complex. Odadar and Mokar villages of Porbandar District (Fig. 1). The Short-eared Owl is a common to uncommon It is located about a distance of 5km from Porbandar winter visitor to Gujarat (Ganpule 2016). The species Somnath Natonal Highway and connected by a tar is usually present from September/October to March/ road with Odadar and Mokar villages. The study area April in the Indian Subcontnent (Grimmet et al. 1998; is Gosabara Mokarsagar Wetland Complex (here afer Ali & Ripley 2001; Srinivasulu & Srinivasulu 2007). Mokarsagar) which was declared an Important Bird and The species usually nests and roosts on the ground Biodiversity Area by the Bombay Natural History Society and prefers grassland habitat. It is ofen seen fying low and Birdlife Internatonal in March 2017 (Rahmani et al. like harriers; its opportunistc diet consists mainly of 2016). small mammals and rarely small birds. It is an actve Mokarsagar (21.5650N & 69.7640E) is the largest hunter, fying low over the ground (less than 6 feet) wetland of Porbandar District and spread across in search of prey; usually hovers and drops vertcally 106km2. The wetland complex supports more than pouncing on prey. The species is considered to be a 20,000 waterbirds annually and thus is shortlisted as a highly migratory in the northern limits of its global potental Ramsar site as well as Biodiversity Heritage range. Banding data shows 1,000-mile movements in 50 Site. Recently, a public interest litgaton has been also days. These movements also vary and large movements fled in Gujarat High Court to declare it as a wildlife are ofen related to juvenile dispersals. The longevity sanctuary. record for a Short-eared Owl in the wild is 13 years The wetland complex is drained by the Bhadar (Rumet 2012). River, the longest river of the Saurashtra region along with River Billeshwari (Minsar). Before the 1970s, the Material and Methods region was an intertdal mudfat due to the ingress of sea Observatons and counts were recorded in November water through the mouth close to Gosabara (21.5350N 2016 for nine days in the Shiroda region, located between & 69.7100E) which mixed with fresh water during the Figure 1. Study area (Shiroda island of Mokarsagar) of Short-eared Owl covering an area of 1km2 Journal of Threatened Taxa | www.threatenedtaxa.org | 26 October 2018 | 10(11): 12566–12570 12567 Winter roost count of Short-eared Owl Varagiya & Chakraborty monsoon season. The culvert was created near Gosa any of the other islands of Mokarsagar. Thus, the data Village and resident fshermen used fxed oja nets for presented is from Shiroda only. catching Prawns Penaeus penicillatus (Mansuri 1986). Gradually the tdal infux started impactng the soil and Observation and Discussion fresh water biota of the region. In order to prevent The species was found to roost in bushes of Prosopis and control the impactng phenomenon Salinity Ingress julifora on Shiroda island. Realizing the fact that the Preventon Cell (SIPC), Gujarat, built structures across species was spoted for the frst tme, an efort for the creek such as tdal regulators (masonry wall) and identfying communal roosts was undertaken by going bunds at diferent locatons (Singh et al. 2014). These on foot surveys. A total 20 individuals (Table 1) were structures prevented the free fow of tdal ingress. As observed to co-exist with grazing catle in the grasslands a result prawn fshing was stopped but the quality of spread over an area of 1km2 between November 9–17, agricultural soil improved. 2016 (Table 2; Fig. 2). The species prefers bushes to hide In Mokarsagar, there are four elevated inland islands (Image 2) but, when unknowingly