SANDGROUSE 1996 Volume 17 SOUTHERN YEMEN mvt) SOCOTRKA ...this world is a green and sweet thing. Allah has left you in charge in it and is looking at how you will behave. So be careful of the things of this world... Hadith (the collected traditions about the Prophet Muhammad) OSME OSME OSME was founded in 1978 as the successor to the Ornithological Society of Turkey. Its primary aims are: e Tocollect, collate, and publish data on all aspects of the birds of the Middle East. e To promote an interest in ornithology and bird conservation throughout the Middle East. e To develop productive working relationships with other governmental and non-govern mental organisations with an interest in conservation and/or natural history in the region. Publications OSME publishes a scientific journal, Sandgrouse, containing papers on all aspects of Middle Eastern ornithology.. The OSME Bulletin contains more popular articles, letters, Society news, and other news and information from around the region. Both are published twice a year and are issued free to members. Meetings An Annual General Meeting is held in London at which guest speakers provide new perspectives on ornithology in the region. OSME usually joins forces with other societies for a second meeting each winter and organises occasional special meetings of its own; some meetings take place outside the UK. Projects OSME organises field expeditions to collect data on birds in little-known parts of the region and in areas where OSME can assist by teaming up with local societies. In addition, the Sites Register Scheme collects records from all interested ornithologists of important bird areas in the Middle East. Grants The Conservation & Research Committee disburses funds to valuable field projects and desk studies that further the conservation of birds in the region. Grants have been awarded to over 25 such projects since the Conservation & Research Fund was set up in 1982. Membership OSME is open to all, and its membership spans over 40 couniries. Annual membership Life membership Individual £10 (£13 air mail outside Europe) Individual £200 (£100 if 60 or over) Family £15 (£18 air mail) for two Family E275 members, plus £3 for each additional family member Please add £3 if payment is made in non-sterling currency. For details of payment by banker's order, and for any other information on the Society, write to the Secretary at the address below. Vice Presidents Prof. Abdulaziz H. Shaika Noora Bint Lord Barber of M. D. Gallagher Abuzinada Isa Bin Sulman Al Tewkesbury N. Yazgan Sherif Baha El Din Khalifa Prof. W. Buttiker Council as at April 1995 Dr G. Allport R. P. Morris R. Parslow G. R. Welch Conservation & Secretary Membership Chairman Research G. M. Kirwan H. Scott H. J. Welch A. Colston Information Officer (co-opted) (co-opted) Librarian Treasurer R. P. Martins Publications Officer P. A. D. Hollom (co-opted) Turkey F.E. Warr S. Howe Bird Report (co-opted) Sales ORNITHOLOGICAL SOCIETY OF THE MIDDLE EAST clo THE LODGE, SANDY, BEDFORDSHIRE SG19 2DL, UK SANDGROUSE NUMBER 17 SOUTHERN YEMEN AND SOCOTRA the report of the OSME survey in spring 1993 Edited by R. F. Porter and R. P. Martins with editorial assistance from Francine Stone, Ben Hoare, J. W. Spencer and Mark Boyd Designed by HH: I>Seott Supported by ya uo fe INTERNATIONAL Published by THE ORNITHOLOGICAL SOCIETY OF THE MIDDLE EAST 1996 Citation: Porter, R. F. and Martins, R. P. (1996) Southern Yemen and Socotra: the report of the OSME survey in spring 1993. Sandgrouse 17. Further copies, price £10.00, from OSME, c/o The Lodge, Sandy, Bedfordshire SG19 2DL, UK. ISSN 0260-4736 © 1996 Ornithological Society of the Middle East CONTENTS 5 Ik) 22 102 130 132 134 138 142 145 148 151 155 158 165 170 181 185 188 The Ornithological Society of the Middle East's survey of southern Yemen and Socotra, March-May 1993: an introduction R. F. PORTER, R. P.. MARTINS AND FRANCINE STONE Some aspects of southern Yemen: an introduction for field ornithologists and conservationists R. P. MARTINS The status of non-passerines in southern Yemen and the records of the OSME survey in spring 1993 R. F. PoRTER, R. P. MARTINS, K. D. SHAW AND UFFE SORENSEN The status of passerines in southern Yemen and the records of the OSME survey in spring 1993 R. P. MARTINS, C. G. BRADSHAW, ALAN BROWN, G. M. KIRWAN AND R. F. PORTER An introduction to Socotra and its birds R. F. PORTER AND FRANCINE STONE Taxonomic treatment of endemic taxa in Socotra R. P. MARTINS The status of birds in Socotra and 'Abd Al-Kuri and the records of the OSME survey in spring 1993 G. M. KIRWAN, R. P. MARTINS, K. M. MORTON AND D. A. SHOWLER Habitats and bird communities in southern Yemen and Socotra PETER DAVIDSON Ostrich Struthio camelus eggshell fragments in Yemen J. W. SPENCER The Plain Nightjar Caprimulgus inornatus in Yemen J. N. DYMOND The Buteo population in Socotra R. P. MARTINS AND R. F. PORTER Forbes-Watson's Swift Apus berliozi in Socotra R. F. PorTER, J. N. DYMOND AND R. P. MARTINS The Socotra Warbler Incana incana J. N. DYMOND The Socotra Cisticola Cisticola haesitata J. N. DYMOND AND R. F. PORTER The Socotra Sunbird Nectarinia balfouri D. A. SHOWLER AND PETER DAVIDSON The Socotra Starling Onychognathus frater and Somali Starling O. blythii R. F. PORTER AND R. P. MARTINS The Socotra Bunting Emberiza socotrana K. M. MORTON Biometric data of birds in southern Yemen and Socotra, spring 1993 J. N. DYyMOND Mammal observations in Yemen and Socotra, spring 1993 D. A. SHOWLER Reptile observations in Yemen, spring 1993 D. A. SHOWLER Amphibian observations in Yemen, spring 1993 D. A. SHOWLER Reptile observations in Socotra, spring 1993 D. A. SHOWLER Odonata observations in Yemen, spring 1993 C. G. BRADSHAW Sandgrouse (1996) 17:3 SANDGROUSE woumerr 19% FOREWORD s a member of the 1993 OSME team that surveyed southern Yemen and Socotra, I am very pleased to introduce this special issue of Sandgrouse. It is a most important contribution to the knowledge and understanding of the wildlife of my country. Yemen is undergoing a period of rapid change. Its population growth is among the highest in the world. There is much pressure on the remaining areas of forest for fuel and food for livestock. Water is becoming an increasingly precious resource, as it is for all countries in Arabia. As an agriculturalist, I know only too well how people and wildlife both need trees and water. But it is Allah alone who knows how important natural places are for our spiritual life. Recently I was appointed the Yemen Representative for BirdLife International. This has enabled me to ensure that the OSME findings are used for the benefit of wildlife conservation. Let me give a few examples: planners involved in the development of Aden Harbour as a Free Zone have been made aware of the most important sites for wildlife; the unique bird biodiversity of Socotra was highlighted at an international scientific symposium — part of a process of seeking international conservation status for this remarkable island; and the Children’s Bird Book that OSME sponsored will be distributed to all schools in Yemen this autumn by the Environmental Protection Council. The Republic of Yemen has now ratified the Convention on Biodiversity and the government, like many throughout the world, is starting work on its Action Plan. I will ensure that the information collected by the two OSME surveys is fed into the process. The expedition’s ornithologists have made a vital contri- bution to wildlife conservation in our country. Dr Omar Al-Saghier, Agricultural Research and Extensions Authority, Dhamar, Republic of Yemen, June 1996 Ow why: chewed aay noah r in oe, Sine ey jd tone eae = eral Sand grouse (1996) 17: 5-14 The Ornithological Society of the Middle East's survey of southern Yemen and Socotra, March-May 1993: an introduction R. F. PORTER, R. P. MARTINS AND FRANCINE STONE ituated in the mountainous south-west corner of Arabia, the Republic of Yemen supports a unique and diverse assemblage of habitats and species. Many are endemic, occurring only within this region and are ecologically isolated by surrounding deserts and seas. Until the mid-1970s, little systematic research in the environmental sciences had been conducted in Yemen owing to difficulty of access, both politically and geographically. The revolutions of the 1960s which overthrew the monarchy in northern Yemen and colonialism in southern Yemen paved the way for the creation of two modern states which united in May 1990, forming the Republic of Yemen. This event prompted OSME to extend the work commenced in 1985 in north Yemen (the then Yemen Arab Republic) to southern Yemen (previously the People's Democratic Republic of Yemen) and to Socotra. Thus OSME's second expedition was launched in spring 1993. Southern Yemen and Socotra are poorly known ornithologically and this influenced the choice of these regions for attention during the eight week period 16 March to 9 May. This volume of Sandgrouse presents the results of the 1993 survey, complementing the results of the 1985 expedition to (the then) North Yemen detailed in Sandgrouse 9. Copies of all published and unpublished records and material collected by survey participants are held by the leaders and lodged in the OSME archives. AIMS OF THE SURVEY The principal aims of the survey were: To establish: & the status, distribution and ecology of birds, especially species endemic to south-west Arabia. The avifaunas of the Afrotropical zone in the extreme east (contiguous with the Dhofar region of Oman) and Socotra naturally commanded special attention. & the importance of southern Yemen as a migratory flyway for birds, especially diurnal raptors. B priorities for bird conservation (for inclusion in the BirdLife publication Important Bird Areas in the Middle East). @ an active dialogue between OSME, the Environmental Protection Council and the Ministry of Agriculture of the Republic of Yemen and to train Yemeni R. F. Porter, R. P. Martins and Francine Stone Sandgrouse 17 scientists and technicians in both fieldcraft and the development of strategies to advance conservation. To collect: ® information for the forthcoming Atlas of the Breeding Birds of Arabia (ABBA). @ incidental records of other vertebrates and plants. ® information to enable the publication of an illustrated bird book for distri- bution to schools treating a selection of 96 of the most econ te or significant species (in the context of conservation) in Yemen. @ footage for a film or video to promote the work of the survey. To document the results of the survey in appropriate journals. SURVEY COVERAGE Survey activities were arranged so as to maximise coverage of as many areas as possible in the available time, given available resources, in order to define key areas for conservation attention with a view to future intensive studies. Two consecutive teams of survey participants were in the field from 16 March to 10 May. This period coincides with the breeding season and spring migration through the region. For the purpose of this survey we have defined southern Yemen as the area of the former People's Democratic Republic of Yemen (South Yemen) and, in addition, the areas south of al-Mukha on the Red Sea coast, south of al-Turbah including the Jabal Iraf massif in Ta'izz province and the environs of al-Mardam near al-Bayda'’. Maps showing the sites surveyed and other localities where ornithological observations were undertaken in southern Yemen and on Socotra are presented in Figures 1 and 2. The itinerary was as follows: March April 15 arrive Sana'a 1-6 Socotra 16-20 northern Yemen 7-9 al-Mukalla 21-23 Jabal Iraf Wadi Himarah 23-26 Aden and adjacent interior al-Mardam (north-west of al- plain Bayda’) 26-29 Wadi al-Jahr Wadi Yashbum 9-17 northern Yemen Wadi Hajr 17-21 al-Jadid 30-31 Socotra Dhubab Bab al-Mandab Sandgrouse 17 OSME survey of southern Yemen and Socotra Acacia savannah east of Bab Shahrut hills in the Mahrah al-Mandab and coast to 30 al-Ghaydah Aden May 21-23 Aden 1-3 al-Ghaydah to Tarim al-Mukalla 4-5 Tarim to Shabwah, through Wadi al-Masilah Ramlat al-Sab'atayn on Sayhut fringe of Rub’ al-Khali 23 Pelagic transect by boat from 7-10 northern Yemen Sayhut 10 depart Sana'a 23-26 Sayhut to the Mahrah 26-30 Wadi Mararah in the. Mahrah NOTES ON LOGISTICS Transportation was by three long-wheelbase Toyota Land Cruisers with Yemeni drivers, except on Socotra where two flat-bedded trucks (with drivers) were used. In addition, on mainland Yemen we engaged guides to assist us in navigating problematical dune systems east of Sayhut and through the sands of Ramlat al-Sab'atayn between Shabwah and Marib. On Socotra we were supported by guides, porters and cooks. Fishing vessels were used to undertake a pelagic transect off the coasts of both southern Yemen and Socotra. Camping allowed extended periods in the field, maximising opportunities early and late in the day. Tents were not essential but mosquito nets were considered indispensable. Care in protection against malaria is crucial in the region as resistant forms of the disease are now endemic. An extensive range of medical equipment proved useful in combating such ailments as a twisted ankle, a scorpion bite, severe diarrhoea and a two-day high fever. Participants in the survey were selected from the OSME membership. Selection reflected the need for a broad range of expertise beyond ornithology, notably in mammals, amphibians, reptiles and botany. Sound ecological and - conservation qualifications and experience were also considered important, as well as practical photography skills, video recording and bird trapping techniques. Six survey members participated for its full eight week duration and were joined by two additional teams of six during the first and second months. Throughout the entire period, the survey benefited substantially from the opportunity to work with Yemeni counterpart Dr Omar al-Saghier of Yemen's Agricultural Research and Extension Authority (AREA) in Dhamar, who undertook training in ornithological research techniques and facilitated work in innumerable practical ways. Sandgrouse 17 R. F. Porter, R. P. Martins and Francine Stone | Bios ; ONG 1yep-/e IDpe, ge WNUSE, @ LI iley IDEM yemqeys @ L WeEAIUS @ 81 = uAeje. ges-/e s queus ; jeIWeY YEHNPAY. A ° GN, ee? pet pen ‘ISNOLSPUVG JO ANSSI STY} UL POdUdIIJaI IIL YDTYM SIdAIOSqO snotAoid Aq says ay} [[e Moys jou soop deur styy, ‘aytsoddo saa}49ze3 3Y} UI Pa}SI] SUOT}LDO] 0} JOJaI SIOqUINN “E66 Bulids ut Aoains AINSO 2u3 Aq a104} paraaod says dy} pue AOdaI sn} Aq pajyeasy UdWIDX UIOYNOS Jo Rare dy} 7UdUIAX Jo dI|Gndoay “[ amnBry Sandgrouse 17 Gazetteer OSME survey of southern Yemen and Socotra To be read in conjunction with Figure 1. The positions of localities marked * are shown by name on the map ‘Abdullah Gharib Dhubab* Wadi al-Jahr* Aden* 5 Hiswat al- Wadi al-Jiz’* Al-Bayda™ Hujaymah 12 Wadi al-Khabt 30 Al-Fatk Jabal Iraf* Wadi al-Masilah* 28 Al-Faydami 29 Jabal Rub'ut 21 Wadi Fughmah Al-Ghaydah* Lahej* 17 Wadi Habban 4 Al-Hajaf 24 Mar'ayt springs Wadi Hadramawt* 1 Al-Jadid Marib* Wadi Hajr* 13 Al-Khaw'ah 26 Qishn 3 Wadi Harim Al-Mardam* 15 Ramlat al-Sab'atayn 16 Wadi Himarah 9 Al-Mihal 6 Rasal-'Arah 25 Wadi Irkhawt Al-Mukalla* Ras Fartak* 32 Wadi Mararah Al-Mukha* Rub’ al-Khali* 23 Wadi Sh'hout 18 Al-Qatn Sana'a* 22 Wadi Wa'shah 20 Al-Sawm 27 Saqr Wadi Yashbum* Al-Shihr* Sayhut* 10 Wadi Zirayqah 2 Al-Sugayyah 19 Sayun 14 Zinjibar 8 Al-Turbah Shabwah* Bab al-Mandab* 31 Shahrut hills Jabal - mountain 7 Biram Shuqra Wadi - watercourse Muhammadiyah Tarim* 11 Dar al-Qudaymi The Mahrah* \ Pelagic ‘ transect tadia, NA0'PY shidadah OW, . HAJHIF ® Rookib marsh (HAGGHIER) & MTS. Jabal Jaaft PLATEAU Fikhah ® Di-Ishal SO COT AR A Hakari Wells ® Shibrhoh 03730) Figure 2. Socotra: the sites covered during the OSME survey in spring 1993. Note: this map does not show the islands of ‘Abd al-Kuri, The Brothers and Sabuniya or all of the sites visited by previous observers referenced in this issue of Sandgrouse. R. F. Porter, R. P. Martins and Francine Stone Sandgrouse 17 Survey personnel Gier Anderson 13 April—10 May Pieter Bison 15 March-10 May Chris Bradshaw 13 April—10 May Alan Brown 13 April-10 May Peter Davidson 15 March-10 May Nick Dymond 15 March-12 April David Farrow 15 March-12 April Chris Heard 13 April-10 May Guy Kirwan 15 March-12 April Fiona Lowry 15 March-12 April Rod Martins, co-leader 15 March-10 May Keith Morton - 15 March-12 April Richard Porter, leader 15 March-10 May Dr Omar al-Saghier 15 March-10 May Ken Shaw — 15 March-12 April - David Showler 15 March-10 May Uffe Sorensen 13 April-10 May Jonathan Spencer 13 April-10 May Francine Stone, co-leader 8 March-10 May Richard Porter took overall responsibility for ensuring the success of the survey including directing the field work and liaising with sponsors. He was assisted by Rod Martins and by Francine Stone who was also responsible for managing the finances in the field and for liaison with Yemeni authorities and support personnel. This required her travel to Sana'a for one week in advance of the arrival of the first team. SPONSORS The survey was facilitated through generous sponsorship from the following organisations: The American Institute of Yemeni Studies (in Sana'a) The British Council The British Ornithologists' Union Cable and Wireless plc Canadian Oxy Lasmo Oil (Aden) Ltd The Ornithological Society of the Middle East The Royal Society for the Protection of Birds, the UK partner of BirdLife International Shell International Petroleum Company Ltd sun International Exploration and Production Company Ltd TeleYemen Yemen Airways 10 Sandgrouse 17 OSME survey of southern Yemen and Socotra ENDORSEMENTS In addition to sponsorship, endorsement was received from: The Atlas of the Breeding Birds of Arabia (ABBA) BirdLife International Fauna and Flora International The Harrison Zoological Museum The Society for Arabian Studies The World Conservation Union (IUCN) ACKNOWLEDGEMENTS We thank the government of the Republic of Yemen for welcoming us to their remarkable country through, in particular, the Ministry of Agriculture, the Environmental Protection Council and the Yemen Embassy in London. Dr Derek Harvey of the Joint Oil Companies' Medical Clinic was paramount in ensuring the success of the survey through hospitality in Sana'a and tireless support through the life of the project and beyond. In addition OSME is very grateful to Faisal Abd al-Aziz, Muhammad al- Basahi, Yahya al-Haifi and the staff of Al Mamoon Travel, Dr Omar al-Saghier and his family, Abdullah Salim Ali, HE Sa'id Salim Ba Hagiba, Grahame Binns, Renaud Detalle, Yasin Dutton, MacGuire Gibson, HE Douglas Gordon, Martin Herzog, Gordon Kirby, Irena Knehtl, Daniel L'Emaillet (CGG), HE Mark Marshall, HE Col Al-Iryani, Shaykh Muhammad Ali Mazariya, Dr McKenzie (Canadian Oxy), Taoufik Oaunes (UNHCR), Nabil Obadi, Katie Read (Nabors Drilling), Nicki Rush, (Canadian Oxy), Jamaledine Saadallah, the late Haj Salih, Dr David Warburton, and Carlos Zaccagnini (UNHCR). In the UK and Europe, we are most grateful for active assistance from Samar Damluji, Michael Jennings (especially for the loan of his Magellan 2000), Dawn Lakin, Antione Lonnet, Anthony Miller and Dr Miranda Morris, Julian Paxton (Shell), Dr Mike Rands (BirdLife), Khalid Rashad (Yemen Airways), HE Dr M. Shaya, Marie-Claude Simeone-Senelle, Mrs F. E. Warr and Paul Woodman and staff of PCGN. | Finally, we would like to express our grateful thanks to Duncan Brooks for advice on presentation and for preparing the maps in Figures 1 and 2, also to Pat Hall and particularly Kirsty Cheshire for coping with the onerous task of typing this report. SUMMARY OF ACHIEVEMENTS In the field, the survey: 1. Undertook systematic surveys of 77 locations in southern Yemen, recording 266 bird species and completing 350 kilometres of standardised habitat transects, with an additional 17 hours of spot-count observations. 2. Undertook systematic surveys of 18 locations on Socotra, recording 79 bird species and completing 66 kilometres of habitat transects and 4 hours of spot-count observations. 11 R. F. Porter, R. P. Martins and Francine Stone Sandgrouse 17 — 3. Undertook two 10-hour pelagic transects, from Sayhut on the Gulf of Aden coast of Yemen and along part of the north coast of Socotra, to investigate the status of pelagic seabirds (and whales and dolphins). 3 4. Discovered 4 and 10 previously unrecorded species in Yemen and Socotra respectively. 5. Collected data within 64 half-degree latitude/longitude squares for the forthcoming Atlas of the Breeding Birds of Arabia. Each square covers an area of 55 km x 55 km. ae 6. Identified 16 sites, based on habitat quality and species diversity, meriting international recognition as Important Bird Areas (IBAs) within the Middle East. 7. Observed spring migration through southern Yemen. 8. Undertook studies of Arabian Bustard Ardeotis arabs,13 south-west Arabian and 6 Socotran bird species of global conservation significance. 9. Photographed over 100 species, concentrating on endemics and species of global conservation significance within Yemen and Socotra. 10. Collected sound recordings of 55 species (these are listed in the Appendix). 11. Collected video recordings of selected bird species, of other wildlife encountered and of aspects of the survey's work. 12. Documented the occurrence of 5 species of amphibian, 55 species of reptile and 20 species of mammal. CONSERVATION EDUCATION The project: 13. Completed the planned book on Yemen's birds for children to be distributed to schools by the Environmental Protection Council of Yemen, and coordinated with this organisation to provide interpretive slide sets and text on Yemen's birds for future educational programmes within the country. 14. Participated with UNICEF in drafting a section concerning ‘bird / wildlife awareness’ for an environmental questionnaire for completion by 2,000 Yemeni youths during June and July 1993. 15. Lectured to the British Council and The American Institute of Yemeni Studies and consulted with the Yemen Ornithological Society to progress future conservation in Yemen. 16. Gave interviews to The Yemen Times and Yemeni radio. 17. Provided the opportunity to work closely with Yemeni counterpart Dr Omar al-Saghier of the Agricultural Research and Extension Authority (AREA), through training in bird survey and identification techniques and planning discussions for collaboration on future conservation work in Yemen. 18. Culminated with a presentation to the Deputy Minister of Agriculture, Dr _ - Abdullah Zabarah, and representatives of the AREA and the Environmental Protection Council. At this the importance of Yemen's birds, their habitats, threats to their future survival and priority areas for follow-up action were 12. Sandgrouse 17 OSME survey of southern Yemen and Socotra discussed. This meeting clearly demonstrated the interest and commitment to the conservation of nature currently emerging in Yemen. RESULTS The results of the survey appear in this issue of Sandgrouse (Volume 17). While a modified system of transliterated Arabic has been adopted for place names in the presentation of the survey results, no similar attempt has been made to standardise place names cited from historical records and references. R. F. Porter, BirdLife International, Wellbrook Court, Girton Road, Cambridge CB3 ONA, UK. R. P. Martins, 6 Connaught Road, Norwich, Norfolk NR2 3BP, UK. Francine Stone, Grimsdyke Cottage, Nuffield Lane, Crowmarsh Gifford, Wallingford, Oxon OX10 6QW, UK. APPENDIX Bird vocalisations recorded during the OSME surveys of Yemen in 1985 and Yemen and Socotra in 1993 Species Hamerkop Scopus umbretta Philby's Rock Partridge Alectoris philbyi Arabian Red-legged Partridge Alectoris melanocephala Sand Partridge Ammoperdix heyi Arabian Bustard Ardeotis arabs Lichtenstein's Sandgrouse Pterocles lichtensteinii Chestnut-bellied Sandgrouse Pterocles exustus African Collared Dove Streptopelia roseogrisea Turtle Dove Streptopelia turtur Namaqua Dove Oena capensis Bruce's Green Pigeon Treron waalia Didric Cuckoo Chrysococcyx caprius African Scops Owl Otus senegalensis Little Owl Athene noctua Plain Nightjar Caprimulgus inornatus Nubian Nightjar Caprimulgus nubicus Forbes-Watson's Swift Apus berliozi White-throated Bee-eater Merops albicollis - Little Green Bee-eater Merops orientalis Blue-cheeked Bee-eater Merops superciliosus Hoopoe Upupa epops African Grey Hornbill Tockus nasutus Arabian Woodpecker Dendrocopos dorae Singing Bushlark Mirafra cantillans Yemen PH PD PD PD PH PD PD & PH PD PD PD PD PD PD PD PD PD PD PD PH PD PD PD & PH PD PD Socotra Recorded by 13 R. F. Porter, R. P. Martins and Francine Stone Black-crowned Finch Lark Eremopterix nigriceps Dunn's Lark Eremalauda dunni Desert Lark Ammomanes deserti Hoopoe Lark Alaemon alaudipes Red-capped Lark Calandrella cinerea Long-billed Pipit Anthus similis Yellow-vented Bulbul Pycnonotus xanthopygos Arabian Accentor Prunella fagani Black Bush Robin Cercotrichas podobe Blackstart Cercomela melanura Red-breasted Wheatear Oenanthe bottae South Arabian Wheatear Oenanthe lugentoides Little Rock Thrush Monticola rufocinerea Yemen Thrush Turdus menachensis Yemen Warbler Parisoma buryi Socotra Warbler Incana incana Socotra Cisticola Cisticola haesitata Graceful Prinia Prinia gracilis Scrub Warbler Scotocerca inquieta Olivaceous Warbler Hippolais pallida Arabian Warbler Sylvia leucomelaena Barred Warbler Sylvia nisoria Desert Lesser Whitethroat Sylvia curruca minula Brown Woodland Warbler Phylloscopus umbrovirens Gambaga Dusky Flycatcher Muscicapa gambagae African Paradise Flycatcher Terpsiphone viridis Arabian Babbler Turdoides squamiceps Nile Valley Sunbird Anthreptes metallicus Shining Sunbird Nectarinia habessinica Orange-tufted Sunbird Nectarinia osea Socotra Sunbird Nectarinia balfourit White-breasted White-eye Zosterops abyssinica Black-crowned Tchagra Tchagra senegala Great Grey Shrike Lanius excubitor Fan-tailed Raven Corvus rhipidurus Tristram’s Grackle Onychognathus tristrami Socotra Starling Onychognathus frater Somali Starling Onychognathus blythii Socotra Sparrow Passer insularis Bush Petronia Petronia brachydactyla Rtippell's Weaver Ploceus galbula Arabian Serin Serinus rothschildi Yemen Serin Serinus menachensis Golden-winged Grosbeak Rhynchostruthus socotranus Yemen Linnet Carduelis yemenensis House Bunting Emberiza striolata African Rock Bunting Emberiza tahapisi Recordists: PH =P. A. D. Hollom (1985) PD =P. Davidson (1993) 14 Sandgrouse 17 a PD & PH PD -PD& PH PD PD a PD & PH PH PH PD PD PD PD PD PD PD PD a PD PD & PH PD & PH | BRBEREHRHE SS HBHRHRRBHR EG rg rg U U SERS HBP BBR BRB OD rd 0 & rd
(Meinertzhagen 1954); the species is a locally common migrant breeder in
northern Yemen.
African Paradise Flycatcher Terpsiphone viridis
37 recorded at five sites. Most numerous in Anogeissus/Commiphora woodland
in the Mahrah, where 19 at Wadi Mararah (360 m) 29 April and 13 in the
Shahrut hills (680 m) 30 April; in addition recorded at Jabal Iraf, Wadi al-
Masilah and Wadi Hayr.
A localised resident breeder, especially in areas of riparian vegetation. Eggs
have been recorded in February.
Arabian Babbler Turdoides squamiceps
103 recorded at 12 sites. None recorded from the Mahrah.
A fairly common resident where scrub is present but apparently absent from
the Mahrah. Eggs have been recorded in April.
Nile Valley Sunbird Anthreptes metallicus
326 recorded from widespread localities up to 1,200 m, but none in the Mahrah.
Highest counts were 34 at Wadi al-Khabt 24 March, 65 at Wadi Himarah 8 April
and 30 at Shabwak: 5 May.
A fairly common and widespread resident but apparently absent from the
Mahrah.
Shining Sunbird Nectarinia habessinica
175 recorded from widespread localities. The largest concentrations were 41 at
Wadi al-Masilah 22 April and 75 at Wadi Mararah (the Mahrah) 28 April. Both
areas support extensive vegetation.
A widespread resident breeder, with eggs recorded in May and June.
Orange-tufted Sunbird Nectarinia osea
141 recorded from widespread localities. Most counts were of 1-15 birds but
65
R. P. Martins et al. Sandgrouse 17
larger numbers were recorded in the Mahrah, with 22 at Wadi Mararah 28 April
and 53 in the Shahrut hills 29 April. |
A widespread resident.
White-breasted White-eye Zosterops abyssinica
109 recorded at eight sites between 360 and 1,760 m. Highest counts were 26 in
Juniperus woodland at Jabal Iraf (1,450 m) 22 March, and in
Anogeissus/Commiphora woodland in the Mahrah, with 36 at Wadi Mararah (360
m) 29 April and 16 in the Shahrut hills (680 m) 30 April.
A widespread local resident, not recorded below 360 m.
Golden Oriole Oriolus oriolus
16 at Wadi Harim 19 April and singles in Acacia savannah between al-Hajaf and
Hiswat al-Hujaymah 20 April, at Wadi al-Masilah 22 April and at Shabwah 6
May.
A passage migrant from March to May, (passage perhaps peaking during the
second half of April) and from late August to early October. One additional
record, 5 July 1947 (Browne 1950).
Black-crowned Tchagra Tchagra senegala
39 recorded at seven sites between 360 m and 1,450 m. Most common in the
Mahrah where nine at Wadi Mararah 29 April and 14 in the Shahrut hills 30
April. |
An uncommon resident occurring, apparently disjunctly, in the south-west
and the Mahrah.
Isabelline Shrike Lanius isabellinus
20 recorded at 11 sites between 23 March and 1 May.
A common winter visitor and passage migrant between September and May.
Red-backed Shrike Lanius collurio
16 recorded at nine sites between 18 April and 6 May.
A passage migrant during April and May and from September to early
November.
Lesser Grey Shrike Lanius minor
Two at Shabwah 6 May.
A passage migrant during September to October and April to May. An
exceptional count of 100 was in gardens at Aden 29 April 1940 (Bark Jones &
Hartley 1957).
Great Grey Shrike Lanius excubitor
139 recorded from at least 13 localities between 10 m and 2,000 m. Especially
common in Acacia savannah between al-Hajaf and Hiswat al-Hujaymah, where
78 recorded 20 April. Not recorded from the Mahrah.
66
Sandgrouse 17 Status of passerines in southern Yemen
A widespread and locally common resident, although apparently absent from
the Mahrah, breeding from March to June. Probably also occurs as a passage
migrant and winter visitor.
Woodchat Shrike Lantus senator
One between Aden and Wadi al-Jahr 26 March.
Records from Amiri district in January and March suggest this species is an
uncommon passage migrant and/or winter visitor.
Masked Shrike Lanius nubicus
Not recorded during the survey.
An uncommon winter visitor and passage migrant, recorded mainly from the
Aden area between September and early April.
Drongo sp. Dicrurus sp.
Not recorded during the survey.
A Drongo generally resembling Black Drongo D. adsimilis was present at Aden from
28 October 1946 to 28 February 1947 (Browne 1950).
House Crow Corvus splendens
966 recorded, mostly in the Aden area, where the peak count was 210 on 25
March.
An abundant breeding resident, mainly in Aden and its environs but
increasingly recorded in villages along the coast east to al-Mukalla. Eggs
recorded February to September (MDG, HPM). One at al-Ghaydah in autumn
1989 (Jennings et al. 1991).
Brown-necked Raven Corvus ruficollis
119 recorded, most records involving 1-10 birds but a concentration of 53 was
noted at Wadi al-Khabt, north of Aden, 24 March.
A widespread and locally abundant breeding resident, with flocks of up to
150 recorded at Abyan cotton fields (MDG, HPM).
Raven Corvus corax
Not recorded during the survey.
Claimed sightings at Sheikh Othman and Lahej (Bark Jones & Hartley 1957) lack
supporting details. Therefore, occurrence cannot be considered proven.
Fan-tailed Raven Corvus rhipidurus
542 recorded at numerous and widespread localities. The largest concentrations
were 50 at Ras al-’Arah 20 April and 137 in the Mahrah 28 April.
A common and widespread breeding resident. Flocks of up to 1,000 recorded
near Lahej and 2,000 at Dhala (MDG, HPM).
Tristram's Starling Onychognathus tristramii
459 recorded. Widespread through most of the south, fairly common in the east,
67
R. P. Martins et al. Bees Sandgrouse 17
but few in Wadi Hadramawt.
A widespread resident breeder.
Amethyst Starling Cinnyricinclus leucogaster
108 recorded at 18 localities. Highest counts were ten at al-Mihal 21 March, nine
at Wadi Yashbum 28 March and ten at Wadi Harim 19 April.
A passage migrant, which may breed in the west. Recorded from March to
May and in October.
Starling Sturnus vulgaris
Not recorded during the survey.
A vagrant, the only record being 100 at Aden 8 December 1965 (MDG, HPM).
Rose-coloured Starling Sturnus roseus
Not recorded during the survey. :
A vagrant, one near Aden 30 October 1946 (Browne eo, and one there 7
November (Ennion 1962).
Wattled Starling Creatophora cineracea
Not recorded during the survey.
An irregular visitor, recorded in the Aden area in April and from July to
September (MDG, HPM). Two recorded at sea off southern Yemen, July 1963
(Bailey 1966).
House Sparrow Passer domesticus
1,545 recorded, all in areas with human settlements.
A widespread resident breeder.
Arabian Golden Sparrow Passer euchlorus
Ten recorded, six on the Tihamah 30 km inland from Aden, 25 March and four
near Hisn al-Sawat 21 April.
A scarce local breeding resident on the Tihamah north of Aden and eastward;
the record from Hisn al-Sawat demonstrates an eastward range extension of 400
km.
Passer sp.
A small juvenile sparrow superficially resembling juvenile House Sparrow was
trapped at Wadi Himarah 8 April. Measurements (in millimetres, excepting
weight in grams) were: max wing chord 68; head and bill 28.1; max tarsus 19.1;
tail 54.0; weight 18.3. A number of slides were taken but identification remains
unclear and the possibility remains that the bird could perhaps be Somali
Sparrow Passer castanopterus or a hybrid.
Pale Rock Sparrow Petronia brachydactyla
Not recorded during the survey.
A vagrant; three at Habilayn 27 December 1965 (Latham 1967).
68
Sandgrouse 17 Status of passerines in southern Yemen
Bush Petronia Petronia dentata
Not recorded during the survey.
Apparently a very local resident breeder, with records from Amiri and Dhala
in the west (Sclater 1917, Meinertzhagen 1954; MDG, HPM).
Riippell's Weaver Ploceus galbula
1978 recorded, from the Tihamah near Aden to Wadi al-Masilah in the east, with
a maximum of 263 roosting at Wadi Himarah 7 April. Common in Wadi
Hadramawt, for example 150 at al-Sawm 3 May and 174 at Sayun 4 May.
A resident breeder throughout western and central regions east to Wadi al-
Masilah. Apparently absent from the Mahrah.
Arabian Waxbill Estrilda rufibarba
159 at eight localities: from 625 m (Wadi Hadramawt) to 1,450 m (Jabal Iraf). No
large concentrations noted. Highest counts were: 20 at Jabal Iraf 22 March; 18 at
Wadi al-Jahr 27 March and 37 at Wadi Yashbum 27 March. Recorded in Wadi
Hadramawt on an intensively farmed silt plain and elsewhere in highland
wadis, often in cultivated or wetter areas; also in Juniperus woodland on Jabal
Iraf. Recently fledged juveniles were recorded at Jabal Iraf and Wadi al-Jahr
and a bird was carrying nest material at Tarim 4 May, the first breeding
evidence from southern Yemen.
A resident breeder, fairly common from the south-west east to Wadi
Hadramawt.
African Silverbill Euodice cantans
280 recorded at numerous and widespread localities at low elevations.
Localities include Wadi al-Jahr, Wadi Hajr, Wadi Himarah, Saqr, al-Ghaydah
and, in Wadi Hadramawt, al-Sawm, Tarim, Sayun, and al-Qatn. On the fringe
of the interior desert three were noted on the desert crossing from al Qatn to
Shabwah.
A widely distributed resident breeder.
Arabian Serin Serinus rothschildi
57 recorded from near sea-level to 1,450 m. Common in Juniperus woodland on
Jabal Iraf; also recorded at Wadi al-Jahr, Wadi Yashbum and Wadi Hajr.
Apparently a localised resident breeder in the west, extending east to Wadi
Hadramawt and Wadi Hajr.
Yemen Serin Serinus menachensis
Not recorded during the survey. /
Status unclear. Two records, both collected by Meinertzhagen, at Amiri,
February 1923 and Dhala, November 1948.
Golden-winged Grosbeak Rhynchostruthus socotranus
104 recorded at three sites: in Juniperus woodland on Jabal Iraf (1,450 m), at
Wadi Mararah (360 m) and in the Shahrut hills (680 m) in the Mahrah.
69
R. P. Martins et al. Sandgrouse 17
Clearly a resident, although previously recorded only in January, July and
December, with no proof of breeding. Singing birds were noted at all localities
but no other evidence of breeding was recorded; display and song have been
noted in October to November and spring in northern Yemen (Martins 1987). In —
northern Yemen the species is primarily dependent on Euphorbia scrub but all
observations from southern Yemen were associated with Juniperus, Acacia, or (in
the Mahrah) Anogeissus/Commiphora woodland.
Yemen Linnet Acanthis yemenensis
13 recorded on the escarpment at 2,000 m in the al-Mardam area on the border
of former North and South Yemen are the first records.
Probably an uncommon breeding resident.
Trumpeter Finch Bucanetes githagineus
Three in rocky hills near al-Sawm in eastern Wadi Hadramawt, 3 May.
Probably an uncommon breeding resident in Wadi Hadramawt, previously
recorded March to June 1985 and 1986 (J. F. Pavey pers. comm.).
House Bunting Emberiza striolata
97 recorded; 90 were in Wadi Hadramawt between Mar'ayt and al-Qatn (with 39
at Wadi Fughmah, 2 May). In addition, five at Wadi Harim in the extreme
south-west, one at Wadi Irkhawt and one between Shabwah and Marib on the
fringe of the interior desert. |
A scarce and remarkably localised resident breeder, most common in Wadi
Hadramawt; apparently absent in the east.
African Rock Bunting Emberiza tahapisi
77 recorded at five sites, including Jabal Iraf and Wadi Himarah in the Mahrah.
A rather localised resident breeder in rocky hills.
Ortolan Bunting Emberiza hortulana
Seven recorded at al-Mihal 21 March, the first spring record.
A scarce passage migrant, recorded in September, October and March.
Cretzschmar's Bunting Emberiza caesia
Not recorded during the survey.
A vagrant, one on a ship near Aden Spring 1891 (Tristram 1891).
REFERENCES
ASH, J. S. (1988) Some observations in South Yemen in 1984 and a selected bibliography of
the region. Sandgrouse 10: 85-90.
BAILEY, R. (1966) The sea-birds of the southeast coast of Arabia. Ibis 108: 224-264.
BARK JONES, R. AND HARTLEY, P. H. T. (1957) A list of birds of Aden and the Aden Protectorate
1944-1945, Privately printed.
BARNES, H. E. (1893) On the birds of Aden. Ibis (18) 6: 57-84, 165-181.
BATES, G. L. (1938) On birds from Hadhramaut. Ibis (14) 2: 437-462.
70
Sandgrouse 17 Status of passerines in southern Yemen
BOURNE, W. R. P. (1960) The Petrels of the Indian Ocean and adjacent waters. Sea Swallow
13:9-39 ;
BOURNE, W. R. P. AND BUNDY, G. (1990) Records of Brown-headed Gull Larus brunni-
cephalus and Grey-headed Gull L. cirrocephalus around Arabia. Sandgrouse 12: 37-42.
BROOKS, D. J., EVANS, M. I., MARTINS, R. P. AND PORTER, R. F. (1987) The status of birds in
North Yemen and the records of the OSME expedition in autumn 1985.
Sandgrouse 9: 4-66.
BROWN, L. H. (1969) A Bird Count on the Arabian ‘Jol’. J. Bombay Nat. Hist. Soc. 66 (2):
327-337.
BROWNE, P. W. P. (1950) Notes on birds observed in Saudi Arabia. Ibis 92: 52-65.
Bury, G. W. (1911) The Land of Uz. London.
CLARKE, G. (1966) Flamingos at Khormaksar, Aden Colony. RAF Orn. Soc. J. 1: 11-19.
CLARKE, G. (1967) Bird notes from Aden Colony. Ibis 109: 516-520.
CRAMP, S. AND SIMMONS, K. E. L. (EDS) (1983) The Birds of the Western Palaearctic Vol. 3.
Oxford University Press, Oxford.
DowseTT, R. J. AND DowSETT-LEMAIRE, F. (1993) Afrotropical avifaunas: annotated country
checklists. Tauraco Research Report 5. Tauraco Press, Liege.
DYMOND, J. N. (1996) The Plain Nightjar in Yemen. Sandgrouse 17: 132-133.
ENNION, H. E. (1960) Birds of western Aden. Country Life 4 August 1960: 246-247.
ENNION, H. E. (1962) Notes on birds seen in Aden and the western Aden Protectorate. Ibis
104: 560-562.
Evans, M. I. (ed.) (1994) Important Bird Areas in the Middle East. BirdLife Conservation
Series No 2. BirdLife International , Cambridge.
Farrow, D. (1994) Occurrence and breeding of Malachite Kingfisher Alcedo cristata in
Yemen. Sandgrouse 16: 58-59.
GALLAGHER, M. D. (1986) Additional Notes on the Birds of Oman, Eastern Arabia 1980-
1986. Sandgrouse 8: 93-101
GALLAGHER, M. D. (1986) Abdim's Stork in Arabia. Sandgrouse 8: 107-111.
GALLAGHER, M. D. AND STANLEY PRICE, K. (1990) The Spotted Thick-knee Burhinus capensis
and Stone Curlew B. oedicnemus in Arabia. Sandgrouse 12: 8-24.
GALLAGHER, M. D. AND Woopcock, M. (1980) The Birds of Oman. Quartet, London.
GRIMWOOD, I. R. (1963) Notes on birds seen in the eastern Aden Protectorate. Bull. Brit.
Orn. Club 83: 50-51.
GUICHARD, K. M. AND GOODWIN, D. (1952) Notes on birds collected and observed in Oman
and Hadhramaut. Ibis 94: 294-305.
Ho.tom, P. A. D., PorTER, R. F., CHRISTENSEN, S. AND WILLIS, I. (1988) Birds of the Middle East
and North Africa: a companion guide. Poyser, Calton.
JENNINGS, M. C., ABDULLA, I. A. AND MOHAMMED, N. K. (1991) Atlas of the breeding birds of
Arabia: Survey No.8. Results of an ornithological survey of South Yemen 23 October to 9
November 1989. NCWCD Technical Report 25.
KiRWAN, G. (1994) First record of White-breasted Waterhen Amaurornis phoenicurus in
Yemen. Sandgrouse 16: 55.
LATHAM, J. J. (1967) Bird notes of Aden Protectorate - Salalah and Habilayn. RAF Orn. Soc.
Je 328-12.
MARTINS, R. (1987) The Golden-winged Grosbeak in North Yemen. Sandgrouse 9: 106-110.
MEINERTZHAGEN, R. (1923) [New species and subspecies: exhibited and described]. Bull.
‘Brit. Orn. Club 43: 156-159.
MEINERTZHAGEN, R. (1924) A contribution towards the birds of the Aden Protectorate. Ibis
(11) 6: 625-642.
MEINERTZHAGEN, R. (1949) A new race of Melierax gabar from Aden. Bull. Brit. Orn. Club
69: 82-83.
MEINERTZHAGEN, R. (1954) Birds of Arabia. Oliver and Boyd, Edinburgh.
71
R. P. Martins et al. Sandgrouse 17
MEININGER, P. M. AND SORENSEN, U. G. (1986) The occurrence of skuas (Stercoraridae) in
the Middle East with special reference to Egypt and the northern Red Sea. Vogelwarte
33: 281-294. .
OBADI, N. (1989) The Birds of Yemen. Singapore. (In Arabic.)
OGILVIE-GRANT, W. R. (1900) On the birds of Southern Arabia. With field notes by A.
Blayney Percival. Novit. Zool. 7: 243-273.
PAIGE, J. P. (1960) Bird notes from Aden and Oman. Ibis 102: 520-525.
PAIGE, J. P. (1965) Field identification and winter range of the Asiatic Dowitcher,
Limnodromus semipalmatus. Ibis 107: 95-97.
PORTER, R. F., MARTINS, R. P. AND STONE, F. (1996) The Ornithological Society of the Middle
East's Survey of southern Yemen and Socotra, March-May 1993: an introduction.
Sandgrouse 17: 5-14.
PORTER, R. F., MARTINS, R. P., SHAW, K. D. AND SORENSEN, UFFE. (1996) The status of non-
passerines in southern Yemen and the records of the OSME sumeey, in spring 1993.
Sandgrouse 17: 22-53.
SAGE, B. L. (1959) Some recent observations at Aden. Ibis 101: 252-253.
SCLATER, W. L. (1917) The birds of Yemen, south-western Arabia. Ibis (10) 5: 129-186.
SMITH, K. D. (1956) On the birds of the Aden Protectorate. Ibis 98: 303-307.
SPENCER, J. W. (1996) Ostrich eggshell fragments in Yemen. Sandgrouse 17: 130-131.
THESIGER, W. (1959) Arabian Sands. Longmans, London.
TRISTRAM, H. B. (1891) [Letter to the editor which includes Emberiza caesia ‘near' Aden.] Ibis
(6) 3: 470-472.
YERBURY, J. W. (1886) On the birds of Aden and the neighbourhood. Ibis (5)4: 11-24.
YERBURY, J. W. (1896) Further notes on the birds of Aden. Ibis (7) 2: 13-14.
R. P. Martins, 6 Connaught Road, Norwich, Norfolk NR2 3BP, UK.
C. G. Bradshaw, 6 Collet Walk, Parkwood, Gillingham, Kent ME8 9LQ, UK.
Alan Brown, 23 King’s Court, Longniddry, East Lothian EH32 0QP, UK.
G. M. Kirwan, 6 Connaught Road, Norwich, Norfolk NR2 3BP, UK.
R. F. Porter, BirdLife International, Wellbrook Court, Girton Road, Cambridge
CB3 ONA, UK.
Vig
Sandgrouse (1996) 17: 73-80
An introduction to Socotra and its birds
R. F. PORTER AND FRANCINE STONE
he island of Socotra lies in the Gulf of Aden some 800 km east of Aden and
350 km from the nearest coastline of the Republic of Yemen. It is 110 km
from east to west, 40 km from north to south and reaches an altitude of over
1,500 m. Together with the neighbouring island groups of The Brothers (al-
Ikhwan), ‘Abd al-Kuri and Sabuniya, it is much closer to the Horn of Africa than
Yemen, from which it is administered. The human population is estimated at
between 20,000 and 80,000, but it is probably nearer the lower figure. There are
no port facilities or metalled roads, the availability of electricity is restricted and
medical facilities do not exist. The population is supported primarily through |
subsistence animal husbandry, farming and fishing.
GEOLOGY
It is commonly held that the Socotra archipelago is a fragment of the Afro-
Arabian tectonic plate which began to break away from the African mainland at
least 10 million years ago in the upheavals that created Arabia and the Gulf of
Aden. Geologically, Socotra comprises an igneous and metamorphic basement
dating from the Pre-Cambrian Era and a complex of early Paleozoic volcanic
rocks which are overlain by a mantle of limestones, marls and sandstones of
Cretaceous and Eocene age. Intrusive granites of the Hajhir massif break
through the older metamorphic and magmatic formations exposing riebeckite,
an unusual form of peralkaline mineral first found and identified on Socotra by
Aemilius Riebeck in 1881 (Naumkin 1993, Beydoun & Bichan 1970).
TOPOGRAPHY
The topography of Socotra can be divided into three main zones: 1) the alluvial
coastal plains which range in width up to 5 km, the longest being the Noged
plain which stretches 60 km along the south coast; 2) the limestone plateaux
covering a majority of the island and averaging 300-700 m in altitude, with poor
soils except in the gullies and rock crevices on the surface and in fissures of the
nearly vertical escarpments; and 3) the Hajhir mountains in the north-west
where the soils can be well developed in the valleys and on the more gentle
slopes.
The Hajhir mountains, with their jagged granite pinnacles, form the spine of
the island. They rise dramatically to a height of 1,519 m (Jabal Mashanig) on the
sheer northern face and slope off more gently on the south and eastern flanks.
The limestone plateaux which surround this elevation to the east, west and
south drop away at the edges in steep cliffs and are eroded on their surfaces into
a karst topography aptly described as 'clint fields with grooved, fractured,
cellular and cavernous holes' (Naumkin 1993) that make heavy going for the
sturdiest of footwear (Bent 1900). The northern coastal plain lying at the feet of
73
R. F. Porter and Francine Stone Sandgrouse 17
the Hajhir granites and the limestone bluffs consists of alluvial gravels, stones
and coarse sands. The sector of the island south of the Hajhir massif descends in
terraces to the Noged plain, the marine sediments of which meet a strip of dunes
at the shoreline and continue at a shallow gradient at least 15 km out to sea. To
the west there is very little wadi drainage off the limestone plateaux except at
Ras Sha'b and Ras Katanahan, and it is here that coral reefs are the best
developed. In the east toward Ras Momi sections of aeolian sand deposits on
the northern exposure, so-called 'leaned dunes’, can reach as high as 360 m
where they are blown against the cliff faces of the Hamadiroh plateau by the
monsoon winds. The sea shelf at Ras Dehammeri (Rhiy di-Hamri) drops away
precipitously to a depth of 1,000 m within 5 km of the shore. Otherwise, the
coastal waters surrounding the archipelago are relatively shallow. The interior
of the island is dissected by wide basins studded with outcrops of lightly-eroded
volcanic rock, and the rolling relief of the limestone platforms is broken in
places by spectacular gorges (Naumkin 1993, WWF & IUCN 1994, Beydoun &
Bichan 1970).
VEGETATION
The Socotra archipelago is relatively sparsely vegetated and dominated by
xeromorphic plants. Its botany has been extensively studied and is renowned
for its high level of endemism: of about 800 vascular plants recorded, some 30%
are endemic (A. G. Miller in prep). Desiccating winds associated with the
summer monsoon restrict lush vegetation to the sheltered vaileys in the
mountains, to gullies and clefts in the cliffs not exposed to the elements. Sparse
shrubland characterises the open summits of the limestone plateaux, and on the
coastal plain conditions are best described as semi-desert, in some places almost
devoid of vegetation, notably on the Noged plain. In this context, the unique
flora of the islands can nevertheless be found in all the various vegetation zones.
Furthermore, the most abundant plants (Croton socotranus and Jatropha
unicostata), and the most common shrubs and trees are endemic to the islands.
A. G. Miller of the Royal Botanic Garden Edinburgh, who is developing the
authoritative description of Socotran flora, divides the island's vegetation into
four principal categories (further subdivided into seven main types in Figure 1).
1. Open deciduous shrubland of coastal plains and low inland hills, up to 150 m
(types 1 & 2 on Figure 1). As this terrain is dominated by the endemic Croton
socotranus, he terms it 'Croton shrubland’ but also notes the scattered
emergent trees, Euphorbia arbuscula, Dendrosicyos socotranus and Zizyphus
spina-christi, and low cushion shrubs and a good ground cover of grasses and
herbs after the rains.
2. Open deciduous or succulent shrubland of lower mountain slopes, limestone
plateaux and escarpments, sea-level to 550 m (type 3 on Figure 1). This zone
is richer in species than the Croton shrubland and the vegetation is the most
widespread of any zone on the island. It is here, notably on the seaward
74
Sandgrouse 17 An introduction to Socotra and its birds
escarpments, that one finds the distinctive succulent trees, such as the
Adenium obesum ssp. sokotranum, which give Socotra its other-worldly aspect.
The emergent trees include Euphorbia arbuscula, Dendrosicyos socotranus,
Sterculia africana var. socotrana, Boswellia spp. and Commiphora spp., and the
main shrubs are Croton socotranus and Jatropha unicostata.
3. Submontane, semi-deciduous thicket, mainly 380 - 750 m (types 4,5 & 6 on
Figure 1). In this topography of limestone plateaux and middle slopes of the
granite mountains, the dominants which thrive in rich quantities of species
include Rhus thyrsiflora, Buxus hildebrandtii, Carphalea obovata, Sterculia africana,
with emergent Dracaena cinnabari, the famed Dragon's Blood tree. Here too,
the pomegranate species, Punica protopunica, once mistakenly thought
endangered, is readily found.
4. Mosaic of dense thicket, low shrubland, grassland and rock vegetation 750 -
1,500 m (type 7 on Figure 1). Over the higher slopes and rock pinnacles of the
granite mountains, one encounters this patch-work of dense thicket, at times
impenetrable at the feet of the pinnacles, which merges higher up into a low
shrubland mainly of Hypericum spp. and grassland on the gentler slopes
where cattle graze. The thicket feature is dominated by Rhus thyrsiflora,
Cephalocroton socotranus and Allophylus rhoidiphyllus with emergent Dracaena
cinnabari.
53°30’ 53°40’ 93°50’ 94°20’
Herb communities Limestone plateau with low
woody herb communities. 500-720 m.
Degraded Croton shrubland Coastal plains
mainly devoid of vegetation. 0-50(-150) m.
Sub-montane thickets Granite limestone
slopes and valleys with semi-deciduous thicket
and emergents. (50-)380-750 m.
Croton shrubland Coastal plains and inland
hills with deciduous shrubs, particularly Croton
Socotranus. 0-50(-150) m.
Succulent shrubland Coastal foothills and Montane thicket Granite slopes and pinnacles
limestone slopes with succulents and emergents. with a mixture of dense thicket, shrubland and
0-550 m. grassland. 750-1,500 m.
Mosaic shrubland Limestone plateau with a
mixture of shrubland types. 500-700 m.
Figure 1. The main vegetation types on Socotra (A. G. Miller pers. comm.; WWF
& IUCN 1994).
75
R. F. Porter and Francine Stone Sandgrouse 17
LAND USE
The grazing of livestock is the major land-use, and there are smaller areas of
cultivation. In recent years water cisterns have been constructed on the island
and are attracting larger grazing stocks than in the past. However, as yet there
is no practicable way to provide supplementary fodder, and drought and
disease continue to provide their traditional control on livestock numbers.
Currently the coastal waters are abundantly stocked with fish, and fishing is a
widespread activity. Communications from the mainland by air and by boat are
severely restricted by lack of harbours, airport facilities and adequate aircraft,
and by monsoon conditions which effectively shut the island off for four months
every year (from July to October). Prospecting for minerals and offshore natural
gas is taking place. There is very little tourism on the island.
Plans for future development of the island include an asphalt runway, a
harbour jetty at Hadibu and extended road infrastructure; tourism is under
discussion. The prospect for these plans is uncertain, but private enterprise has
already constructed a fish refrigeration plant at Sug near Hadibu in anticipation
of a serviceable jetty.
CLIMATE
Socotra's position in the zone of the Indian Ocean where the northern tropical
and the sub-equatorial air masses merge subjects it to a semi-annual climate
cycle. The hot, dry south-west monsoon brings heavy winds from April until
October, and is replaced in November by the wet north-east monsoon. The
period of calm air between the two monsoons in the spring is characterised by
both great heat and humidity. The south-west monsoon can pick up to gale
force on the coasts, and tropical cyclones cause high seas and unstable
conditions, closing the island to access by sea and by air intermittently during
the late spring and summer months. Temperatures range from 17°C in January
to 37°C in July. Average annual rainfall measures 150 mm. However, the west
of the island, lying in the shadow of the Hajhir mountains, experiences greater
aridity, and in the Hajhir peaks above 200 m, average rainfall increases to 300
mm. This is in part because the mountains create their own mists and cloud,
with a fine rain. Amid the granite pinnacles of the Hajhir (above 1,500 m)
annual precipitation can be as great as 1,000 mm, giving rise to permanently
lush vegetation and relatively abundant surface water.
ORNITHOLOGICAL HISTORY
The ornithology of Socotra has been little studied and many areas of the island,
notably the west, remain unvisited by ornithologists. The most extensive survey
was undertaken between 7 March and 14 June 1964 by Alec D. Forbes-Watson,
his results being presented in Ripley & Bond (1966). This involved the collection
of over 500 bird specimens.
Prior to Forbes-Watson's visit, expeditions were conducted by Professor I. B.
Balfour of Glasgow University between February and 30 March 1880 and by Dr
76
Sandgrouse 17 An introduction to Socotra and its birds
Riebeck and Dr Schweinfurth in 1881. These resulted in annotated lists of birds
collected being published by Sclater and Hartlaub (1881).
Further bird collections were made by E. N. Bennett in 1888 and by Henry
Forbes and W. R. Ogilvie-Grant in winter 1898-9, details being presented in
Ogilvie-Grant & Forbes (1903). Prior to the OSME survey, the status of birds on
Socotra and its associated islands was summarised by Dowsett & Dowsett-
Lemaire (1993).
THE 1993 SURVEY
The OSME survey was conducted from 30 March to 6 April 1993. Offshore
islands were not visited. During this period, 12 species of birds previously
unrecorded were observed, bringing the total number of species recorded from
Socotra, its associated islands in the archipelago and neighbouring seas to 110. .
A summary of what is currently known of the status and distribution of birds in
Socotra is presented in Kirwan et al. (1996).
AREAS COVERED
The areas covered by the survey are mapped in Figure 2 in Porter et al. (1996);
the itinerary was as follows:
March
30 Flight: al-Mukalla to Socotra
lagoons at Erhina (Hadibu)
Ras Hebak
31 Ras Hebak
Hadibu
Qariyah lagoons
Rizeleh (or Dihur) below
Hamadiroh plateau
Hamadiroh plateau
April
1 Rizeleh below Hamadiroh plateau
Hamadiroh plateau
Fikhah
Ras Momi
2 Fikhah
~ Ras Momi
Pelagic transect from Ras Momi
Pass south of Rookib
Shidadah
3 Shidadah
Pass south of Rookib
Jabal Jaaf
Hakari wells
Ras Diblih (south coastal plain)
4 Ras Diblih
Wadi near Shibrhoh (south coastal
plain)
Di-Ishal
Jabal Jaaf
Rookib pass
5 Hadibu
Wadi Ayhaft
Di-Ishal
Ehrina
6 Ras Hebak
Qadub marsh
Dunes west of the airport
Flight: Socotra to al-Mukalla
Wider coverage was achieved by splitting the survey team into two groups.
ad
R. F. Porter and Francine Stone Sandgrouse 17
ORNITHOLOGICAL OVERVIEW
110 species have been recorded from Socotra, of which 31 are known or thought
to breed. Of these, six are endemic to the island (Sibley & Monroe 1990), whilst
the populations of a further ten have been treated as endemic sub-species —
(Ripley & Bond 1966). With one exception, we have followed this approach,
which is discussed in further detail by Martins (1996).
Common birds
Based upon survey observations the most common and widespread species are
(in systematic order): Egyptian Vulture Neophron percnopterus, Laughing Dove
Streptopelia senegalensis, Forbes-Watson's Swift Apus berliozi, Long-billed Pipit
Anthus similis, White-breasted White-eye Zosterops abyssinicus, Great Grey Shrike
Lanius excubitor, Socotra Sunbird Nectarinia balfouri, Somali Starling
Onychognathus blythii and Socotra Sparrow Passer insularis. The population of
Egyptian Vulture may exceed 1,000 pairs, signifying that Socotra supports the
most important breeding population in the Middle East. The relative
abundance and densities of these and other species encountered during
systematic transects of the island is presented in Davidson (1996).
Endemics
Study of the endemic species occurring on Socotra was one of the main
objectives of the survey and the information collected is presented through
various relevant papers in this report.
The Socotra Sparrow was found to be by far the most common and
widespread endemic species, often occurring in large concentrations. Less
common but also widespread were Socotra Sunbird and Socotra Warbler Incana
incana, though this species has a more patchy distribution, occuring in low scrub
from sea-level to 1,000 m. The Socotra Starling Onychognathus frater is also
patchily distributed (and is much rarer than the non-endemic Somali Starling),
generally occurring in hilly areas with fruiting trees at altitudes up to at least
500 m. The Socotra Cisticola Cisticola haesitata appears to require areas of low
scrub and, together with the apparently montane Socotra Bunting Emberiza
socotrana, is probably the rarest endemic.
Collar et al. (1994), categorise three endemic species occurring on Socotra as
‘vulnerable’ in the world list of threatened species: Socotra Starling, Socotra
Cisticola and Socotra Bunting, each having an estimated world population of
less than 1,000 individuals. These clearly present the highest priority for conser-
vation action. Initially, this should include a survey of their populations and
habitat requirements.
IMPORTANT BIRD AREAS
A major objective of the survey was to identify sites meriting inclusion in
Important Bird Areas in the Middle East (Evans 1994). Selection of such sites is
based on carefully agreed criteria which review such issues as the presence of
78
Sandgrouse 17 An introduction to Socotra and its birds
globally-threatened species, concentrations of regional populations, presence of
regionally-threatened or declining species and species with small world ranges.
Whilst this survey of Socotra was not comprehensive, we benefited greatly from
discussions with A. G. Miller and Dr Miranda Morris, and thus combined the
known ornithological data with their extensive vegetation surveys. This enabled
identification of predicted Important Bird Areas based upon their clarification of
the vegetation zones of the island. Nineteen important bird areas were
identified, ten resulting from our surveys. Protection of these sites and identifi-
cation of new ones through further surveys is the highest conservation priority.
FUTURE ACTION
As the ornithology of the island is poorly known, further studies are imperative.
Suggested priorities include:
B collection of further information on unsurveyed Important Bird Areas listed
in Important Bird Areas of the Middle East and identification of new areas.
m™ breeding surveys and assessment of conservation requirements of the three
globally-threatened species ocurring in Socotra: Socotra Bunting, Socotra
Starling and Socotra Cisticola.
™ further study of the taxonomy and ecology of the 11 putative endemic
sub-species listed in Martins (1996).
® further study of the taxonomy and ecology of the sedentary Buteo population.
= identification of areas for breeding seabirds: for example, do Jouanin's Petrel
Bulweria fallax and Socotra Cormorant Phalacrocorax nigrogularis breed?
REFERENCES
BALFOUR, I. B. (1888) The Botany of Sokotra. Transactions of the Royal Society of Edinburgh 31:
1-446.
BENT, T. AND MRS THEODORE BENT (1900) Southern Arabia. Smith, Elder and Company,
London.
BEYDOUN, Z. R. AND BICHAN, H. R. (1970) The Geology of Socotra Island, Gulf of Aden.
Quarterly Journal of the Geological Society of London 125, part 3, 1970: 413-446.
COLLAR, N. J., CRosBy, M. J. AND STATTERSFIELD, A.J. (1994) Birds to Watch 2: The World List
of Threatened Birds. BirdLife Conservation Series No. 4. BirdLife International,
Cambridge.
DAVIDSON, P. (1996) Habitats and bird communities in southern Yemen and Socotra.
Sandgrouse 17: 102-129.
DowsETT, R. J. AND DowseEtTT-LEMAIRE, F. (1993) Afrotropical avifaunas: annotated country
checklists. Tauraco Research Report 5. Tauraco Press, Liege.
EVANS, M. I. (ed.) (1994) Important Bird Areas in the Middle East. BirdLife Conservation
Series No. 2. BirdLife International, Cambridge.
79
R. F. Porter and Francine Stone Sandgrouse 17
KIRWAN, G. M., MARTINS, R. P., MORTON, K. M. AND SHOWLER, D. A. (1996) The status of
birds in Socotra and ‘Abd Al-Kuri and the records of the OSME survey in spring 1993.
Sandgrouse 17: 83-101.
MARTINS, R. P. (1996) Taxonomic treatment of endemic taxa in Socotra. Sandgrouse 17:
81-82
NAUMKIN, V. (1993) Island of the Phoenix. Reading.
NAVAL INTELLIGENCE DIVISION. (1946) Western Arabia and the Red Sea. 609 - 615 et passim.
OGILVIE-GRANT, W. R. AND Forses, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In
FORBES, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
RIPLEY, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri. Smithsonian
Miscellaneous Collections 151, No. 7. |
PORTER, R. F., MARTINS, R. P. AND STONE, F. (1996) The Ornithological Society of the
Middle East’s survey of southern Yemen and Socotra, March-May 1993:
an introduction. Sandgrouse 17: 5-14.
SCLATER, P. L. AND HARTLAUB, G. (1881) On the birds collected in Socotra by Prof I. B.
Balfour. Proc. Zool. Soc. London 1881: 165-175.
SIBLEY, C. G AND MONROE, B. L. JR. (1990) Distribution and Taxonomy of Birds of the World.
Yale University Press, New Haven.
WWE AnD IUCN (1994) Centres of plant diversity. Vol. 1. UCN Publications Unit,
Cambridge.
R. F. Porter, BirdLife International, Wellbrook Court, Girton Road, Cambridge
CB3 ONA, UK.
Francine Stone, Grimsdyke Cottage, Nuffiela Lane, Crowmarsh Gifford,
Wallingford, Oxon OX10 6QW, UK.
MAPS
Abd al Kuri to Suqutra (Socotra) 1:350000, inset Ghubbet Kallansiya 1:360000 and Tamrida or
Hadibo 1:720000, chart No. 5. British Admiralty, London: 1987.
Peoples Democratic Republic of Yemen 1:500000, sheet No. 4. Petroleum and Minerals Board.
Aden: 1979 (from Landsat imagery 1972/3).
Socotra 1:125000. Royal Geographical Society. London: 1978.
80
Sandgrouse 17
ee | ee ee
Plate 1. Acacia tortilis Woodland, southern Yemen, April; this savanna woodland
extends for over 100 km in the coastal plain between Bab al-Mandab and Aden. (R. F. Porter)
Plate 2. Montane juniper forest on Jabal Iraf, southern Yemen, March. (RK. P. Martins)
Sandgrouse 17
ty Ye
Plate 3. The coast east of al-Fatk, southern Yemen, April; coastal beaches provide
important breeding sites for marine turtles. (KR. P. Martins)
Plate 4. Al-Sawm, the Hadramawt, southern Yemen, May; an example of an uncultivated
foothill wadi in the interior. (C. G. Bradshaw)
Sandgrouse 17
a
iar ae? _ ‘ ape * - : sak
Plate 5. Small scale subsistence agriculture on coastal dunes at Saqr, southern Yemen,
April. (C. G. Bradshaw )
: 4 cae Sr i fy : 2 f : : oe : /
Plate 6. The Ramlat al-Sab’atayn, southern Yemen, May; grassland growth has been
induced by recent rainfall. (RK. P. Martins)
Sandgrouse 17
ep ee : a i aiericite a s
Plate 7. The Mahrah, southern Yemen, April; typical Commiphora/Anogeissus woodland
on the hills adjacent to the Oman border. (R. F. Porter)
Plate 8. Boscia arabica and termite mound in the Mahrah hills, southern Yemen, April;
termite mounds are frequent in parts of this heavily-overgrazed area. (J. W. Spencer)
Sandgrouse 17
Plate 10. The Hamadiroh plain, Socotra, April. (R. P. Martins)
Sandgrouse 17
Bec eee Ps me é é
Plate 11. Adenium obesum, Socotra, April; this is a common species on the foothills and
highlands. (R. P. Martins)
the limestone plateaux. (R. P. Martins)
Sandgrouse 17
Plate 13. Frankincense Trees Boswellia elongata, Socotra, April; apparently an important
habitat for African Scops Owl Otus senegalensis. (R. F. Porter)
Plate 14. Wooded foothills, Wadi Ayhaft, Socotra, April; the lower slopes of the Hajhir
mountains are in the background. (R. F. Porter)
Sandgrouse 17
Plate 15. Spotted Eagle Owl Bubo africanus, al-Mahwit (northern Yemen), April; heard in
the Mahrah, southern Yemen in late April. (P. Bison)
Plate 16. African Scops Owl Otus senegalensis, Wadi Yashbum, March. (P. Bison)
Sandgrouse 7
Plate 17. Arabian Woodpecker Dendrocopos dorae, female, Jabal Iraf, March; Jabal Iraf is
the most southerly breeding site of this species in Arabia. (P. Bison)
Plate 18. Dunn’s Lark Eremalauda dunni, Ramlat al-Sab’atayn, May; 25 were observed
including displaying pairs. (P. Bison)
Sandgrouse 17
Plate 19. Brown Woodland Warbler Phylloscopus umbrovirens, Jabal Iraf, March: the most
southerly breeding site of this species in Arabia. (P. Bison)
Plate 20. Juvenile Great Grey Shrike Lanius
excubitor, Hiswat al-Hujaymah, April; a
common breeding species in Acacia
woodland between Bab al-Mandab and
Aden. (R. F. Porter)
Plate 21. House Bunting Emberiza striolata,
Wadi Hadramawt, April; a localised
resident breeder in southern Yemen. (VP.
Bison)
Sandgrouse 17
Plate 22. Jouanin’s Petrel Bulweria fallax,
southern Yemen and Socotra. (R. F. Porter)
Plate 23. The breeding Buteo in Socotra,
April. For discussion of the taxonomy of
this species, see Martins & Porter, this
volume. (R. F. Porter)
off Socotra, April;
: eA “hy ai a ar chal eee 4
widespread at sea off
Plate 24. Egyptian Vultures Neophron
percnopterus scavenging for food at a camp
site in Socotra, April; the island supports a
population of conservation significance.
(R. F. Porter)
Sandgrouse 17
Plates 25 and 26. Forbes-Watson’s Swift Apus berliozi, Socotra, April. For discussion of
this species, see Porter, Dymond & Martins, this volume. (R. F. Porter)
‘et,
Plate 27. Long-billed Pipit Anthus similis,
Socotra, April; a common resident breeder
in Socotra. (P. Bison)
Sandgrouse 17
Plates 28 and 29. Socotra Sunbird Nectarinia balfouri, Socotra, April; a common endemic
in Socotra. For discussion of this species, see Showler & Davidson, this volume. (P. Bison)
— Sandgrouse 17
Plates 30 and 31. Socotra Warbler Incana incana, Socotra, April; endemic in Socotra. For
discussion of this species, see Dymond, this volume. (P. Bison)
Peeks ae e re see : i : » dil mM oe 3 i ce
Plate 32. White-breasted White-eye Zosterops abyssinica, Socotra, April; widespread in
Socotra. (P. Bison)
Sandgrouse 17
Plate 33.
endemic.
Plate 34. Somali Starlings Onychognathus
blythii, male and female, Socotra, April;
widespread and common in Socotra. For
discussion of this species, see Porter &
Martins, this volume. (R. F. Porter)
ocotra Starling Onychognathus frater, Socotra, April;
For discussion of this species, see Porter & Martins, this volume. (KR. F. Porter)
a globally threatened
Plate 35. Socotra Bunting Emberiza
socotrana, Socotra, April; one of two
individuals seen in Socotra in April 1993.
For discussion of this species, see Morton,
this volume. (P. Bison)
Sandgrouse 17
Plate 36. African Rock Bunting Emberiza tahapisi, Socotra, April. A common breeder in
Socotra. (P. Bison)
Plate 37.. Socotra Sparrow Passer insularis, Plate 38. Socotra Sparrow Passer insularis,
male, Socotra, April. A common breeder male, Socotra, April. (R. F. Porter)
in Socotra, April. (P. Bison)
Sandgrouse (1996) 17: 81-82
Taxonomic treatment of endemic taxa in
Socotra
R. P. MARTINS
Be populations endemic to Socotra are little studied. Some comments on the
systematic treatment adopted in this report are, therefore, appropriate.
During the survey, field-time on Socotra was very limited. It has, therefore, not
been possible to conduct the detailed study necessary for a full review of
endemic taxa described from Socotra (either at species or ‘sub-species’ level).
Excepting the local Buteo populations the approach taken here is simply to adopt
the treatment proposed by Sibley & Monroe (1990) where six taxa are treated as
species endemic to Socotra. These are:
Onychognathus frater Socotra Starling
Nectarinia balfouri Socotra Sunbird
Cisticola haesitatus Socotra Cisticola (Island Cisticola)
Cisticola incanus/Incana incana Socotra Warbler
Passer (motitensis) insularis Socotra Sparrow
Emberiza socotrana Socotra Bunting
The most recent review of the Socotran avifauna (Ripley & Bond 1966) lists an
additional ten or eleven (including the local Buteo, for which no firm conclusions
were offered) local populations as endemic sub-species as follows (taxa - or
putative taxa - marked * were not encountered during the survey):
Buteo buteo ‘sub-species?’
Centropus superciliosus sokotrae*
Otus scops socotranus
Caprimulgus nubicus jonesi*
Eremopterix nigriceps forbeswatsoni
Lanius elegans uncinatus
Anthus similis sokotrae
Zosterops abyssinicus socotranus
Passer insularis hemileucus (on Abd-el-Kuri only)*
Rhynchostruthus socotranus socotranus
Fringillaria (=Emberiza) tahapisi insularis
While it is beyond the scope of this report to undertake a reassessment of these
taxa, the serious need for this is well illustrated by recent work in the Cape
Verde archipelago (Hazevoet 1995) where similar difficulties in interpreting
local taxa exist. The Cape Verdes and Socotra are located off continental Africa
at similar latitudes, show limited but significant zoogeographical similarities
and have apparently experienced a parallel history of environmental change
since the Tertiary. Conclusions from a comprehensive reassessment of the
systematics of Cape Verdean taxa, therefore, constructively inform any analysis
81
R. P. Martins Sandgrouse 17
of similar phenomena on Socotra. The analysis conducted by Hazevoet employs
the Phylogenetic Species Concept, which views a species as the smallest
diagnosable cluster of individual organisms "within which there is a parental
pattern of ancestry and descent" (Cracraft 1983 and 1987, see also Hazevoet 1995).
By contrast, the past treatment of certain populations on Socotra at the level of
locally endemic ‘sub-species’ has reflected the application of the more
traditional Biological Species Concept. There is a clear need for a review of the
avifauna of Socotra which reflects contemporary systematic thinking. Thus sub-
species which have been described from Socotra in the past may or may not
merit recognition as valid and discrete taxa (perhaps as Phylogenetic species).
Hopefully, this problem will receive more attention in the future.
Two important conclusions from Hazevoet's work in the Cape Verdes of
relevance to the Socotran avifauna are:
1. Endemic breeding populations may be more closely related to (common)
ancestral stock than widespread continental congeners (or conspecifics). The
former may be relict populations derived from pre-pleistocene, previously
widespread African populations, now extinguished through environmental
change, while the latter (at least in Eurasia) are of more recent origin. This may
imply that the treatment, for example, of the endemic(?) Socotran populations of
Apus and Buteo as (phylogenetic) species more accurately reflects their true
evolutionary history and relationship to more widely distributed continental
congeners. Arguments for the adoption of this approach to the systematic
treatment of, for example, Apus and Buteo populations on the Cape Verdes are
presented by Hazevoet.
2. Morphological differences (e.g. minor variation in plumage characters)
between local populations of species which are extralimitally widespread are
often most meaningfully interpreted as a reflection of the influence of local
environmental conditions and not as evidence which adequately justifies
treatment as a unique taxon. Under the traditional approach to avian systematics
(through application of the Biological Species Concept) such populations would
qualify for treatment as ‘sub-species’ while, under the Phylogenetic Species
Concept, such differences are viewed as virtually insignificant. The Socotran
population of Long-billed Pipit Anthus similis (sokotrae?) offers a good example of
a situation where such considerations are perhaps relevant.
REFERENCES
CRACRAFT, J. (1983) Species concepts and speciation analysis. Current Ornithol. 1: 159-187
CRACRAFT, J. (1987) Species concepts and the ontology of evolution. Biol. Philos. 2: 63-80.
HAZEVOET, C. J. (1995) The Birds of the Cape Verde Islands. B.O.U. Checklist No. 13. British
Ornithologists’ Union, Tring.
SIBLEY, C. G. AND MONROE, B. L. (1990) Distribution and Taxonomy of Birds of the World. Yale
University Press, New Haven.
- RIPLEY, S. D. AND BOND, G. M. (1966) The Birds of Socotra and 'Abd al-Kuri. Smithsonian
Misc. Coll. 151, No. 7.
R. P. Martins, 6 Connaught Road, Norwich, Norfolk NR2 3BP, UK.
82
Sandgrouse (1996) 17: 83-101
The status of birds in Socotra and 'Abd AI-
Kuri and the records of the OSME survey
in spring 1993
G. M. KIRWAN, R. P. MARTINS, K. M. MORTON
AND D. A. SHOWLER
his paper presents the results of the OSME survey of Socotra from 30 March
to 6 April 1993.
The itinerary and area surveyed are presented in Porter & Stone (1996), which
also outlines the previous ornithological studies undertaken on the island and
describes the general habitats. The observers (the survey team members) are
listed in Porter et al. (1996).
The first paragraph of each species account details observations made during
the survey. Figures quoted for the number of individuals recorded are day
totals summed for the whole period; where a site was visited on more than one
day, the highest count has been used. Generally, this gives an accurate picture
of relative abundance. The second paragraph summarises the known status to
date.
Jouanin's Petrel Bulweria fallax
Ten on 30 March from the shore at Hadibu/Ras Hebak. 260 on a pelagic
transect, north-east of the island, 2 April; all more than 4 km from shore and
fairly evenly distributed to 20 km from shore, with up to 55 recorded per hour.
Recorded at sea around Socotra and in the Arabian Sea and Gulf of Aden,
apparently throughout the year. No breeding colony has yet been found.
Ripley & Bond (1966) postulate that ‘it probably breeds in burrows on Socotra,
‘Abd al-Kuri, and the Kuria Muria islands off eastern Aden, possibly from
October to March’.
Streaked Shearwater Calonectris leucomelas
Not recorded during the survey.
A vagrant from the western Pacific. Mackworth-Praed & Grant (1952) report
that it is ‘recorded in April from seas just east of Socotra Island, and may occur
in the Gulf of Aden’.
Persian Shearwater Puffinus (Iherminieri) persicus
Six on a pelagic transect, north-east of the island, 2 April. Seven from the shore
at Ras Hebak, 6 April.
Occurs in the Arabian Sea and Gulf of Aden throughout the year. Breeds in
the Persian Gulf, perhaps also the Red Sea (Brown et al. 1982, Harrison 1985) and
on the Kuria Muria islands (Hollom et al. 1988).
83
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A. Showler Sandgrouse 17
Red-billed Tropicbird Phaethon aethereus
Two off Ras Hebak, 30 March. Two on a pelagic transect, north-east of the
island, 2 April.
Resident in the region. Forbes-Watson considered that three or four birds in.
March on Jazirat Sabuniya were preparing to breed (Ripley & Bond 1966).
Red-footed Booby Sula sula
Not recorded during the survey.
Socotra is on the very edge of its known pelagic range in the Indian Ocean.
There is no evidence of breeding. Referring to this species, Ogilvie-Grant &
Forbes (1903), under the heading Sula piscatrix, ambiguously report ‘an
immense flock of Gannets’ from the seas around Socotra a a ‘small flock of
the White Booby’ off 'Abd al-Kuri.
Masked Booby Sula dactylatra
One off south coast, near Ras Diblih, 4 April.
A resident, breeding on outlying islands. Forbes-Watson recorded about 100
pairs on Kaal Firaon and Jazirat Sabuniya in mid-March. All stages of
incubation and nestling development were noted (Ripley & Bond 1966).
Brown Booby Sula leucogaster
Seen daily between 30 March and 6 April with a total of 32 records. The
maximum was 15 off Ras Hebak and Erhina, 30 March.
A resident, breeding on outlying islands.
Socotra Cormorant Phalacrocorax nigrogularis
Maximum of 35 off Ras Hebak, 6 April. One off Fikhah, 2 April. Three off
south coast, 2 km west of Ras Diblih, 4 April. Six off Erhina, just east of Hadibu,
5th April.
A non-breeding visitor. Although recorded at all the island groups in the
Socotran archipelago, breeding has not been proven. Forbes-Watson considered
breeding unlikely (Ripley & Bond 1966).
Night Heron Nycticorax nycticorax
Single immatures at Hadibu, 31 March, and en-route from the south coast to
Rookib pass, 4 April. |
These are the first records for Socotra. It seems likely that this species is a
scarce or very scarce passage migrant.
Striated Heron Butorides striatus
One at Erhina lagoon, just east of Hadibu, 5 April.
This species is largely sedentary throughout its range but some passage is
reported from Oman (Hollom et al. 1988), so its status on Socotra is possibly that
of scarce passage migrant. Two or three records by Forbes-Watson in March are
the only others on Socotra (Ripley & Bond 1966).
84
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
Cattle Egret Bubulcus ibis
One at Erhina lagoon, just east of Hadibu, 30 March.
A scarce or very scarce passage migrant. One seen by Forbes-Watson in early
June is the only previous record (Ripley & Bond 1966).
Western Reef Heron Egretta gularis
Three at Qariyah lagoons, 31 March. 12 between Rizeleh and Ras Momi, 1
April. One during a pelagic transect, north-east of the island, 2 April. Three at
Ras Hebak, 5 April. Six between Ras Hebak and Qadub marsh, 6 April.
Principally sedentary, but apparently undertakes at least limited dispersion,
which may account for the Socotran records. Forbes-Watson recorded birds in
March but none remained until April (Ripley & Bond 1966).
Little Egret Egretta garzetta
One at Erhina lagoon, 5 April. Two at Qadub marsh, 6 April.
A scarce passage migrant.
Grey Heron Ardea cinerea
38 seen at 12 sites. Most records were of one to three birds, but 14 were
observed at Qariyah lagoons, 31 March.
A passage migrant. Although Forbes-Watson recorded the species from
March to June (Ripley & Bond 1966), he found no evidence of breeding.
Purple Heron Ardea purpurea
Not recorded during the survey.
A passage migrant or scarce passage migrant. Forbes-Watson recorded two in
May (Ripley & Bond 1966) and Ogilvie-Grant & Forbes (1903) collected a single
immature.
Glossy Ibis Plegadis falcinellus
One at Wadi Ayhaft, 5 April is the first record for Socotra.
Spoonbill Platalea leucorodia
Not recorded during the survey.
Sclater and Hartlaub (1881 (who collected one at Cadhoop)) mention
Spoonbills as having been seen by Balfour on the margins of stagnant pools near
the villages on the north coast. Mackworth-Praed & Grant (1952), without
indicating their source, state that the migrant Palearctic race leucorodia and the
mainly sedentary north-east African race archeri both occur, the latter as a non-
breeding visitor. There are no modern records.
Greater Flamingo Phoenicopterus ruber
49 at Qariyah lagoons, 31 March and eight at Ras Momi, 2 April.
A passage migrant. The Bent expedition recorded ‘quantities of Flamingos on
the beach’ in 1888 (in Ogilvie-Grant & Forbes 1903). Forbes-Watson saw small
85
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A. Showler Sandgrouse 17
numbers of flamingos, presumably of this species, as late as mid- os (Ripley &
Bond 1966).
Wigeon Anas penelope
Not recorded during the survey.
A common winter visitor to adjacent areas of north-east Africa. Ogilvie-Grant
& Forbes (1903) ‘found the Wigeon fairly common about the mouths of the
rivers near Hadibu and met with large flocks in a patch of marshy ground
bordering the Dimichiro river near its entrance into Khor Garieh’.
Gadwall Anas strepera
Not recorded during the survey.
A common winter visitor in the adjacent parts of north-east Africa. Ogilvie-
Grant & Forbes (1903) describe the species as ‘fairly common on the brackish
estuaries of the rivers traversing the Hadibu plain and in the swamps near Khor
Garieh’.
Teal Anas crecca
Not recorded during the survey.
A common winter visitor in the adjacent parts of north-east Africa. Sclater
and Hartlaub (1881) state that Balfour found the species ‘specially prevalent on
the Debeni river and Khorfariah’, with up to 14 recorded together.
Mallard Anas platyrhynchos
Not recorded during the survey.
Ogilvie-Grant & Forbes (1903) state that Bennett obtained Mallard on Socotra.
Neither they nor Forbes-Watson (Ripley & Bond 1966) recorded the species.
Garganey Anas querquedula
Not recorded during the survey.
A female obtained by Forbes-Watson in March at a lagoon near Hadibu is the
only record (Ripley & Bond 1966).
Ferruginous Duck Aythya nyroca
Not recorded during the survey.
Ogilvie-Grant & Forbes (1903) recorded ‘a small flock swimming in a brackish
estuary of the Wadi Dinehan’. Hartlaub (1881) reports that Riebeck shot a
female at Gollensir. :
Egyptian Vulture Neophron percnopterus
A total of 618 recorded. Seen daily in all areas visited, often in considerable
numbers. Greatest densities occurred in association with human settlements
and activity; often very tame. Largest concentrations were: 100 between the
airstrip and Hadibu, 30 March; 60 at Hadibu, 31 March; 35 at Hamadiroh
plateau, 1 April (attracted by survey campsite); 40 at airport, 6 April.
86
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
A conspicuous resident. Forbes-Watson describes it as ‘one of the most
obvious birds on Socotra’. He found one nest at Kishin at 500 m with young
between mid-April and mid-May. He did not find the species on 'Abd al-Kuri
(Ripley & Bond 1966). Ogilvie-Grant & Forbes (1903) likewise found the species
‘very common at all our camps’.
Marsh Harrier Circus aeruginosus
Not recorded during the survey.
Forbes-Watson saw a single on two or three occasions in March flying over
the lagoon at Hadibu (Ripley & Bond 1966).
Buzzard Buteo buteo
A total of 31 sightings, the maximum being six at Jabal Jaaf, 4 April. Five
recorded at Di-Ishal, 5 April, were a family party. |
A resident and possibly a rare passage migrant though this is far from clear.
Ogilvie-Grant & Forbes (1903) were the first to record the species and found ‘a
good many pairs’ nesting. Forbes-Watson ‘noted these birds occasionally on the
Hadibu plain, the cliffs near the sea, and in the limestone country to the east of
Kallansiya’. In the Hajhir mountains, he observed a pair carrying sticks to a
nest on a cliff at Kishin (Ripley & Bond 1966). For discussion of the taxonomy
see Martins & Porter (1996).
Osprey Pandion haliaétus
One between Rizeleh and Ras Momi, 1 and 2 April.
Possibly a resident but no confirmed breeding. Ripley & Bond (1966) report
that Forbes-Watson ‘found ospreys to be common on Socotra and 'Abd al-Kuri,
but no nests were seen.’ Ogilvie-Grant & Forbes (1903) recorded ‘a good many’
on 'Abd al-Kuri where they collected ‘a pair of very old birds’.
Kestrel Falco tinnunculus
Widespread and common throughout the area covered by the survey, with up
to seven daily.
A resident breeder.
Lanner Falco biarmicus
Not recorded during the survey.
Perhaps a resident breeder. Two pairs of possible Lanners were recorded on
Dimimi (in the Hagghier range) and in the Dimichiro valley in 1898-99 (Ogilvie-
Grant & Forbes 1903) but it appears that comprehensive views were not
obtained of either pair. Occurrence of this species on Socotra perhaps requires
confirmation, as indicated by Dowsett & Dowsett-Lemaire (1993).
Peregrine Falco peregrinus
One, about ten kilometres south of Jabal Jaaf, 3 April.
Status uncertain; at least a winter visitor. Previously recorded in winter and
87
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A. Showler Sandgrouse 17
in the breeding season but confusion with Barbary Falcon Falco pean
cannot be ruled out.
Barbary Falcon Falco pelegrinoides :
One, Rizeleh, 31 March and two, apparently paired, Hamadiroh plateau, 1
April.
Probably a resident breeder, although not previously recorded from Socotra.
Quail Coturnix coturnix
One, Jabal Jaaf, 3 April.
A passage migrant. Forbes-Watson saw ‘one coturnix’ near Suk at the end of
March 1964 (Ripley & Bond 1966) and Ogilvie-Grant & Forbes (1903) report
‘only a few’ from Socotra and 'Abd al-Kuri. The species is easily confused with
Harlequin Quail Coturnix delegorguei if seen only in flight. The extent to which
this problem might be reflected in-past observations of the two species is
unknown.
Harlequin Quail Coturnix delegorguei
Not recorded during the survey.
A vagrant. Mackworth-Praed & Grant (1952) list the species as occurring on
Socotra but there are apparently no published records. See remarks under
Quail Coturnix coturnix. It is suggested that this species is removed from the
Socotran list pending further evidence.
Spotted Crake Porzana porzana
Not recorded during the survey.
A vagrant. One was collected by Bennett, but no date or locality is recorded
(Ogilvie-Grant & Forbes 1903).
Moorhen Gallinula chloropus
Not recorded during the survey.
A vagrant. Riebeck obtained five adults (Hartlaub 1881), but no date or
locality was given.
Black-winged Stilt Himantopus himantopus
Up to 16 at Erhina lagoons, 30 March - 5 April.
A passage migrant, not previously recorded from Socotra.
Crab Plover Dromas ardeola
Not recorded during the survey.
A vagrant. Balfour reported the species to be common at Kallansiya (Sclater &
Hartlaub 1881). No further observations were detailed in Ripley & Bond (1966)
and this is apparently the only record.
88
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
Cream-coloured Courser Cursorius cursor
A pair with two fledged young at Hakari wells, 4 April.
A migrant or resident breeder, recorded from areas on both north and south
coasts. Seven reported breeders were collected by Forbes-Watson between
March and June 1964, who regarded the species as ‘common’ east of Hadibu on
the Ras Kharma airstrip and near Eriosh (Ripley & Bond 1966).
Little Ringed Plover Charadrius dubius
Two, Erhina Lagoons 31 March and 5 April.
A passage migrant. Forbes-Watson collected one near Hadibu, 9 March 1964
(Ripley & Bond 1966).
Ringed Plover Charadrius hiaticula
Eight at three localities in the eastern half of the north coast, 30 March - 5 April, »
and 14 on the south coast at Ras Diblih, 3 April.
A passage migrant. Forbes-Watson collected one east of Hadibu, 13 March
1964 and saw the species on 'Abd al-Kuri during this month (Ripley & Bond
1966).
Kentish Plover Charadrius alexandrinus
A total of 24 at three localities along the eastern half of the north coast, 30 March
- 5 April. Maximum ten at Qariyah lagoons, 3 April.
A common resident breeder. Forbes-Watson found the species to be common
along the ponds and lagoons on the north coast (Ripley & Bond 1966).
Lesser Sandplover Charadrius mongolus
One, Qariyah lagoons, 31 March and four, Ras Momi, 1-2 April.
Presumed to be a passage migrant. Not previously recorded from Socotra.
Greater Sandplover Charadrius leschenaultii
Three, Ras Momi, 2 April.
Presumed to be a passage migrant. Not previously recorded from Socotra.
Pacific Golden Plover Pluvialis fulva
Two, Erhina lagoons, 30 March and one there, 5 April.
Apparently a scarce passage migrant (as is the case on the fringe of mainland
Arabia). Forbes-Watson collected one, two miles east of Hadibu, 17 May 1964
(Ripley & Bond 1966). This is the only other record from the islands.
Grey Plover Pluvialis squatarola /
Eight along the eastern half of the north coast, 31 March - 6 April.
A passage migrant. Presumably also a winter visitor. Forbes-Watson
collected one near Hadibu, 13 March 1964 (Ripley & Bond 1966).
89
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A. Showler Sandgrouse 17
Common Snipe Gallinago gallinago
One, Erhina lagoons, 30 March, where two, 5 April and one on the Hamadiroh
plateau, 1 April.
A passage migrant and perhaps also a winter visitor. Ogilvie-Grant & Forbes |
(1903) found the species common at Homhil, although it was not recorded by
Forbes-Watson (Ripley & Bond 1966).
Pintail Snipe Gallinago stenura
Not recorded during the survey.
A vagrant. Two shot at Homhil during the Ogilvie-Grant & Forbes (1903)
expedition of 1898-99 are the only records. No date, locality or description are
given. Recent records indicate that this species is a scarce but regular passage
migrant and a winter visitor to the eastern fringe of Arabia. There are also three
records from Yemen.
Bar-tailed Godwit Limosa lapponica
Not recorded during the survey.
Ripley & Bond (1966) reported that Forbes-Watson saw this species during the
period 7 March - 14 June 1964. There are apparently no further details available
and this is the only record.
Whimbrel Numenius phaeopus
29 at four sites along the eastern half of the north coast, 30 March - 6 April.
A common passage migrant. Presumably also a winter visitor.
Curlew Numentus arquata
One, Qariyah lagoons, 31 March and one, Ras Momi, 2 April.
A passage migrant.
Redshank Tringa totanus
Nine, Qariyah lagoons, 31 March and three, Qudub Marsh (east of the airstrip),
6 April.
A common passage migrant.
Marsh Sandpiper Tringa stagnatilis
One, Qudub marsh (east of the airstrip), 6 April.
A passage migrant. Not previously recorded from Socotra.
Greenshank Tringa nebularia
Widespread in small numbers at five localities along the eastern half of the
north coast and at one locality on the south coast.
A common passage migrant. Presumably also a winter visitor.
Wood Sandpiper Tringa glareola
Two, Qariyah lagoons, 31 March.
A passage migrant.
90
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
Common Sandpiper Actitis hypoleucos
Widespread in small numbers; at least 33 at a minimum of six localities along
the eastern half of the north coast.
A passage migrant and perhaps also a winter visitor. Recorded from 'Abd al-
Kuri (Ogilvie-Grant & Forbes 1903) and from near Hadibu where Forbes-
Watson collected two, 11 and 15 March 1964 (Ripley & Bond 1966).
Turnstone Arenaria interpres
18 recorded at three localities (Ras Hebak, Erhina lagoons and Ras Momi) along
the eastern half of the north coast, 30 March - 5 April.
A winter visitor (although non-breeders perhaps linger through the spring
and summer).
Red Knot Calidris canutus
One near Di-Lishah, 3 April was the first record for Socotra.
A vagrant or rare passage migrant in east and north-east Africa. There are
two extralimital records from Somalia (Urban et al. 1986). The species is a
vagrant in Yemen and Oman (Hollom et al. 1988).
Sanderling Calidris alba
One at Ras Momi, 1 April, and two at the same locality, 2 April.
Probably a scarce passage migrant, although listed as a vagrant by Dowsett &
Dowsett-Lemaire (1993). In winter this species is widespread on coasts
throughout north-east and east Africa (Urban et al. 1986). Forbes-Watson (in
Ripley & Bond 1966) did not record this species on Socotra in 1964. Bennet is
credited with having obtained a specimen in 1898 or 1899 (Ogilvie-Grant &
Forbes 1903).
Temminck's Stint Calidris temminckii
Three records, two at Erhina lagoon, 30 March, 12 on shoreline at Hadibu, and 7
on Qariyah brackish lagoons, 31 March.
Probably a regular passage visitor in small numbers. Ogilvie-Grant & Forbes
(1903) report having shot one from a flock along the Hanefu river, 20 Feb 1899.
The only other records are of two males and a female collected near Hadibu by
Forbes-Watson in March 1964 (Ripley & Bond 1966).
Black-headed Gull Larus ridibundus
Two at Erhina lagoon, 30 March was the first record for Socotra.
In east Africa this species winters regularly from the Red Sea south to Kenya
(Harrison 1985).
Lesser Black-backed Gull Larus fuscus
Three at Erhina lagoon, 30 March.
In 1964 Forbes-Watson noted small numbers of gulls including L. fuscus along
the entire north coast. Probably an uncommon non-breeding/winter visitor.
a1
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A: Showler Sandgrouse 17
L. f. fuscus is apparently the only subspecies wintering in the Middle East and
east Africa (Grant 1986). 3
Lesser black-backed Gull Larus fuscus complex
The systematics of the Lesser Black-backed Gull complex are open to much
debate. We have included the sub-species heuglini and taimyrensis under Lesser
black-backed Gull, though often they are treated as sub-species of Herring Gull.
No Yellow-legged Gulls L. cachinnans were observed.
A total of 1,015 recorded, principally along the north coast from Ras Hebak to
Ras Momi with maximum counts of 74 off Hadibu, 31 March and 650 at Ras
Momi, 1 April. Recorded once on the south coast: five at Ras Diblih, 4 April.
All birds examined from slides taken were either heuglini or taimyrensis.
Observed in 1964 by Forbes-Watson (Ripley & Bond 1966) along the north
coast, this species is a regular non-breeding visitor. In this region L. a. heuglini is
known to winter in the southern Red Sea, Gulf of Aden and south along the
African coast to Tanzania. The winter range of taimyrensis is not fully
understood, but some birds wintering in Kenya may be this subspecies (Grant
1986) and so it could possibly occur on Socotra.
White-eyed Gull Larus leucophthalmus
Two at Ras Momi, 1 April.
In 1964 Forbes-Watson (Ripley & Bond 1966) encountered small numbers of
gulls, including this species, along the north coast. Probably a regular non-
breeding visitor in small numbers.
Sooty Gull Larus hemprichii
A total of 688 recorded. Regularly seen off the north coast with the following
maxima: 50 off Ras Hebak, 30 March; 60 off Ras Momi, 2 April and 53 during a
north coast pelagic transect, 2 April.
Forbes-Watson (Ripley & Bond 1966) noted small numbers of gulls including
L. hemprichii along the north coast in 1964. Apparently a fairly common non-
breeding visitor. Breeding occurs in the southern Red Sea to Gulf of Aden, off
the Makran coast and locally along the east Somalia coast to Kiunga, Kenya and
also the Arabian Gulf. It is present off the Arabian coast throughout the year,
but many migrate south to Kenya and Tanzania in the winter (Harrison 1985).
Swift Tern Sterna bergii
A total of 417 recorded, principally on the north coast, with the following
maxima: 80 off Ras Hebak, 30 March; 50 between Riseleh and Ras Momi, 1
March; and 66 off Fikhah, 2 April. On the south coast, 20 at Ras Diblih, 4 April.
Noted as the most common tern species along the north coast in 1964 by
_ Forbes-Watson (Ripley & Bond 1966). Either a common migrant or present
throughout the year in Socotran waters, where it may breed on islands in the
archipelago.
92
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
Lesser Crested Tern Sterna bengalensis
A total of 17 recorded along the north coast, from Ras Hebak, Ras Momi, Fikhah
and the coast near the airport.
Recorded at Qadhub and Kallansiya with Swift Terns by Forbes-Watson
(Ripley & Bond 1966). Either a migrant or a resident in waters around Socotra,
where it may breed on islands in the archipelago.
Sandwich Tern Sterna sandvicensis
A total of 268 recorded, with a maximum of 150 off Ras Hebak, 30 March.
A passage migrant and non-breeding visitor to waters around Socotra.
Roseate Tern Sterna dougallii
Two off Ras Hebak, 6 April was the first record for Socotra.
Probably a scarce migrant; the sub-species concerned, S. d. bangsi, breeds in .
the Arabian Sea on islands off Oman (Harrison 1985).
White-cheeked Tern Sterna repressa
A total of 10,261 recorded, with large numbers counted on three sea-watches:
400 (+ 1,000 terns that were either this species or S. hirundo) off Ras Hebak, 30
March; an estimated 2,500 per hour flying east near Dibleh, 4 April; 4,380 per
hour flying west and 2,390 per hour flying east during a timed count off Ras
Hebak, 5 April (with additional feeding flocks of up to 300 present offshore).
Apparently a regular and common passage migrant.
Saunders' Tern or Little Tern Sterna saundersi or S. albifrons
Not recorded during the survey.
Forbes-Watson noted a few pairs in late May 1964 near Eriosh that had just
started to make nest scrapes (Ripley & Bond 1966). These seem more likely to
have been Saunders’ Tern than Little Tern. The former is known to breed from
the southern half of the Red Sea to the Seychelles and possibly Madagascar,
whereas Little Tern occurs much farther north.
Brown Noddy Anous stolidus
One caught by local fishermen near Di-Lishah, 4 April. In addition, a noddy,
presumably A. stolidus, was recorded during a north coast pelagic transect, 2
April, with another observed from the shore near Ras Diblih, 4 April.
Two previous records: one close inshore near Jebel Bitzobur, 14 January 1899
(Ogilvie-Grant & Forbes 1903) and a single observed by Forbes-Watson on Ras
Hebak in late May 1964 (Ripley & Bond 1966).
Lichtenstein's Sandgrouse Pterocles lichtensteinii
A minimum of 34 recorded at four localities in the north of the island: one on
the Hamadiroh plateau, six at Rizeleh, two between Ras Momi and Shidadah
and 25 at Di-Ishal.
A resident breeder. In addition, has also been recorded from Qaysuh, the
Hadibu plain and near Kallansiya (Ripley & Bond 1966).
93
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A. Showler Sandgrouse 17
Laughing Dove Streptopelia senegalensis
A total of 982 recorded. Seen daily, the highest density occurring at Wadi
Ayhaft where 100+, 5 April.
A common breeding resident on Socotra, occurring from sea-level to at least
850 m on Jabal Jaaf. Often recorded around habitation and in date palm Phoenix
dactylifera groves and other well vegetated areas.
Namaqua Dove Oena capensis
Not recorded during the survey. |
An adult male at Gollonsir (Hartlaub 1881) is the only record.
Bruce's Green Pigeon Treron waalia
A total of 28 recorded at five localities: Rizeleh (1), Hakari wells (4), Wadi
Ayhaft (9), en-route to Di-Ishal (2) and at Di-Ishal (12).
A resident breeder, most commonly found in date palm P. dactylifera groves
and other wooded areas.
White-browed Coucal Centropus superciliosus sokotrae
Not recorded during the survey.
The race sokotrae is endemic. A resident breeder, though nest and eggs have
apparently never been found. Forbes-Watson in 1964 (Ripley & Bond 1966)
considered it uncommon, being confined to water courses and their environs.
Also found rarely in palm groves on the coastal plain, but more common in the
Hajhir mountains. Ogilvie-Grant & Forbes (1903) also observed the species in
the Hajhirs and recorded it as being nowhere common, but widespread in small
numbers over all parts of the island visited. It is possible that the species has
become more localised in response to increasing aridity.
African Scops Owl Otus senegalensis (subspecies?)
The population encountered on Socotra, and treated as Otus senegalensis, is
presumably the same as that described by Ogilvie-Grant & Forbes (1903) and
Ripley & Bond (1966), who assign it to Otus scops socotranus.
Heard or seen at five localities: eight on the Hamadiroh plateau, one at Jabal
Jaaf, one at a pass south of Rookib, two or four at Di-Ishal, and four at Wadi
Ayhaft.
Apparently a widespread breeding resident in wooded areas to at least 850 m
on Jabal Jaaf.
Nubian Nightjar Caprimulgus nubicus jonesi
Not recorded during the survey.
A male obtained in the Dimichiro valley on the Garieh plain, east Socotra, 16
_ January 1899 (Ogilvie-Grant & Forbes 1903) was accorded subspecies status.
This is the only record for Socotra.
Forbes-Watson's Swift Apus berliozi berliozi
Approximately 300 birds recorded. Seen almost daily, principally in small
94
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
flocks, along the coast and inland to 850 m on Jabal Jaaf, where one was
trapped. The largest flocks observed were as follows: 40 at Fikhah, 2 April; 30
on Hamadiroh plateau, 3 April; 60 at Jabal Jaaf, 4 April and 54 at Ras Diblih, 4
April.
A fairly common breeder. Movements outside the breeding season are
unclear. Occurs from sea-level to the Hajhir mountains. Forbes-Watson noted
birds in May 1966 at the high cliffs in the Hajhirs and considered that they were
almost certainly breeding in cracks in the cliffs (Ripley & Bond 1966). For
further details see Porter et al. (1996).
Blue-cheeked Bee-eater Merops superciliosus
One at Erhina, 5 April was the first record for Socotra.
European Roller Coracias garrulus
Not recorded during the survey.
A vagrant with one record: a female collected by Forbes-Watson near Hadibu,
15 March 1964 (Ripley & Bond 1966)
Abyssinian Roller Coracias abyssinicus
Not recorded during the survey.
A vagrant. The only record is of a skeleton found on 'Abd al-Kuri in 1899
(Ogilvie-Grant & Forbes 1903).
Hoopoe Upupa epops
Not recorded during the survey.
A vagrant, the only record is one flying between Socotra and 'Abd al-Kuri in
1899 (Ogilvie-Grant & Forbes 1903).
Black-crowned Finch Lark Eremopterix nigriceps forbeswatsoni
A total of 284 recorded. Seen daily, especially numerous in arid coastal
scrubland, often in the vicinity of habitation but also encountered up to 850 m
on Jabal Jaaf. The largest concentration was 64 at Hakari wells.
The race forbeswatsoni is endemic to Socotra. A common breeding resident.
Short-toed Lark Calandrella brachydactyla
Not recorded during the survey.
No records from Socotra, but a specimen of one of the paler south-western
forms, possibly the race artemisiana, was obtained on ‘Abd al-Kuri, 21 March
1964 (Ripley & Bond 1966).
Sand Martin Riparia riparia
Not recorded during the survey.
A passage migrant (Dowsett & Dowsett-Lemaire 1993). Two males and a
female collected by Forbes-Watson in May 1964 near Hadibu (Ripley & Bond
1966).
95
G. M. Kirwan, R. P. Martins, K.M. Morton & D. A. Showler Sandgrouse 17
Rock Martin Ptyonoprogne fuligula
Not recorded during the survey.
Apparently breeds. A few pairs were seen (and three birds collected) in the
Hajhir mountains (500-1,100 m) and around limestone cliffs at Homhil (800 m)
in 1898-99 (Ogilvie-Grant & Forbes 1903). Forbes-Watson obtained two males
and two females at Adho Dimellus in May 1964 (Ripley & Bond 1966).
Crag Martin Ptyonoprogne rupestris
One at Wadi Ayhaft, 5 April was the first record for Socotra.
A vagrant. The species is a scarce autumn passage migrant and winter visitor
to Yemen (Brooks et al. 1987). There are no records from adjacent continental
Africa (Dowsett & Dowsett-Lemaire 1993).
Barn Swallow Hirundo rustica
Not recorded during the survey.
A vagrant. A female collected by Forbes-Watson near Hadibu, 17 May 1964
(Ripley & Bond 1966).
House Martin Delichon urbica
Not recorded during the survey.
A passage migrant. Forbes-Watson observed the species on several occasions
over Hadibu in mid-May 1964 (Ripley & Bond 1966).
Tawny Pipit Anthus campestris
Not recorded during the survey.
A vagrant. Two on ‘Abd al-Kuri, 23 February 1899, one of which was
collected (Ogilvie-Grant & Forbes 1903).
Long-billed Pipit Anthus similis sokotrae
A total of 284 recorded, principally from inland and montane areas. Observed
from sea-level to 850 m (Jabal Jaaf), usually in poorly vegetated, rocky localities.
A common resident breeder. Ogilvie-Grant & Forbes (1903) found newly-
fledged young in mid-December as well as fresh eggs, both in the same period
in early February. Recorded up to at least 1,200 m. Apparently absent from
'Abd al-Kuri.
Yellow Wagtail Motacilla flava
Not recorded during the survey.
A passage migrant. Balfour collected three of the race lutea, in March 1880
near Ghor Gharrieh (Sclater & Hartlaub 1881; Keith, Urban & Fry 1992).
- Grey Wagtail Motacilla cinerea
One at Wadi Ayhaft, 5 April is the first record for Socotra.
A vagrant. The species is a fairly common passage migrant and winter visitor
to northern Yemen (Brooks et al. 1987). Uncommon on passage and in winter in
Somalia (Ash & Miskell 1983).
96
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
White Wagtail Motacilla alba
Not recorded during the survey.
A winter visitor (Dowsett & Dowsett-Lemaire 1993). Balfour described it as
common along the lower reaches of perennial streams (Sclater & Hartlaub 1881).
Ogilvie-Grant & Forbes (1903) found it to be fairly common on the Hadibu
plain, in the Dimichiro valley and on 'Abd al-Kuri. Forbes-Watson collected
seven in March 1964 (Ripley & Bond 1966). All records apparently refer to
dukhunensis, which breeds in Russia, east to central Siberia and south to
northern Iran (Keith, Urban & Fry 1992).
Isabelline Wheatear Oenanthe isabellina
Two at Ras Momi, 2 April.
Status uncertain. Recorded twice previously; a specimen taken in March 1880
(Sclater & Hartlaub 1881) and a male collected on 'Abd al-Kuri, 23 February
1899 (Ogilvie-Grant & Forbes 1903)
Desert Wheatear Oenanthe deserti
Not recorded during the survey.
A winter visitor. Found commonly on the plains by Balfour in March 1880
(Sclater & Hartlaub 1881) and noted as numerous by Ogilvie-Grant & Forbes
(1903) who recorded it up to 1,000 m in the Hajhir mountains, and up to 500 m
on ‘Abd al-Kuri. Nine females and a male on 'Abd al-Kuri in March 1964
(Ripley & Bond 1966) were considered, on wing measurements and the amount
of white in the wing, to be the race oreophila which breeds in Tibet, Ladakh and
the Kunlun Shan range and winters in southern Arabia and possibly southern
Somalia (Keith, Urban & Fry 1992).
Socotra Warbler Incana incana
A total of 135 recorded at 11 sites, principally from localities between sea level
and 150 m, but found up to 850 m on Jabal Jaaf (15, 4 April). Usually found in
sparse, halophytic vegetation in both rocky and sandy areas, but also recorded
from thickets and grassy uplands. Maximum was 20 in dunes at Fikhah (10 m),
2 April.
A resident breeder, endemic to Socotra. Recorded to approximately 1,400 m
by Ogilvie-Grant & Forbes (1903) and Forbes-Watson (Ripley & Bond 1966). For
further details of the species see Dymond (1996).
Socotra Cisticola (Island Cisticola) Cisticola haesitata
A total of 25 recorded at four localities: two on the coastal plain east of Ras
Diblih (0-5 m), 11 at Hakari wells (0-5 m), ten 2 km west of Ras Diblih (0-5 m)
and 15 in dunes west of airport (2-3 m). All observations were in areas where
the dominant vegetation was low coastal scrub, typically tamarisk and/or
halophytic scrub. Most records related to singing males, but no other
indications of breeding were noted.
A resident breeder. Both Ogilvie-Grant & Forbes (1903) and Forbes-Watson
(Ripley & Bond 1966) observed fledged young. In upland areas it is found in
97
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A. Showler Sandgrouse 17
grassland with scattered bushes. Probably local and uncommon, and
considered globally vulnerable (Collar et al. 1994). For further details of the
species see Dymond & Porter (1996).
Common Whitethroat Sylvia communis
Not recorded during the survey.
A vagrant (Dowsett & Dowsett-Lemaire 1993). One collected on 'Abd al-Kuri,
23 February 1899 (Ogilvie-Grant & Forbes 1903).
Chiffchaff Phylloscopus collybita
Not recorded during survey.
A vagrant {(Dowsett & Dowsett-Lemaire 1993). One collected on 'Abd al-Kuri,
23 February 1899 (Ogilvie-Grant & Forbes 1903). i
Socotra Sunbird Nectarinia balfouri
A total of 149 at 14 sites between 50 m (Ras Hebak) and 850 m (Jabal Jaaf), with
maxima of 50 at Wadi Ayhaft, 16 at Shidadah, and 15 at Jabal Jaaf. All other
observations involved 1-13 birds. A nest with three unfledged young at Ras
Hebak, 30 March. Recorded in most well-vegetated areas.
A resident breeder. Widespread and fairly common, recorded from sea-levei
up to 1,500 m. For further details of this species see Showler & Davidson (1996).
White-breasted White-eye Zosterops abyssinica socotrana
A total of 149 recorded at 12 sites from sea-level to 850 m on Jabal Jaaf. Occurs
in small numbers at lower altitudes, with largest concentrations of 50 in climax
woodland on Jabal Jaaf and 25 in sub-montane woodland at Wadi Ayhaft.
Elsewhere, usually found in mixed Adenium obesum and Zizyphus woodland,
principally above 250 m. Two of three trapped at Jabal Jaaf, 4 April were in
active wing-moult.
A resident breeder. Ogilvie-Grant & Forbes (1903) found newly fledged but
still dependent young, 17 December 1898 and 1 January 1899, but Forbes-
Watson found no evidence of breeding between March and June (Ripley & Bond
1966). Described as equally common at high and low altitudes (Ogilvie-Grant &
Forbes 1903).
Great Grey Shrike Lantus excubitor uncinatus
A total of 139 recorded at 19 sites . Widespread and common in most areas with
mature trees, from sea-level to 850 m. Maximum of 46 on the Hamadiroh
plateau and 21 at Shidadah. Most other observations were of 1-6 individuals.
A resident breeder. Forbes-Watson made no mention of nesting (Ripley &
Bond 1966), but Ogilvie-Grant & Forbes (1903) found fully fledged young being
fed by adults on many occasions and a nest with small young at Homhil.
Evidently common in suitable habitat, principally at lower to middle elevations.
Ogilvie-Grant & Forbes (1903) found the species to be scarce above 1,000 m,
although recorded up to 1,200 m by Forbes-Watson (Ripley & Bond 1966).
98
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
Brown-necked Raven Corvus ruficollis
A total of 54 recorded at 13 sites. Usually observed in pairs or small groups of
up to eight individuals, except for 20 at the airport, 6 April. Most observations
were from the coastal plain but recorded up to 460 m (Hamadiroh plateau). No
instances of breeding noted.
Presumably a resident breeder but nesting never established. Riebeck shot a
pair (Hartlaub 1881), Forbes-Watson shot a female (Ripley & Bond 1966) and
Ogilvie-Grant & Forbes (1903) recorded it as comparatively rare, typically in
pairs.
Socotra Starling Onychognathus frater
A total of 41 recorded at six sites, from near sea-level to 850 m on Jabal Jaaf.
Maximum 16 on Hamadiroh plateau, where a nest site in a hole in a limestone ~
cliff was discovered. More common in well wooded areas.
An endemic resident breeder, below 60 m in towns, around lagoons and on
plains; 60-1,200 m in foothills, in valleys and thickets and grassy uplands; and
on the high peaks of the Hajhir mountains between 1,200 and 1,500 m (Ripley &
Bond 1966). For further details of this species see Porter & Martins (1996).
Somali Starling Onychognathus blythii
A total of 538 recorded from almost all sites visited. Common throughout
(although apparently most common in higher, rocky areas), from sea-level to
850 m (Jabal Jaaf). Three counts exceeding 100 birds: 111 on Hamadiroh
plateau, 110 at Shidadah, and 100 between Rookib and Ras Diblih.
A resident breeder on Socotra and 'Abd al-Kuri. For further details of this
species see Porter & Martins (1996).
Socotra Sparrow Passer insularis
A total of 1,142 recorded from nearly all localities, from sea-level up to 850 m.
Largest concentrations were: 231 at Hamadiroh plateau, 133 at Shidadah, at least
200 between Rookib and Ras Diblih, 121 at Di-Ishal. Most other observations
involved 10-50 individuals.
An endemic resident breeder, widespread and common. Records suggest that
nesting occurs throughout the year (Ripley & Bond 1966). Recorded up to at
least 1,200 m. The sub-species hemileucus is found commonly on 'Abd al-Kuri
(Ogilvie-Grant & Forbes 1903). Of four young birds trapped during the survey,
one had fledged in 1993, one in late 1992 and the other two were judged to have
almost certainly fledged in late 1992.
Golden-winged Grosbeak Rhynchostruthus socotranus socotranus
A total of 46 recorded at three sites: on rocky, scrub-covered hillsides at Rizeleh
(100 m), in sub-montane woodland at Wadi Ayhaft (200 m) and in Adenium
scrub at Di-Ishal (150 m). Most common at Wadi Ayhaft where 42 were
counted.
A resident breeder. Ogilvie-Grant & Forbes (1903) obtained fully fledged
young but no other evidence of breeding has been recorded. Apparently locally
99
G. M. Kirwan, R. P. Martins, K. M. Morton & D. A. Showler Sandgrouse 17
common, principally in the Hajhir and Adho Dimellus mountains. Ogilvie-
Grant & Forbes (1903) also found it to be fairly common in the Addah, east of
Hadibu, while Forbes-Watson shot one near Kallansiya (Ripley & Bond 1966).
Recorded from 60 to 1,200 m.
African Rock Bunting Emberiza tahapisi insularis
A total of 76 recorded at five sites between 100 and 850 m: 30 at a pass south of
Rookib, 19 at Shidadah, 25 at Jabal Jaaf (850 m), one between Rookib and Jabal
Jaaf and one between Di-Ishal and Hadibu. Ail were in rocky upland areas with
sparse vegetation.
A common resident breeder. Ogilvie-Grant & Forbes (1903) found three nests
with either eggs or young in January 1899 and adults with dependent young in
February. Apparently common in all suitable open areas with scattered
vegetation, principally at low to middle elevations; Ogilvie-Grant (1903) stated
that it was replaced at high altitude by E. socotrana.
Socotra Bunting Emberiza socotrana
Two at the pass south of Rookib (500 m), 3 April were wit 15 African Rock
Buntings, on a dry, rocky hillside with scrub and a few scattered small trees.
An endemic resident. Ogilvie-Grant & Forbes (1903) collected a pair and three
singing males on the slopes of Adho Dimellus between 6-15 February 1899, at
over 1,200 m. Forbes-Watson obtained a total of 17 specimens in 1964 (Ripley &
Bond 1966). Probably prefers upland thickets and scrub for nesting, but Collar
& Stuart (1985) speculate that the species may descend to low altitudes during
the non-breeding season. For further details see Morton (1996).
REFERENCES
ASH, J. S. AND MISKELL, J. E. (1983) Birds of Somalia. Their Habitat, Status and Distribution.
Scopus Special Supplement No. 1. Ornithological Sub-Committee of the East African
Natural History Society, Nairobi.
BROOKS, D. J., EVANS, M. I., MARTINS, R. P. AND PORTER, R. F. (1987) The Status of Birds in
North Yemen and the Records of the OSME Expedition in Autumn 1985. Sandgrouse 9:
4-66.
BROWN, L. H., URBAN, E. K. AND NEWMAN, K. (1982) The Birds of Africa Vol. 4. Academic
Press, London.
COLLAR, N. J., CRosBy, M. J. AND STATTERSFIELD, A. J. (1994) Birds to Watch 2: The World List
of Threatened Birds. BirdLife Conservation Series No. 4, BirdLife International,
Cambridge.
CoLaR, N. J. AND STUART, S. N. (1985) Threatened Birds of Africa and Related Islands. ICBP,
Cambridge. ;
DowsETT, R. J. AND DOWSETT-LEMAIRE, F. (1993) Afrotropical avifaunas: annotated country
checklists. Tauraco Research Report 5. Tauraco Press, Liege.
DYMOND, J. N. (1996) The Socotra Warbler. Sandgrouse 17: 142-144.
- DYMOND, J. N. AND PorTER, R. F. (1996) The Socotra Cisticola. Sandgrouse 17: 145-147.
GRANT, P. J. (1986) Gulls: a guide to identification. (2nd ed.). T. & A. D. Poyser, Calton.
HARRISON, P. (1985) Seabirds: a guide to identification. Croom Helm, Beckenham.
HARTLAUB, G. (1881) On the birds collected in Socotra and Southern Arabia by Dr Emil
Riebeck. Proc. Zool. Soc. London 1881: 953-959.
100
Sandgrouse 17 The status of birds in Socotra and ‘Abd Al-Kuri
HOoL.o, P. A. D., PORTER, R. F., CHRISTENSEN, S. AND WILLIS, I. (1988) Birds of the Middle
East and North Africa. T. & A. D. Poyser, Calton.
KEITH, S., URBAN, E. K. AND Fry, C. H. (1992) The Birds of Africa. Vol.4. Academic Press,
London.
MACKWORTH-PRAED, C. W. AND GRANT, C. H. B. (1952) Birds of Eastern and North-eastern
Africa Vol. 1. Longmans, London.
MARTINS, R. P. AND PORTER, R. F. (1996) The Buteo population in Socotra. Sandgrouse 17:
134-137.
Morton, K. M. (1996) The Socotra Bunting. Sandgrouse 17: 155-157.
OGILVIE-GRANT, W. R. AND FORBES, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In:
Forses, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
PORTER, R. F., DYMOND, J. N. AND MARTINS, R. P. (1996) Forbes-Watson's Swift in Socotra.
Sandgrouse 17: 138-141.
PORTER, R. F. AND MARTINS, R. P. (1996) The Socotra Starling and Somali Starling.
Sandgrouse 17: 151-154.
PORTER, R. F. AND STONE, F. (1996) An introduction to Socotra and its birds. Sandgrouse 17:
73-80.
PORTER, R. F., MARTINS, R. P. AND STONE, F. (1996) The Ornithological Society of the Middle
East's survey of southern Yemen and Socotra, March-May 1993: an introduction.
Sandgrouse 17: 5-14.
RipLey, S. D. AND BOND, G. M. (1966) The Birds of Socotra and 'Abd al-Kuri. Smithsonian
Misc. Coll. 151, No. 7.
SCLATER, P. L. AND HARTLAUB, G. (1881) On the birds collected in Socotra by Prof. I. B.
Balfour. Proc. Zool. Soc. London 1881: 165-175.
SHOWLER, D. A. AND DAVIDSON, P. (1996) The Socotra Sunbird. Sandgrouse 17: 148-150.
URBAN, E. K., Fry, C. H. AND KEITH, 5S. (1986) The Birds of Africa. Vol. 2. Academic Press,
London.
G. M. Kirwan, 6 Connaught Road, Norwich NR2 3BP, UK.
R. P. Martins, 6 Connaught Road, Norwich NR2 3BP, UK.
K. M. Morton, 31 Braehead Avenue, Edinburgh EH4 6QN, UK.
D. A. Showler, clo OSME, c/o The Lodge, Sandy, Bedfordshire SG19 2DL,
UK.
101
Sandgrouse (1996) 17: 102-129
Habitats and bird communities in southern
Yemen and Socotra
PETER DAVIDSON
hilst knowledge of the status and distribution of bird species in arid
tropical environments has advanced, quantitative assessments of species’
abundance are few. A major objective of the OSME survey of spring 1993,
therefore, was to investigate, by means of standardised quantitative transects,
the bird communities of different habitats, thus enabling broad comparisons
between them and assessment of the relative abundance and densities of the
species they support. Employing simple survey techniques, large areas were
covered by survey teams in relatively short periods. This strategy is essential
for the coverage of extensive areas in a climate where bird activity occurs
primarily during the first two hours of daylight.
No comparison has been attempted between results presented here and those
from surveys undertaken in the Tihamah of northern Yemen in autumn 1985
(Rands et al. 1987). Differences in the season of survey and methodology used
prevented meaningful comparison.
METHODS
Habitat categorisation
The principal vegetation types and land-use characteristics encountered on each
transect were recorded on standardised forms. This information was used to
develop a series of broadly defined habitat and land-use categories.
Comparisons of bird species' density and relative abundance could thus be
made between the categories using techniques described below. Within
southern Yemen, these habitat/land-use categories have been classified into
three altitudinal bands: Tihamah and coastal lowlands (<500 m), Foothills (500-
1,800 m) and Highlands (>1,800 m). For the Socotra data, three zones, mainly
based on altitude, have been used.
Bird census techniques and data analysis
Two census techniques were employed: line transects and encounter rates. Line
transects are particularly suitable for surveying extensive tracts of relatively
uniform terrain, especially ‘open’ or sparsely vegetated habitats. Such a survey
approach offers an efficient way of collecting a large volume of data per unit
effort. The methodology followed for conducting the line transects was that
detailed in Bibby et al. (1992). At each survey site up to ten transects were
walked by different observers simultaneously, attempting to achieve a constant
pace of one km per 20 minute period. Transects, which were a minimum of 400
m apart, were distributed in such a way as to ensure that no large areas of
102
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
habitat were left uncovered. During each transect, every individual bird contact
was recorded and divided into those within 25 m of each observer, and those
beyond. In instances where bird contacts involved individuals or groups flying
over, this was noted separately, but these data were excluded from the density
analyses. Transects were generally undertaken between 05.30 and 10.00 and
16.30 and 18.00 hours, the periods of maximum bird activity.
For each species, a density value (expressed as birds/km*) was calculated
according to the formula (from Bibby et al. 1992):
D
10N ((1-SQRT(I - Ni/N))/W)/L
where = density in birds per ha (x100 for density per km)
= total number of birds recorded on transect
number of birds recorded within 50 m belt
= width of inner belt (i.e. 50 m)
= transect length (km)
ean
Density estimates were summed and divided by the number of transects,
generating a mean density for each species at each site. In cases where habitat
categories were represented at more than one site, site means were summed and
divided by the number of sites to give an overall mean for each habitat.
Using the above formula produces a density of zero in cases where no birds
were recorded within the 50 m belt. Since data from all transects (including
those with zero density) must be used when calculating site and habitat
densities, the density of some species may have been slightly underestimated.
Point counts, based on the method described in Bibby et al. (1992) were also
conducted at four sites where the structural complexity of the vegetation (e.g.
densely wooded habitats) made line transects impracticable. No further
analysis of the point count data was attempted because of its incompatability
with line transect data. Fortunately though, sufficient line transect data were
collected in three of the point count habitats (Juniperus woodland, Mahra
woodland, and Socotra foothills) to enable calculation of a density estimate.
When insufficient time was available to organise full line transects, encounter
rates (the number of individuals of each species encountered per kilometre
walked) were calculated. Since observer effort was judged to be similar to that
on full line transects, the data have been combined with that from the transects
to derive a relative abundance index for each species in each habitat. This
makes full use of all observations made during the bird surveys. The original
data recording sheets are lodged in the OSME archives.
RESULTS AND DISCUSSION
During the survey, a combined total of 377 transects and encounter rate walks
was conducted, covering 390 km at 45 different sites, including 52 transects on
Socotra. Co-ordinates are given for most of these, but all can be located by
103
Peter Davidson Sandgrouse 17
reference to Figures 1 and 2 in Porter et al. (1996). A total of 120 species was
recorded (on both transects and encounter rate walks): 80 breeding species, and
40 passage migrants. Details of the habitats covered, together with a summary
of species numbers recorded, are given in Table 1 (page 116). Densities and
relative abundance indices are presented in Table 2 (breeding species page 118)
and Table 3 (passage migrants page 126).
The following sections covering first southern Yemen and then Socotra discuss
the characteristics of each habitat in turn, broadly identifying the relative
importance of each to the bird species occurring, especially those endemic to
south-west Arabia or for which the habitat holds high densities. Under Breeding
Species with highest density, species are listed in descending order of abundance.
Table 1 provides an appraisal of the relative importance of the habitats surveyed
and gives details of the coverage achieved and census methods used. For full
details of the species recorded in each habitat see Tables 2 and 3.
SOUTHERN YEMEN
Tihamah and Coastal Lowlands (<500 m)
Sabkha
Desiccated saline mud coastal plain, with scattered small dune systems
(<3 m high) formed and maintained through an aggregation of sand around
substantial shrubs and bushes. Scattered Suaeda bushes were present and the
dominant grass was Odyssea mucronota; Halopyrum mucronatum also present.
Ground cover generally <5%. An unidentified club rush was present at very
low density on the landward side of this habitat strip.
Altitude: <10m.
Land use: Apparently undisturbed, except for limited low intensity grazing
and occasional vehicle tracks.
Site: 13°02'N 45°04'E, c.25 km north-east of Aden on the Arabian Sea
coast.
Breeding species with highest density: Hoopoe Lark* (the only species recorded).
Virtually birdless. No migrants were found in the habitat.
Subdesert plain
Fixed low sand dunes (c.3 m high), flats and vegetated sand hummocks
comprising c.30% ground cover, comprising Salvadora persica (Arak) scrub and
Odyssea mucronota and Panicum turgidum grass cover. Also widely scattered,
unidentified Acacia spp. and a ridge of sand fringing beach covered with dense
_Suaeda fruticosa scrub and, in wet patches, Avicennia marina.
Altitude: <10m.
Land use: Apparently undisturbed. Scattered settlements at very low density.
* Scientific names appear in tables 2 and 3 (pages 118-129)
104
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
Site: Al-Jadid (13°04'N 43°20'E), on the Red Sea coast south of al-Mukha.
Breeding species with highest densities: Hoopoe Lark, Crested Lark,
Yellow-vented Bulbul, African Collared Dove.
The most striking feature of this habitat was the high number of migrant species
recorded (14) compared with a mere five breeding species. Although relatively
well vegetated, plant diversity was limited (mostly halophytes and xerophytes).
Due to close proximity to the coast the area provides a good staging post for
migrants of which Pied Wheatear, Redstart and Willow Warbler were recorded
at their highest density. It should be noted that although African Collared Dove
was recorded at its highest relative abundance in this habitat, density was
greatest in sandy wadis and cultivated plains inland.
Herbaceous grassland
Dry, flat or gently undulating sand and fine gravel plain. Dominant herbs
include Tribulus arabicus, Dipterygium glaucum and Heliotropium sp. Panicum
turgidum is the dominant grass; sward height 230 cm. Ground cover generally
<30%. Scattered, unidentified shrubs and bushes c.1 m high.
Altitude: 80-150 m.
Land use: Extensive low to medium intensity grazing. Scattered semi-nomadic
settlements.
Sites: 12°57'N 44°49'E, 20 km north-west of Aden; 12°9'N 44°38’'E, 30 km
north-west of Aden.
Breeding species with highest densities: Black-crowned Finch Lark, Hoopoe
Lark, Crested Lark, Nile Valley Sunbird.
This habitat held a low number of breeding species (10) probably reflecting a
lack of structural complexity (the vegetation is predominantly at ground level).
The very high density of Black-crowned Finch Larks breeding (much higher
than in other habitats) reflects the seasonal nature of optimal breeding
conditions for this species, recent rain having promoted the profuse flowering of
herbs and grasses in the rather fine sand and gravel substrate. Chestnut-bellied
Sandgrouse also occurred but at very low density. Few migrants were recorded.
Acacia woodland
Gently undulating gravel plain supporting Acacia tortilis, the dominant tree
species, at a density of 10-20 trees per ha, with rather sparse Panicum turgidum
grass cover and a low shrub understorey, with Zygophyllum sp. in gravel areas.
Slightly more species-rich along dry runnels where more annual herbs present.
Some sandy grassland with patches of Salvadora persica along a narrow (0.5 km
wide) coastal strip.
105
Peter Davidson Sand grouse 17
Altitude: 30-60 m.
Land use: Extensive light grazing and browsing of Acacia by camels.
Scattered semi-nomadic settlements.
Site: Hiswat al-Hujaymah. This Acacia woodland belt (5-10 km in
width) stretches for at least 80 km along the coastal plain of western
southern Yemen from a few kilometres east of Bab al-Mandab to the
herbaceous grassland north-west of Aden. It is one of the largest
stands of Acacia woodland in Yemen.
Breeding species with highest densities: Great Grey Shrike, Black-crowned
Finch Lark, Crested Lark, African Collared Dove.
This highly distinctive habitat, typical of the Sudan Savanna zone of continental
Africa, held only eight breeding species, perhaps surprisingly as the vegetation
structure is more complex in Acacia woodland than in many of the other
lowland habitats studied. Great Grey Shrike occurred at its highest density
which was considerably higher than in any other habitat on the mainland being
comparable with its density in the Socotran Highlands. Chestnut-bellied
Sandgrouse and Arabian Babblers occurred at low density. More importantly in
conservation terms, Arabian Bustard was found to occur, although the species
was not recorded during formal censusing. This extensive habitat tract may still
support an important population of the species.
Perhaps surprisingly only four migrant species were recorded, all at low
densities.
Alluvial coastal plain
Sparsely vegetated flat or gently undulating sand and gravel plains. Typical
species include Salvadora persica, Acacia spp. (particularly Acacia tortilis),
occasional Adenium obesum, Zizyphus spina-christi and Calotropis procera,
generally comprising not more than 5% ground cover, mainly restricted to dry
gullies.
Altitude: 50m.
Land use: Mainly undisturbed, but perhaps with some seasonal light grazing.
Sites: Al-Sugayyah (12°40'N 43°37'E, just east of Bab al-Mandab; Wadi
Irkhawt, 2 km east of Sayhut (both sites east of al-Mukalla); plain
below Jabal Rub'ut (eastern southern Yemen).
Breeding species with highest densities: Sand Partridge, Yellow-vented Bulbul,
Desert Lark, Orange-tufted Sunbird, Blackstart, Arabian Babbler.
_ Of 20 breeding species recorded, Sand Partridge was recorded at the highest
density found in any habitat. This was the only lowland habitat where south-
west Arabian endemics were encountered during transects: Arabian Partridge
and South Arabian Wheatear (both were scarce). High densities of a number of
106
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
passage migrants were recorded, notably Rufous Bush Robin and Upcher's
Warbler, both at considerably higher densities than in any other habitat.
Sandy wadis
Flat, open dry sandy wadis, often traversed by smaller gullies and bordered by
agricultural land. Generally well vegetated; plant species include Tamarix
nilotica, Salvadora persica, Zizyphus spina-christi, occasional Acacia spp. Calotropis
procera, Euphorbia spp. in western southern Yemen, and the introduced Prosopis
juliflora in eastern southern Yemen. Intermittent herb cover, commoner species
including Dipterygium glaucum and Tribulus arabicus. Small, dense thickets of
vegetation often encountered, particularly where Prosopis juliflora and Tamarix
nilotica dominate. Percentage vegetation cover usually >30%, often much
greater. Surface running water present at Wadi al-Masilah and Wadi Hajr
(where apparently permanent).
Altitude: 20-460 m.
Land use: Sandy wadis often fringed by cultivation, generally comprising
sorghum fields with occasional date palms. Some areas lightly
grazed. Wadis mainly undisturbed.
Sites: South of Dar al-Qudaymi (13°05'N 44°20'E); Wadi al-Khabt
(13°03'N 44°30'E) (both below Jabal Iraf); Wadi Hajr (14°06'N
44°10'E) west of al-Mukalla; Wadi al-Masilah (15°04'N 51°08'E) in
eastern southern Yemen.
Breeding species with highest densities: Yellow-vented Bulbul, Black-crowned
Finch Lark, African Collared Dove, Ruppell's Weaver, Arabian
Babbler, Brown-necked Raven.
This habitat had the greatest species diversity among lowland habitats. A total
of 53 species were recorded including 33 breeders. Although this may, in part,
reflect the number of kilometres surveyed, the structural complexity of the
vegetation and the presence of running water at two sites were clearly
significant. Four breeding species were found at their highest relative densities
in sandy wadis: Chestnut-bellied Sandgrouse, Little Swift, Nile Valley Sunbird
and Brown-necked Raven. 20 species of passage migrants were recorded, the
longest number in any single habitat. Barred Warblers were present in the
highest density recorded for the species.
Degraded Coastal Plain
Relatively flat gravel plain with some small hillocks and sand dunes. Very
sparse vegetation comprising grass tussocks, halophytes and patches of
Zygophyllum simplex. Ground cover generally <2%, except for an area adjacent
to a brackish creek which was fringed by Tamarix scrub and a few palms.
107
Peter Davidson | Sandgrouse 17
Altitude: 20-50 m. |
Land use: Minimal cultivation (some Sorghum and fallow land), but
much disturbance through the creation of foundations for
residential development.
Site: Al-Shihr, east of al-Mukalla.
Breeding species with highest densities: Black-crowned Finch Lark, Great Grey
Shrike, Nile Valley Sunbird, Graceful Prinia.
Despite the disturbed nature of the habitat, 23 species were recorded, of which
17 were breeding. This habitat was poor for migrants with only six species
recorded; of these Spotted Flycatcher occurred at its highest density in any
habitat.
Foothills (500-1,800 m)
Juniper woodland
Gently sloping rocky, species-rich plateau traversed by infrequent steep-sided
wadis, dominated by Juniper woodland, dense in patches with occasional Acacia
spp. and substantial trees (e.g. Ficus spp.); area interspersed with open
grassland rich in herbs and patchy cultivation. Vegetation cover 60%-80%.
Altitude: 1,350-1,500 m.
Land use: Extensive low to medium intensity grazing with minimal browsing.
Some cultivation (10%), primarily Sorghum, although many fallow
fields. Some clearance for cultivation and lopping of Junipers for
firewood.
Site: Jabal Iraf (13°07'N 44°15'E) at the summit of the foothill escarpment
of western southern Yemen.
Breeding species with highest densities: Yellow-vented Bulbul, Laughing Dove,
Arabian Waxbill, Long-billed Pipit, Graceful Prinia, Ruppell's
Weaver, White-breasted White-eye, Arabian Serin.
This habitat has an exceptionally complex structure and is highly restricted in
range, occurring only on the Jabal Iraf plateau. It held an important bird
community with four south-west Arabian endemics recorded during formal
surveys: Arabian Serin occurred at its highest density in any habitat; Arabian
Partridge and Arabian Waxbill (at the second highest recorded densities) and
Golden-winged Grosbeak. Six other species were also found at their highest
densities: Dark Chanting Goshawk and African Grey Hornbill (not encountered
~in most other habitats), Little Rock Thrush, Brown Woodland Warbler (both
fairly common), Gambaga Dusky Flycatcher (found at very low densities, but
absent from most other habitats), and Tristram's Grackle, which probably
utilises the rocky cliff faces fringing the habitat more than the Juniper woodland
108
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
itself. At the time of study (21-23 March), the bird community was composed of
over 80% breeding species. Of the five migrants noted only Blackcap was
encountered commonly and at a very high density. This was presumably
because the habitat affords both shelter and feeding opportunities, and is
prominently positioned at the summit of a south-facing escarpment.
Open Acacia woodland
Gently sloping rocky plateau traversed by infrequent steep-sided wadis.
Sparsely vegetated with some Acacia including A. tortilis and A. asak. Sparse
ground cover of succulents and flowering herbs interspersed with open rocky
areas. Vegetation cover 10%.
Altitude: 1,200-1,350 m.
Land use: Light grazing, perhaps with some lopping for firewood.
Site: Jabal Iraf (13°07'N 44°15'E).
Breeding species with highest densities: African Rock Bunting, Long-billed Pipit,
Blackstart, Laughing Dove.
Located adjacent to Juniper woodland, this habitat supported a similar number
of breeding and passage migrant species, but there were some notable
differences as may be seen by comparing the breeding species showing the
highest densities. Five endemics were recorded during formal censusing,
including Arabian Woodpecker and South Arabian Wheatear. Two species
recorded at their highest densities in any habitat surveyed on the mainland of
southern Yemen: African Rock Bunting and Long-billed Pipit. Arabian
Warbler, Golden-winged Grosbeak and Arabian Serin also occurred but were
not common.
Surprisingly, only four migrants were recorded, all at low densities. This may
reflect the relatively early survey dates (20-23 March).
Uncultivated foothill wadis
Stony wadis (bordered by steep rocky slopes) up to 5 km wide, some dissected
by dry sandy channels. Vegetation dominated by Acacia with some Commiphora
spp., Zizyphus spina-christi, and Tamarix in sandy areas. Rather sparse, though
quite diverse ground flora, the most common species being Salvadora persica, the
herbs Aerva javanica atid Dipterygium glaucum and the grass Panicum turgidum.
Occasional patches of Pandanus scrub. Occasional standing water present with
intermittent stretches of running water in some wadis. Typha beds in one large
pool of standing water at Wadi Jahr.
Altitude: 600-900 m.
Land use: Mostly undisturbed although some areas influenced by light
grazing. Habitat occasionally fringed by cultivation in more fertile
areas with alluvial deposits.
109
Peter Davidson ; Sandgrouse 17
Sites: Wadi al-Jahr (13°58'N 46°23'E); Wadi Himarah (14°03'N 46°53'E);
Wadi al-Jiz' c.40 km west of al-Ghaydah; Wadi Sh'hout (16°20'N
50°43'E); al-Sawm (16°08'N 49°18'E); Wadi Ardah, just west of al-
Sawm; 5 km west of al-Qatn (15°50'N 48°25'E); Shabwah (15°23'N
47°01'E).
Breeding species with highest densities: House Sparrow, Yellow-vented Bulbul,
African Silverbill, Blackstart, Pau mue Dove, Rock Dove,
Nile Valley Sunbird.
The greatest observer effort occurred in this habitat, both in terms of kilometres
walked and sites surveyed. It is perhaps not surprising, therefore, that the
highest number of species was recorded on formal transects. A relatively high
proportion (70%) were residents and included eight found at their highest
densities in any habitat: Lichtenstein's Sandgrouse, Namaqua Dove, Little
Green Bee-eater, Desert Lark, Blackstart, Scrub Warbler, African Silverbill and
House Bunting. The three south-west Arabian endemics encountered (Arabian
Partridge, Arabian Serin and Arabian Waxbill) were all scarce and found more
commonly in other habitats. Four species, Hamerkop, Little Button Quail, Little
Owl and Nubian Nightjar were not found in any other habitat during formal
surveys. Passage migrants were recorded in very low numbers.
Cultivated foothill wadis
Intensively cultivated fertile wadis with agricultural terraces (many fallow) with
a high human population density. Field margins marked by larger trees partic-
ularly Acacia spp. including A. asak, some Zizyphus spina-christi and Ficus spp.
Crops include sorghum and vegetables (e.g. onions). Adjacent hillsides sparsely
vegetated, often with Euphorbia spp. including E. cactus and E. ammak. Surface
running water present in some wadis, including one well vegetated with
Tamarix sp. and bordered by cultivation.
Altitude: 800-1,750 m.
Land use: Almost exclusively sorghum cultivation but with much fallow land;
other crops include onions.
Sites: Wadi al-Sahi (two sites); Shawhat (13°14'N 44°02'E); al-Mihal, near
Shawhat; Wadi Yashbum (14°20'N 46°59'E); al-Sawm (c. 16°08'N
49°18'E).
As only encounter rates were recorded when surveying this habitat (see
Methods), species densities have not been calculated so comparisons with other
habitats are liable to be misleading. A similar habitat to uncultivated wadis in
terms of total number of species recorded. Again, the proportion of south-west
Arabian endemics was low - only four species. Of these, South Arabian
Wheatear and Arabian Waxbill were found to be common. Although six species
were found at their highest relative abundance in cultivated wadis, they include
110
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
three seldom encountered raptors (Tawny Eagle, Long-legged Buzzard and
Lanner), Red-eyed Dove (rarely encountered, but with a widespread distri-
bution), Black Kite, and Amethyst Starling. In addition, both Egyptian Vulture
and Bruce's Green Pigeon occurred at their highest mainland relative abundance
(but were found more commonly on Socotra). Of the 15 species of passage
migrant recorded none was found to be particularly common. Some interesting
comparisons can be made between the two foothill wadi habitats, which
probably cover a larger area than any other vegetation/land-use type in the
foothills. The presence of more fruiting and flowering trees in cultivated wadis
presumably accounts for the higher relative abundance of species such as
Bruce's Green Pigeon and possibly Orange-tufted Sunbird, whereas the less
disturbed wadis provide a more suitable haven for Desert Larks compared to
cultivated tracts. These two habitats are perhaps the most diverse in terms of
plant and tree species structure and composition and variety of land-use
activities which may account for the high numbers of species recorded.
Drought deciduous woodland (The Mahrah)
Extensively wooded limestone escarpment with overlying lateritic clay. Dense
Commiphora habessinica/Anogeissus dhofarica/Acacia senegal woodland, with
abundant Adenium obesum, forming c. 5 m high canopy with occasional Boscia
arabica and Sterculia africana trees. Wadis and ravines often floristically richer,
with managed groves of Tamarindis indica, Anogeissus spp., Acacia spp., date
palms and occasional Ficus spp. (e.g. Ficus vasta and Ficus salicifolia). Rich shrub
and herb understorey with abundant climbers such as Jasminium grandiflorum,
Capparis cartilaginea and Cissus quadrangularis. Herb layer absent in some areas
through over-grazing and drought. The entire region was extremely dry,
apparently following a severe drought.
Altitude: 300-700 m.
Land use: Limited woodland management: trees harvested for fruits,
pollarded for firewood, used as building material and browsed by
camels. Also subject to extensive grazing by goats at or near ground
level and more limited browsing by camels.
Sites: Wadi Mararah (16°39'N 52°55'E); Shahrut, 20 km west of Wadi
Mararah. Both sites are in the Mahrah in the extreme east of
southern Yemen.
Breeding species with highest densities: Shining Sunbird, White-breasted White-
eye, Yellow-vented Bulbul, Orange-tufted Sunbird, Laughing Dove,
Golden-winged Grosbeak, Blackstart, Black-crowned Tchagra.
This is one of largest continuous tracts of woodland in southern Yemen,
supporting eight species at their highest recorded densities in any habitat:
Arabian Partridge, Arabian Warbler, African Paradise Flycatcher, Shining and
Orange-tufted Sunbirds, White-breasted White-eye, Black-crowned Tchagra,
111
Peter Davidson Sandgrouse 17
Fan-tailed Raven and Golden-winged Grosbeak. It is of particular importance
in southern Yemen for Arabian Partridge and Golden-winged Grosbeak, found
to be common and very common respectively (based on the relative abundance
index). The Mahrah in late April was surprisingly poor for migrants, only
Spotted Flycatchers occurring in notable numbers.
Intensively cultivated silt plain (Wadi Hadramawt)
Fertile agricultural region comprising the alluvial plain of Wadi Hadramawt.
Extensive areas comprised agricultural fields, many fringed with palm groves
and occasional fruiting trees. Many fields fallow with leguminous herbs and
grasses, and scattered Zizyphus spina-christi bushes, or under preparation for the
cultivation of sorghum, onions, tomatoes and potatoes. One site (al-Gubbah
Hotel gardens) was a managed urban garden. Much of the region intensively
irrigated and fertilisers and other chemicals (e.g. pesticides) apparently in use.
Altitude: 700-800 m.
Land use: Intensive agriculture.
Sites: Allin Wadi Hadramawt: 10 km south-west of Tarim; al-Gubbah
Hotel gardens in Tarim; 2 km west of Sayun; 1 km east of al-
Mudhur (15°49'N 48° 25'E).
Breeding species with highest densities: Ruppell's Weaver, Yellow-vented
Bulbul, Rock Dove, House Sparrow, Laughing Dove, Graceful
Prinia, Black Bush Robin.
This is the habitat most strongly influenced by man. Modern agricultural
methods are used to exploit the fertile substrate. A very high proportion (89%)
of the 27 species encountered during formal surveys were breeding, ten of these
occurred at their highest recorded densities in any habitat: Rock Dove,
Laughing Dove, Bruce's Green Pigeon, Grey-headed Kingfisher (scarce, and
only found in this habitat), Yellow-vented Bulbul, Black Bush Robin, Graceful
Prinia, House Sparrow, Rtippell's Weaver and the endemic Arabian Waxbill (the
only endemic encountered in this habitat). In addition, it held relatively high
densities of African Collared Dove, Bruce's Green Pigeon, Crested Lark, African
Rock Martin and African Silverbill. Wadi Hadramawt provides a good example
of a bird community adapting to change brought on by human activity.
Although many of the species found are widespread, occurring in a variety of
other habitats, Wadi Hadramawt is an important habitat simply because of the
numbers of breeding birds it supports. However, it was poor for migrants, only
Blackcap occurring in any numbers.
- Highlands (>1,800 m)
Highland plateux
Undulating barren rocky plateaux (granitic in places) interspersed with shallow
112
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
flat wadis and cultivated outwash fans with scattered Acacia trees. Ground
cover generally very light, excepting scattered agricultural areas, a few with
irrigated fields.
Altitude: 2,000 m.
Land use: Undisturbed (barren, rocky) or cultivated ground. Some light
grazing at periphery of cultivation.
Sites: All in the southern highlands of previous North Yemen: al-
Mardam (14°03'N 45°34'E); Am Daqigq, north-west of al-Mardam,; al-
Khaw'ah, north-west of Am Dagigq.
Breeding species with highest densities: House Sparrow, Crested Lark, Desert
Lark, South Arabian Wheatear.
This habitat is not widely represented in southern Yemen (where there is a
relatively small proportion of ground above 1,800 m). It is most akin to the
highlands of northern Yemen in land-use characteristics and bird communities.
Two of the four species recorded at their highest densities of any habitat
surveyed were south-west Arabian endemics: South Arabian Wheatear and
Yemen Linnet. A relatively high proportion (33%) of the 43 species recorded
were migrants, but all occurred at low densities.
SOCOTRA
Coastal plain (<100 m)
A relatively flat, barren, sandy coastal plain traversed by dry wadis. Very
sparsely vegetated except for scattered Adenium obesum, Zizyphus spina-christi, an
unidentified dominant low scrubby tree in wadis and a large date palm
plantation at Hakari wells road. Plains surrounding wadis typically
unvegetated except for scattered clumps of halophytes on low dunes and some
Tamarix sp. on higher dunes. Evidence of at least two substantial fires at Ras
Diblih. Area apparently occasionally inundated by sea-water.
Altitude: 40m.
Land use: Extensive but very light grazing, some areas apparently
- undisturbed. One large date palm plantation.
Sites: Hakari wells road, 2 km west of Ras Diblih; wadi near Shibrhoh
(12°22'N 53°48'E).
Breeding species with highest densities: Black-crowned Finch Lark, Long-billed
Pipit, Socotra Cisticola, Socotra Warbler, Laughing Dove,
Great Grey Shrike.
This was the least species-rich habitat on Socotra, only 13 species being
recorded. However, this includes four of the six species endemic to the island:
Socotra Warbler, Socotra Cisticola, Socotra Starling and Socotra Sparrow. In
113
Peter Davidson : Sandgrouse 17
addition, Forbes-Watson's Swift was only recorded in this habitat (during
formal censusing), where it was abundant. Four species occured at their highest
densities recorded in any habitat on Socotra: Black-crowned Finch Lark, Long-
billed Pipit, Socotra Warbler, Socotra Cisticola. As with other habitats surveyed
on Socotra, no migrants were recorded.
Foothills (100-400 m) |
Undulating rocky or gravel hills and plains. Well vegetated, primarily with an
unidentified low shrubby tree (2-3 m high), Adenium obesum, various succulents
and a small number of Frankincense Boswellia elongata trees in higher areas.
Occasionally interspersed with patches of open, rather stony, grassland.
Altitude: 100-200 m.
Land use: Extensive light grazing and browsing.
Sites: Shidadah (12°37'N 54°09'E); Di-Ishal (12°22'N 54°11'E).
Breeding species with highest densities: Socotra Sparrow, Somali Starling,
Laughing Dove, Egyptian Vulture, Long-billed Pipit, Great Grey
Shrike, African Rock Bunting.
Four endemic species were recorded in this habitat, three during formal
surveys. Ten species were found at their highest densities recorded in any
habitat on Socotra: Egyptian Vulture, Buzzard, Kestrel, Bruce's Green Pigeon,
Socotra Sunbird, White-breasted White-eye, Somali Starling, Socotra Sparrow,
Golden-winged Grosbeak and African Rock Bunting.
Perhaps of greatest importance, Socotra Bunting (not encountered during
formal surveys) was found only in this vegetation zone.
Highlands (>450 m)
Predominantly rocky slopes and elevated plateaux, well vegetated with
numerous limestone outcrops. Plateaux grassy with areas of open woodland
and scattered Dragon's Blood Trees Dracaena sp., and abundant Adenium obesum.
Vegetation on higher slopes stunted (<1.5 m high), interspersed with patches of
grassland and substantial stands of Box Buxus sp. scrub.
Altitude: 470-1,100 m.
Land use: Extensive light grazing with some browsing. Cave settlements still
exist in the Socotran highlands.
Sites: Hamadiroh Plateau (12°36'N 54°18'E); Jabal Jaaf a2 36'N 54°07'E).
Both sites are in central eastern Socotra.
Breeding species with highest densities: Laughing Dove, Socotra Sparrow,
Somali Starling, Great Grey Shrike.
The same species total (16) was found in this vegetation zone as in the foothills.
114
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
All were resident breeders including four endemic to the island, Socotra
Warbler, Socotra Sunbird, Socotra Starling and Socotra Sparrow. The starling
was found at a higher density here than in other habitats on Socotra. In
addition, the highest densities of Laughing Dove, Great Grey Shrike and Somali
Starling on Socotra were recorded.
ACKNOWLEDGEMENTS
Grateful thanks are due to Phil Atkinson (University of East Anglia) for generously
allowing use of his computer for analysis, Dr Paul Dolman (University of East Anglia) for
help with the data analysis, Dr Lennox Campbell (RSPB), Dr Colin Bibby (BirdLife
International) and Duncan Brooks for comments on the draft paper, and Richard Porter
and Rodney Martins for extensive discussion on the presentation of the results. Anthony
Miller (Royal Botanic Garden, Edinburgh) provided invaluable information to help
determine the habitat categories on which the analyses were based.
REFERENCES
Bibby, C. J., BURGESS, N. D. AND HILL, D. A. (1992) Bird Census Techniques. Academic Press.
London.
PORTER, R. F., MARTINS, R. P. AND STONE, F. (1996) The Ornithological Society of the Middle
East survey of southern Yemen and Socotra, March-May 1993: an introduction.
Sandgrouse 17: 5-14.
RANDS, M., RANDS, G. AND PorTER, R. (1987) Birds in the Yemen Arab Republic: a report of the
expedition of the Ornithological Society of the Middle East, October-December 1985.
Cambridge.
Peter Davidson, clo OSME, The Lodge, Sandy, Bedfordshire SG19 2DL, UK.
115
Peter Davidson Sandgrouse 17
Table 1: Summary of habitats covered, methods used and species recorded during censusing in
southern Yemen and Socotra, spring 1993.
TABLE 1: TIHAMAH AND THE COASTAL LOWLANDS
ALTITUDINAL ZONE (<500m)
Sub- Herba- Acacia Alluvial Sandy Degraded
HABITAT TYPE Sabkha desert ceous woodiand coastal wadis coastal
plain grassland plain plain
Total transect length (km) i 9.5 38 13.5 23.4 44.2 11.25
No of sites censused 1 1 2 1 4 4 1
Census methods used ER T ii J T T& E.R. yf
Total species recorded 1 19 We 12 32 53 23
Total breeding species 1 5 10 8 20 33 Wi
Total migrant species 0 14 3 4 17 20 6
% breeding species 100 26.3 76.9 66.7 62.5- = . 62.3 73.9
Total endemic species 0 0 0 0 2 0 0
Tables 2 & 3 (pages 118-129): Relative abundance and density estimates for bird species recorded
during formal censusing of different habitats in southern Yemen and Socotra, spring 1993. Table 2,
breeding species; Table 3, passage migrants.
Densities are the number of individuals per square kilometre. The relative
abundance index is based on the following, arbitrarily defined categories:
* ~~ <0A9/km scarce
** — 0.2-0.49/km uncommon
#2%" --0).5-1.99/km common
= 2-499) very common
5 KM abundant
116
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
Juniper
wood-
land
15.3
1
T+E.R.
29
24
5
82.8
3
FOOTHILLS HIGH- SOCOTRA
(500-1,800m) LANDS
Open Un- Culti- Mahrah Hadramawt Highland Coastal Foothills Highlands
Acacia cultivated vated wood- (cultivated plateaux plain (100- (>450m)
woodland wadis wadis land silt plain) >1,800m (<100m) 400m)
10 18.75 29 9 22.5 29.5 15.2 11 21
1 9 5 2 4 3 3 2 2
T Peek ER; i T+ER. TER. T+ ER. T T+E.R.
26 60 59 23 27 43 13 16 16
22 42 44 20 24 29 13 16 16
= 18 15 3 3 14 0 0 0
84.6 70 74.5 87 88.9 67.4 100 100 100
- 3 + 1 1 4 1 3 3
Abbreviations (for Tables 1, 2 & 3):
i
Bake
Gale
£/O::
n.d -
transect census methods used
encounter rate census methods used
most contacts during transects were of individuals flying over which
have been ignored when calculating densities; they have nevertheless
been included in the tables for completeness.
all contacts during transects were of individuals flying over, and are thus
not included in the density analyses.
not recorded during line transects; only during encounter rate walks
(enabling a relative abundance calculation), hence absence of density
estimate.
11Z
Peter Davidson | Sandgrouse 17
TABLE 2: TIHAMAH AND THE COASTAL LOWLANDS
ALTITUDINAL ZONE (<500m)
Sub- Herba- Acacia Alluvial Sandy Degraded
HABITAT TYPE Sabkha desert ceous woodland coastal wadis coastal
plain _ grassland plain plain
Total transect length (km) if 9.5 38 13.5 23.4 44.2 WES)
No of sites censused 1 1 2 1 4 4 1
SPECIES
Hamerkop
Scopus umbretta |
Black Kite oe ike
Milvus migrans f/o flo f/o
Egyptian Vulture <
Neophron percnopterus : flo
Dark Chanting Goshawk :
Melierax metabates flo
Tawny Eagle
Aquila rapax
Bonelli’s Eagle
Hieraaetus fasciatus
Long-legged Buzzard
Buteo rufinus
Buzzard
Buteo buteo
Kestrel
Falco tinnunculus 0.8 n.d. f/o
Lanner
Falco biarmicus
Barbary Falcon
Falco pelegrinoides
Arabian Partridge
Alectoris melanocephala 0.61
Sand Partridge ie z sie
Ammoperdix heyi 21.4 n.d. 6.7
Little Button Quail
Turnix sylvatica
Lichtenstein’s Sandgrouse
Pterocles lichtensteinii 2.8 n.d.
Chestnut-bellied Sandgrouse
Pterocles exustus 3:3 2.2 7.1 (f) 2.2 (f)
Rock Dove :
Columba livia . n.d. a2
African Collared Dove
Streptopelia roseogrisea 14.6 12.4 1.4 32
Red-eyed Dove
Streptopelia semitorquata
Laughing Dove
Streptopelia senegalensis 0.6 15.1
* kkk
118
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
FOOTHILLS HIGH- SOCOTRA
(500-1,800m) LANDS
Juniper Open Un- Culti: Mahrah Hadramawt Highland Coastal Foothills Highlands
wood- Acacia cultivated vated wood- (cultivated plateaux plain (100- (>450m)
land woodland wadis wadis land siltplain) >1,800m (<100m) 400m)
15.3 10 78.75 29 9 22.5 29.5 15:2 11 21
1 1 9 5 2 + 3 3 2 2
n.d.
n.d. n.d.
n.d flo 41.0(f) 17.0 (f)
4.4 3.3 n.d.
n.d.
f/o
n.d.
3 0
1.3 n.d 15 1.7 0.8
n.d.
flo flo flo
8.8 6.7 n.d. n.d eed
3 n.d n.d
n.d.
3.9 n.d. 17
n.d.
274 n.d. 149.6 flo
15.4 n.d. 26.5
n.d. n.d
34 22.2 36.4 n.d. 41 126.3 15 25 128.3 206.3
119
Peter Davidson | Sandgrouse 17
TABLE 2 CONTINUED: TIHAMAH AND THE COASTAL LOWLANDS
ALTITUDINAL ZONE (<500m)
Sub- Herba- Acacia Alluvial Sandy Degraded
HABITAT TYPE Sabkha desert ceous woodland coastal wadis coastal
plain _ grassland plain plain
Total transect length (km) if 9.5 38 13:5 23.4 44.2 11.25
No of sites censused 1 1 2 1 4 4 1
SPECIES
Namaqua Dove ne
Oena capensis . n.d.
Bruce’s Green Pigeon
Treron waalia
Didric Cuckoo
Chrysococcyx caprius
Little Owl
Athene noctua
Nubian Nightjar
Caprimulgus nubicus
Little Swift cone
Apus affinis flo
Forbes-Watson’s Swift
Apus berliozi
Grey-headed Kingfisher
Halcyon leucocephala
White-throated Bee-eater
Merops albicollis flo
Little Green Bee-eater
Merops orientalis fe n.d. 1.3
Hoopoe
Upupa epops 8.6
African Grey Hornbill
Tockus nasutus
Arabian Woodpecker
Dendrocopos dorae
Singing Bush Lark
Mirafra cantillans
Black-crowned Finch Lark Ze rate aise foie ey
Eremopterix nigriceps f/o 222.6 42.9 42.6 29.7
Desert Lark ae : i
Ammomanes deserti 19.6 1.4 el
Hoopoe Lark wk keke kin ake wh *
Alaemon alaudipes 14.8 34 1731 3.7 5:Om 7: 1.3
Red-capped Lark
Calandrella cinerea
Crested Lark sec aoe news =
Galerida cristata 24.3 14.6 18.1 3.7
African Rock Martin hee
Ptyonoprogne fuligula 1.1 (f)
120
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
FOOTHILLS
_ (500-1,800m)
Juniper Open Un- Culti-
wood- Acacia cultivated vated wood-
land woodland wadis_ wadis
1523 10 78.75 29
1 1 g 5
5.4 n.d
2.2 n.d.
0.4
0.1
n.d.
10 n.d.
n.d. 2 n.d.
n.d.
oS
n.d.
Oi
1.9 28.2 n.d.
4.2 n.d.
n.d. n.d.
Mahrah Hadramawt Highland Coastal
(cultivated plateaux
land
S)
2
n.d.
silt plain
225
4
0.8
6.4
n.d.
HIGH-
LANDS
>1,800m
29.5
3
plain
<100m
Ae
3
wank
flo
SOCOTRA
Foothills Highlands
(100-
400m
11
2
(>450m)
21
e
121
Peter Davidson Sandgrouse 17
TIHAMAH AND THE COASTAL LOWLANDS
(<500m)
Sub- Herba- Acacia Alluvial Sandy Degraded
desert ceous woodland coastal wadis coastal
plain grassland plain plain
TABLE 2 CONTINUED:
ALTITUDINAL ZONE
HABITAT TYPE Sabkha
Total transect length (km)
No of sites censused
SPECIES
Long-billed Pipit
Anthus similis
Yellow-vented Bulbul
Pycnonotus xanthopygos
Black Bush Robin
Cercotrichas podobe
Blackstart
Cercomela melanura
Red-breasted Wheatear
Oenanthe bottae
South Arabian Wheatear
Oenanthe lugentoides
Little Rock Thrush
Monticola rufocinerea
Graceful Prinia
Prinia gracilis
Socotra Warbler
Incana incana
Socotra Cisticola
Cisticola haesitata
Scrub Warbler
Scotocerca inquieta
Arabian Warbler
Sylvia leucomelaena
Brown Woodland Warbler
Phylloscopus umbrovirens
Gambaga Flycatcher
Muscicapa gambagae
African Paradise Flycatcher
Terpsiphone viridis
Arabian Babbler
Turdoides squamiceps
Nile Valley Sunbird
Anthreptes metallicus
Shining Sunbird
Nectarinia habessinica
Orange-tufted Sunbird
Nectarinia osea
Socotra Sunbird
Nectarinia balfouri
122
7 9.5 38
1 1 2
ak
7.6
13.5
1
6.7
23.4 44.2
4 4
n.d.
n.d.
11.25
1
3.5
2.2
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
Juniper
wood-
land
15.3
ae
5.6
ku
6.1
Open:
Acacia cultivated vated
woodland wadis
18:15
10
6.7
8.6
3.3
FOOTHILLS
(500-1,800m)
Un-
9
10.6
ae
3.3
Culti-
wadis
29
5
n.d.
anes
Mahrah
wood-
land
9
2
18.3
ue
10
10
wake
93.3
kkk
47.6
Hadramawt
(cultivated
silt plain)
22.5
4
kkkk
104.8
n.d.
HIGH-
LANDS
Highland
plateaux
>1,800m
29.5
3
n.d.
n.d.
n.d.
SOCOTRA
Foothills Highlands
(100- (>450m)
400m)
11 21
2 2
26.4 13.9
3.9 n.d.
12:2 6.6
123
Peter Davidson
TABLE 2 CONTINUED:
ALTITUDINAL ZONE
HABITAT TYPE Sabkha
Total transect length (km) 7
No of sites censused 1
SPECIES
White-breasted White-eye
Zosterops abyssinica
Black-crowned Tchagra
Tchagra senegala
Great Grey Shrike
Lanius excubitor
Brown-necked Raven
Corvus ruficollis
Fan-tailed Raven
Corvus rhipidurus
Tristram’s Starling
Onychognathus tristramii
Somali Starling
Onychognathus blythii
Socotra Starling
Onychognathus frater
Amethyst Starling
Cinnyricinclus leucogaster
House Sparrow
Passer domesticus
Socotra Sparrow
Passer insularis
Ruppell’s Weaver
Ploceus galbula
Arabian Waxbill
Estrilda rufibarba
Zebra Waxbill
Amandava subflava
African Silverbill
Euodice cantans
Arabian Serin
Serinus rothschildi
Golden-winged Grosbeak
Rhynchostruthus socotranus
Yemen Linnet
Carduelis cannabina
House Bunting
Emberiza striolata
African Rock Bunting
Emberiza tahapisi
124
Sandgrouse 17
TIHAMAH AND THE COASTAL LOWLANDS
Sub-
desert
plain
9.5
1
Herba-
ceous
grassland
38
2
flo
flo
(<500m)
Acacia Alluvial
woodland coastal
plain
13:5 23.4
1 4
49
flo
Sandy Degraded
wadis coastal
plain
44.2 125
4 1
1.4 3.8
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
Juniper
wood-
land
15.3
8.9 (f)
x
3.3
Open
FOOTHILLS
(500-1,800m)
Un-
Culti-
Acacia cultivated vated
woodland’ wadis
10
ue
2.6
ak
flo
xk
flo
ak
“102
78.75
9
wadis
29
HIGH-
LANDS
Mahrah Hadramawt Highland
wood-
land
AS)
2
(cultivated plateaux
silt plain) >1,800m
22.5 29.5
4 3
a7 1.5
flo
flo
n.d.
129.4 94.7
353.6 n.d.
31.9
22.2
n.d.
1.5
n.d.
Coastal
plain
(<100m)
15:2
ae
n.d.
20
kkk
SOCOTRA
Foothills Highlands
(100- (>450m)
400m)
11 21
2 2
15.3 n.d
25.4 49.1
flo
198.3 66.4
23
232.4 178
2.6
19.4 1
125
Peter Davidson Sandgrouse 17
TABLE 3: TIHAMAH AND THE COASTAL LOWLANDS
ALTITUDINAL ZONE (<500m)
Sub- Herba- Acacia Alluvial Sandy Degraded
HABITAT TYPE Sabkha desert ceous woodland coastal wadis coastal
plain grassland plain plain
Total transect length (km) 7 9.5 38 13.5 23.4 44.2 11.25
No of sites censused 1 1 2 1 4 4 1
SPECIES
Montagu’s Harrier
Circus pygargus | flo
Steppe Eagle
Aquila nipalensis
Booted Eagle
Hieraaetus pennatus
Lesser Kestrel
Falco naumanni flo
Quail
Coturnix coturnix
Turtle Dove
Streptopelia turtur
Cuckoo
Cuculus canorus
Alpine Swift ge
Apus melba flo
Pallid Swift ag iy
Apus pallidus flo flo
Blue-cheeked Bee-eater
Merops superciliosus flo f/o
European Bee-eater
Merops apiaster
Roller
Coracias garrulus n.d.
Barn Swallow
Hirundo rustica flo
Red-rumped Swallow
Hirundo daurica
Tawny Pipit
Anthus campestris 4.3
Red-throated Pipit
Anthus cervinus
Tree Pipit 2
Anthus trivialis 3.3
Yellow Wagtail
Motacilla flava flo
Rufous Bush Robin : . eke as e
Cercotrichas galactotes 1.3 Cf 35 2.9 2.2
White-throated Robin . 5
lrania gutturalis Pf n.d.
126
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
FOOTHILLS HIGH-
(500-1,800m) LANDS
Juniper Open Un- Culti: Mahrah Hadramawt Highland Coastal Foothills Highlands
wood- Acacia cultivated vated wood- (cultivated plateaux plain (100- (>450m)
land woodland wadis wadis land silt plain) >1,800m (<100m) 400m)
SOCOTRA
15.3 10 78.75 29 9 22.5 29.5 15.2 14 21
1 1 9 5 2 4 3 3 2 2
n.d.
n.d.
n.d. n.d. n.d.
cd
0.5
n.d n.d.
flo
n.d.
flo flo
n.d flo
“n.d.
4.4
flo
0.7 n.d.
127
Peter Davidson
TABLE 3 CONTINUED:
ALTITUDINAL ZONE
HABITAT TYPE Sabkha
Total transect length (km) 7
No of sites censused 1
SPECIES
Black Redstart
Phoenicurus ochruros
Redstart
Phoenicurus phoenicurus
Isabelline Wheatear
Oenanthe isabellina
Pied Wheatear
Oenanthe pleschanka
Rock Thrush
Monticola saxatilis
Marsh Warbler
Acrocephalus palustris
Olivaceous Warbler
Hippolais pallida
Upcher’s Warbler
Hippolais languida
Barred Warbler
Sylvia nisoria
Lesser Whitethroat
Sylvia curruca
Common Whitethroat
Sylvia communis
Blackcap
Sylvia atricapilla
Willow Warbler
Phylloscopus trochilus
Chiffchaff
Phylloscopus collybita
Spotted Flycatcher
Muscicapa striata
Golden Oriole
Oriolus oriolus
Isabelline Shrike
Lanius isabellinus
Red-backed Shrike
Lanius collurio
Lesser Grey Shrike
Lanius minor
Ortolan Bunting
Emberiza hortulana
128
Sandgrouse 17
TIHAMAH AND THE COASTAL LOWLANDS
(<500m)
Sub- Herba- Acacia Alluvial Sandy Degraded
desert ceous woodiand coastal wadis coastal
plain grassland plain plain
9.5 38 13.5 23.4 44.2 11.25
1 2 1 4 4 1
8.9
19.1 - 0.3 4.3
2,
n.d.
6.7 3.7 n.d.
33.2 n.d
11.3 2.2 2.2 4.1 7a fe, 2.2
5 8.9 n.d
3 Wei 0.6 41.4 2.2
20.8 15.6 1.6 n.d. 2.2
Ws. n.d
Wee! 2.2 5:2 n.d. 12
6 3.8
0.4
Sandgrouse 17 Habitats and bird communities in southern Yemen and Socotra
FOOTHILLS
_ (500-1,800m)
Juniper Open Un- Culti-
wood- Acacia cultivated vated wood-
land woodland wadis wadis
15.3 10 78.75 29
1 1 g 5
1.9
n.d. n.d.
f/o n.d.
5.3 n.d.
24
ss n.d.
n.d.
4.7 n.d.
131.8 3.6 0.3 n.d.
0.8
Pall n.d.
Nel:
0.5
0:5 n.d.
0.3
0.9
n.d.
land
g
2
11.3
Mahrah Hadramawt
(cultivated
silt plain)
22:5
4
n.d.
uk
8.9
HIGH-
LANDS
Highland Coastal
SOCOTRA
Foothills Highlands
plateaux plain (100- (>450m)
>1,800m (<100m) 400m)
29.5 Toe 11 21
3 3 2 2
x
Zia
n.d.
129
Sandgrouse (1996) 17: 130-131
Ostrich Struthio camelus eggshell
fragments in Yemen
J. W. SPENCER
ragments of Ostrich Struthio camelus eggshells were found on two occasions
during the 1993 OSME survey: in the vicinity of Marib and, in association
with human artefacts and other archaeological material, in the Ramlat al-
Saba'tayn between Marib and Shabwa. Both sites are described in detail below.
The Ostrich is known to have been widely distributed across the Arabian
peninsula in the past, with records and sightings occurring up until the early
decades of the twentieth century (Gallagher 1988; Walker 1981; Jennings 1986).
Wilfred Thesiger reports the reminiscences of Bedu tribesmen in the Empty
Quarter recalling the presence of Ostriches in the days of their grandfathers
(Thesiger 1959).
Whilst the eggshell fragments were clearly associated with signs of human
activity at Ramlat al-Saba'tayn, at the Marib site they were far more abundant,
scattered over a wider area and not obviously associated with any human
artefacts. In neither case could their importation by human agency be
completely discounted. Ostrich eggs can be transported long distances by
hunter gatherers, both as food and in their use as water carriers (Van der Post &
Taylor 1984). It does seem likely, given the evident antiquity of the Ramlat al-
Saba'tayn fragments, that these at least are of the Arabian race of Ostrich S. c.
syriacus.
SITE DESCRIPTIONS
Marib-Sana'a Road (15°31'N 45°16'E)
Large numbers of fragments were found strewn amongst lava blocks and small
lava bombs in the volcanic lava fields south-west of Marib, on the Marib-Sana'a
road. The volcanic fields of nearby Marib are relatively recent and the lava
flows in this area are known to have flowed over alluvial terraces formed
behind the Marib dams. These flows are possibly as recent as post-600 BC when
the dams were constructed, and the eggshell fragments certainly post-date the
flows. Given the intensity of settlement in the area for much of the ancient
period, it seems quite possible that the eggshells may have been carried and
discarded by nomadic people travelling between settlements. —
Ramlat al-Saba'tayn (Rub al-Khali) (15°55'N 46°46'E)
A number of small fragments of Ostrich eggshell were found in an ablated
hollow in extensive sand dunes in the area known as Ramlat al-Saba'tayn, some
ten kilometres north-west of the two small, conspicuous hills known as Turbaq
and ‘Arayn. The fragments were in clear association with an assortment of
130
Sandgrouse 17 Ostrich eggshell fragments in Yemen
artefacts including chert arrowheads, obsidian points, stone knives and stone
flakes. Also present was the partial headless skeleton of a gazelle (or just
possibly a young ibex). Both the eggshell fragments and the artefacts rested on a
grey, dusty soil horizon below the yellow siliceous sand, believed to be the
surface of an ancient lake bed. The artefacts have been examined and tentatively
dated to the early holocene, some 9,000 BP, during one of the more humid
climatic periods in Arabia's history.
The collection of artefacts probably represents a temporary, though possibly
regularly used, camp site. Though the Ostrich eggshell fragments appeared to
be contemporary and associated with the campsite, it is nevertheless possible
that they arrived at the site at a later date.
ACKNOWLEDGEMENTS
I would like to thank Dr Martin Menzies of the Yemen Geological Research Group (Royal
Holloway College, London) and Ms M. L. Inizian of the CNRS (Centre National des
Recherches Scientifiques) in Paris, for their help in the preparation of this paper.
REFERENCES
GALLAGHER, M. D. (1988) The Ostrich in Oman. Sandgrouse 10: 97-101.
WALKER, F. J. (1981) Notes of the birds of Dhofar, Oman. Sandgrouse 2: 50-85.
JENNINGS, M. C. (1986) The distribution of the extinct Arabian Ostrich Struthio camelus
syriacus. Rothschild, 1919. Fauna of Saudi Arabia 8:447-461.
THESIGER, W. (1959) Arabian Sands. London.
VAN DER Post, L. AND TAYLOR, J. (1984) Testament to the Bushmen. Viking, London.
J. W. Spencer, 123 Greenham Road, Newbury, Berkshire RG14 7JE, UK.
131
Sandgrouse (1996) 17: 132-133
The Plain Nightjar Caprimulgus inornatus
in Yemen
J. N. DYMOND
he Plain Nightjar Caprimulgus inornatus occurs widely across sub-Saharan
Africa north of the Equator, where its status and distribution is reasonably
well understood. Knowledge of the species’ status in the Arabian peninsula,
however, is poor. The species forms a super-species with Star-spotted Nightjar
C. stellatus, which has a more restricted range: regular occurrence is apparently
restricted to parts of Ethiopia and northern Kenya.
STATUS AND DISTRIBUTION IN AFRICA
The species is resident in north-west Somalia, but elsewhere in Africa is
apparently a rainy season breeding visitor to arid steppe habitats from southern
Mauritania in the west to Ethiopia and north-west Kenya in the east. Some birds
do breed farther south in the Guinea savanna zone and forest-edge habitats, with
nesting data recorded in Liberia and southern Nigeria. With the exception of the
Somali resident population, the species is thought to migrate southwards during
October to December to wintering areas mainly in northern Zaire, Uganda,
Kenya and northern Tanzania, perhaps also westwards towards the Gulf of
Guinea. Northward return migration occurs mainly during April to June.
STATUS AND DISTRIBUTION IN THE ARABIAN PENINSULA
In Saudi Arabia there are records from four half-degree squares, all in the south-
west highlands where it is considered to be local, with all records in the period
March to August (M. C. Jennings pers. comm.). They occur in barren habitats,
either rocky outcrops and plateaux inland of the Asir mountains or in the
foothills at the edge of the escarpment (Symens et al. 1992).
In Yemen, prior to the OSME survey in 1993, there are a total of 11 records
from the following collecting trips: August to October 1899, June 1907 and May
1934 (F. E. Warr in litt.) and one record of a female/immature found dead 13 km
north of Ta'izz (1,200 m), 25 April 1985.
The survey recorded up to three birds singing on the nights of 21 March and
22 March at Jabal Iraf (1,400 m), of which one was mist-netted; two at al-Sawm
(820 m), 3 May, three seen/heard near al-Ghuraf, near Tarim (800 m), 3 May and
five seen/heard at al-Qatn (780 m), 4 May. The last three sites are all in the
Wadi Hadramawt region and suggest that there may be a good population of
the species in that area.
Present data suggest that Arabian birds are breeding summer visitors from
Africa, though non-calling birds would be very hard to detect during the winter
months.
132
Sandgrouse 17 The Plain Nightjar in Yemen
YEMEN CAPTURE
During the survey, one male bird was mist-netted during darkness, 22 March at
Jabal Iraf. Under torchlight the bird was examined critically in the hand and its
plumage features were compared directly with the description given in Fry et al.
(1988). The sole slight discrepancy was that the captured bird did not show any
pale or whitish patch in the centre of the throat; otherwise it matched perfectly.
Biometric data of the trapped bird (lengths in mm, weight in grammes):
Age Sex Wing Tail Maximum Billto Weight Primary
tarsus feathers moult score
Full-grown Male 167 116 20.6 Gs: 48.2 0
VOICE
The song is a prolonged churr very similar to that of European Nightjar C.
europaeus, though perhaps more directional and less ventriloquial. Song in
Yemen commenced just prior to dusk and continued for spells of 20-60 seconds
at intervals of 2-20 minutes. The intervals between churring increased during the
evening, with song ceasing around 22.30 hours. The male that was caught at
Jabal Iraf had earlier been observed singing from a perch on a side branch of a
Juniper tree, about two metres from the ground.
HABITAT AND CONSERVATION
Jabal Iraf is an elevated plateau with scattered Acacia spp. and Euphorbia sp.,
grading at higher elevation into scrubby woodland dominated by Juniperus sp.,
with more densely vegetated shallow rocky gullies. The habitat at al-Sawm, al-
Ghuraf and al-Qatn was bare or sparsely vegetated rocky hillsides with more
vegetated wadi bottoms. Acacia scrub was extensive at al-Qatn.
This species seems to need quite remote dry rocky hillsides with neighbouring
vegetated areas of native woodland or agriculture. Therefore it would not
appear to require any active conservation measures and is unlikely to be
influenced by the activities of man.
REFERENCES
BROOKS, D. J., EVANS, M. I., MARTINS, R. P. AND PORTER, R. F. (1989) The Status of Birds in
North Yemen and the Records of OSME Expedition in Autumn 1985. Sandgrouse 9: 4-66.
Fry, C. H., KEITH, S. AND URBAN, E. K. (1988) The Birds of Africa. Vol. 3. Academic Press,
London.
JENNINGS, M. C. (1981) The Birds of Saudi Arabia: a Check-list. Whittlesford, Cambridge.
MaRrrIINS, R. P. (1986) Spring Observations on the Birds of North Yemen. OSME Bulletin
17: 2-13.
SYMENS, P., NEWTON, S. F., WINKLER, H. AND STAGG, A. J. (1992) Mountain Nightjar
Caprimulgus poliocephalus in Arabia: identification, status and distribution. Sandgrouse
14: 81-92.
J. N. Dymond, Burgadies, South Punds, Levenwick, Shetland ZE2 9HX, UK.
133
Sandgrouse (1996) 17: 134-137
The Buteo population in Socotra
R. P. MARTINS AND R. F. PORTER
he systematic position of the highly isolated, resident, endemic population of
buzzards on Socotra is unclear and requires further study. Ripley & Bond
(1966) imply that the population may merit treatment as a sub-species but,
because of the scarcity of available material, it is difficult to resolve this issue
(Frost & Siegfried 1970). Past authors have variously linked its origins to the
Steppe Buzzard Buteo buteo vulpinus or have included it under Mountain
Buzzard B. oreophilus (e.g. Brown et al. 1982) although without supporting
evidence.
The taxonomic and evolutionery context in which the Socotra Buteo should be
considered is helpfully informed by recent work on analogous non-migratory
populations, such as that on the Cape Verde islands (Hazevoet 1995).
This paper presents details of field observations made in Socotra during the
OSME survey in April 1993, against the background of previous studies.
DESCRIPTION
Between 31 March and 7 April 1993, the survey made a total of 31 sightings,
including several pairs, one accompanied by three flying juveniles and another
which was attending a nest with young. Individuals seen closely were studied
carefully and notes taken on shape, structure, plumage and moult. Photographs
were taken including that depicted in Plate 23. The main field characters are
shown in Figure 1.
General points emerging from the observations are:
a) Shape and structure differ noticably from migratory Buteo buteo vulpinus
that migrates through Arabia; Socotran birds being broader-winged and
shorter-tailed, with a proportionally shorter ‘arm’ and less pointed wing-tips,
thus more closely resembling Buteo buteo buteo. In addition to the photograph
presented here, another of a bird in flight is presented in Ripley & Bond (1966).
b) Little plumage variation was noted between individuals, except for
differences in the extent of streaking on the underparts (see Figure 2).
Streaking generally extended well towards the rear-flanks, but was not
obvious across the centre of the upper-breast, which appeared unmarked in
most individuals.
The main plumage characters of the Socotran birds were:
Underparts: pale throughout with variable blackish-brown streaking on flanks
extending to rear flanks, prominent brown carpal-patches, light brown mottling
on underwing-coverts and extensive white undersides to most primaries
forming a conspicuous pale patch recalling Long-legged Buzzard B. rufinus. Tail
134
Sandgrouse 17 The Buteo population in Socotra
greyish or off-white, regularly and lightly barred throughout, with an
inconspicuous narrow dark terminal-band.
Upperparts and head: mainly mid-brown; upperside to tail appeared either
greyish-white or gingery-brown, narrowly barred brown throughout excepting
broader brown terminal-band; a small pale patch is formed by whitish bases to
the inner-primaries. Head generally paler than rest of upperparts with an
obvious off-white supercilium.
Soft parts: bill and irides appeared dark; legs and feet yellow.
Figure 1. Socotra Buteo from
below showing the main field
characters.
Figure 2. Socotra Buteo
showing variation in
extent of markings on
underbody, observed in
April 1993.
——
rt
or
ih oa
MOULT
The bird depicted in Plate 23 showing moult of the inner primaries, secondaries
and tail is an adult photographed on 1 April. This does not conform to the
moult sequence typical of B. b. buteo, which does not commence primary and tail
moult until late April/early May (Cramp & Simmons 1980), or B. b. vulpinus
which commences moult of both primaries and tail in early May.
STATUS, DISTRIBUTION AND BREEDING
The buzzards on Socotra appear to be widely distributed and not uncommon
residents (Ogilvie-Grant & Forbes 1903, Ripley & Bond 1966 and survey
observations). Breeding has been shown to occur in November, January (nest
with one month old young, Clouet et al. 1994) and 'winter' (many pairs with
young, Ogilvie-Grant & Forbes 1903).
Apparent breeding was also recorded by Forbes-Watson (Ripley & Bond
1966), who observed a pair carrying sticks to a nest between 10 April and 13
May (dates deduced from itinerary quoted). During the 1993 survey a nest was
discovered on 5 April on a rocky cliff, above a wadi at Di-Ishal (150 m), where
adults were carrying food to an unknown number of unfledged young. A pair
with three fledged young were seen nearby on the same date. These
T35
R. P. Martins and R. F. Porter Sandgrouse 17
observations, supported by those of Forbes-Watson, demonstrate that the
breeding season extends much later than the period as by Ogilvie-Grant &
Forbes (1903) and Clouet et al. (1994).
It would appear that the duration of breeding can extend from October to at
least April (and possibly May), thus differing markedly from that of the
migratory vulpinus. Indeed it would be important for Socotra Buteos to have
completed their breeding before the onset of the monsoon winds which could
hamper the ability to hunt. This difference in breeding seasons may constitute
an additional isolating mechanism for the Socotra population.
ACTIVITY
Often soaring, either alone or with Egyptian Vultures Neophron percnopterus. On
several occasions seen standing erect on rocks or trees.
SYSTEMATIC POSITION
The existence of an apparently sedentary, insular population of buzzards over
2,600 km south of the southern limits of the range of B. b. vulpinus in northern
Iran and over 1,700 km from the nearest population of the Mountain Buzzard B.
oreophilus of Africa is zoo-geographically intriguing, considering the systematic
link that has been made with these two species in the past. Past authors have
been unable to form a clear opinion regarding the most appropriate and
meaningful systematic treatment of buzzards on Socotra because only five
specimens indisputably from the Socotran population (and not migrant
vulpinus) are available for study (see Frost & Siegfried, 1970) and because the
systematics of old world Buteo populations present a problem which is
challenging in its complexity.
Ripley and Bond (who did not visit Socotra) did not adopt any formal
systematic treatment, simply listing the population as Buteo buteo sub-species?
Similar difficulties are presented by sedentary buzzard populations in
Macronesia - the Atlantic islands including the Cape Verdes. Such populations
are apparently shorter-winged, more clearly resembling nominate B. b. buteo in
structure than the highly migratory vulpinus and markedly less variable in
plumage characters than trans-Eurasian Buteo populations.
The suggestion that such populations could be derived from colonists
originating from extensively distributed more northern migrant populations has
been made in the past, despite a lack of supporting evidence.
Discussion of the systematic position of any group of species or sub-species
must reflect their respective evolutionary histories if it is to be meaningful.
Ideas advanced by Naurois (1987) and comprehensively developed by Hazevoet
(1995) to explain the origin of the Cape Verde Buzzard Buteo bannermani on the
Cape Verdes may usefully inform discussion of the origins of the Socotran
population. Naurois suggested that the Cape Verde and Socotran buzzard
populations have comparable and analogous origins, perhaps representing relic
derivatives of a now extinguished African population that existed during or
136
Sandgrouse 17 The Buteo population in Socotra
before the Pleistocene. According to this hypothesis Eurasian Buzzard taxa
would be derived from an ancestral 'proto-Buzzard' population, the range of
which has presumably shifted north into Eurasia as climatic conditions
ameliorated after the Pleistocene and as speciation progressed.
Populations on the Cape Verdes and Socotra are perhaps therefore derived
from early colonists from this, more ancient, population. If this is true, such
populations are derived through an evolutionary history which is less related to
that of Eurasian Buteo taxa than has been thought previously, representing a
separate evolutionary lineage which has proceeded independently on these
oceanic islands.
Under the Phylogenetic species concept, such a population, if 'consistently
diagnosable' from related forms according to morphological or other criteria,
constitutes a ‘basal evolutionary unit’ and is therefore most appropriately
treated as a species. As indicated above, this approach is adopted by Hazevoet
who treats the Cape Verde populations as Buteo bannermani. It would seem
appropriate to consider this same approach for the buzzards on Socotra.
Further study of the ecology of the Socotran birds and detailed field and
museum comparison with the Eurasian Buteo buteo and African B. oreophilus is
therefore planned.
ACKNOWLEDGEMENTS
Weare most grateful to C. J. Hazevoet for helpful comments on the draft of this paper and
to M. J. Everett for the illustrations in Figures 1 and 2 which were based on the authors'
field sketches and photographs.
REFERENCES
BROWN, L. H., URBAN, E. K. AND NEWMAN, K. (1982) The Birds of Africa Vol. 2. Academic
Press, London.
CLouET, M., CANU, J. G. AND LIPINSKI, F. (1994) Sur la nidification de la Buse de Socotra.
Alauda. Vol 62 No. 2: 144-145.
CRAMP, S. AND SIMMONS, K. E. L. (1980) The Birds of the Western Palearctic Vol. 2. Oxford.
DOWSETT, R. J. AND DOWSETT-LEMAIRE, F. (1993) Afrotropical avifaunas: annotated country
checklists. Tauraco Research Report 5. Tauraco Press, Liege.
Frost, P. G. H. AND SEIGFRIED, W. R. (1970) Notes on the plumage of Buzzards from
Socotra. Bull. Brit. Orn. Club 90: 136-142.
HAZEVOET, C. J. (1995) The Birds of the Cape Verde Islands. B.O.U. check-list No. 13. B.O.U.,
Herts.
Naurols, R. DE (1987) Les oiseaux de l'archipel du Cap Vert: peuplements, adaptations,
endémisme. Bull. Soc. Zool. France 112: 307-326.
OGILVIE-GRANT, W. R. AND ForRBES, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In
ForseEs, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
RipLey, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri. Smithsonian
Misc Coll. 151, 7.
R. P. Martins, 6 Connaught Road, Norwich, Norfolk NR2 3BP, UK.
R. F. Porter, BirdLife International, Wellbrook Court, Girton Road, Cambridge
CB3 ONA, UK.
137
Sandgrouse (1996) 17: 138-141
Forbes-Watson's Swift Apus berliozt in
Socotra
R. F. PORTER, J. N. DYMOND AND R. P. MARTINS
orbes-Watson's Swift forms a super-species with Pallid Swift A. pallidus,
African Black Swift A. barbatus and Bradfield's Swift A. bradfieldi (Fry et al.
1988, Chantler & Driessens 1995). Two sub-species are recognised, nominate A.
b. berliozi apparently breeding exclusively in Socotra and A. b. bensoni breeding
in Somalia and wintering along the Kenyan coast (Chantler & Driessens 1995).
There is some evidence to suggest the Socotran population is migratory. During
the OSME survey of spring 1993 over 300 were recorded.
DESCRIPTIONS
The following descriptions are based upon observations made during the
survey. For clarity of presentation descriptions in the field and in the hand are
given separately. All references to primaries are numbered ascendantly.
In the field:
Typical Apus shape. Flight typical of the genus, with long, sweeping, tilting
glides with limited or no wing-beats, interspersed by occasional short bursts of
rapid wing-beats. Plumage colouration dark blackish-brown with distinct white
chin and throat patch and less obvious white forehead; both these features were
variable.
Upperparts: crown and nape grey-brown, mantle, back and rump darker
blackish-brown with pale fringes to tips of feathers sometimes visible at close
range in good light. Upperside of tail much paler brown than upper body.
Underparts: dark earth-brown, paler than mantle, back and rump. Undertail
coverts, especially at sides, obviously pale. Pale fringes to feathers were not
apparent in the field.
Upperwing: dark brown with iridescent sheen, appearing oily, occasionally
discernible on median and primary coverts; blackish outer primaries.
Underwing: coverts brown, paler than underbody.
Underwing: medium greyish-brown with paler, almost translucent, secondaries
and inner primaries and darker outer primaries.
In the hand:
This description is based upon a single individual trapped (by flick-netting) at
1,450 m on Jabal Jaaf on 3 April. The bird is illustrated in Plates 25 and 26.
Upperparts: forehead pale grey-brown with very fine whitish fringes. Crown,
nape, mantle, back, rump and uppertail coverts grey-brown, also with very
narrow pale fringes becoming more obvious on mantle and back and most
prominent on rump and uppertail-coverts. Tail grey-brown with a bronzy-
green sheen in some lights. Tips of uppertail coverts fell 8 mm short of tips of
138
Sandgrouse 17 Forbes-Watson’s Swift in Socotra
central tail feathers.
Underparts: chin and throat white with very fine, blackish shaft-streaks to
feathers at sides of chin and throat (in malar area). Lores sooty-black. Rictal
bristles prominent, short and black. White of throat extended to upper breast,
level with carpal bend of closed wing, this colouration merging into earth-
brown on breast. Lower breast, belly, flanks and undertail coverts earth-brown
with prominent narrow whitish fringes to feathers. Tips of undertail-coverts fell
2 mm short of tips of central tail feathers.
Upperwing: primaries and primary coverts dull earth-brown with bronzy-green
sheen, most noticeable on five outer primaries. Secondaries and greater coverts
as primaries but paler. Median and primary coverts slightly darker than greater
coverts with an oily green sheen and very narrow pale fringes to inner and
lesser median coverts. Pale fringes to leading row of lesser coverts, producing
pale leading edge to inner wing.
Underwing: coverts grey-brown, paler than base colour of underbody with
broadest fringes (up to 2 mm in width) on greater coverts. Prominent silvery
cast to underside of tertials and secondaries, diminishing towards inner
primaries.
Soft parts: bill black; iris dark chocolate-brown; legs and toes blackish, soles of
feet pinkish grey, claws black.
Measurements (length in millimetres, weight in grammes):
Wing Head & bill Tail Tail cleft depth Weight
172 Cews 69.5 26.2 39.5
When compared with details of 18 male and 11 female A. bD. berliozi, for which
details are given in Fry et al. (1988), these measurements suggest the trapped
individual was a male.
A detailed description of Forbes-Watson's Swift (Chantler & Driessens 1995)
concurs with the characters of this bird.
THE PROBLEM OF IDENTIFICATION
There is no doubt that Forbes-Watson's Swift is difficult to identify.
Examination of the species in the field and hand and subsequent comparison of
skins at the BMNH with an extensive series of Apus apus pekenensis (the race of
Common Swift that migrates through eastern Arabia) and Apus pallidus
suggested the following to assist with identification:
Differences from Apus a. pekenensis:
pale fringes to feathers on upperparts
larger, whiter throat
oily sheen to secondary and median coverts on uppermine
slightly paler overall colouration
slight dark saddle effect on mantle
10th primary longest (9th longest in pekenensis)
voice
139
R. F. Porter, J. N. Dymond and R. P. Martins Sandgrouse 17
Differences from Apus pallidus:
less noticable saddle on mantle
slightly darker plumage
oily sheen to primaries and secondary and median upperwing coverts
voice
However, much caution is needed. A bird trapped on mainland Yemen, on 25
April (which was not seen in the hand by the authors) and identified as Pallid
Swift was later considered to possibly have been Forbes-Watson's Swift upon
examination of the slides. However there was insufficient detail in the
photographs or measurements taken for a confident identification to be made.
VOICE
The call is a rather flat, screeching ‘schweee’, not as high-pitched or loud as that
of A. apus. A trisyllabic ‘schweee-weee-eee’ was also noted.
TAXONOMIC HISTORY
The population of Apus swifts breeding on Socotra were first named Apus
pallidus berliozi (Ripley 1965) after examination of birds collected by A. D.
Forbes-Watson in 1964. Ripley treated this population as a race of pallidus based
upon size, colouration and measurements which were judged to best fit this
species. The history of the taxonomic treatment since then has been
complicated. A useful account appears in Brooke (1969), who also examined the
position of other closely related taxa in what is now regarded as the pallidus
super-species. In this group Sibley & Monroe (1990) recognise pallidus (Pallid
Swift), barbatus (African Black Swift), berliozi (Forbes-Watson's Swift), bradfieldi
(Bradfield's Swift), as well as balstoni in Madagascar. Few other authors support
Sibley & Monroe's specific recognition of balstoni and Chantler & Driessens
(1995) do not treat it as specifically distinct. All agree that the pallidus super-
species presents particular difficulties within Apus and, from a field identifi-
cation perspective and from the limited information available to us, we concur
with this view.
It is now recognised that Forbes-Watson's Swift comprises two sub-species, A.
b. berliozi (breeding in Socotra) and A. b. bensoni (breeding in Somalia).
STATUS AND DISTRIBUTION
The species was recorded throughout the survey (31 March - 7 April). Birds
were often seen in pairs or groups of less than five, although on one occasion a
loose flock of 45 was observed; in total about 300 were recorded and the species
was judged to be fairly common and quite widely distributed. During the 1898-
9 (December to February) expedition to Socotra the only swifts observed were
several on 12 December (Ogilvie Grant & Forbes 1903). Although these birds
were not positively identified, assuming they were Forbes-Watson's Swift, this
observation suggests that the species is rare or absent during winter.
140
Sandgrouse 17 Forbes-Watson’s Swift in Socotra
HABITAT AND BREEDING
Most common in the interior of the island e.g. in the Hajhir mountains around
Jabal Jaaf, although small numbers were recorded over the coastal plains. No
evidence of breeding was observed. Forbes-Watson collected 32 individuals,
nearly all in breeding condition, 14 to 9 May 1964, and suggested the breeding
season was largely complete by mid-May (Ripley 1965). He found the species
most often in mountain areas above 600m and thought it bred in cracks in cliffs.
No display was observed during the survey but Forbes-Watson in 1964 found
that most birds in the flocks encountered were in pairs with the female leading
the male (discovered by collecting). On a few occasions birds were seen to cling
onto their partner and then drop with flexed wings to near the ground. In
addition to much screaming, ‘whip-crack’ noises emanated from the pair,
probably made by the wings.
FOOD
Birds were observed catching flying insects. Stomach contents examined by
Forbes-Watson included beetles, flying ants and grasshoppers. He also saw
them catching flying termites at sea level after rain (Ripley 1965).
CONSERVATION AND INFLUENCE OF MAN
The species is apparently neither threatened nor influenced by human activities.
REFERENCES
BROOKE, R. K. (1969) Apus berliozi Ripley, its races and siblings. Bull. Brit. Orn. Club. 89,
11-16.
CHANTLER, P. AND DRIESSENS, G. (1995) Swifts: a guide to the swifts and treeswifts of the world.
Pica Press, East Sussex.
Fry, C. H., KEITH, S. AND URBAN, E. K. (1988) The Birds of Africa. Vol. 3. Academic Press,
London.
OcILviE-GRANT, W. R. AND Fores, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In
FORBES, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
RIPLEY, S. D. (1965) Le Martinet Pale de Socotra. L’Oiseau et la Revue Francaise
d’ornithologie. Vol. 35: 101-102.
RIpLey, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri. Smithsonian
Misc. Coll. 151, No. 7.
SIBLEY, C. G. AND MonroE, 8. L. (1990) Distribution and taxonomy of birds of the world. Yale
University Press, New Haven.
R. F. Porter, BirdLife International, Wellbrook Court, Girton Road, Cambridge
CB3 ONA, UK.
J. N. Dymond, Burgadies, South Punds, Levenwick, Shetland ZE2 9HX, UK.
R. P. Martins, 6 Connaught Road, Norwich, Norfolk NR2 3BP, UK.
141
Sandgrouse (1996) 17: 142-144
The Socotra Warbler Incana incana
J. N. DYMOND
ormerly placed in the genus Cisticola, Socotra Warbler Incana incana, endemic
to Socotra, has more recently been treated as a monospecific genus, though
not by Sibley & Monroe (1990). Plumage and wing-formula show close
similarities to Piping Cisticola (or Neddicky) C. fulvicapillus of eastern and
southern Africa, but it is longer-billed and certain aspects of its behaviour and
appearance recall some Sylvia warblers, notably Desert Warbler S. nana. The
species has a reddish orbital-ring, a feature not present in any species of the
genus Cisticola but often present in Sylvia.
The observations of the OSME survey of spring 1993 are presented here.
DESCRIPTION
Sexes apparently alike. In general impression, a fairly small sandy warbler
resembling both Desert Warbler and a Cisticola, but with a noticeably long,
prominent bill. The tail is sometimes held slightly cocked. One of the
individuals observed during the survey is illustrated in Plates 30 and 31.
The following description applies to adults. Juvenile plumage is apparently
undescribed.
Plumage
Crown and nape sandy-grey with a distinct rufous tinge. Upperparts uniform
sandy-brown. Ear-coverts and sides of neck greyish-white. Upperside of tail
slightly darker than upperparts with greyish tinge to central pair of tail feathers.
Extensive white tips and blackish subterminal bands present on underside of
tail feathers. Occasional narrow white tips present on upperside also, although
these are absent from some birds having apparently been lost through wear.
The prominence of these features is accentuated by the graduated tail structure.
Excluding blackish centres to tertials and black alulas, general colouration of all
coverts and flight-feathers on closed wing sandy-brown, concolorous with
mantle. Entire underparts pure 'silky' white to greyish-white, excepting a
greyish cast to rear flanks. Plumage soft and loose (from examination of skins).
Soft Parts Bill: upper mandible dark grey; lower mandible straw-yellow or
pinkish-yellow with a dark tip. Legs and feet orange-yellow or pink, faintly
tinged orange. Irides reddish-brown or tawny-orange.
Measurements Forbes-Watson collected 22 birds in 1964: wing-lengths were 49-
53 mm (mean 50.8) in 12 males and 46-51 mm (mean 48.5) in 10 females, with
tail-lengths of 43-48 mm (mean 45.2) and 41-47 mm (mean 43.1) respectively; the
weight range was 9-12 g (Ripley & Bond 1966).
142
Sandgrouse 17 The Socotra Warbler
VOICE
The quiet song is a slightly hesitant, unmusical trill or a spluttering series of
identical notes lasting 1-1.5 seconds. Ogilvie-Grant & Forbes (1903) considered
the song similar to that of Stonechat Saxicola torquata, but not often heard. A
harsh, chattering call-note was occasionally heard during the survey. This was
described by Ogilvie-Forbes & Grant (1903) as a scolding “'chip, chip, chip, chip-
it, chip-it, chip-it' which can be reproduced by striking a flint and steel together
quickly.”
STATUS AND DISTRIBUTION
About 88 were recorded at ten sites during the survey at altitudes from sea-level
to 800 m. The species was encountered at most well-vegetated sites visited. The
more arid west of the island was not visited but in 1964 Forbes-Watson found
the species in extensively vegetated plains at Kallansiya in the west and up to
1,400 m in the Haggier mountains (Ripley & Bond 1966). From December to
February the species was common in almost all bushy areas on the island up to
1,100 m (Ogilvie-Grant & Forbes 1903).
HABITAT
The species was found in three habitat types: (1) Dense tamarisk Tamarix with
dwarf halophytic vegetation on coastal sand-dunes, at two sites on the southern
coastal plain (Hakari wells and 2 km west of Ras Diblih) and just west of Fikhah
on the north coast where tamarisk thickets and associated Croton
socotranus/Jatropha unicostata shrubland is sustained by a freshwater spring
emerging from windblown dunes at the base of cliffs. (2) Lowland hill slopes
(near Rizeleh) and the sides of wadis at Wadi Ayhaft, near Shibrhoh and Wadi
Shidahah supporting moderately dense cover. (3) Higher mountain slopes (e.g.
on Jabal Jaaf at up to 800 m) in patchy climax woodland interspersed with dense
low shrub cover. Balfour encountered the species on high grassy plains
(Ogilvie-Grant & Forbes 1903).
BREEDING
No evidence of breeding was observed in April. Ripley & Bond (1966) do not
refer to breeding during the period March to June but Ogilvie-Grant & Forbes
(1903) found a pair with three young on 7 January. At the end of January they
observed many birds with nesting material and females about to lay eggs
(deduced from collected birds). On 12 February they found a nest: a dome-
shaped structure with a side entrance constructed from grass and lichen and
situated in a bush one metre above the ground.
143
J. N. Dymond | Sandgrouse 17
ACTIVITY
Unobtrusive, favouring lower levels in scrub but-not shy, responding well to
‘pishing’. Two were seen to make flights for distances of up to 200 m at a height
of 1.5-2 m. It is unclear whether such activity was related to a territorial
dispute, courtship or some other purpose. Foraging on the ground was
observed, individuals often carrying the tail slightly raised at such times.
CONSERVATION AND INFLUENCE OF MAN
The Socotra Warbler, although endemic to Socotra, is not considered
endangered. While it was not possible to conduct an accurate assessment of the
population during the brief survey period, the species is widespread in suitable
habitat, perhaps suggesting a total population exceeding 5,000 individuals.
Although pressures from grazing and wood-cutting for firewood may be
locally intense, such activities do not appear to effect the habitats typically used
by this species.
REFERENCES
OGILVIE-GRANT, W. R. AND ForBES, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In
ForBES, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
RIPLEY, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri. Smithsonian
Misc. Coll. 151, 1-37.
SIBLEY, C. G. AND MONROE, B. L. JR. (1990) Distribution and Taxonomy of Birds of the World.
Yale University Press, New Haven.
]. N. Dymond, Burgadies, South Punds, Levenwick, Shetland ZE2 9HX, UK.
144
Sandgrouse (1996) 17: 145-147
The Socotra Cisticola Cisticola haesitata
J. N. DYMOND AanpD R. F. PORTER
ormerly considered to be an endemic sub-species of Fan-tailed Warbler
(Zitting Cisticola) Cisticola juncidis by Ripley & Bond (1966), the Socotra
Cisticola C. haesitata is treated by Sibley & Monroe (1990) as a full species - as
indeed it was by Ogilvie-Grant & Forbes (1903). Forbes-Watson found the
species in only two localities during his expedition in 1964 (Ripley & Bond 1996),
one close to sea-level and the other at an altitude of 870 m, and there were
apparently no further observations until those by the OSME survey of spring
1993, the results of which are presented here.
DESCRIPTION
Socotran birds differ from populations of juncidis chiefly in the distinct greyish
cast to the upperparts, notably the crown, nape, mantle and scapulars, which
contrast with the distinctly rufous uppertail and uppertail-coverts. The fringes
to the secondaries are pale grey rather than buff, as in juncidis. The supercilium
of haesitata is perhaps less prominent and greyer (reducing the impression of the
‘pare-faced' appearance typical of juncidis) and the sides of the face lack the
warm buffy tones of juncidis. The tail pattern and colouration, and entire
colouration of the underparts show no obvious differences from juncidis.
Soft Parts (from Ripley & Bond 1966): iris tawny; bill blackish with cutting edge
of upper and lower mandible yellowish to pale yellowish-horn; feet pale flesh.
Males have inside of mouth bluish-black while in females this is flesh-coloured.
Measurements No birds were trapped, but Ripley & Bond (1966) give
measurements for six birds caught in 1964: five males had a wing length of 45-50
mm (mean 47.6) and a female a wing length of 43 mm; weight 6-8 g. The species
had the same wing-formula as juncidis.
VOICE
The characteristic song consists of an emphatic, loud ‘chip’ or 'chit' repeated
monotonously during undulating display-flights over the breeding territory, but
sometimes given from a prominent perch on a bush. The notes become shorter
and quicker as the song progresses, a fact also noted by Ogilvie-Grant & Forbes
(1903). Some observers thought this note was slightly different from that of
juncidis, being likened to two stones being clicked together, and this was borne
out when a recording made near Socotra airport was compared with a recording
made by K. Mild at Jericho, Palestine. The individual notes of the Socotra bird
-are shorter and harsher, more metallic or drier, and the pause between notes is
shorter. However, recordings of juncidis in various parts of its range show that
the frequency of notes can vary (Cramp 1992).
145
J. N. Dymond and R. F. Porter | Sandgrouse 17
Another note, possibly an alarm call, delivered when perched before or after
song-flight, was transcribed as ‘phut'. It has a spitting or spluttering quality and
is audible at close range only. Forbes-Watson also mentions a quiet and
subdued 'tititi...', uttered after alighting or at the end of a song delivered from a
bush. (Ripley & Bond 1966).
STATUS AND DISTRIBUTION
Survey records of 1993 and those of Ogilvie-Grant & Forbes (1903) and Forbes-
Watson in 1964 (Ripley & Bond 1966) do not suggest that the species is
widespread. The survey found it fairly common at three sites: Ras Diblih,
Hakari wells and the dunes west of the airport. Large areas of the island,
including much coastal habitat, have never been visited by ornithologists and
may be suitable for the species. However, in several apparently suitable areas it
seemed to be absent, notably the coastal halophytic scrub near Ras Momi where
the Socotra Warbler Incana incana was a common - indeed the only -— bird
species. It is possible that the distributions of the cisticola and warbler are
mutually exclusive, though, if so, the reasons are not clear.
Forbes-Watson found an unspecified number of birds in light scrub below the
foothills of Ras Hebak, some 2 km west of Hadibu, and he also found a family
group of two adults and three juveniles on an upland meadow near Adho
Dimellus, at an altitude of 870 m, on 16 and 17 April 1964. Our survey recorded
the species on three dates at three sites: 11 birds were seen at Hakari wells on
the southern coastal plain, 3 April, 10 were seen at Ras Diblih on the southern
coastal plain, 4 April, and 15 were found on the northern coastal plain just west
of Socotra airport, 6 April. At these localities it was the commonest passerine.
Ogilvie-Grant & Forbes (1903) found Socotra Cisticola only on the southern
part of the Hadibu plain between the Hanetu river and base of the Haggier
mountains.
HABITAT
All the survey observations were made in similar habitats: low sandy dunes and
flats with sparse, dwarf halophytic vegetation and scattered tamarisk Tamarix
sp., mostly on the dune hummocks. All sites were less than 5 m above sea-level.
Forbes-Watson (Ripley & Bond 1966) described the habitat of his upland
observation as ‘short grass meadow with clumps and scattered bushes, with a
stream flowing through’, and mentioned that the birds also 'foraged over the
edge of this plateau where the bush was thicker’. Ogilvie-Grant & Forbes (1903)
found the species on stony ground covered with thick, bush-like grass 60 cm
high, interspersed with larger bushes.
BREEDING
No evidence of breeding, other than song-flight, was observed during the
survey but, as noted above, Forbes-Watson found a family group of two adults
146
Sandgrouse 17 The Socotra Cisticola
and three juveniles; 16-17 April 1964. Ogilvie-Grant & Forbes (1903) found no
evidence of breeding in December and January.
ACTIVITY
At all sites where the species occurred it was readily encountered, even at mid-
day, undertaking active song-flights and singing from exposed perches. This
bird was very similar in its behaviour to C. juncidis. Forbes-Watson (Ripley &
Bond 1966) noted foraging in bushes, but at a lower level than Socotra Warbler
and thought it doubtful that the two species compete.
CONSERVATION AND THE INFLUENCE OF MAN
With a total of some 36 birds at three sites the survey helped to establish the
cisticola as a species threatened on a global scale, with a status classified as
vulnerable (IUCN Category D). This is afforded to those species that have a
world population of fewer than 1,000 mature individuals (Collar et al. 1994).
Even though many potential sites for the species were not visited, it is our best
judgement that the population would satisfy this criterion. Two other Socotran
species, the Socotra Starling and Socotra Bunting, also fall into this category.
The most urgent conservation requirement is a full survey of all coastal and
lowland habitats to establish the full range (and population) of the species.
These habitats are likely to be the most threatened if developments, including
those to support tourism, start to take place on the island. It is essential that
such developments avoid areas where this globally threatened bird occurs.
REFERENCES
COLLAR, N. J., CRosBy, M. J. AND STATTERSFIELD, A. J. (1994) Birds to Watch 2: The World List of
Threatened Birds. BirdLife Conservation Series No. 4, BirdLife International,
Cambridge.
CRAMP, S. (ed.) (1992) The Birds of the Western Palearctic Vol. 6. Oxford University Press.
OGILVIE-GRANT, W. R. AND Fores, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In
Forbes, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
RIPLEY, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri. Smithsonian
Misc. Coll. 151, No. 7.
SIBLEY, C. G. AND MONROE, B. L. (1990) Distribution and Taxonomy of Birds of the World. Yale
University Press, New Haven.
J]. N. Dymond, Burgadies, South Punds, Levenwick, Shetland ZE2 9HX, UK.
R. F. Porter, BirdLife International, Wellbrook Court, Girton Road, Cambridge
CB3 ONA, UK.
147
Sandgrouse (1996) 17: 148-150
The Socotra Sunbird Nectarinia balfouri
D. A. SHOWLER AnpD PETER DAVIDSON
he Socotra Sunbird Nectarinia balfouri, previously Cyanomitra balfouri (Sclater
and Hartlaub 1881) is endemic to Socotra. It is the most common of the
endemic bird species, being widely distributed from sea-level to at least 1,370m
(Ripley & Bond 1966). It is found in areas with a scattering of trees and bushes,
but is most abundant in areas of more substantial vegetation. It is unusual but
not unique amongst the Nectariniidae in that it exhibits no obvious sexual
dimorphism. The observations made by the OSME survey of spring 1993 are
presented here.
DESCRIPTION
The sexes are similar and usually inseparable in the field, except on occasions
when males are singing and displaying their yellow pectoral-tufts. A relatively
large, deep-chested, robust sunbird, with a stout bill and thick legs. An adult
near a nest is shown in Plates 28 and 29.
Plumage: crown dull brown (perhaps somewhat darker in presumed male)
streaked greyish-white, extending through nape onto mantle. Ear-coverts
darker than crown, streaked greyish-white. Lores sooty black, with this
colouration extending around eye. Thin greyish-white supercilium extending
behind eye to rear of ear-coverts. Narrow sooty black moustachial and striking
white sub-moustachial stripe broadening markedly towards cheeks. Sooty black
malar stripe bordering dark grey, somewhat mottled throat. Sooty biack centres
to upper-breast feathers broadly fringed white, creating a scaly pattern recalling
Cyprus Warbler Sylvia melanothorax. Rear-flanks pale greyish-brown. Belly and
undertail-coverts white. Mantle brown to grey-brown. Coverts dull brown
with paler, greyer tips to lesser and median coverts, fringes to greater coverts
greyish-tan. Tertials dark grey-brown, fringed pale grey-brown. Secondaries
dull brown with pale greyish-white fringes, some with an olive sheen, forming
pale wing-panel. Primaries dark brown; primary-projection beyond tips of
tertials, very short. Tail notched, blackish-brown with pale tips to two outer-
feathers and white webs to outer tail-feathers.
Soft parts: iris reddish-brown. Bill black, moderately decurved and thick-based
around nostrils. Legs and feet black. Juvenile similar to adult but iris brown
(not reddish-brown), lower mandible pale yellowish. Feet dark grey with pale
soles (Ripley & Bond 1966).
Measurements: Biometric data from one adult netted on Jabal Jaaf, 4 April 1993
is as follows: (lengths are in mm, weight in grammes):
148
Sandgrouse 17 The Socotra Sunbird
Wing Tail Max.tarsus Billtofeathers Billandhead Weight
59.0 45.0 21:5 19.1 36.5 10.5
VOICE
The frequently delivered call note is a squeaky, strident 'zii' or 'zee'. An
apparent alarm or territorial dispute call is a repeated harsh, grating 'tchee-up'
or 'tchee'. The song, which may either be delivered in short bursts or be of a
longer duration, is usually delivered from a prominent perch. It comprises a
series of quick jangling notes fairly typical of sunbirds. The Socotra Sunbird has
also been noted by Ogilvie-Grant & Forbes (1903) to mimic the calls of other
birds, especially that of Socotra Warbler Incana incana.
STATUS AND DISTRIBUTION
Common and widespread in most areas with scattered trees. Not present on the
bare limestone plateaux (Ripley & Bond 1966) and probably absent from the
sparsely vegetated southern Noged plain. Occurs from sea-level up to at least
1,370m (Ripley & Bond 1966).
HABITAT
This species is most abundant in densely wooded areas, e.g. Wadi Ayhaft, where
the dominant tree species include Rhus thyrsiflora, Buxus hildebrandtii, Carphalea
obovata and Sterculia spp. (A. Miller pers. comm.) It is also common on more
open, sparsely wooded rocky hillsides where Adenium obesum socotranum and
Euphorbia arbuscula trees are often present. In some montane areas it occurs in
box scrub.
FOOD
From stomach contents of collected birds and field observations by Forbes-
Watson (Ripley & Bond 1966) it was noted that the diet consists predominantly
of arthropods, mainly insects but also small spiders. Vegetable material is
apparently also an important constituent of the diet and includes small fruit and
seeds. Forbes-Watson also recorded an immature bird feeding on fruit from a
Euphorbia bush, but did not see any visiting flowers. During the survey an
observation of apparent nectar feeding was made, one bird visiting the flowers
of Calotropis procera. Given the other information available, nectar is perhaps a
less important constituent of the diet than might be expected, but this remains
speculative and further information is needed.
BREEDING
Eggs undescribed. Nesting probably occurs from January to May and perhaps
beyond.
149
D. A. Showler and Peter Davidson Sandgrouse 17
A nest examined, 30 March 1993 at Ras Hebak, was sited at a height of .
approximately 2.5 m in a Euphorbia arbuscula tree, on a rocky hillslope at 100 m
altitude. This nest contained three pulli approximately four days old. Two
juveniles were observed on the Hamadiroh plateau, 31 March, indicating that
eggs had been laid at the beginning of March, perhaps earlier. Ogilvie-Grant &
Forbes (1903) observed a family party, including two or three well-grown
fledged young, 5 February, indicating a laying date in early January. Ogilvie-
Grant & Forbes found a used nest from which the young had flown, 10
February. Forbes-Watson in 1964 (Ripley & Bond 1966) found a nest with young
as late as 1 May.
The nest is dome-shaped, about 8cm high and 6cm wide, with a large oval
entrance, usually concealed in the stems or branches of a tree. The entrance is 4-
6 cm high and 2-4 cm wide. The nest is constructed from fine, loosely woven
grasses and cobwebs, which is extensively lined with woolly white plant
material and possibly goat hair.
During 11/: hours of observation at the nest, 30 March, five nest visits were
noted. Adults were seen removing faecal sacs on two occasions. Both birds
frequented an area within a radius of about 80 m from the nest. Calling was
frequent, the male occasionally singing.
ACTIVITY
Most commonly seen singly or in pairs. Noisy territorial chases observed.
Often actively foraged for food in trees and shrubs.
CONSERVATION AND INFLUENCE OF MAN
Overgrazing and browsing by introduced livestock may have diminished the
extent of primary habitat available to this species, which is most common in
more wooded localities. However, it persists in areas with fairly sparse
vegetation, so there would appear to be no immediate threat to the species.
REFERENCES
OGILVIE-GRANT, W. R. AND ForBES, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In
FORBES, H. O. The natural history of Sokotra and 'Abd al-Kuri. Porter, London.
RIPLEY, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri. Smithsonian
Misc. Coll. 151, No. 7.
SCLATER, P. L. AND HARTLAUB, G. (1881) On the birds collected in Socotra by Prof. I. B.
Balfour. Proc. Zool. Soc. London: 165-175.
D. A. Showler, clo OSME, The Lodge, Sandy, Bedfordshire SG19 2DL, UK.
Peter Davidson, clo OSME, The Lodge, Sandy, Bedfordshire SG19 2DL, UK.
150
Sandgrouse (1996) 17: 151-154
The Socotra Starling Onychognathus frater
and Somali Starling O. blythi1
R. F. PORTER AND R. P. MARTINS
wo resident species of starling occur on Socotra, the endemic Socotra
Starling Onychognathus frater (also called Socotra Chestnut-winged Starling)
and the Somali Starling Onychognathus blythti (also called Somali Chestnut-
winged or Brown-winged Starling), which also occurs in northern Somalia,
northern Ethiopia and Eritrea (Dowset & Forbes-Watson 1993; Hall & Moreau
1970). The Socotra Starling is local and uncommon and is, from a conservation
perspective, most appropriately classified as 'vulnerable', while the Somali
Starling is common and widespread throughout the island.
Ripley & Bond (1966) suggest that as Socotra Starling is endemic to the island,
it evolved from a common ancestor that arrived from the African mainland a
considerable time before Somali Starling. During this time-period biological
mechanisms would have developed in the pioneer species to prevent random
mating with Somali Starling, when it colonised the island.
The observations of the OSME survey of spring 1993 are presented here.
DESCRIPTION
Both species are large with fairly broad wings. Structurally, their relatively long
necks, slim bodies and long tails combine to produce a rather attenuated
appearance. The plumage of both species is predominantly glossy and
iridescent blue-black, excepting pale chestnut, or dull orange primaries which
are conspicuous in flight. The two species are illustrated in Plates 33 and 34.
Socotra Starling
Sexes alike. The smaller species, contrasting with its congener in having a much
shorter, square-ended tail (although corners sometimes slightly rounded) and a
longer, thinner bill with culmen slightly down-curved at the tip.
Plumage: blue-black with iridescent bottle-green sheen to head, mantle and
wing-coverts, although in certain light conditions shows a sooty-brown cast to
entire plumage. Predominantly chestnut primaries not usually visible in closed
wing. Juvenile similar.to adult but with slightly shorter tail, greyish-black bill
and duller primaries.
Soft parts: bill, legs and feet black; irides dark brown with a reddish tone.
Somali Starling
Sexes differ. Slightly larger than Socotra Starling with longer, narrower-based
and markedly graduated tail and shorter, stouter bill-shape, recalling Magpie
Pica pica.
151
R. F. Porter and R. P. Martins : _ Sandgrouse 17
Plumage: iridescent blue-black plumage of male similar to Socotra Starling,
although more glossy. The chestnut in primaries also extends onto outer
secondaries and is always visible as a thin panel on the closed wing (unlike in
Socotra Starling). No difference between the two species in the richness, tone or
extent of chestnut in the spread primaries was detectable in the field, but in
skins the Socotra Starling is slightly darker. Adult female differs from male in
uniform light grey head, chin, throat and upper-breast, forming a sharply
defined pectoral band. At close range shows a diffuse whitish ring around eye. ©
Juveniles noticeably shorter-tailed and sooty brown (but with dull orange
primaries). In 'young' females the head and neck is black as in the males.
(Ogilvie-Grant & Forbes 1903).
Soft parts: bill, legs and feet black; salon of irides not precisely noted but
appeared dark.
Measurements: Neither species was trapped, but the following measurements of
birds caught in 1964 by Forbes-Watson are presented in Ripley & Bond (1966).
All measurements are in millimetres.
Socotra Starling (weight 100 g)
Culmen from
Wing Tail feathers
Male Range 157-163 139-146 28-32
(N=7) Mean 15955 141.8 29:2
Female Range 148-156 127-136 27-29
(N=9) Mean 151c5 131.2 27.8
Somali Starling (weight 100 g)
Culmen from
Wing Tail feathers
Male Range 165-175 172-190 23-25
(N=10) Mean T7AeC 177.0 24.3
Female Range 155-164 155-169 22-24
(N=7) Mean 1592 163.2 22.6
VOICE
Both species are very vocal, the calls of Socotra Starling tending to be louder. At
times Somali Starling was exceptionally vocal, especially when flying in flocks.
Socotra Starling: the most frequent call was a pure, far-carrying whistle ‘tyooo’
(or ‘pseeeoo’ or ‘psoo’) recalling the calls of Golden Plover Pluvialis apricaria or
Bullfinch Pyrrhula pyrrhula to the ears of some observers. A harsh ‘scraich’
alarm note was also heard.
152
Sandgrouse 17 The Socotra Starling & Somali Starling
Somali Starling: the most frequent call, often delivered in flight, was a musical
high-pitched ‘tleep’ (or ‘chuit’). Other calls included a soft ‘chee-wee’ or ‘chwee’
and a harsh alarm note similar to that of Socotra Starling. Oglivie-Grant &
Forbes (1903) transcribe the call note as ‘chee-chee-chee-che-whoup’.
STATUS AND DISTRIBUTION
Both species appear widespread and resident on Socotra, occurring up to 1,100 m
with Somali Starling, the more common (by 13:1 from survey observations).
HABITAT
Both species occur throughout the island, usually where trees are present,
though these may only be isolated groups on otherwise open plains or rocky
hillsides. Trees are apparently more important for Socotra Starling, which was
most common in the wooded habitats at Wadi Ayhaft. However, the species
was also seen in gardens in the town of Hadibu. The presence of water did not
appear to influence the distribution of either species. |
FOOD
Socotra Starling was seen feeding on Zizyphus berries, the fruit of a Ficus sp.,
small red berries probably from a Dragon's Blood Tree Dracaena cinnabari (also
fed to accompanying juveniles) and the white pea-like seeds from an uniden-
tified legume which were obtained by splitting pods open. A pair feeding
actively on Ficus consumed two fruits per minute during a five minute period.
Forbes-Watson observed the species feeding on insects, and grasshoppers have
been found in stomach contents (Ripley & Bond 1966).
Somali Starling was seen feeding on fruit-bearing trees. Ogilvie-Grant &
Forbes (1903) recorded the species feeding on a variety of fruits, especially figs
and the berry of Dragon's Blood Tree, grasshoppers and other insects. Beetles
and large black seeds have been recorded in stomach contents (Ripley & Bond
1966). Unlike Socotra Starling, the species often appears remarkably closely
associated with cattle, often foraging on them, presumably for ticks or other
parasites. The highly mobile and flocking habits of the species and the
frequency of its occurrence in areas lacking substantial cover perhaps suggest
greater adaptability to man-managed environments.
The foraging behaviour of Socotra Starling is methodical, recalling the
behaviour of a thrush Turdus sp. Birds in groups of up to five individuals were
observed feeding within the canopy (or leaf-cover) of trees for up to 20 minutes.
BREEDING
In the first week of April 1993 many Socotra Starlings were feeding fledglings or
recently-fledged young. Several nests were located in natural cavities in the roof
and walls of a limestone cave at 550 m on rocky slopes above the Hamadiroh
plateau. Nests, which were only partially visible, were untidy, recalling those of
Starling Sturnus vulgaris in construction, containing much grass and small sticks.
153
R. F. Porter and R. P. Martins _ Sandgrouse 17
Two pairs were giving alarm calls. These observations suggest that the species
may be a colonial breeder. No evidence of breeding of Somali Starling was
recorded in April, and Forbes-Watson did not mention nesting activity in spring
1964 (Ripley & Bond 1966). Furthermore, Ogilvie-Grant & Forbes (1903) suggest
the breeding season was over by December. The breeding season of the two
starlings would therefore seem to be quite separate.
ACTIVITY
Both species were encountered in pairs and small groups, Somali Starling not
infrequently in flocks of at least 20 individuals. The flight of this species often
appeared buoyant and masterful, but is also direct and undulating when
covering substantial distances: brief bursts of wing-beats are interspersed by
long glides and occasional abrupt changes in direction.
The Socotra Starling is shyer, more closely associated with trees and seldom
forages on the ground, a fact also noted by Forbes-Watson (Ripley & Bond 1966);
but Ogilvie-Grant & Forbes (1903) found the Socotra Starling to be the tamer
species. No evidence of competition between the two species was observed.
CONSERVATION AND INFLUENCE BY MAN
The endemic Socotra Starling merits the category ‘vulnerable’ when considering
its world status. This category is applied to those species where less than 1,000
mature individuals exist (Collar et al. 1994). During the survey, 41 individuals
were counted, including an unknown number of juveniles. Though many
potential sites where the species could occur were not visited, the judgement
made during the survey was that the population satisfies this criterion. There is
apparently no threat to nesting sites, but woodland with fruit-bearing trees must
be preserved for the population to persist. Conversely, the Somali Starling is a
common species which has undoubtedly benefited from pastoralism.
REFERENCES
COLLAR, N. J., CRosBy, M. J. AND STATTERSFIELD, A. J. (1994) Birds to Watch 2: The World List of
Threatened Birds. BirdLife Conservation Series No. 4. BirdLife International, Cambridge.
DOowsETT, R. J. AND FORBES-WATSON, A. D. (1993) Checklist of the Birds of the Afro-tropical and
Malagasy Regions. Tauraco Press. Liege, Belgium.
HALL, B. P. AND MoREAU, R. E. (1970) An Atlas of Speciation in African Passerine Birds. British
Museum (Nat Hist), London.
OGILVIE-GRANT, W. R. AND Forses, H. O. (1903) Birds of Sokotra and 'Abd al-Kuri. In
ForBES, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
RIPLEY, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri. Smithsonion
Misc. Coll. 151, No.7.
R. F. Porter, BirdLife International, Wellbrook Court, Girton Road, Cambridge
CB3 ONA, UK.
R. P. Martins, 6 Connaught Road, Norwich, Norfolk NR2 3BP, UK.
154
Sandgrouse (1996) 17: 155-157
The Socotra Bunting Emberiza socotrana
K. M. MORTON
he Socotra Bunting Emberiza socotrana is one of two resident bunting species
on Socotra (the other being African Rock Bunting E. tahapisi of the supposed
endemic sub-species insularis). The 1993 OSME survey (30 March to 6 April)
recorded only two individuals at one site, indicating that this is apparently the
rarest Socotran endemic. The survey observations are presented here.
DESCRIPTION
The following description relates to the species in general but is substantially
informed by a female seen by all observers. The bird is shown in Plate 35.
Sexes similar, although females are generally duller, as are first-year birds
(Byers et. al. 1995). A small bunting with markedly pale underparts, brown
upperparts with uniform rich russet coverts (i.e. lacking the pale fringes typical
of many Emberiza species) and a complex black-and-white head pattern. Size,
shape and structure recall Rustic Bunting E. rustica, while general plumage
pattern most closely resembles Cape Bunting E. capensis, which is extensively
distributed through (mainly southern) Africa.
Head: very thin almost white central crown-stripe, often indistinct, originating
on the crown or forehead and extending to junction of crown and nape. Broad
white supercilium, broadening substantially behind eye, extending down side of
nape behind ear-coverts; distinct black eye-stripe broadening behind the eye
and curving down behind ear-coverts; black moustachial and white sub-
moustachial stripe bordering lower edge of ear-coverts, the former meeting eye-
stripe and thus forming part of a complete black surround to ear-coverts; thin
black malar-stripe broadening slightly at sides of throat; ear-coverts brownish
buff.
Upperparts: mantle and scapulars warm brown with moderately distinct darker
brown streaking on mantle; lower mantle and uppertail-coverts greyer, merging
with extensive unstreaked whitish upper rump and lower mantle/back
(prominent in flight). Lesser, median and greater coverts uniform rich chestnut
brown, excepting paler, greyish fringes and blackish subterminal spots on three
innermost greater coverts; alula dark and distinct; secondaries dark brown with
pale fringes to outer webs; primaries dark brown to black with thin pale tips;
four primary tips visible in primary projection; tertials brownish black with
broad fulvous fringes; tail dark brown to black with pale fringes to entire length
_of feathers, but lacking white outer webs to the outer pairs of tail feathers typical
of many Emberiza species.
155
K. M. Morton 7 | Sandgrouse 17
Underparts: chin, throat and upper breast creamy buff with pinkish or rufous
wash extending across upper breast as indistinct streaking; rest of underparts
uniform creamy white.
Soft parts: legs and feet pale flesh; upper mandible dark, lower mandible
yellowish-buff with blackish tip. Irides brown; indistinct whitish orbital ring.
VOICE
No vocalisations were heard during the survey. Forbes-Watson noted the call as a
high thin whistle (sometimes repeated two or three times) followed by a soft gurgle.
This he expressed as 'tseep.......guruguruguru' (Ripley & Bond 1966). Ogilvie-
Grant and Forbes (1903) described the song as a ringing and metallic whistled
‘hue-he, hu-hey', recalling Golden-winged Grosbeak Rhynchostruthus socotranus.
STATUS AND DISTRIBUTION
Endemic to Socotra. In 1964 Forbes-Watson found the species to be less
common than E. tahapisi. He also noted a preference for higher altitudes than
those typically frequented by tahapisi, a factor which perhaps limits the species
distribution. However, Forbes-Watson also recorded non-breeding flocks at low
altitudes. The survey encountered only two individuals at a single site,
although coverage of high altitude locations was rather limited.
HABITAT
The two individuals observed frequented a grassy boulder-strewn plateau with
scattered patches of low shrubs at about 500 metres. The birds were loosely
associated with a small flock of E. tahapisi. Forbes-Watson, comparing the
habitat of socotrana with that typically frequented by tahapisi, recorded that the
species preferred open hillsides, whereas tahapisi favoured rocky gullies and dry
water-courses. He found socotrana feeding within ‘thickets’ but did not observe
such behaviour in tahapisi. Forbes-Watson did not record socotrana and tahapisi
together at any time during 15 weeks.
FOOD
Forbes-Watson noted the stomach contents of 17 birds collected in 1964 as small
seeds and grit.
BREEDING
No breeding activity was observed. Forbes-Watson did not record any
information on breeding when on Socotra from early March to mid-June. This
period is apparently late in, or after, the breeding season, as Forbes heard birds
singing on 6th and 15th February (and before the first date). There is no other
information on the breeding biology of this species and the nest and eggs remain
undescribed.
156
Sandgrouse 17 The Socotra Bunting
ACTIVITY
Forbes-Watson recorded that the species perches more readily than tahapisi, is
more approachable and less prone to long escape flights when flushed.
CONSERVATION AND INFLUENCE OF MAN
With only two birds recorded, the very limited survey observations concur with
the view that this is a threatened species with a vulnerable status (IUCN
Category D). This status is defined by the existence of less than 1,000 mature
individuals (Collar et. al. 1994). Although many areas potentially suitable for the
species were not visited, it seems likely that it satisfies this criterion. Further
work is needed to establish a full understanding of the distribution and
population of this species.
ACKNOWLEDGEMENTS
I would like to express my thanks to Guy Kirwan and Rod Martins for helpful comments
on the description and for information contained in Byers et al. (1995) when still in press.
REFERENCES
RIpLey, S. D. AND BOND, G. M. (1966) The Birds of Socotra and Abd-el-Kuri Smithsonian
Misc. Coll. 151, No. 7.
COLLAR, N. J., CrosBy, M. J. AND STATTERSFIELD, A. J. (1994) Birds to Watch 2: The World List
of Threatened Birds. BirdLife Conservation Series No. 4. BirdLife International,
Cambridge.
OGILVIE-GRANT, W. R. AND ForsES, H. O. (1903) Birds of Sokotra and ‘Abd al-Kuri. In
FORBES, H. O. The natural history of Sokotra and ‘Abd al-Kuri. Porter, London.
BYERS, C., OLSSON, U. AND CURSON, J. (1995) Buntings and Sparrows: a guide to the buntings
and North American sparrows. Pica Press, East Sussex.
K. M. Morton, 31 Braehead Avenue, Edinburgh EM4 6QN, UK.
157
Sandgrouse (1996) 17: 158-164
Biometric data of birds in southern Yemen —
and Socotra, spring 1993
J. N. DYMOND
|B ie the OSME survey of southern Yemen and Socotra in spring 1993, mist
netting was undertaken on 12 dates at six sites in southern Yemen and three
sites on Socotra. Biometric data were collected for 114 individuals of 30 species.
The purpose of this paper is to present this data. Biometric data for an
additional six species are presented in separate papers in this issue of
Sandgrouse.
In the following tables EURING age codes are used as follows : 3 = hatched
during year of capture (i.e. 1993); 4 = hatched before year of capture but exact
year unknown; 5 = hatched during previous calendar year (i.e. 1992). All
measurements are given in millimetres or grammes. Fat scores on a 0-5 scale
are given for migrant passerines; 'n/r' denotes ‘not recorded’ and * indicates
suspended moult. Primaries are numbered ascendantly.
Common Sandpiper Actitis hypoleucos
One first-winter bird west of Fikhah (north coast of Socotra), 2 April.
Age Wing Weight
5 117.0 65.5
Laughing Dove Streptopelia senegalensis
Two individuals of the small, endemic sub-species socotrae at Wadi Ayhaft
(Socotra), 5 April. One of nominate senegalensis at Wadi Mararah (extreme
eastern Yemen), 28 April.
Primary moult
Age Sex Wing Weight score
socotrae 4 2 126.0 66.5 29
socotrae 4 2 128.0 67.0 44.
senegalensis 4 ? 141.0 91.8 ny i
African Scops Owl Otus senegalensis
One at Wadi Habban (Yemen), 27 March.
Bill to
base of Max. ?
Age Sex Wing culmen tarsus Tail Weight
4 fem? 141.0 16.1 34.7 — 63.5 63.5
Primaries ist’ * 2nd’ “3rd; 4th. Sth oth: 7th eth
-23 -4 L L =5 13 -19°5 --27:5
Slight emargination was present on 2nd, 3rd and 4th primaries.
158
Sandgrouse 17 Biometric data of birds in southern Yemen and Socotra
Plain Nightjar Caprimulgus inornatus
One at Jabal Iraf (Yemen), 22 March. See Dymond (1996).
Forbes-Watson's Swift Apus berliozi
One at Jabal Jaaf (Socotra), 3 April. See Porter, et al. (1996).
Yellow-vented Bulbul Pycnonotus xanthopygos
Eighteen at three sites in Yemen: Jabal Iraf, 22 March, Wadi Himarah, 8 April
and Wadi Mararah, 28, 29 April.
Age Wing Weight Primary moult score
4(all) 88-100 (mean 93.4) =. 28.9-35.8 (mean 32.2) 0 (all)
Wing measurements match those given in Cramp (1988), but weights are
markedly lower than a series from Israel, 35-46 (mean 44, sample 56).
Black Bush Robin Cercotrichas podobe
One at Wadi al Khabt (Yemen), 24 March and one at Wadi Himarah (Yemen), 8
April. Arabian breeders are sub-species melanoptera.
Primary
Head = Max. moult Brood
Age Sex Wing +bill tarsus Tail Weight score patch
L 2 89.0 39.4 30.7 104.0 220 0 full
a ? 89.0 38.9 30.7. 104.5 22.) 0 full
Blackstart Cercomela melanura
Two at Wadi Mararah (Yemen), 28 April.
Primary
Head = Max. moult Brood
Age Sex Wing +bill tarsus Tail Weight —— score patch
4 male 82.0 36.1 27:14. 60.5 17.0 0 none
4 fem» 76.0 o7a1 24.6 54.0 15:1 0 full
Sexed in the hand by cloacal examination: Cramp (1988) gives wing lengths of
81-86 for males and 76-82 for females.
Little Rock Thrush Monticola rufocinerea
Three at Jabal Iraf (Yemen), 22 March. Arabian breeders are sub-species sclateri.
Primary
3 Head Max. moult Brood
Age Sex Wing +bill tarsus Tail Weight score patch
4 2 85.0 43.2 28,2: , 59.0 25.0 0 none
4 ¢ 84.0 42.7 29.0 60.5 25.0 (0 small
a ? 85.0 41.5 28.2 58.0 24.4 0 small
159
J. N. Dymond Sandgrouse 17
Graceful Prinia Prinia gracilis
One at Wadi Himarah (Yemen), 8 April.
Primary
Head = Max. moult Brood
Age Sex Wing +bill tarsus Tail Weight score’ patch
a 2 47.0 26.8 1977 260.5 6.8 0 n/r
Arabian Warbler Sylvia leucomelaena
One at Wadi Habban (Yemen), 27 March.
Primary
Head Max. | moult Brood
Age Sex Wing +bill tarsus Tail Weight score patch
4 male 71.0 35.7 244 69.5 14.3 0 slight
Barred Warbler Sylvia nisoria
One at Wadi Himarah (Yemen), 8 April.
Primary
Head = =Max. - moult Brood
Age Sex Wing +bill tarsus Tail Weight score patch
& ? 91.0 37.5 QT OO 29:9 0 4,
With a fat score of 4 it is not surprising that this bird's weight was toward the
upper end of the range given in Cramp (1992) for March-April (21.0-34.2);
onward migration was clearly imminent.
Blackcap Sylvia atricapilla
Ten at three sites in Yemen: Jabal Iraf, 22 March, Wadi al Khabt, 24 March and
Wadi Himarah, 8 April. Weights varied from 15.4 to 21.4 g and five individuals
had fat deposits, with scores of 1, 3,3, 4 & 4.
Brown Woodland Warbler Phylloscopus umbrovirens
Five at Jabal Iraf (Yemen), 22-23 March.
Bill Primary
Head to Max. moult Brood
Age Sex Wing +bill skull tarsus Tail Weight score patch
4. 2 SOO 29:0 127655 208 40.5 6.8 0 n/r
4 ? 54.0 28.4 7520.8 44.0 8.1 0 n/r
4. ? 54:00 27.8 12s 20 43.0 es: 0 n/r
4 male 58.0 28.6 126 e216 45.0 8.1 0 n/r
4 2 54.0 28.3 123 eee 42.5 Mes) 0 n/r
The male was in full song adjacent to the net. Wing formulae (primaries
numbered ascendantly) were as follows:
160
Sandgrouse 17 Biometric data of birds in southern Yemen and Socotra
Primaries Ist 2nd 3rd 4th Sth 6th 7th 8th 9th 10th Emargination
A pe+11 -8 Bir. Ty ide) Lie A 4 5 6 3rd 6th
B peri Ze