516 G. CLARKE : BIRD NOTES FROM ADEN CDLONY IBIS 109

BIRD NOTES FROM ADEN COLONY

GORDON CLARKE

Received on 23 August 1966

INTRODUCTION From 24 April to 28 August 1961 I was able to study the birds in an area of about

240 acres at Khormaksar in Aden Colony. The area is a tidal basin, connected to the sea by Khormaksar Creek which lies to the north. Muddy sand forms the shore, which slopes gently downwards to the west to water which is little more than thigh deep. Three sewage pipes discharged into the area, of which the central and southernmost were cracked and broken, allowing the sewage to escape near the high water mark. Large numbers of birds were attracted to drink and feed at a stream running from the central pipe, around which grew coarse tufted grass, 12-18 inches high; the birds fed up to a hide placed there. The other pipes also had areas of grass about them, with a clump of salt-bush at the northernmost. The southernmost pipe produced a stream to which many " freshwater ) ) waders were drawn, and also had the largest area of grass. Unfortunately the use of the sewage pipes was discontinued at the end of August.

The importance of the ground immediately around the sewage pipes may be judged by the fact that 300-400 birds of 15-20 species were commonly seen there; whilst, on occasion during the migration period, no less than 15 species of waders were seen feeding within 54 yards of the hide at once. Of the 65 species of birds noted during the study, 54.previously known to have occurred in Aden are listed, together with a brief note of their abundance, in the Appendix; whilst the remaining nine, plus two additional species, are commented upon in the text.

Unless otherwise stated all the birds mentioned below were seen on the study area, and all are sight records with the exception of the River Warbler. Two species, the Glossy Ibis and the River Warbler, appear to be new to Aden, whilst three others, the Lesser Flamingo, Sandwich and Whiskered Terns, are recorded for the second time.

Although I was not in Aden throughout the recognized migration periods, some move- ment of Palaearctic migrants was noted. On 7 May, following a day with cloud covering over half the sky, and winds of 5-12 knots from E.N.E. to S.E., a fall of passerines occurred, including a River Warbler, four Phylloscopids, two Bed-backed Shrikes and an Isabelline Shrike followed by a Spotted Flycatcher on 10 May. On 8 July 33 Swallows moved s~uthwest, and thereafter small numbers followed in the same direction until 3 August; after this day they moved south.

The majority of wader movements were noted in August but Redshanks increased in numbers from a few to 41 on 21 July after E.N.E.-S.E. winds of 5-20 knots overnight and a sandstorm late the previous evening. Numbers rose further to 53 on 3 August, on which date four Common Sandpipers, one Wood Sandpiper, and 25 Greenshanks also appeared, though some Greenshanks and Redshanks were present in small numbers throughout the hot weather. On 2 August the cloud cover was five-eighths to seven-eighths, the wind N.N.W.-N.W. at 6-18 knots, and slight rain occurred. The following day the cloud decreased somewhat, and the wind speed rose to 34 knots. By 6 August a further increase was noted involving 30 Grey Plovers with 40 on 7 August, 25 Oystercatchers, one Green Sandpiper, eight Bar-tailed Godwits, and 36 Curlews. The numbers of Herring/Lesser Black-backed Gulls also rose at this time from the usual 150 first and second summer birds present all summer, to 200, a number which included a few subadults; whilst at least nine White-winged Black Terns also

1967 G. CLARKE : BIRD NOTES FROM ADEN COLONY 517

appeared. On 13 August eight Curlew Sandpipers, one Ruff and one Black-tailed Godwit were present. Birds continued to trickle in with four Turnstones and a Terek Sandpiper on 16 August, a Caspian Plover and a Green Sandpiper, one or two Marsh Sandpipers and two Garganey on 18 August, followed by four Ruffs on 19 August. The weather over these few days was generally fine with winds S.S.W.-W. during the mornings, and E.N.E.-E.S.E. during the afternoons, with wind speeds of 6-23 knots. On 20 August two Broad-billed Sandpipers and a Tree Pipit appeared, whilst Whimbrel increased from three to 13 on 27 August; and over 100 Mongolian Sand Plovers appeared.

The water level fell so much that only pools remained over a large area of the inlet. Fish stranded in the pools attracted numbers of birds, including 129 Pink-backed Pelicans, 24 Grey Herons, and at least 40 Reef Herons, the largest numbers of these particular species to be seen.

An extremely low tide on 5 August was of particular interest.

NOTES ON SELECTED SPECIES

PELECANUS RUFESCENS Pink-backed Pelican Two on 9 May increased to 40 by 11 May, the average number present thereafter

being 60-70. The fishing action previously described by Paige (1960, Fig. 1) was noted when shoals of small fish were present. T o expel unwanted water and rubble from the pouch when the prey is caught, the bird rotates its head, keeping the bill against the forebody (Paige 1960, Fig. l(b) ).

EGRETTA GARZETTA Little Egret The

species has now been recorded in Aden in every month except March, September, October and December. Pattering with one foot, as noted by Paige (1960), was seen.

PLEGADIS FALCINELLUS Glossy Ibis Two

very wild birds were seen from 25 May to 5 July, feeding on occasion close to the hide. The all-blackish coloration, including the bill and feet, the brownish head and neck, bottle green mantle, and long decurved bill were unmistakable. At close range the upperparts showed a plum-coloured sheen, and a bluish line of bare skin was visible from the eye to the forehead and along the base of the lower mandible. The head and neck were flecked with whitish, and the iris was dark.

PHOENICONAIAS MINOR Lesser Flamingo Ennion (1962) was apparently the first to record this species in Aden, where it is

known to a number of residents. Nine were seen on 9 May, increasing to 30-32 during June and the first half of July, 60-63 from the second week in July to 23 August, with a minimum of six on 3-5 August.

While at Aden, I spent much time observing the behaviour of the Lesser Flamingoes, a detailed account of which has been published elsewhere (Clarke 1966). The birds, which usually arrived at dawn and left at dusk, fed almost continuously throughout the day on about.one acre of sewage-flooded mudflat on which a green alga grew profusely. In contrast to the Greater Flamingo Phoenicopterus ruber, which spread widely over the inlet, they fed in a close flock.

Breeding displays are usually performed by adult birds in breeding plumage, but in this flock only grey-necked and white-necked birds participated and never four very pink, apparently mature, birds. As observed by Brown (1959), only the grey-necked birds actually built nests. I recorded six forms of display, five of which have previously been described and named for this species by Brown (1959). whose nomenclature is followed. The " Head wave ", recorded by Brown only for the Greater Flamingo,

From one on 31 May, numbers gradually increased to nine on 20 August.

This species does not appear to have been recorded previously from Aden.

Pattering was seen only once.

518 G. CLARKE : BIRD NOTES FROM ADEN COLONY IBIS 109

was also noted, although the “ Communal stomp ” and “ Head drop ” were the displays most frequently seen; ‘( Head swaying ’’ was recorded only once.

20 August was the last day on which display was seen, for within the week the use of the sewage pipes was discontinued, the numbers declined, and Major M. D. Gallagher reports that the birds moved elsewhere.

LARUS GENEI Slender-billed Gull Previously recorded only in small numbers in the cold weather months (Browne

1950, Ennion 1962). The first hot-weather records of this species in Aden appear to be a single bird present from 25 June to 20 August and six on 28-29 June. One adult, observed throughout this period, had a deformed bill in which the terminal half of the lower mandible was bent downwards at about right angles from the normal line. On 26 July I watched this bird for 40 minutes trying to feed amongst a seething shoal of small fish in very shallow water, amongst which Pink-backed Pelicans and Spoonbills were also feeding. The gull half ran, with wings extended above the back, stabbing down into the water, but owing to the distance of observation I could not say if it was successful.

Black-headed Gulls L. ridibundus fed regularly about the sewage stream, but the Slender-billed Gull visited the stream only to drink, quickly returning to the shoreline afterwards. With practice this species was easily distinguished from the Black-headed Gull by its larger size, paler colour, and longer legs, which were orange, not deep red. The head shape also appeared slightly different, the crown being flatter and not SO

“ peaked ” as in the Black-headed Gull.

LARUS RIDIBUNDUS Black-headed Gull Previous

records refer to cold weather months only, though Archer & Godman (1937) state that (( Colonel Meinertzhagen’s collector procured an immature female there (Aden) on 15 July ”, but no mention is made of this by Meinertzhagen (1954).

Some six to eight first summer birds were present during the whole period.

STERNA SANDVICENSIS Sandwich Tern There appears to be only one previous record of this species in Aden (Ennion 1962),

though Medhurst (quoted by Bailey 1966) states that it is regular on passage. A single bird in winter plumage was seen at Khormaksar Beach on 20 May, in company

with a flock of Crested Terns, amongst which it was most conspicuous owing to its small size, pale mantle, black feet, and slender black bill with yellow tip. The forehead to the centre of the crown was white, the aftercrown and nape grizzled grey-black, the ear- coverts black.

CHLIDONIAS HYBRIDA Whiskered Tern A bird in breeding dress was seen on 22 June feeding for a time with a White-winged

Black Tern. The cap and nape were black, the side of the face immediately below the cap white, gradually shading through grey to a sooty black on the abdomen. The wings and tail were light smoky grey, above the undertail white, the underwing whitish, the feet red, and the bill reddish black. It was slightly larger than the White-winged Black Tern. There is one previous record for Aden (Ennion 1962).

HALCYON LEUCOCEPHALA Grey-headed Kingfisher A single bird was seen on 10 May, when passerine movement was recorded.

Meinertzhagen (1954) states that this species is resident in southwest Arabia, but the occurrence of this bird (the only one seen) at this time suggests that it may be partly migratory, as also indicated by recorded occurrences at sea off Arabia.

1967 G. CLARKE : BIRD NOTES FROM ADEN COLONY 519

LOCUSTELLA FLUVIATILIS River Warbler Apparently the first to be recorded in Aden, a single bird was seen to kill itself by

flying into a wall at Khormaksar on 8 May. Details of the specimen, which was extremely fat, are listed below.

No emargination, 1st primary nearly 2 mm. shorter than the primary averts , 2nd primary longest, 3rd primary 3 mm. shorter than 2nd, 4th 7 mm. shorter than 2nd. Tail 57 mm., undertail coverts 12 mm. shorter than tail.

Wing 77-78 mm.

The skin was not preserved.

CORWS SPLENDENS House Crow Meinertzhagen (1954) recorded that “ only a few pairs remain ”, but it is now a

common bird about human habitations, and was noted throughout the period. (It has also spread to Djibouti, French Somaliland (150 miles S.W.), where several birds were seen in May 1958.)

ACKNOWLEDGMENTS I wish to record my thanks to the Senior Meteorological Officer, Royal Air Force Khormaksar,

for supplying the meteorological data, to Major M. D. Gallagher for information regarding the use of the study area by the birds after my departure from Aden, and to Drs. F. J. Monk and W. R. P. Bourne who each read successive drafts of this paper, and offered much invaluable advice.

REFERENCES ARCHER, G. F. & GODMAN E. M. 1937.

Vol. 2. BAILEY, R. S. 1966. BROWN, L. H. 1959. BROWNE, P. W. P. 1950. CLARKE, G. 1966.

ENNION, H. E. 1962.

MEINERTZHAGEN, R. 1954. PAIGE, J. P. 1960.

The Birds of British Somaliland and the Gulf of Aden,

London: Country Life.

London & Edinburgh: Gurney & Jackson. The sea-birds of the southeast coast of Arabia. Ibis 108: 224-264. The Mystery of the Flamingoes.

Notes on birds observed in south Arabia. Ibis 92: 52-65. Flamingoes at Khormaksar, Aden Colony. Royal Air Force Om. SOC. Journ.

Ibis 104: 1 : 11-19.

560-562. Notes on birds seen in Aden and the western Aden Protectorate.

Edinburgh & London: Oliver & Boyd. Ibis 102: 520-525.

Birds of Arabia. Bird Notes from Aden and Oman.

APPENDIX SPECIES SEEN ON THE STUDY AREA WHICH ARE NOT MENTIONED I N THE TEXT

Ardea cinerea Grey Heron Egretta gularis Reef Heron Common Butorides striatus Little Green Heron Plutalea leucorodia Spoonbill Phoenicopterus ruber Greater Flamingo

Anus querquedula Garganey Anas acuta Pintail Neophron percnopterus Egyptian Vulture Common Milvus migrans Black Kite Pandion haliaetm Osprey Charadrius hiaticula Ringed Plover Charadrius alexandrinus Kentish Plover Charadrius mongolus Mongolian Sand Plover Charadrius asiaticus Caspian Plover Charadrius squatarola Grey Plover Haematopus ostralegus Oystercatcher Recurvirostra avosetta Avocet

Himantopus himantopus Black-winged Stilt Calidris testacea Curlew Sandpiper Calidris minuta Little Stint Calidris temminckii Temminck’s Stint Calidris alba Sanderling Limicola .falcinellus Broad-billed Sandpiper Philomachus pugnax Ruff Arenaria interpres Turnstone Tringa cinerea Terek Sandpiper Tringa hypoleucos Common Sandpiper

Usually a few present

Single birds on four occasions A few 23 July onwards Common, average number present 105 to

1 June, 56 1 J u n e 4 July, 120 subsequently Two on 18 August and one on 27 August One skeleton found

Common; day roost of c. 30 at hide Frequent, 8 June onwards Common, but absent from 31 May to 24 July Resident, breeding in small numbers Few in May, and again in late August One 18 August Few to end of April reappearing 6 August Two to three, increasing in early August Few from 22 June to 23 August, maximum

Maximum seven, 10-14 June Few till 10 May, reappearing 13 August Common, but absent from 7 May to 1 August One 26 May Small parties until 31 May Two on 20 August 13 August onward, maximum four Few after 16 August Common after 16 August One to two birds, but absent 20 May-18

July; four on 3 August

15 on 3 1 July

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Tringa ochropus Green Sandpiper Tringa glareola Wood Sandpiper

Tringa totanus Redshank Tringa stagnatilis Marsh Sandpiper Tringa nebularia Greenshank Limosa limosa Black-tailed Godwit Limosa lapponica Bar-tailed Godwit

Numenius arquata Curlew Numenius phaeopus Whimbrel Glareola sp. (pratincola or nordmanni) Pratincole Larus argentatuslfuscus

Herring/Lesser Black-backed Gull Larus leucophthalmus White-eyed Gull Larus hemprichii Hemprich’s Gull. Gelochelidon nilotica Gull-billed Tern Hydroprogne tschegrava Caspian Tern Sterna bengalmsis Lesser Crested Tern Sterna bergii Crested Tern Chlidonias leucoptera White-winged Black Tern Motacilla ffawa Yellow Wagtail Anthus trivialis Tree Pipit Muscicapa striota Spotted Flycatcher Acrocephalus schoenobaenus Sedge Warbler Phylloscopus sp. Hirundo rustica Swallow Lanius collurio Red-backed Shrike Lanius isabellinus Isabelline Shrike C m u s corax Brown-necked Raven Passer domesticus House Sparrow

One on 5 and 18 August One to two until 4 June, one 28 June, one to two 3 August onwards

Few, 41 on 21 July, 53 on 5 August One to two, 18-23 August Few, 25 on 3 August One 13-20 August 25 on 26 April and 10 May, single birds

One to two, influx on 6 August Normally three, influx in August Two 23 July 150, rising to 200 on 6 August, mainly fuscus

Few Abundant 6-12, occasionally 30-40 Few, maximum 22 Frequent, 32 on 27 June, seven on 18 July Abundant One on 10 and 22 June, nine on 6 August Small numbers April-early May One 20 August One 10 May Single birds until 25 May, two on 17 May Few early May, four on 8 May Few 29-30 April, and 8 July onwards Two 8 May One 8 May Infrequent Common

throughout June, eight on 6 August

G. Clarke, c/o Hon. Sec., R.A.F. Ornithological Society, Mr. A. D. McDonald, 2, Mountain View, Queens Road, Kendal, Westmorland.