Bulletin 37 - March 1989: Socotran Cormorant (Phalacrocorax nigrogularis) Breeding in the UAE



Socotran Cormorant (Phalacrocorax nigrogularis) Breeding in the UAE

by S. Howe

On 5.10.88 between 1000 and 1300 hours, a circumnavigation of a certain island in the Northern Emirates was made by Messrs. Colin Richardson, 'Bish' Brown, David Fuggle and Stan Howe. A landing was made on the north shore of the eastern end of the island in order to inspect a locally known colony of Socotran Cormorant Phalacrocorax nigrogularis.

On leaving the sheltered bay of the mainland to turn seaward through the channel towards the island, long lines of Socotran cormorants ('kuwhar' to our Bangladeshi boatman) were immediately seen flying 1 to 2km out to sea. White-cheeked tern Sterna repressa and Caspian tern Sterna caspia were diving close to the launch. On the near tip of the island were some 20 Crab plovers Dromas ardeola in association with Oystercatchers Haematopus ostralegus, as they often tend to be in the UAE. When we got closer to the cormorants they were seen to be moving in counter-current flows to east and west; lines of as few as 10 to as many as 300 rising and falling in sinusoidal motion but generally staying close to the sea surface. Others were sitting on the sea with a few diving. The whole chain appeared to be emanating from a point on the northern shore (in alignment with a prominent cement works on the mainland at Rafaa). Some of the birds were not totally black, but with a lighter browner cast suggesting juvenile/immature plumage. Last year's young would be at least 8 or 9 months old at this time, Colin reckoned. Those birds flying back towards the island were overtaking our launch doing a steady 10 knots. After some 6km, just beyond a palace which was the only building on the island, birds were crossing to inshore of the launch (still about 1km offshore) to a point where many more juveniles with brown upper parts and dirty buff below were sitting on the narrow sandy beach in association with 50 or so Herring Gulls Larus argentatus. The flying birds appeared to be coming and going to an area just beyond the low (2 to 3m) dunes backing the beach.

A landing was made about 100m west of the birds on the beach, and on crossing the dunes, a large expanse of breeding Socotran Cormorants was seen stretching away to the left in a band about 100m wide, parallel to the dunes, and not penetrating towards the other (inshore) coast of the island which was clearly visible about 1km away. All the birds were facing in the direction of the open sea. The number of sitting birds was clearly very large and the sight most impressive, but 5000 to 10000 would probably be a reasonable estimate (30000 to 40000 having been mentioned in the past for other islands in the Gulf). However, the area in use was not totally saturated, and the ground over which we approached the colony had certainly been used by birds in the past. It was littered with nest scrapes, eggshell fragments and skeletal/feather remains of part-grown Socotran Cormorants.

At 50m range the birds appeared to be silent and tolerant of both their neighbors and a number of Herring Gulls (ssp. Armenicus) in close attendance. In outlying segments of the colony some opportunistic gulls were seen to steal eggs and carry them off in their bill. Most of the cormorants appeared to be standing over their nests with wings folded, gapes open, and gular flaps oscillating. A minority was sitting closer to the ground in brooding posture. A very few were engaged in wing drying. Hardly any aggression was noted; only a little indolent bill fencing by two juxtaposed brooding birds in a 15-minute vigil. The colony was divided into numerous linearly arranged segments of from 20 to 200 birds within which the individual nests were contiguous. Adjacent segments were up to 20m apart. The terrain was soft sand with scattered Cyperus sedge and various Halopeplis saltbushes (1). The nest bowls were built up at the edges with balls of droppings-soaked sand and small (Carangid?) fish remains. No rock outcrops or stony ground was observed in the vicinity. There was no smell even at close range, the sand absorbing all moisture.

On closer approach, a low murmuration, a quiet KE-KE-KE and a hoarse GRRRR could be heard coming from a wide stretch of the colony. Whether this was a reaction to our approach or is the normal conversation within a colony is hard to say. There was also constant motion overhead as birds entered and left the colony to forage. BWP (2) reports a colony is totally silent, but it would be perhaps more apposite to say of this one it was quietly active and talkative.

At a range of 10m, the outermost birds began to show some concern, and those that had been sitting now stood up and were audibly grunting. It appeared each segment within the colony was synchronized differently. The closest to us was entirely with eggs, varying from one to as many as five. The next was almost totally with young, still with bare pink heads and bluish backs; but rather well-grown and about 25cm tall as they stretched up to solicit food. Assuming an incubation period of 3 to 4 weeks and the young to be two weeks old, this part of the colony could have been occupied since late August. With other potential ground still to be colonized, breeding activity could continue well into December at least.

No adult birds were seen to have any white feathers or filoplumes about the head by any of us, even at extremely close range. There was some suggestion of white flecking about the backs and flanks of a few birds, but subsequent inspection of photographs indicate this may be from soiling by neighboring birds.

The birds on a small sector of the colony took to the air with little effort, other than a short run over the open ground between nest segments, giving us the opportunity to photograph their eggs. These were unmarked pastel blue beneath a chalky white coating. No markings were seen on any, although some of the shell fragments from the unoccupied section of the colony gave the impression of light freckling. Certainly no large blotches were seen as remarked in BWP (after Meinertzhagen), nor were they particularly dirty as many Pelecaniform eggs often become. Michael Walters (egg curator at the British Museum of Natural History) has remarked to me that true markings are unlikely on eggs of Cormorant texture, and those reported in BWP may have been blood staining from lice-infected birds.

Continuing our journey after reconnoitering the colony for 45 minutes we rounded the northeastern tip of the island to return to the mainland via the inshore channel. Birds seen here included Gull-billed tern Gelochelidon nilotica, Slender-billed gull Larus genei, Swift tern Sterna bergii, Lesser-crested tern Sterna benghalensis, White-cheeked tern and more Herring gulls. A dark phase Reef heron Egretta gularis and an Osprey Pandion haliaetus stood on the beach while Grey heron Ardea cinerea and a light phase Reef heron waded in the shallows. Only a couple of juvenile Socotran cormorants were present on the island coastline facing the mainland. Flamingoes Phoenicopterus ruber, a Little green heron Butorides striatus and Oystercatchers were level with the colony we had visited, although there was little to be seen to betray the fact that there were 5000+ breeding cormorants hardly more than 1km away. Their habit of flying low across the dunes and out to sea clearly has value in maintaining the privacy of the colony.

As we rounded the southwest end of the island we were amidst good stands of Grey Mangrove Avicennia marina; some on small islets, some in clumps that constituted islands in themselves. On these Great white egret Egretta alba and Grey heron stood, while Curlew Numenius arquata, Bar-tailed godwit Limosa Lapponica and Reef herons were recognizable among a mass of small waders on the shelving mainland shore. With the contrasting white ultra-modern architecture and the sandy colored buildings of the old fort and fishing village drawing closer, our last thrill was a loafing group (c. 100) of terns on a sand spit. Sandwich tern Sterna sandvicensis and Saunders little tern Sterna saundersi were in roughly equal number in the group.

The weather throughout had been one of clear blue skies with a gentle sea breeze out of the northwest. The air temperature on the island had been close to 40'C with no shade. Notwithstanding this, Club sandwiches and cold drinks afterwards helped to glamorize the memory of a splendid day with a little studied species, and one that on this island at least is doing well despite being widely believed to be under threat in the Gulf as a whole.

(Note that this island is a privately owned nature reserve and access is impossible without permission from the relevant Sheikh. In fact, unauthorized visitors and those otherwise disturbing the site have been arrested in the past. The name of the island and its exact location has therefore been omitted from this article, but for bona fida researchers, more information may by obtained from the ENHG Bird Recorder. - Editor)

(1) On a subsequent visit to the area on 9.12.88, the following plants were collected by Bish Brown: Halopeplis perfoliata, Arthrocnemum macrostachyum, Salsola baryosma, Heliotropium kotschyi, Arnebia hispidissima, Limonium axillare and the grass Halopyrum mucronatum, distinguished by its long stolons.

(2) Handbook of the Birds of Europe, the Middle East and North Africa - Birds of the Western Palearctic, ed. By Stanley Cramp.

 


Back Home Up Next

Copyright 1977-2011 Emirates Natural History Group
Patron: H.E. Sheikh Nahayan bin Mubarak Al Nahayan

Served from Molalla, Oregon, United States of America