It is not uncommon for pleasure boaters and fishermen to witness long lines of these birds flying in single file low over the sea, with occasional undulations as if rising to avoid some invisible obstacle in the flight path.

I stirred from my light sleep bathed in sweat, the strange acrid smell in the air filling my nostrils. The wind had died in the night and the humidity had risen. We thought that we had got away with it this time, fooled by the pleasant coolness of the evening before. However, this was October on the Hawar Islands in the Arabian Gulf and at this time of year the humidity makes for discomfort which would befit any of the world's rainforests.

The continuous throaty burping linked the stench to its owner. We had set up camp on the periphery of one of the world's largest Socotra Cormorant colonies, there to photograph the 50,000 or more birds which congregate on South Sowad Island to breed in October each year.

From the tent flap we peered out across the low, flat, sandy scrub covered island into the mist hanging eerily over the mass of jostling black shapes stretching to the horizon. The sun had not yet risen as it was only 5 am, but it was evident that many birds had arrived in the night since the colony was almost twice the size of the previous evening. Most of the new arrivals were loafing around the edge of the main nesting areas and soon took flight as the large orange sun peered over the horizon. Many of the birds stopped initially to bathe about a hundred metres offshore in the shallow waters surrounding South Sowad Island.

The Socotra Cormorant is a little-studied species which has a very restricted world distribution. How the name originated seems to be something of a mystery as, to our knowledge, there has not been any record of a breeding colony of Socotra Cormorants on the island of Socotra in the Arabian Sea. There are two main breeding populations. One on various islands of the Arabian Gulf which mostly nest in the winter months (Ed:-see accompanying article concerning international research on Socotra cormorants). Many of these sites are being subjected to increasing human disturbance. A second population breeds during the summer on Al Hasikiya Island off the coast of Southern Oman.

The Socotra Cormorant is mainly a sedentary species but large movements of unknown significance are made within the breeding range. It is not uncommon for pleasure boaters and fishermen to witness long lines of these birds flying in single file low over the sea, with occasional undulations as if rising to avoid some invisible obstacle in the flight path. Between September and April flights, numbering up to 20,000 birds, may be seen on the mainland of Bahrain. Such large assemblies of birds seem to be mainly made up of adult birds roaming far in search of huge shoals of fish. Once a shoal is located some birds settle on the surface of the water and dive for fish from there, whilst others plunge-dive from the air. Since most of these dense flocks are seen in the breeding season it is tempting to suppose that they originate from the biggest colony in the region, South Sowad Island, in the Hawar group.

Our observations indicate that birds start to leave the Hawar colony from around 5 am, flying in a north-westerly direction, and that by 7 am the number of individuals remaining has reduced dramatically - indeed the colony is almost silent. The first birds start to arrive back at the colony at around 10 am when they begin to fly in, making 'V' formations of up to a hundred birds. Return 'squadrons' continue to arrive until sunset and our observation of this particular colony suggest that large numbers continue to arrive after dark. This would be consistent with fishing grounds around and well to the north of Bahrain.

In the Hawar population Socotra Cormorants appear to begin to congregate during September and in 1994, at least, numerous nests had birds incubating 2 to 4 pale blue eggs on 6 and 7 of October, when we visited. Interestingly, at this time there were very few Herring Gulls attendant upon the colony. Later in the breeding season predators feed voraciously on the young birds. There is almost no information recorded relating to the breeding behaviour of the Socotra Cormorant and it is certainly in need of further study. Nests consist of a circular scrape or depression in the ground, with raised edges, often decorated with stones. Throughout the colony nests are arranged in groups of various sizes and may almost be touching. Excrement appears to add concretion to the nests as the season advances such that old nests are evident for many seasons. As expected with the close proximity of nests, much bickering takes place between neighbours and we have observed that birds returning to the colony frequently make their way to the wrong nest, eventually either realizing their mistake or being chased off by the rightful owner. On the ground the birds are relatively clumsy and often knock eggs out of the nest or even break them.

At the start of the breeding season the adults are in peak condition with velvet black head, neck, rump and underparts. The mantle, scapulars and upper wing coverts exhibit a shiny dark bronze-green colour. It has previously been recorded that breeding birds of both sexes acquire white filoplumes on the head neck and rump. We, however, have only observed such filoplumes behind the eyes and even these were present in a relatively small percentage of birds.

As the breeding season progresses the feathers become 'tatty' as a result of wear and coating with excrement. Breeding is asynchronous and later in the season eggs, small and large chicks are present in the colony. The incubation period is unknown but is probably around 28 days. On hatching the young are rather ugly, naked pink individuals with a disproportionately large head. After a few days they become covered in a sparse white down on the back which later covers most of the body but spares the face and underside of the neck. At some stage, as they grow bigger, the parent birds leave them in creches guarded by a few adult birds. They still, however, remain vulnerable to predation by the large contingent of Herring Gulls which take up residence on the edge of the colony, using any disturbance as an opportunity to take even large chicks. As time passes the colony becomes strewn with the bodies of chicks of all ages. Marauding Herring Gulls will usually take large chicks to the edge of the colony where they kill them by pecking a hole in the chest cavity and leaving the rest of the carcass uneaten, such is the abundance of potential prey.

Time to fledgling is also unknown but is probably about two months. By late January the colony appears to be considerably smaller, because most of the adults are away fishing, leaving a mobile mass of nearly fledged young to form large groups around the breeding area. Many dead and dying birds litter this section of the island at this time. Since there is no evidence of injury from Herring Gulls to many of the carcasses it seems likely that this is either the result of parasitic infestation or starvation.

Chicks are fed by partial regurgitation. As adult birds land after fishing trips they are chased around for several minutes by a group of hungry youngsters, finally giving up food as the young bird puts its head into the parents bill. Small chicks have also been noted to seek food from larger chicks in a similar manner. As the young birds mature grey-brown feathers with pale edges replace the down but the breast and belly remain white for some time. Immature birds exhibit a dark brown head and neck with a paler throat and chin. The feathers of the mantle, scapulars and upper wing coverts are dark grey with a brown-black spot at the tip and a narrow white margin. The flight feathers are a matte grey-black. Adult plumage is probably attained by the third year. Ticks are said to be a major problem in some colonies and observers who have strayed too close complain of a bite which causes intense itching for days afterwards. In some cases a virus is transmitted, which causes fever and severe flu-like symptoms. Fortunately we have not experienced this inconvenience on the Hawar colony - yet!

An annual excursion has taken place for many years to the Hawar colony from the villages of Askar, Jau, and Dur. On such occasions the young men of these villages arrive in motorboats to collect eggs from the nests of the Socotra Cormorants. It usually occurs in early October at the start of the breeding season. Large cool boxes are filled these with the pale blue eggs. It is said that the old men of the village believe that if they do not eat cormorant eggs at least once a year they will become ill.

It seems unlikely that this practice causes any great threat to this breeding colony as the timing coincides with the beginning of the breeding season and thus the birds have time to lay a second clutch of eggs. Some fishermen eat the meat of the cormorant during the breeding season having caught them at sea. Birds caught outside of this period are said to be scrawny and louse-ridden and are therefore not taken. Presumably eating cormorant flesh must be an acquired taste as the meat is said to taste strongly of fish.

Human activity in the Hawar islands is on the increase with more visits to the main island but access to the main breeding island is still controlled. There is a very strong case to be made for continuing to protect this important breeding colony from human disturbance. Whereas the early season egg-collecting is a traditional pursuit calculated to sustain the breeding colony, visits in the middle of the season will result in increased predation by the large numbers of gulls ever present at the colony and will be likely to severely impact upon the population. The Socotra Cormorants is also vulnerable to the effects of oil spillages and is probably the most commonly found oiled dead bird around the Bahrain coastline.

The Hawar Socotra Cormorant colony is just one of the treasures of these stark and desolate but beautiful islands. With the added attraction of breeding Sooty Falcons, ospreys, wintering Greater Flamingoes and large numbers of dugong in the shallow waters just to the north, it must surely be an area worthy of international recognition and protection.