The Saudi Arabian Gulf coral islands are very important sites for birds, both breeding seabirds and migrant passerines and hold internationally important numbers of breeding Lesser Crested Terns (Thalasseus bengalensis) and Bridled Terns (Onychoprion anaethetus).
All six Saudi Arabian, Gulf Coral Islands were formed when sand, produced by wave action, boring of some worm species and grazing by Parrot Fish as well as other factors, builds up on a submerged coral reef and finally breaks through the water surface.
The islands are thus surrounded by extensive, shallow coral reefs which are the most diverse in the Arabian Gulf and are excellent for diving and snorkeling as well as supporting local fisheries. The islands have grown in size over time, but all still have elevations of less than three metres above the high tide line.
They are all aligned along the edge of where the Gulf increases in depth to 35 metres with the exception of Arabiyah which is located in deeper water. The islands, excluding Arabiyah, are located 35 – 90 kilometres offshore Jubail Industrial City, which is 125 kms north of Dhahran / Al Khobar / Dammam in the Eastern Province of the Kingdom of Saudi Arabia.
Permission is required to visit the islands from the Saudi Wildlife Commission (SWC) and the Coast Guard, which is not easy to obtain, and helps protect the wildlife. The nesting Hawksbill Turtles (Eretmochelys imbricate) arrive to lay eggs, on the wide sandy beach platforms of each island, in mid-May and the larger and commoner Green Turtle (Chelonia mydas) in mid-June and they start leaving the islands in September.
The islands are internationally important for breeding terns, especially Bridled Tern and Lesser Crested Tern but are also important for breeding larks including Crested Lark (Galerida cristata), Lesser Short-toed Lark (Calandrella rufescens) and occasionally Bimaculated Lark (Melanocorypha bimaculata).
Birds, mainly passerines such as wheatears, warbles and shrikes, often stop on the islands during migration to feed and rest. Other migrants such as Pratincoles and Corncrake (Crex crex) occur in good numbers with Red-necked Phalarope (Phalaropus lobatus) using the surrounding waters.
As a result they are listed as an important bird area by BirdLife International.
The descriptions of the islands below are listed with the southern-most first and the northern-most last.
Juraid (27°11’N, 49°52’E) is the third largest island measuring 20 hectares in size (732 x 282m) and is vegetated primarily with suaeda vermiculata and Salsola baryosma bushes. The vegetation is quite dense in places reaching a height of up to one metre and is mainly located in the central area of the island. There is a narrow bare beach platform and this island holds the largest breeding population of Bridled Terns in Saudi Arabia, with good numbers of breeding Lesser Crested Terns and White-cheeked Terns. The seabird nesting density is 65 birds per hectare. After Jana and Karan this is the next best nesting island for Hawksbill Turtle and Green Turtle and is probably less favorable then the two other islands due to its steeper sloping beach which the turtles find hard to climb.
Jana (27°22’N, 49°54’E) is the second largest island being 33 hectares in size (1105m x 300m) and is vegetated primarily with Suaeda vermiculata and Salsola baryosma bushes. The vegetation is quite dense in places, reaches one metre in height and is located mainly in the center of the island. Beach rock occurs on the northern side in the lower portion of the beach and the upper inter-tidal zone. There is a narrow bare beach platform and the largest colony of White-cheeked terns on the coral islands occurs on this island. Large numbers of Bridled tern and small numbers of Lesser Crested Terns and Swift Terns also nest here. The seabird nesting density is 28 birds per hectare. Hawksbill Turtle and Green Turtle nest on the island in preference to all other islands excepting Karan, probably as it has a gently sloping beach with good substrate to lay eggs in.
Kurain (27°39’N, 49°50’E) is the second smallest island with a size of 8 hectares (312m x 251m), has a narrow beach platform and is vegetated primarily with Suaeda vermiculata and Salsola baryosma bushes with the annual Mesembryanthemum nudiflorum also present. The vegetation is quite dense in places, can reach one metre in height and is located mainly in the center of the island. Large numbers of Lesser Crested Terns along with good numbers of Bridled Terns and White-cheeked Terns nest on this island along with 30 pairs of winter nesting Socotra Cormorant. The seabird nesting density is 404 birds per hectare and small numbers of Hawksbill Turtle and Green Turtle also nest on the island.
Karan (27°44’N, 49°50’E) is the largest of the six coral islands measuring 128 hectares in size (2025m x 625m) and it has a bare beach platform. It is vegetated primarily with Suaeda vermiculata and Salsola baryosma bushes with the annual Mesembryanthemum nudiflorum also present. The vegetation is much the same as on the other islands, being quite dense in places, up to one metre in height and located primarily in the center of the island. Beach rock occurs on the northern side in the lower portion of the beach and upper inter-tidal zone. This island has the largest breeding population of Lesser Crested terns in Saudi Arabia as well as good numbers of Bridled Terns and White-cheeked terns and a small number of Swift Terns. The seabird nesting density is 42 birds per hectare. The island is the main breeding location for Hawksbill Turtle and Green Turtle due to its gently sloping beach and suitable substrate for egg laying.
Arabiyah is quite a small island being just over 13 hectares in size (488m x 267m), with a narrow bare beach platform. It is now a coast guard station, which occupies almost the entire surface area and as a result has been abandoned by breeding seabirds. It is located about 125 kilometres from the Saudi Arabian coast and previously had vegetation cover all of which has been destroyed.
Harqus(27°56’N, 49°41’E) is the smallest of the six coral islands being only two hectares in size (259m x 76m) and has a narrow bare beach platform. It is very low lying and has no vegetation due to the fact that during severe storms, waves wash over the entire island. The largest breeding colony of Swift Terns nest on this island with Lesser Crested terns also breeding. Very small numbers of both Hawksbill Turtle and Green Turtle also breed.
The primary breeding species on the islands are terns and the following are details of the main species that breed on the islands with the commonest first and scarcest last.
Bridled Tern (Onychoprion anaethetus) is a summer visitor from March or April until September or October and is widely distributed through the Arabian Gulf. It prefers islands with fairly dense vegetation that can provide nesting cover, though sometimes it breeds in cavities on rocky slopes. It nests on Juraid, Jana, Karan and Kurain Islands where it has an even nest distribution covering the entire well vegetated sections containing Suaeda vermiculata and Salsola baryosmabushes. An internationally important percentage of the world population breed in the Arabian Gulf with more than 34,000 pairs breeding each year. It is the most common of the four main Arabian Gulf Island breeding Terns, with the six Gulf Coral Islands being among the five most important breeding sites for the species in the world.
Lesser Crested Tern (Thalasseus bengalensis) is a summer visitor from March or April until September or October, with a few hundred birds remaining throughout the winter. It is widely distributed as a breeding species throughout the Arabian Gulf. It breeds in large colonies on the islands of Juraid, Jana, Kurain, Harqus and Karan where it nests in dense and very localized colonies on the bare ground. In the past the species has nested on Arabiya. An internationally important percentage of the world population breed in the Arabian Gulf with more than 20,000 pairs breeding on the Coral Islands, which are the largest know breeding colonies in the world.
White-cheeked Tern (Sterna repressa) is a summer visitor from March or April until September or October with a few birds remaining throughout the winter. They occur throughout the Arabian Gulf and are probably the most widely distributed Tern in the region, breeding in colonies of varying size not only on islands but also, where undisturbed, on sand-spits and mainland beaches. They breed regularly on Juarid, Jana & Karan Islands where more than 10,000 pairs breed in small colonies spread over the islands in areas of scattered vegetation and low annual plants such as Mesembryanthemum nudiflorum. The Saudi Arabian breeding population is of considerable importance as the species has a very limited world distribution, being confined to the seas of around the Arabian Peninsula.
Swift Tern (Thalasseus bergii) is almost as large as Caspian Tern and breeds off the coasts of Iran, Kuwait and Saudi Arabia’s Eastern Province. They breed on Harqus, Kurain, Karan and Jana Islands with the largest numbers on Harqus and Kurain where they breed in large, dense, very localized colonies on bare ground. Of the four main island breeding species of Terns they are the least common but still number more than 3500 breeding pairs each year.
These islands have been proposed as a Special Nature Reserve and Resource Use Reserve and have been included within the boundaries of the proposed Wildlife Sanctuary for the Gulf Region which should be ratified as a Marine Protected Area. They are currently being monitored, and have been since 1991, for breeding terns and turtles, at least Karan and Jana, and a lot of information has been gathered about them over the years. The islands have no permanent habitation, but local fisherman use them as shelter in poor weather and occasionally for collecting eggs of birds and turtles, although this is not thought to have a large impact. Recreational diving is also popular at the reefs and divers sometimes use the islands for picnics.
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