It was just before dawn on the salt flat, but already the damp heat was oppressive. Small shrubs broke the horizon. Here, in the center of the habitat of the largest known population of wild mountain gazelles in Saudi Arabia, on the southern Red Sea island of Farasan, I looked out at an expanse of unmoving grass, bushes and rocks.
I had known the Farasan gazelle would be elusive at best. The latest estimate puts their numbers on this island at only 1000 individuals. No one is sure how they got here in the first place, 50 kilometers (30 miles) off Saudi Arabia's southwestern coast in the Red Sea. Residents claim fishermen from the mainland brought them several hundred years ago and confined them in corrals of rocks; some escaped and established the wild population. Another hypothesis is that the gazelles have lived here ever since the last Ice Age, when the island was probably linked to the mainland. This latter theory is preferable, in my opinion, because the physiological changes that distinguish the Farasan gazelle from the mainland mountain gazelle could not have come about in just a few hundred years.
There were plenty of signs of gazelles that dawn, but it took an hour of stalking among the rough, sharp coral rocks and low ravines before a bush seemed to rustle. A male gazelle—the males' horns are larger than the females'—stotted gracefully out from his bedding site. I held still in fear that too much of a fright might cause him to break one of his fragile-looking legs as he hopped among the knee-high rocks, but these animals have lived here long enough to have adapted well: He ran with stunning agility. I saw no more until dusk, as the gazelles wisely kept out of the day's heat in the slightly cooler and sparsely verdant protection of the low ravines.
Millions of years ago, geological upheavals in what is now the Red Sea caused salt domes to push up existing coral reefs until they became the Farasan archipelago. Until recently, local fishermen were the only permanent human inhabitants of the largest island, Farasan. Since most of the island's surface is composed of limestone rock, and rainfall averages less than 10 centimeters (4") a year, the land is ill-suited for agriculture. Nevertheless, soil accumulates in the ravines, and some residents nurse crops in rare, irregular patches.
The pattern of rainfall is far better suited to the gazelle population. Although heavy rain may cause flash floods in one part of the island, areas only a few hundred meters away can remain dry. A sudden, local outburst of annual flowers and grasses will follow the rain, but within days or weeks the green carpet dries and dies under the blistering sun. Water not absorbed into the ground runs into the ravines and supports the island's sparse permanent flora. It is this vegetation that supports the gazelles.
Recent studies of skull measurements of the Farasan gazelle, formerly thought to be a unique species, indicate that although they are smaller—a typical trait of an isolated population—they are actually a subspecies of the idmi, the mountain gazelle (Gazella gazella) that lives among the western mountains of the Arabian Peninsula and eastward into the mountains and plains of Oman. Several other subspecies have been identified, from the grey-brown Palestinian mountain gazelle of the northern Arabian Peninsula to the reddish cora gazelle of the south.
The Farasan gazelle has a red-grey coat, and its facial markings and flank stripes closely resemble those of the mainland mountain gazelles. A prominent dark nose spot marks the gazelles of Farasan Island, but those of nearby, uninhabited Zufaf Island have a white nose spot.
The Farasan gazelle is a territorial species, not a gregarious one. By marking their borders with dung and urine, dominant males establish individual territories in a site with sufficient vegetation, and strive to drive other males away. Males probably stay in their respective areas throughout the year, unless they are forcibly dislodged.
When an intruding, competitor male appears, the territorial gazelle will first walk toward his rival with neck muscles bulging and head held stiffly in the air. Sometimes he will break into a threat-charge. Usually such behavior effectively scares off the intruder, but if the adversary is persistent, a mock battle may ensue. The rivals face each other and go through a sequence of head movements as though they were clashing their horns together—yet no contact is actually made. Because it looks as though a cushion of air keeps the animals apart, this sequence is known as air-cushion movements. They are followed—if necessary—by actual horn clashes, pushing and shoving until one animal or the other gives up, and the territory is either maintained or changes owners.
The mountain gazelle is also a solitary species; the few small groups of gazelles usually consist of a mother and her offspring, perhaps accompanied by another female. Although bachelor males and the young each have a tendency to huddle together, their groups remain small. Territorial males do not keep their own groups of females, and there is no fixed mating season; rather, courtship takes place throughout the year, whenever a female enters the territory of a male. If the female is receptive, mating takes place; if she is not, there is a chase in which the lighter, more agile female has the advantage.
After six months of gestation, the lambs are born in secluded spots, usually in thickets among rocks in ravines. The mother leaves the newborn alone when it is only a few hours old, and visits it several times a day to nurse it. When in danger, the lamb holds its head low to the ground and flattens its huge ears against its neck to make its outline as inconspicuous as possible, although its coloring makes it nearly invisible anyway. The mother always exercises great caution approaching the lamb's hiding place, to avoid revealing the spot to watching predators.
Young gazelles stay close to their mothers until they are about eight weeks old. Somewhat older males start to gather in small groups preoccupied with feeding and ritualized patterns of fighting, including head-butting, chasing and leaping in the air. This is the prelude to the establishment of a hierarchy in which the dominant males will be recognized by their cohorts later in life—a pattern of behavior that minimizes the damage done in the sometimes bloody competition for females.
Just what the gazelles eat, and when, is still not entirely clear. Patterns of tracks near clumps of vegetation suggest they browse on some plants while neglecting others; this selectivity is vital to survival, for their water requirements are met entirely by the vegetation. The islands have no sources of permanent surface water. Earlier, it was believed that the gazelles drank seawater, but lately it has been found that salty water upsets their digestive systems.
The island of Zufaf is smaller than Farasan, mostly hilly, with a number of dry wadis, or stream beds, and a large plain in its southern part. It supports a population of perhaps 200 gazelles, although the large number of carcasses found by biologists indicates that even this small population may have experienced a crash in recent years. Fishermen who regularly visit Zufaf from Farasan told me that the animals most likely died, in their opinion, during the drought and exceptional heat of the summer of 1986. Some plant species also show browse lines at the limits of the gazelles' reach, indicating that past populations may have been larger. The gazelles on Zufaf are somewhat easier to observe than on Farasan, because in feeding, all but the territorial males use the open plain daily.
At first the coral-rock plain of Zufaf looks barren, but on a closer look I found the prickly herb Blepliaris ciliaris and several grass species abundant in the runnels. Here, gazelles arrive in the early morning and feed on the herb intermittently until noon. In the afternoon heat, most of them retreat to the security of the low hills, where they find shady bedding sites under shrubs and bushes. Near evening, they repeat the long journey to the plain. Though the gazelles also eat more than a dozen other varieties of shrubs and grasses, Blepharis seem to be their favorite food. They eat the prickly leaves without difficulty, a skill likely developed in response to the plant's high water and protein content.
Although humans may not have first introduced the mountain gazelles to the Farasan archipelago, it is now the human presence that threatens their well-being, and indeed their very survival. On Farasan Island and the adjacent Sajid Island, the gazelles now compete increasingly with domestic livestock. Because the goats and camels are allowed to range free, they congregate where the most food is available, increasing competition and damaging the fragile plant life in the ravines. The gazelles on Farasan have thus retreated to the roughest terrain on the island: uplifted limestone ledges that rise, in some places, as high as 20 meters (60 feet)—terrain too harsh for domestic stock. It is here that the largest portion of the gazelle population is found, with concentrations of females and young and some territorial males.
Throughout mainland Saudi Arabia, human development and overhunting have caused a loss of habitat and the depression of gazelle populations. Once-abundant herds that migrated over the desert plains until a few decades ago have now all but vanished. Of the three known species of gazelle native to the kingdom, the 'afri, or Saudi gazelle (Gazella saudiya), is now extinct in the wild, the rheem, or sand gazelle (Gazella subgut-turosa marica) has survived only in two reserves in the north of the country, and the mountain gazelle holds out in small pockets in the highlands of the western shield. Both surviving species are now endangered and, without strict protection, risk extinction.
Among the mountain gazelles, the Farasan gazelle (Gazella gazella farasani) is the largest grouping of a unique subspecies gene pool. Its isolation from the mainland has insulated the Farasan population from the decline among mainland gazelle populations. Still, in past years, trapped or hunted Farasan gazelles have been known to fetch up to 5000 riyals each on the mainland ($1300). The introduction of motorized transport, and the arrival of tourists on the archipelago in numbers now reaching 5000 to 6000 each year, has lead to harassment of the gazelles—frequently unintentional—and disruption of their feeding patterns.
In 1988, the Farasan Islands were declared a reserve by Saudi Arabia's active National Commission for Wildlife Conservation and Development (See Aramco World, November-December 1990). Hunting is banned, as is any approach to the animals that comes close enough to disturb them, though grazing competition continues. With the Commission's increasing emphasis on public education about the significance of wildlife as a natural resource, future generations, too, will be able to see and enjoy the gazelles of the Farasan Islands.
Dr. Khushal Habibi, a specialist consultant to the National Commission for Wildlife Conservation and Development in Riyadh, has studied Arabian gazelles for several years.