Nightjars Caprimulgidae are passage migrants in the UAE, with the birds we see here likely to breed in Central Asia, although their range extends from Western Europe across to Far Eastern Russia, Mongolia and even China in suitable habitats. Central Asia probably provides the bulk of the birds that pass through the UAE on their way to wintering areas in Eastern Africa, although we also see the occasional one whose plumage suggests they are of European races. To date, two species have been recorded locally, the Nightjar Caprimulgus europaeus and the Egyptian Nightjar Caprimulgus aegyptius, the latter only in the Northern Emirates. Most UAE records are of the former species.
It has been suggested that Nightjars pass from their breeding areas to wintering areas across a broad front, probably making the long journey in small parties rather than the flocks of many thousands we associate with other bird families. Undoubtedly many more Nightjars pass through the UAE than our small band of active recorders manage to spot. The reasons for this are fairly obvious. Firstly, as their name implies, Nightjars are crepuscular and nocturnal, while they are also silent during migration. 'Silet birds in the dark are not easily seen!
Most of our local records refer to chance encounters with resting birds in daylight, but even these are not always satisfactory, as all have extremely cryptic plumages which afford them excellent camouflage against a wide variety of backgrounds. It can be almost impossible to find a Nightjar at point-blank range if it sits motionless amongst dense undergrowth, tree branches, gravel or stones.
This utter confidence in their own invisibility, however, can provide us with our best chance of noting them during migration, as they often rest in unsuitable places, and can occasionally be found perched quite prominently. Because they think they cannot be seen, they also allow observers to approach quite close before flying.
In daytime, when disturbed they tend to fly in a confused silent zig-zag and clumsy manner, suddenly closing their wings and tail to swoop down to find another unsuitable perch, usually not far off. This behaviour provides the opportunity to identify the species positively.
Such clumsiness, almost reluctance to fly is in sharp contrast to their usual flying behaviour. As befits an aerial insectivore, Nightjars are true artists in the sky when feeding, fast silent fliers possessing a repertoire of twists, turns, swoops, wheels and glides that are a real treat for any bird-watcher.
My first sighting on October 2nd 1989 occurred at around 0800 hours, near the end of the marine jetty on the southern tip of Zirku Island. Stealing towards a couple of Pied Wheaters Oenanthe pleschanka on the top of boulders near the jetty, I was startled by a Nightjar which took to wing almost under my feet. It alighted some ten metres away on the flat concrete at the end of the jetty and crouched motionless.
Even without binoculars, it was obviously not the dark general colour of the European races of the Nightjar Caprimulgus europaeus. It had no white or pale tips to its outer tail feathers, and showed no white in the wings. On the ground, it was quite evenly plumaged allover the upper parts, generally what I would describe as 'gingery,' or a pale pinky sand colour. All the upper parts were delicately vermiculated, slightly more boldly marked on the flight feathers.
As I crept nearer to the bird, to within about three metres, it took off again, in a clumsy zig-zag, almost lazy flight, and dropped down well-hidden in the rocks beyond the police checkpoint, a location which dampened my enthusiasm for a further chase. In flight at close range, the bird was noticeably plainer and paler beneath, with primary flight feathers slightly darker than the remainder of the wings both above and below. From this close encounter, I am confident that the bird was an Egyptian Nightjar, a first record for the ENHG List, and for Abu Dhabi Emirate, though not a UAE first.
Later I visited the ADPPOC Tug M.V. Bassi, anchored by the oil terminal radio control tower twelve miles north of Zirku Island. No sooner had I stepped on board the tug than I disturbed another resting Nightjar. This bird was seen at close range several times, and steadfastly refused to leave the tug. It looked strangely out of place wheeling around the fire monitors atop the wheelhouse or swooping over the waves when disturbed, but returned each time to alight and to try to hide in the many nooks and crannies on board. This bird was identical to the previous one. Again, I am confident it was a Egyptian Nightjar.
On my return to shore, I had half an hour to spare before my flight back to Abu Dhabi, and decided to check the sea-water intake to see whether anything was swimming around. Again I disturbed a resting Nightjar, 'hiding' on the ground in the shade of a small salt-bush. When disturbed, it flew lazily and chaotically around, landing on a nearby window ledge. Creeping to within five metres of it, I could see it was not the same general colour as the others, and had a much more cryptic colouration, with silvery vermiculations on a brown background.
The most prominent markings were almost white throat patches, a separate white line extending from the gape below the eye, and white or creamy spots in a row along the scapulars which formed a pale line both while the bird was at rest and prominent in flight. It had a mass of pale on dark bars and streaks on all upper parts and in flight the pale wing patches in the primaries and outer tail feathers were only just visible. I am of the opinion that the bird was of the race of Nightjar from Iran and further east, Caprimulgus europaeus unwini.
Other species seen during the day trip included around 3,000 Socotra Cormorants, immature Herring/Lesser Black-backed Gulls, Lesser Crested Tern, Sooty Gull, Whir\chat and Swallow.