Surveying Lebanon's migrating raptors

Vital corridors

Taking part in the raptor survey

Many migrating birds prefer to avoid long flights over sea and take routes that allow them to fly over land where warm air currents can give them lift and aid their journey. The result is a series of well-known and spectacular migration highways across the earth's surface. Lebanon is on one of these great bird routes as millions of birds fly backwards and forwards between Africa and Europe every spring and autumn. Yet because Lebanon is mountainous, it acts as a barrier to migration and the birds tend to take specific routes that allow them to conserve energy by avoiding summits and making the most of favourable updrafts and air currents. The result is that these narrow migration corridors can provide one of the great spectacles of nature: line after line of buzzards, eagles and storks passing low overhead.

For the scientist, such corridors offer a unique chance to monitor birds. Raptors, in particular, tend to live solitary lives so that counting, say, how many Honey Buzzards Pernis apivorus there are spending the summer in Europe is far from easy. Yet because almost all these birds migrate to and from Europe using these migration corridors, a survey program at key points along them allows almost an entire population to be counted. Yet if these migration corridors are of value to the scientist, they pose problems for conservation; large birds flying low and slow over mountain passes make an irresistible - and often unmissable - target for hunters. If these raptors are to be protected - and many raptor species are declining at alarming rates - these migration routes need to be known and protected.

Despite the importance of these raptor migration routes, prior to 2000 there had been no systematic studies of raptor passage through Lebanon and the only data was either from casual observations or from short-term counts over part of the migration period. Because of the need to better identify the migration routes and the birds that used them, Colin Beale of A Rocha Lebanon, acting with Lebanon's senior ornithologist, Ghassan Ramadan-Jaradi, organised a raptor survey programme in autumn 2000.

The survey

The survey program had two components: a general survey planned to run from late August until early November and an intensive survey in the last week of September and first week of October when, from previous records, most birds were expected to pass.

Map of Lebanon showing autumn raptor migration routes

The general survey was begun in late August and involved continuous observations being made between 08.00 and 18.00 one day a week, from a hillside vantage point above Beirut. Unfortunately, due to political tension in the region, the survey had to be curtailed from mid-October and observations in the final migration period were not possible. The intensive survey ran from 25 September to 6 October with observations being made on weekdays between 08.00 and 18.00 at five sites in an approximate line across the country, with three sites visited each day. For this intensive program, a number of volunteers came from the UK to join the survey.

Conclusions

During the survey a total of 16,904 birds of 33 species (29 of them raptor species) were counted. By extrapolation from the data, it can be estimated that well over 107,000 raptors passed over Lebanon between late August and mid-October 2000.
Some of the main species observed had specific migration periods. For example:

Honey Buzzard Pernis apivorus: mid or late August to early September
Levant Sparrowhawk Accipiter brevipes: mid-September
Steppe Buzzard Buteo buteo vulpinus: early to mid-October
Lesser Spotted Eagle Aquila pomarina: late September to early October
Red-footed Falcon Falco vespertinus: late September

The surveys revealed a large stream of birds flying down a narrow corridor over the western slopes of the Mount Lebanon range east of Beirut. This was joined by a second stream crossing the Mount Lebanon range, probably from the northern Bekaa. Smaller concentrations of birds occurred along the west and and east sides of the Bekaa valley.
Lebanon has a responsibility for protecting all these species. In order to adequately protect these large soaring migrant birds in Lebanon, it is vital that the hunting ban is rigorously enforced during passage periods, especially along these routes. As such measures must operate throughout the entire passage periods they must be in place from mid-August to late October.

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The full results of the survey were published by Colin Beale and Ghassan Ramadan-Jaradi in the journal Sandgrouse, 23, 2, 2001. For further details contact lebanon@arocha.org.