Surveying roosting harriers in the Aammiq Wetland, Lebanon

The Aammiq Marsh in spring

The Aammiq Wetland in the Bekaa valley is designated as an Important Bird Area and the marsh has been observed to provide roosting habitat for all four European Harrier species, including the endangered Pallid Harrier (Circus macrourus) which is thought to have a breeding population of as few as 310 pairs. In the autumn of 2004 A Rocha Lebanon initiated a survey to ascertain the numbers of roosting harriers as well as their roosting locations.

The aims of the survey were

To monitor the number of harriers, in particular the endangered Pallid Harrier, using the Aammiq Marsh as a roosting site during their migration and over-wintering.
To determine the habitat in the marsh which the harriers prefer for roosting, in order to conserve and manage these areas.

The monitoring, which was conducted between September 2004 and mid-June 2005 recorded four harrier species - Hen Harrier (Circus cyaneus), Marsh Harrier (Circus aeruginosus), Pallid Harrier and Montagu’s Harrier (Circus pygargus) - and assessed the habitat conditions of each roosting site based on four parameters:

Average height of vegetation
Depth of water in cm
Percentage cover of vegetation in the categories reed, sedge, grass, herb, bare earth, crop, etc.
Species of plants

The survey found that the timing of peak numbers of roosting birds varied between species. Hen Harriers were found to peak at the end of January / early February with 25 birds; Marsh Harriers in the third week of Febuary with 38 birds; Pallid Harriers had two peaks, one at the end of November / early December and the other at the end of March / early April, with a maximum of 4 birds; and Montagu’s Harriers in September with 10 birds. The causes of these peaks are not fully known although they are thought to relate to migration patterns and seasonal changes in vegetation structure that alter habitat roosting conditions. The second scenario appears to be have an influence on Marsh Harriers who use the reed beds to roost until the reed shoots mature and become too strong to be suitable.

Observations identified that some clear roosting preferences exist between the species and that there are some patterns common to all. All the harriers used their own "hare-like" form when roosting in the vegetation and the individual sites were at least 5 m apart. But the Montagu’s, Pallid, Hen and ring-tailed harriers (females and immatures of the former 3 species) preferred the lower vegetation (up to 1 m), while Marsh Harriers roosted in the high reed beds (up to 4 m).

The Aammiq Wetland, looking east, at dawn

Aammiq at sunrise

Through this research A Rocha Lebanon has confirmed that the Aammiq Wetland is a very attractive location for roosting harriers, and possibly the most suitable area within the Bekaa Valley. Monitoring has indicated that birds may come from as far as Syria to roost at the site suggesting that the wetlands have a huge catchment area. Records of Pallid Harriers demonstrate the value of the site for this endangered species. The harrier survey is now part of the A Rocha Lebanon monitoring programme of the Aammiq Wetland.

Looking forward A Rocha shall incorporate the results of the roosting sites habitat research in all wetland management strategies and regimes to ensure that healthy roosting habitat is maintained. The survey also highlighted the impact of hunting on roosting birds. In partnership with the Aammiq warden’s patrol, A Rocha Lebanon shall attempt to encourage the enforcement of hunting restrictions within the area to limit its impact on roosting harriers. Further study should be done in other wetlands in the region (e.g. at Aanjar in the eastern Bekaa) to determine whether or not Aammiq is the only site for roosting harriers in Lebanon.

Project leader: Marius P. Teeuw and Colin Conroy. For more information please contact lebanon@arocha.org

Partners: Skaff Family, MedWet Coast, Ministry of the Environment of the Government of Lebanon.