Browsing by Author "Ali Elafri"

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    Local climate conditions impact on breeding performance of house martin (Delichon urbica) populations in Algeria
    (springer, 2020-12-07) Ali Elafri
    The Mediterranean climate of North Africa encompasses an interesting variety of sub-climates, from humid and sub-humid to semi-arid and arid. Such variability may provide vital insights into mechanisms that drive species distribution and offered us an ideal opportunity to test phenotypic variations along gradients. We aim in this study to investigate the breeding behaviour of house martin Delichon urbica (Linnaeus, 1758) populations along regional climatic gradients in north-eastern Algeria. During two consecutive breeding seasons (2016–2017), nine field sites (328 active nests) belonging to three different sub-climates: humid, sub-humid, and semi-arid were surveyed regularly from March to August.We used generalized linear models to test the relevance of local climate and several ecological variables on laying reproductive output. Laying dates were positively correlated with climate condition (GOF = 0.42), the semi-arid climate creating appropriate conditions for advancing the laying process, whereas sub-humid and humid climate delayed it. Clutch-size and number of chicks hatched per nest were affected by local climate conditions; they were greater in humid areas than in sub-humid and semi-arid ones. The other non-climatic variables as brood order, laying date, distance to fields, and distance to water were not significant. The spatial analysis around nest sites of house martins also showed that dense vegetation cover and reduced urbanization levels may be potential predictors of breeding behaviour. Nest sites located in humid areas with dense vegetation cover, and low urbanization levels that characterize the surrounding landscape provide high-breeding success rate to this species if compared to sub-humid and semi-arid areas. These findings can be a useful indicator of environmental change in a country that is already experiencing severe drought stresses, uncontrolled urbanization, and high deforestation rates.
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    Monitoring human disturbance: Factors affecting escape behaviour of waterbirds in North African wetlands
    (John Wiley & Sons Ltd, 2021-11-25) Ismahan Halassi; Ali Elafri
    nderstanding the factors affecting escape behaviour in waterbirds can be useful in the management of human disturbances. A common measure of escape response is flight initiation distance (FID), the distance at which an approaching intruder disturbs an individual bird enough to make it move away. Here, we analyse the escape behaviour of a set of waterbirds for the first time within a North African context. We tested (one- way ANOVA and general linear model) how FID varied with the area where waterbirds were temporal scale, distance at which the observer start approaching to the sampled birds, body size, flock size, species composition of the flock and foraging activity of the sampled birds. We collected 866 individual FIDs for 19 waterbird species wintering at two north Algerian wetlands (the Mekhada marsh, RAMSAR site, El- taref District and the Sebkhet El- Mahmel, unprotected wetland, Khenchela District). The obtained FIDs ranged from 32.6 m in smaller species as the Kentish plover Charadrius alexandrines to 167 m in larger ones as the ruddy shelduck Tadorna ferruginea. The obtained models stated that differences in the absolute levels of FIDs were mostly related to starting distance (Effect size = 0.62), to which is added a relatively little effect of wetland status, taxonomic differences, temporal scale, body size, flock size, species composition of the flock and bird activity. More specifically, FID was lower in smaller and homospecific groups at early winter in the protected wetland. Reserve managers in North Africa could use species and context- specific FIDs in delineating appropriate buffer areas and in the design of management initiatives aimed at minimising eventual potential threat due to human disturbance and guaranteeing animal welfare and wildlife.
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    RÉPARTITION ET ABONDANCE DE L'ÉRISMATURE À TÊTE BLANCHE Oxyura leucocephala DANS LES ZONES HUMIDES DU NORD-EST ALGÉRIEN
    (A lauda, 2016) Ismahan Halassi; Ali Elafri
    The globally threatened White-headed Duck is one the most rare duck species in the Western Palearctic. Its distribution in Algeria is mainly restricted to the northeastern part of the country and the Hauts-Plateaux. In 2013 and 2014, 694 individuals were counted. The studied sites harboured distinct numbers in winter and in summer of the two years. The p-values (KRUSKALWALLIS test) were lower than 0.05. The Lake Tonga showed the highest numbers in winter and the Boussedra wetland in summer. The results indicated a stable occurrence in the studied areas without any difference between the two years. The PCA analysis showed a significant correlation between the distribution of this species and three following main factors: vegetation, surface area and water depth at the Boussedra wetland, Lake Tonga and Garaet Hadj-Taher. The lower occurrence in other parts of the studied areas, particularly on the HautsPlateaux, is mainly the consequence of drying out process and habitat degradation.
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    Responses of Shorebirds to Human Disturbance at Exposed Sandy Beaches of North-Eastern Algeria
    (International Journal of Ecology & Development, 2022) Ali Elafri; Ismahan Halassi
    Throughout this study we present the results of an expert opinion survey on flight initiation distance (FID) estimates for the three beachiest shorebirds species (Lesser Black-backed Gull Larus fuscus, Black-headed Gull Chroicocephalus ridibundus, Audouin's Gull Ichthyaetus audouinii) when overwintering at exposed sandy beaches Annaba Bay, north-eastern Algeria. Our final data set contained 336 flushing events of the three shorebird species, FIDs for both species ranged from 11m up to 151m. The univariate analysis of variance indicates that the studied Gulls behave similarly against human disturbance, since that mean FIDs were not varied significantly between species (F2= 0.24, P = 0.78). In contrast, change in escape behavior of our sampled species was found to be significant (F2-20.54, P<0.05) across the three coastal sites that were under varying human pressures (High, moderate, and low). In fact, individuals reduced their FIDS when anthropogenic levels increased. Additionally, using a regression analysis, the relationship between starting distance (SD), flock size and FIDs was confirmed (SD: r=0.9, F-176.52, P<0.005; Flock size: r=0.68, df=1, F-30.9, P<0.005), the obtained positive correlations (indicate that escape behavior of our birds increases with the starting approaching humans distance, and with flock size. Producing information of the extent and circumstances under which birds may habituate to stresses are an evidence-base which can be used by regulatory authorities to start appropriate site-specific assessments for anthropogenic marine activities with regard to the sensitivity or habituation of seabirds to such activities.