Responses of Shorebirds to Human Disturbance at Exposed Sandy Beaches of North-Eastern Algeria

Abstract

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. In contrast, change in escape behavior of our sampled species was found to be significant 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, 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.