RAT OF THE SKY: A Yellow-legged Gull takes flight near the Tamentfoust harbour, east of the capital Algiers. The Yellow-legged Gull, only recently classified as a species distinct from the Herring Gull, is invasive, aggressive, noisy and very messy. Today it can be found as far as 100 kilometres inland, says Professor Riadh Moulai of the University of Bejaia. The “rat of the sky”, as it has been locally dubbed, has taken advantage of human waste to supplement its normal diet of marine scraps, breeding fast and becoming the region’s most common seabird. — AFP