International Day for Biological Diversity marked in Thessaloniki, Greece

Photo taken on May 21, 2018 shows a Pelophylax Kurtmuelleri frog on the shores of an artificial lake near the town of Thessaloniki, Greece. The United Nations has proclaimed May 22 the International Day for Biological Diversity to increase understanding and awareness of biodiversity issues. (Xinhua/Dimitris Tosidis)