Egg Island is the smallest ecological reserve in Alberta. Located on Lake Athabasca, it was established to protect a major breeding colony of Caspian terns, a "vulnerable species". The terns are believed to have nested on this island since the early 1900's. They usually nest near the middle of the island. The Egg Island colony is the largest in the province, with well over 100 nesting pairs of Caspian terns. Large numbers of California gulls also nest here. The island is nearly devoid of vegetation on the windward side. On the leeward side, raspberry gooseberry and the occasional willow, balsam poplar and aspen are found.