feral Campbell Island sheep were culled during the 1970s and 1980s, with their eventual extermination in 1992. In 2001, brown rats (Norway rats) were eradicated from the island nearly 200 years after their introduction. This was the world's largest rat eradication programme. The island's rat-free status was confirmed in 2003. Since the eradication, vegetation and invertebrates have been recovering, seabirds have been returning and the Campbell teal, the world's rarest duck, has been reintroduced. An undescribed Cyanoramphus parakeet was discovered (in fossil bones) in 2004, along with evidence of a falcon or harrier. Banded dotterel (Charadrius bicinctus) are also believed to have inhabited the island at one point. Other native landbirds include the New Zealand pipit and the Campbell snipe, a race of the Subantarctic snipe, Coenocorypha aucklandica, described race perseverance. It was discovered only in 1997 on a tiny rat-free island off the south coast, Jacqeumart Island. The snipe had survived there and began recolonising the main island after the rats had been removed. Marine mammals have shown gradual recovery in the past decades. Sea lions and southern elephant seals have begun to re-colonize the island. Some southern right whales still come into bays in the winter to winter or calve most notably at Northwest Bay and Perseverance Harbour, but in much smaller number than in the Auckland Islands. Historically, fin whales used to inhabit close to shore. The area is one of five subantarctic island groups designated as a World Heritage Site by UNESCO. Geology Campbell Island is an extinct alkaline shield volcano that marine erosion has worn down into its present shape. The volcano has been extinct for some six million years and glacial ice cover prevented vegetation from growing on the island until approximately 15,000 years ago. Basalt, hawaiite, mugearite and trachyte are the dominant volcanic rocks comprising Campbell Island. They were erupted between 6.5 and 11 million years ago during the Miocene epoch. The island is considered to be part of the submerged continent of Zealandia. Research During World War II, the New Zealand government had coastal watchers on the island with trained naturalists who made observations of the geology, flora, and fauna of Campbell Island. To mark the 200th anniversary of its discovery, the Campbell Island Bicentennial Expedition (CIBE) was undertaken from December 2010 to February 2011. The research expedition was the largest multidisciplinary expedition to the island in over 20 years, and aimed