There’s an island off the coast of Australia where a pair of dogs guard a colony of tiny penguins so they won’t be wiped out by foxes. The ‘little penguin’ colony was nearly extinct until 2006, when the trained Maremma sheep dogs were put on the island to be their protectors. No penguins have been killed by foxes since the program began, and the population increased from fewer than 10 to nearly 200. Source Source 2 Source 3