The vaquita porpoise is small by cetacean standards, averaging just over four feet in length. Identified as a separate species only in 1958, it is found exclusively at the northern end of the Gulf of California. The name is Spanish for “little cow”. In addition to its small size, it differs from other porpoise by having dark rings around its eyes, dark patches on its lips, and a gray line that extends from its dorsal fin to its mouth. The dorsal surface is dark gray and the ventral surface is white. It spends little time on the surface, coming up for a quick breath and then rapidly descending. Like other cetaceans, it uses echo-location to navigate, communicate, and find prey. It feeds on a wide variety of fish and squid. Unlike most other cetaceans, it is not highly social. In addition, it attempts to avoid human contact, swimming away when a boat approaches. Its lifespan is estimated at 20 years. Due to its rarity, there being only about 100 vaquita porpoises remaining, it is not hunted directly. The species faces extinction, though, from use of illegal gill nets by Mexican fishermen seeking fish in those waters. A portion of the northern Gulf of California has been designated as a wildlife preserve where gill netting is banned, but enforcement remains a problem. A conservation campaign seeks to expand the refuge boundaries and enhance enforcement, but has been unsuccessful to date. Other threats to the vaquita porpoise include habitat loss and water pollution.