Least terns are the smallest member of the tern family. They are only 8-9 inches (20-23 cm) long, with a 20 inch (51 cm) wingspan. They havea black crown with a white forehead, gray back, gray wings above and white below, orange legs and a black-tipped yellow bill. Sexes are identical. Apart from the small size, the most easily distinguishing feature of the least tern is the white triangular mark on the forehead.

Look at the least tern in the photo on the left compared with a common tern on the right.

In South Dakota, least terns nest on unvegetated sandbar islands and shorelines near the river. Least terns eat small fish, so they often nest near backwaters where this prey is available. Least terns nest in small numbers on Lake Oahe, but they are primarily a riverine species, and most pairs in South Dakota nest below Gavins Point Dam.

Least terns are extremely sensitive to disturbance. When an intruder enters the area, least terns take to the air, vocalizing loudly, vomiting and defecating. This activity not only wastes a lot of energy, but it also leaves the eggs and young vulnerable to predators or the weather, increasing the likelihood that they will die from exposure. Since the young are dependant on their parents for food, disturbing the birds also increases the likelihood that the young will not survive due to starvation.

Please respect signed areas and stay out!

There have not been any rangewide surveys for the least tern, but experts estimate there may be approximately 12,000 least terns (USFWS 2003).

On the Missouri River, least terns have been surveyed annually since 1993. Numbers vary annually, with a low of 427 adults in 1997, and a high of 741 adults in 2003.

In South Dakota, least terns have ranged from a low of 158 adults in both 1996 and 1997 and a high of 521 adults in 2003. South Dakota is on the northern edge of the least tern's range. Most birds nest on the Lower Mississippi River (USFWS 2003).

Share your enthusiasm with others, and make sure that they understand how important it is to enjoy piping plovers from a distance without disturbing them.

Volunteer your time and energy to conservation agencies and organizations in efforts to restore cottonwood forests for future bald eagle habitat. Local Pierre, South Dakota organizations include the Missouri Breaks Audubon Chapter and the High Plains Wildlife Association.

Be aware of legislation affecting conservation efforts. Contact your elected representatives at all government levels.