Least bittern

The least bittern is a widespread species with a large breeding range consisting of the entire eastern half of the U.S. as well as several additional local sites as far west as California and Oregon. It winters in portions of Mexico and Central America and is a year-round resident in southern Florida, the Caribbean, Mexico, Central America, and portions of South America as far south as northern Argentina.

Least bittern habitat is largely tall emergent vegetation within freshwater marsh, although they may occasionally occupy coastal brackish marsh as well. They will use artificial wetlands as well as wetlands near lakes, rivers, or estuaries. During migration or in winter, bitterns may be found in wetlands, marshes, and grassy fields.

Least bitterns prey on small fish, amphibians, mollusks, crustaceans, insects, and some small mammals.

Hidden by its camouflaged feathers, the bittern stalks prey, standing motionless before striking with its spearlike bill. Bitterns hunt alone. They search for food within marshes or along the shorelines of creeks during the day or at night. They may also cling to reeds and other emergent vegetation in order to forage over deeper water.

The breeding season for the least bittern in New Jersey is between mid-May and late August. A platform nest is built in a dense stand of emergent vegetation over shallow water, about a foot above the water. Both sexes construct the nest out of dried plants among live stalks. 4 to 5 eggs, sometimes as many as 7, are laid in May or June and incubation lasts 16 to 19 days. The young are semi-altrical and are tended to by both parents. The young can leave the nest 4 to 5 days after hatching but normally leave at 13 to 15 days. They are capable of flight at 25 days after hatching.

The least bittern has undergone a decline in population over the last several decades throughout some portions of its range including New Jersey. Such declines are most likely due to loss of wetland habitat. It is listed as a Species of Special Concern in New Jersey (not yet endangered or threatened but possibly on its way).

Wetland destruction has occurred at an alarming rate in New Jersey, destroying wetlands critical to breeding bitterns. Like many species in the state, protecting bitterns is closely tied with protecting their wetland habitats. Strong environmental laws to protect wetlands from disturbance and development help to protect wetlands as well as bitterns.

Because of the secretive nature and patchy distribution of least bitterns, we still have much to learn about their biology and population status. Research needs to be completed to find additional breeding sites, check existing nesting areas, and determine their population status within the state.