which connects with Nu’upia Ponds Photo by Diane Drigot Safeguarding Hawaii’s Endangered Stilts

of Marine Corps Base-Hawaii (MCBH) is a busy military installation on the island of O‘ahu. This 2,951-acre (1,195-hectare) facility also provides safe haven for some 50 species of waterbirds, shore-birds, and seabirds. Among them are all four of Hawaii’s endangered waterbirds: the ae‘o or Hawaiian stilt (Himantopus mexicanus knudseni), ‘alae keo‘keo or Hawaiian coot (Fulica alai), ‘alae ula or Hawaiian gallinule (Gallinula chloropus sandvicensis), and koloa or Hawaiian duck (Anas wyvilliana). The best stilt habitat on base is at Nu‘upia Ponds Wildlife Management Area, a complex of interconnected shallow ponds and vegetated mudflats. Shoreline marshy areas, golf course ponds, and a constructed storm water retention basin also contain waterbird habitat. Management activities at MCBH have more than doubled the number of stilts counted on base from about 60 to 130 over the past 20 years. Currently, the base harbors nearly 10 percent of the state’s total estimated stilt population of 1,500 to 1,800 birds (Rauzon and Tanino 1998). Increased stilt reproduction is most noted where there is deliberate manipulation of invasive plants. Two of the main species targeted for control are mangrove (Rhizophora mangle) and pickleweed (Batis maritima). Mangroves are not native to Hawaii. Introduced in the early 1900s, this species is now a major pest in coastal wetlands, including Nu‘upia Ponds. In the early 1980s, base resource managers and community volunteers began to remove small mangroves with hand-held tools. In the 1990s, more than $2 million was spent on mechanical removal of about 20 acres (8 ha) of mangrove and associated monitoring studies (Drigot 1999). Volunteers keep mangrove regrowth in check. Since the early 1980s, invasive pickleweed has been controlled through annual “mud ops ” maneuvers by Marin