James Campbell National Wildlife Refuge is located near Kahuku Point at the northern tip of the island of O`ahu. The refuge consists of two units, the 51-hectare (126-acre) Ki`i unit and the 54.2 hectare (134-acre) Punamano unit, which is located 1.6 kilometers to the northwest of Ki`i. The Punamano unit contains a natural spring-fed marsh and typically has deeper water than the Ki`i unit. The Ki`i unit contains several large, shallow impoundments that were created as settling ponds for the Kahuku sugar cane mill, which was built in 1890. These ponds were heavily used by waterbirds, but they began to dry up when the mill closed in 1971. In 1976, the ponds were leased from the estate of James Campbell by the U.S. Fish and Wildlife Service and managed as the James Campbell National Wildlife Refuge. The primary purpose of the refuge is to protect and manage habitat for recovery of endangered waterbirds. There are numerous smaller ponds on adjacent private lands that have been used for commercial aquaculture, primarily of prawns, and that are also heavily used seasonally by waterbirds. Water levels in the impoundments at Ki`i can be controlled through a series of water control structures and wells to manage habitat for endangered and migratory waterbirds. Habitats include a freshwater marsh, open water, emergent aquatic vegetation, mudflats, and adjacent grassland and shrubland dominated by alien plants. The refuge is generally not open to the public, but public tours are conducted on a portion of the refuge by volunteers from the third Saturday in October through the third Saturday in February when Hawaiian stilts are not nesting. In July 2005, the lands comprising the refuge were purchased from the Estate of James Campbell. Negotiations are underway to purchase additional lands that would expand the refuge to approximately 1,100 acres. This additional acquisition would involve land between the Ki`i and Punamano units and along the coastal dunes to the north.
James Campbell National Wildlife Refuge contains one of the largest concentrations of wetland birds in Hawai`i. It is an important breeding, feeding, and resting area for three birds listed under the U.S. Endangered Species Act; the Hawaiian Stilt, Hawaiian Coot, and Hawaiian Common Moorhen. The Hawaiian Coot is an endemic species, the Hawaiian Stilt and Hawaiian Common Moorhen are endemic subspecies. Maximum numbers of these taxa recorded on the refuge are 295 coots in August 2000, 276 stilts in August 1994, and 98 moorhens in October 2006. The endangered Koloa or Hawaiian Duck was reintroduced to O`ahu in the 1960s and formerly occurred on the refuge, with a maximum of 63 recorded in January 1988, but hybridization with feral Mallards has become widespread on O`ahu and most or perhaps all of the birds now using the refuge are hybrids. The refuge also supports significant numbers of Bristle-thighed Curlews during fall migration, with a maximum of 53 birds observed in October 2007. The number of curlews using the area has increased recently, and some now spend the entire winter. The refuge also supports a variety of migratory waterbirds. At least 72 species of waterbirds have been documented using the refuge, including 24 waterfowl, 4 herons, 29 shorebirds, and 13 gulls and terns. Some species occur primarily during migration, but others are present throughout the winter. Some of the more common migrants are Northern Pintail (122), Northern Shoveler (160), Lesser Scaup (57), Pacific Golden Plover (300), and Ruddy Turnstone (200). Although these numbers are small by continental standards, they represent some of the largest concentrations of these species in Hawai`i and the Pacific. The refuge has also hosted many unusual vagrants, including Northern Harrier, Peregrine Falcon, Black-tailed Godwit, Hudsonian Godwit, Curlew Sandpiper, Solitary Sandpiper, and Snowy Egret, making James Campbell National Wildlife Refuge one of the top sites for wetland birds in Hawai`i.
The greatest threats to wetland birds at James Campbell National Wildlife Refuge are predation by non-native animals, invasive alien plants, outbreaks of avian botulism, sea level rise, and, for the Hawaiian Duck, hybridization with feral Mallards. Predation by feral dogs, feral cats, mongoose, and rats is a serious threat to all waterbirds on O`ahu, especially their nests. Non-native bullfrogs are a serious predator on small waterbird chicks. These predators are controlled on the refuge to protect waterbirds. Outbreaks of avian botulism have been less severe and have occurred less often at James Campbell than at other Hawaiian wetlands. A few instances of individual dead birds has been documented, but water management capabilities and quick response to correct conditions leading to botulism outbreaks (nutrient-rich sediments, high water temperature, low dissolved oxygen, and fish mortalities) have helped to control this potentially deadly disease. Invasive alien plants, particularly California grass (Brachiaria mutica) and Indian fleabane (Pluchea indica), can degrade habitat quality by encroaching and choking wetlands, and require regular control through prescribed burning, water level fluctuation, and mechanical clearing. The number of feral Mallards on O`ahu has increased since Koloa were reintroduced to the island in the 1960s, and hybridization between Koloa and feral Mallards is now common and widespread. Recent changes in regulations have made it illegal to import Mallards into the State of Hawaii, but there already may be no pure Koloa left on O`ahu. Existing feral Mallards should be removed to prevent hybridization and any further genetic introgression into the Koloa population, and it may be necessary to augment the Koloa population on O`ahu with birds from Kaua`i. Global sea level rise and surge from more intense storms could inundate freshwater and brackish coastal wetlands needed by waterbirds.
All of the land comprising James Campbell National Wildlife Refuge is owned by the U.S. Fish and Wildlife Service.
James Campbell National Wildlife Refuge includes open water habitat, a freshwater marsh, emergent aquatic vegetation, mudflats when water levels are low, and adjacent upland grassland and shrubland habitats that are dominated by alien plants. Water levels in the impoundments are controlled through a network of water control structures and wells in order to provide nesting and foraging habitat during the appropriate seasons and increase habitat diversity. Several small islands provide limited predator-free nesting habitat.
James Campbell National Wildlife Refuge was established for the conservation of four species of endangered waterbirds, and that continues to be its primary purpose. Under recently approved legislation, the purposes of the refuge now also include conservation of the threatened green sea turtles, the endangered Hawaiian monk seal, as well as seabirds. The refuge is not generally open to the public, but public tours are conducted on a portion of the refuge by volunteers from the third Saturday in October through the third Saturday in February when Hawaiian stilts are not nesting. The refuge contains several small buildings and equipment sheds that are used for management purposes, and two small kiosks that contain educational and interpretive information.