The Island of Maui formed from two shield volcanoes that were close enough that their lava flows overlapped, forming an isthmus between them.
The oldest volcano, that formed the West Maui Mountain, is about 5,000-feet high. The younger volcano, Haleakalā, on the east side of the island is over 10,000-feet high.
The isthmus that separates the two volcanic masses is formed from erosional deposits and is the prominent topographic feature for which the island is known: “the Valley Isle.”
Keālia was once an ancient fishpond supplied with water from the Waikapū Stream in the West Maui Mountain and Kolaloa Gulch originating from Haleakalā.
Native Hawaiians may have raised awa (milkfish) and ʻamaʻama (flathead mullet) using a system of ditches and sluice gates to let nearby fish from Māʻalaea Beach into the pond.
Established in 1992, Keālia Pond National Wildlife Refuge encompasses approximately 700-acres and is one of the few natural wetlands remaining in the Hawaiian Islands. Located along the south-central coast of the island of Maui, between the towns of Kīhei and Māʻalaea. (USFWS)
A new visitor center (2012) with exhibition hall and staff offices, replacing a trailer, was dedicated and is in use at the Wildlife Refuge. This, with the coastal boardwalk and interpretive signage, gives a great opportunity to see and learn about the Wildlife Refuge.
Seasonal conditions that occur at Keālia Pond National Wildlife Refuge make it a notable place for people to observe Hawai‘i’s endangered wetland birds, along with a diversity of feathered visitors from as far away as Alaska and Canada, and occasionally from Asia. (USFWS)
At the turn of the century, about 40,000-ducks wintered in Hawaiian wetlands; today, that number is around 2,000. Four of the five native water birds are now classified as endangered.
Keālia Pond serves as a settling basin a 56-square mile watershed that results in seasonal intermittent flooding during winter months and dryer conditions during late summer months.
This creates open water (200-acres) and shallow mud flat areas interspersed with vegetation, which provide suitable resting, feeding, and nesting habitat for endangered water birds. During certain times of the year, the refuge supports at least half of the Hawaiian stilt population.
The pond also supports a diverse group of migratory birds from late summer (August) to early spring (April). It is one of the most important areas in the state for wintering migratory waterfowl.
Migratory shorebirds also congregate here to take advantage of the food resources along the water’s edge. As water recedes, fish are crowded into the remaining water, making them easy prey for ʻaukuʻu (black-crowned night herons).
Baitfish ponds were constructed in the early-1970s for aquaculture of baitfish species; however, the use of these ponds for waterbirds was minimal because of the thick coverage of nonnative, invasive plants on the levees and within the ponds.
This wetland is home to the endangered aeʻo (Hawaiian stilt) and ʻalae keʻokeʻo (Hawaiian coot.) The refuge is adjacent to Keālia Beach, which is a nesting ground for the endangered hawksbill turtle. (USFWS)
The aeʻo adult males and females are mostly black above and white below, with a long, thin black bill and long pink legs. Found generally across the Islands, they also call Keālia home.
The total aeʻo population is estimated to be between 800 to 1,100 birds, depending on the amount of rainfall in any given year. Wetlands are essential for natural foraging areas to feed juveniles. (Goody, WHT)
With between 1,500 and 3,000 individuals, Maui’s Keālia Pond National Wildlife Refuge and Kanaha Pond Wildlife Sanctuary have the second largest population of ʻalae keʻokeʻo in the state (O‘ahu is first).
The ʻalae keʻokeʻo is dark slate gray with a white bill and a large frontal shield (extension of bill onto forehead). The frontal shield is white but some sport a small red dot which is not related to sex or age. ʻAlae keʻokeʻo have white undertail feathers that are visible when adults are defending their territory and during courtship displays. (Lots of information here from USFWS.)
The image shows Keālia Pond Visitor Center sign (MauiNews.) In addition, I have added other related images in a folder of like name in the Photos section on my Facebook and Google+ pages.