Hawaiian Islands Subregion 19

Hawaiian Islands 

Description of the Subregion 

The Hawaiian Archipelago lies within the tropical 

and subtropical North Pacific, and consists of 132 

islands, reefs, and shoals stretching 1,523 miles 

(2,452 km) from the Island of Hawai`i at Latitude 

18 ̊ 54’ N to Kure Atoll at 28 ̊ 15’ N. There are 

eight, large volcanic islands, collectively called the 

Main Islands (Figure 3, Appendix 3) and numerous 

associated rocks and islets. The Leewards, or 

Northwestern Hawaiian Islands, comprise nine 

small islands/atolls extending from Nihoa to Kure.

Main Hawaiian Islands

As one proceeds northwest along the chain from 

the island of Hawai`i (also known as Big Island), 

the largest and youngest island, the islands become 

progressively older. Ni`ihau, the oldest of the Main 

Islands, is privately owned. Until 1990, Kaho`olawe, 

the smallest of the Main Islands, was used as a Navy 

bombing range. Access is restricted on both islands.

The Main Islands lie completely within the tropics 

and comprise 99 percent of the landmass of the 

chain. Limited landmass, only 6,540 mi2 (16,939 km2), 

translates to limited land base for shorebirds. Add 

to this the mostly mountainous nature of the Main 

Islands, and it becomes clear that there is little 

space for lowland wetlands and coastal strands. Thus 

impacts on coastal habitats, used by shorebirds, are 

amplified. There is a distinct wet (windward) and dry 

(leeward) side to each island. Windward coasts and 

slopes have rainfall areas that can exceed 400 inches 

(1,016 cm) per year, whereas leeward habitats can be 

quite arid with less than 10 inches (250 cm) per year. 

As a result of this inequity of precipitation, most 

of Hawai`i’s wetlands are located in river valleys 

and estuaries on the windward coasts of the Main 

Islands. There are exceptions. For example, Pearl 

Harbor is located on O`ahu’s south (dry) coast. In 

addition, basaltic islands possess perched freshwater 

lenses in the porous rock, resulting in coastal springs 

and groundwater wetlands, even on the leeward 

shores. The USFWS estimates the area of coastal 

plain wetlands decreased by 31 percent between 

1780 and 1990, from 22,475 ac (9,095 ha) to 15,474 

ac (6,262 ha) (Dahl 1990). Approximately 70 percent 

of the remaining wetlands are overgrown with 

invasive plants and have altered surface and ground 

hydrology (Shallenberger 1977). Many of 

Hawaiian Islands Subregion

0 200

Kure 

Atoll

Northwestern Hawaiian Islands

Midway 

Atoll Pearl and 

Hermes Reef

Lisianski 

Island

Laysan 

Island

Maro Reef

Gardner 

Pinnacles

French Frigate 

Shoals 

Necker 

Island

Nihoa 

Island

175 ̊ W 170 ̊ W 165 ̊ W 160 ̊ W 155 ̊ W

30 ̊ N

25 ̊ N

20 ̊ N

Miles

Ni'ihau

Kaua'i

O'ahu

Moloka'i

Maui Lana'i

Kaho'olawe

Hawai'i

Main Hawaiian Islands

FIGURE 3. Hawaiian Islands Subregion
 20 U.S. Pacific Islands Shorebird Conservation Plan

Hawaiian Islands 

Hawai`i’s largest wetlands have been protected 

by State and Federal agencies as sanctuaries and 

refuges. However, protection of the remaining 

areas, restoration, and active management are high 

priorities.

In contrast to the loss of wetlands, grassland 

habitats on the Main Islands have increased since 

human colonization. Much of this increase was at 

the expense of native forests, which were cleared 

and converted for agriculture, pastures, and human 

dwellings. Large ranches, especially on the islands 

of Hawai`i and Maui, provide extensive areas of nongrazed and grazed grasslands. Grassland acreage on 

these islands has declined over the past thirty years, 

due to shifts in land values and crop economics, and 

development for an expanding human population 

(Table 3). The Island of Hawai`i accounts for over 55 

percent of the total farm acreage, mostly as pasture, 

and Maui accounts for an additional 20 percent, 

mostly as diversified agriculture (Morgan 1983, 

State of Hawai`i 1999).

Increasing human population has resulted in 

increased amounts of non-agricultural grasslands 

in the form of parks, golf courses, cemeteries, and 

lawns. The majority of this habitat type is privately 

owned or owned by city, county or State agencies 

and managed for uses other than wildlife. However, 

these parklands are widely used by golden-plovers, 

and to a lesser degree other shorebirds.

The Northwestern Hawaiian Islands

These small islands are in stark contrast to the 

Main Islands. In general, they are highly eroded, 

low sand islands and atolls that support extensive 

coastal strands and reefs relative to their landmass. 

Nihoa and Necker (the youngest) are small, steep 

rocky islands supporting only tiny sand beaches. 

Gardner and La Perouse pinnacles are also rocky 

outcroppings. Sandy beaches and bunchgrass 

dunes are the dominant habitat on the remaining 

Northwestern Islands. These islands support a low 

diversity of plants, mostly herbaceous species and 

small shrubs and trees. By definition, the atolls 

(Kure, Midway, Pearl and Hermes, French Frigate 

Shoals) have fringing coral reefs and interior lagoons 

that are open to the ocean. Laysan Island has a 

closed lagoon (technically a lake) that is hypersaline, 

and the only natural wetland in the leeward islands. 

Historically Midway, Kure, and French Frigate 

Shoals were operated as military installations and 

consequently have been highly altered. All have 

runways and permanent buildings. Midway, with the 

longest history of human occupation, has a welldeveloped, non-native ironwood forest (Casuarina 

equisetifolia). Midway Naval Air Station closed 

in 1996, and the Coast Guard Loran Stations on 

Kure and French Frigate Shoals were closed in 

1991 and 1979, respectively. Today, all are protected 

as National Wildlife Refuges or State Wildlife 

Sanctuaries and public access is restricted and 

controlled by permit. USFWS maintains a small 

permanent staff at Midway and French Frigate 

Shoals and a private contractor maintains staff at 

Midway Atoll to support the airfield.

Shorebird Habitat Use 

Wetlands, estuaries, tidal flats, grasslands, and 

uplands are the most important habitats for 

migrant and resident shorebirds. Wetlands and tidal 

flats support the highest diversity and density of 

shorebirds. Grasslands and beaches are important 

for two priority species, Pacific Golden-Plover and 

Bristle-thighed Curlew. Historical notes highlight 

the importance of tidal flats for migrant shorebirds 

(Perkins 1903, Munro 1945, Cogswell 1945). Tidal 

flats of Pearl Harbor were especially important 

through at least the late 1950s (R. L. Pyle pers. 

comm.). In 1945, surveys in Pearl Harbor yielded 

over 1,600 shorebirds (Cogswell 1945, Table 4). Most 

are now overgrown with introduced mangroves.

During high tide, golden-plovers that are utilizing 

tidal flats move inland, but readily return to tidal 

flats at low tide. Today, high numbers of goldenplovers can be found on O`ahu in Kewalo Basin, 

Pearl Harbor, the southeastern shore from Diamond 

Head to Koko Head, and on Moloka`i’s south 

shore (SIGHTINGS Database, Audubon Society 

TABLE 3. ���������������������������������������������������������������������

���� �������������

������������������������

���������������������

�����������������������

�����������

�����������������������

���� 2,300 (932) 1,340 (543) 526 (213) 

���� 1,970 (798) 1,150 (466) 420 (170) 

���� 1,720 (625) 1,010 (412) 290 (118) 

���� 1,440 (588) 870 (355) 290 (118) 

���������� 37% 35% 45% 

��������������������������������������������
 Hawaiian Islands Subregion 21

Hawaiian Islands 

Christmas Counts, A. Engilis, Jr. unpub. data). 

Ephemeral playas and alkali wetlands also support 

large numbers of shorebirds, and are next in 

importance for diversity and abundance. Kealia 

Pond, during fall migration (August through 

October), supports over 1,000 golden-plovers and 

14 species of shorebirds (USFWS unpubl. data). 

The small hypersaline lagoon on Laysan regularly 

supports over 4,000 shorebirds (Ely and Clapp 

1973). Most other playas in the State have become 

overgrown with pickleweed and fleabane and are 

not used by shorebirds. Aerial surveys (DOFAW 

winter waterbird survey records) indicate Ni`ihau’s 

playas are important for shorebirds. However, 

ground surveys are needed to more accurately 

assess shorebird abundance and diversity. The last 

reported ground survey, in 1939, provide only a 

glimpse of the potential of these ephemeral playas. 

Wetland complexes comprised of wildlife refuges 

and aquaculture facilities (involving playas, seasonal, 

semipermanent and permanent ponds, aquaculture, 

and cane waste ponds) historically supported 

numerous birds; particularly on O`ahu’s North 

Shore from Kahuku to Wailua (Figure 4). Peak 

shorebird numbers, in diversity and population are 

in the middle of the fall migration (Oct. – Nov.). 

Many managed water projects in the Main Islands 

have become important habitat for shorebirds 

and the scant data available is summarized for the 

first time in this plan. Indeed some of the highest 

concentrations of shorebirds can be seen at the 

State’s aquaculture farms. However, the endemic 

Hawaiian Stilt as well as migratory shorebirds, 

become dependent upon these managed sites 

and when economic pressures result in closure, 

the ponds are abandoned and allowed to dry. 

This pattern of dependence and loss of habitat 

has occurred numerous times in the past 15-20 

years with the collapse of the sugar cane industry 

(resulting in the loss of reservoirs and wastewater 

ponds) and fluctuations of the heavily subsidized 

mariculture (shrimp) industry. Data from Hawai`i’s 

Kona Coast verifies this over-dependence on waste 

ponds and aquaculture (Figure 5). Reservoirs 

are widely used by shorebirds, particularly when 

drawn down (Shallenberger 1977). Kaua`i and Maui 

support the largest concentration of reservoirs, all 

of which are now being lost due to the collapse of the 

cane industry. Waipi`o Peninsula in Pearl Harbor 

was used by the O`ahu Sugar Company as a site for 

disposal of cane water. Several ponds were created 

that were managed to catch water and sludge. These 

ponds were the most popular sites in the State 

for bird watchers because of the high numbers of 

shorebirds (both diversity and density). The ponds 

dwindled in numbers as production curtailed in the 

FIGURE 4. Shorebird Counts on wetland complexes of O`ahu’s Kahuku Plain (A. Engilis 1988, unpubl. data)

TABLE 4. Summary of Birds Counted (mean) on Pearl 

Harbor Tidal Flats September - December 1945 

(Cogswell 1945) 

�������� �����������

���������������������� 583

���������������� 585

������������������ 35

��������������� 1

����������� 251

��������������� 163

������ 1,618

0

100

200

300

400

500

600

700

800

900

9/10/1988

9/17/1988

9/24/198810/1/198810/8/1988

10/15/1988

10/22/1988

10/29/1988

11/5/1988

11/12/1988

11/19/1988

11/26/1988

12/3/1988

Birds Counted

Pacific Golden-Plover

Ruddy Turnstone

Totals
 22 U.S. Pacific Islands Shorebird Conservation Plan

Hawaiian Islands 

mid-1980s and then were lost entirely when the mill 

went under in the early 1990s. During that time 

shorebird numbers declined at Waipi`o (Figure 6).

As elsewhere in North America, wastewater 

treatment ponds attract large numbers of 

shorebirds. Normally these would not be mentioned 

in a plan of this nature, but with limited wetlands, 

their mere presence has altered patterns of bird use. 

In some cases they represent the only “wetlands” 

on an island or a particular region of an island. One 

need only look at the small facility on L na`i as an 

example. L na`i is a dry island and up until 1989 

did not support native waterbirds. This changed 

with the opening of the L na`i City oxidation ponds. 

Pioneering Hawaiian Stilts quickly found this facility 

and are now nesting on L na`i. Surveys of the 

ponds in 1999 yielded seven species of shorebirds 

in small numbers (A. Engilis, Jr. pers. obs.). As 

long as these managed ponds exist, they will be an 

important resource for Hawaiian Stilt and migratory 

shorebirds.

FIGURE 5. Hawaiian Stilts in Aquaculture and Waste Ponds vs. Natural Wetlands, Kona Coast, Hawai`i

 (Ducks Unlimited 2002)

FIGURE 6. Shorebird Decline Since the Collapse of the O`ahu Sugar Mill in Early 1990s(Source: NAS 2000, 2001)

0

50

100

150

200

250

300

8/21/1997

11/21/1997

2/21/19985/21/19988/21/1998

11/21/1998

2/21/19995/21/19998/21/1999

11/21/1999

2/21/20005/21/20008/21/2000

11/21/2000

2/21/20015/21/2001

Number Hawaiian Stilts 

Waste Ponds/Industry

Natural Wetlands

0

200

400

600

800

1000

1200

77 78 79 80 81 83 84 85 86 87 88 89 90 97 98 99

Year

Total Birds
 Hawaiian Islands Subregion 23

Hawaiian Islands 

The beaches, bunch grasslands, and sparse 

shrublands of the Northwestern Hawaiian Islands 

support a surprising number of shorebirds 

(Amerson, Jr. 1971, Woodward 1972, Ely and 

Clapp 1973). Ample food, seclusion from human 

disturbance, and predator-free conditions are 

ideal for wintering species. Historically, beaches 

on the Main Islands no doubt provided important 

shorebird habitat, and still do, to a limited degree. 

Unfortunately most of the Main Island’s beaches are 

key components to the tourist industry and human 

disturbance is high. A few secluded or protected 

beaches do provide limited habitat for shorebirds 

(e.g. on L na`i, Kaua`i’s Na Pali Coast, and Kaena 

and Kahuku points, O`ahu). 

The final habitat type used by shorebirds is 

grassland. These vary from urban parks and golf 

courses to large grazed pastures on the Island of 

Hawai`i. These habitats support a large number 

of golden-plovers, as well as a few turnstones, and 

Hawaiian Stilts (lowlands only). There are no data to 

quantify the importance of upland pastures, but field 

observations during the past decade indicate they 

are important for golden-plovers (A. Engilis, Jr. and 

K. Uyehara pers. obs.).

Northwestern Hawaiian Islands

Laysan Lagoon (735 ac [300-ha]) is a closed system 

that undergoes seasonal fluctuations in both depth 

and salinity. Brine flies and shrimp are abundant and 

provide an excellent food source for shorebirds. The 

lagoon along with adjacent sandy beaches provides 

important habitat for Pacific Golden-Plover, Bristlethighed Curlew, and Ruddy Turnstone. Numbers 

exceeding 5,000 shorebirds are regularly counted 

during winter months (USFWS unpubl. records, 

NAS 2000, 2001, Ely and Clapp 1973). Another 

closed system is located on Spit Island, Midway 

Atoll. Smaller numbers of turnstone and tattlers 

winter there (A. Engilis pers. obs). An artificial 

water catchment on Midway Atoll also provides 

some wetland habitat for migrant shorebirds. 

The most significant shorebird habitat in the 

Northwestern Hawaiian Islands is the secluded, 

uninhabited beaches and associated dry grasslands. 

The most extensive areas of this habitat type are 

on Kure, Midway, Pearl and Hermes, Lisianski, 

Laysan, and French Frigate Shoals. Fringing reefs 

also occur in association with the islands and support 

a few shorebirds, but are virtually unexplored 

and unsurveyed. The high counts of shorebirds 

on Christmas counts of Laysan and Midway show 

the importance of these islands (and habitats) for 

migratory shorebirds. These remote island habitats, 

particularly bunchgrass, are critical for Bristlethighed Curlew (especially when they are flightless 

during molt) (Marks et al. 2002), but also support 

large numbers of Pacific Golden-Plover, Ruddy 

Turnstone, Wandering Tattler, and Sanderling.

Ni`ihau

As mentioned earlier, the ephemeral wetlands 

on Ni`ihau, are among the most important for 

migratory and endemic shorebirds in the Hawaiian 

Islands (Munro 1940, T. Telfer pers. comm.). State 

waterbird surveys have documented large numbers 

of Hawaiian Stilt (perhaps as many as 50 percent 

of the world population) nesting and foraging on 

Ni`ihau during wet years (Engilis and Pratt 1993). 

Three playas, when flooded, provide 1,900 ac (770 ha) 

of shallow basins. These are privately owned (as is 

the entire island). Little is known about importance 

of the upland habitats and beaches on Ni`ihau for 

shorebirds. Munro (1940) mentions Bristle-thighed 

Curlews present in November 1939 but did not 

directly associate them to habitat. Understanding 

the role of Ni`ihau’s habitats for shorebirds remains 

a high priority in the Hawaiian Islands for recovery 

of endangered waterbirds (Ducks Unlimited 1998, 

USFWS 1999). Ni`ihau has not been surveyed by 

ground since 1939 so numbers and trends are poorly 

documented.

Kaua`i

Kaua`i is the wettest of the archipelago’s Main 

Islands and supports the highest number of 

wetlands. Unfortunately many of the larger sites 

have been drained for agriculture. The 5,000-

ac (2,024 ha) Mana Marsh was once the largest 

wetland in the islands but was drained in 1923 for 

sugar cane. Other coastal wetlands on Kaua`i were 

altered due to extensive hydrologic changes (e.g., 

reservoirs for sugar cane and flood control). The 

remaining wetlands on Kaua`i are mostly overgrown 

with exotic vegetation and provide little habitat 

for shorebirds. Aquaculture is widespread and the 

extensive taro fields of the Hanalei River Valley and 

smaller fields in other valleys (Lumahai, Waimea, 

Hulei`a) support many shorebirds (Hawaiian Stilt, 

golden-plovers, turnstones, Calidris sandpipers). 

Kaua`i used to support several sugar cane effluent 

ponds, most of which have become recently inactive. 

These ponds, when active, supported numerous 

shorebirds; primarily turnstones, tattlers, goldenplovers, and Hawaiian Stilt (SIGHTINGS). The 

most common shorebird on Kaua`i is the Pacific 

Golden-Plover. It occurs in numerous habitats from 

coastal beaches up to the Alakai Swamp at 4,000 

feet (1,219 m). There are no estuaries or playas 

of significance for shorebirds on Kaua`i. USFWS 

manages two refuges for waterbirds on Kaua`i 

(Hanalei and Hulei`a NWRs) and the State has two 

small reserves on the Mana Plain. A few Hawaiian 

Stilt breed at refuges and 
 24 U.S. Pacific Islands Shorebird Conservation Plan

Hawaiian Islands 

State wildlife areas such as Hanalei and Hule`ia 

NWRs when conditions are suitable.

Most of Kaua`i’s uplands are forested and steep, 

harboring only remnant patches of open grasslands 

and some bogs. Although golden-plovers can occur 

in these, they represent a small fraction of birds 

on the island. Lowland grasslands are associated 

with agricultural fields. The collapse of the sugar 

cane industry in Kaua`i jeopardizes much of the 

remaining agricultural lands, which has declined in 

acreage nearly 30 percent since 1970 (Morgan 1983, 

State of Hawai`i 1999). Much of this land is slated 

for urban development. In addition, pastures in some 

of the river valleys, e.g., Hanalei and Wailua rivers, 

support migrant shorebirds, if they are grazed. 

Kaua`i has extensive golf courses and small parks 

that support numerous golden-plovers, but few other 

shorebirds.

The more extensive beaches have resorts and parks 

and thus, support few shorebirds.

O`ahu

O`ahu is perhaps the most diverse island in the 

chain in regards to shorebird habitat, with excellent 

tidal flats, estuaries, playas, ephemeral and 

permanent marshes, managed wetlands, and urban 

grasslands. However, many of the largest wetland 

and lowland sites have now been urbanized. Pearl 

Harbor, the largest estuary in the Pacific Islands, 

is heavily developed and industrialized. West Loch 

is the least developed portion of Pearl Harbor, but 

red mangroves (Rhizophora mangle), an invasive 

species, have overgrown most of the mudflats 

historically used by shorebirds. Prior to mangroves, 

West Loch was heavily used by migratory shorebirds 

for foraging during low tide (Cogswell 1945, R. 

L. Pyle, pers. comm.). Other important tidal flats 

include Paiko Lagoon, Kaneohe Bay, Kewalo Basin, 

and the series of ponds at Nu`upia (Kaneohe Marine 

Corps Station Hawai`i). All are used by flocks of 

shorebirds for foraging at low tide, but mangroves 

have overgrown most flats and threaten others. 

Mangroves have been effectively removed from 

Nu`upia Ponds with positive benefits to shorebirds 

(Drigot 2001). 

Most of the freshwater, ephemeral and managed 

wetlands on the windward and north shores of 

O`ahu are protected but exist in a degraded state 

(Kawainui Marsh, He`eia Marsh, Ka`ele`pulu 

Pond). Only the main complex of ponds at James 

Campbell NWR in Kahuku is widely used by 

shorebirds. Several playas exist on State land at 

Kahuku Point; most are overgrown by invasive 

plants. Historically, one of Hawai`i’s largest wetland 

complexes was Waikiki. It was drained in the 

early 1920s paving the way for the development 

of Honolulu. Another critical wetland drained in 

the 1950s was Ka`ele`pulu Wetland in the town 

of Kailua. The USFWS manages two refuges for 

waterbirds on O`ahu, James Campbell and Pearl 

Harbor NWRs. The State of Hawai`i manages four 

refuges, Hamakua, Kawainui and He`eia marshes 

and Paiko Lagoon. The U.S. Marine Corps manages 

Nu`upia Pond, one of three critical sites for nesting 

Hawaiian Stilt (Drigot 2001). Other smaller outlets 

and estuaries, such as Kaiaka Bay, Opaeula, and 

Poamoho support small numbers of shorebirds.

O`ahu’s historic shorebird habitats are mostly 

urbanized, but part of this development has been 

the creation of extensive mowed grass parks, golf 

courses, and lawns that support a surprising number 

of golden-plovers (Johnson and Johnson 1993). In 

addition, urban O`ahu rooftops provide important 

roosts for golden-plovers (Johnson and Nakamura 

1981). Grasslands associated with dunes (Kahuku 

and Kaena points) provide habitat for golden-plovers 

and Bristle-thighed Curlews. At times curlews 

have been observed on North Shore Golf Courses 

Waikiki circa 1920 and 1990. One of Hawai`i’s largest wetland reclamation projects. 

Photo by: Bishop Museum Photo Archives. Photo by A.J. McCafferty.
 Hawaiian Islands Subregion 25

Hawaiian Islands 

(SIGHTINGS Database, A. Engilis, Jr. pers. obs.). 

Lowland grasslands are generally associated with 

agricultural fields, as fallow fields in crop rotation. 

The collapse of the sugar cane industry in Hawai`i 

jeopardizes many of the agricultural lands that 

are now slated for urban development. These cane 

lands provided open space buffers for wildlife areas, 

minimizing human disturbance to shorebirds and 

native waterbirds. 

Some fringe coral reefs are exposed at low tides 

(Paiko Lagoon and North Shore of O`ahu) and 

frequented by golden-plovers, turnstones, tattlers, 

and Hawaiian Stilts. O`ahu’s windward shore is 

dotted with several small islets and exposed rocks. 

These are important night roosts for migrant 

shorebirds that forage on the main island during 

the day (A. Engilis, Jr. pers. obs.). O`ahu’s offshore 

islets (e.g. Moku Manu and Manana) are protected as 

seabird sanctuaries by the State of Hawai`i.

Maui Nui

Maui Nui comprises the four islands of Maui, 

Moloka`i, L na`i, and Kaho`olawe. Kaho`olawe is 

the driest and smallest island of Maui Nui. L na`i is 

also a dry island and contains no natural wetlands. 

Maui is a relatively young island and consequently 

does not possess the diversity of wetlands seen on 

O`ahu, despite its larger size. The windward slope 

of Haleakala creates high rainfall, but there are 

limited coastal flats to support wetlands. The main 

wetlands of Maui are located in the valley between 

Haleakala and West Maui. Kealia Pond, 740 ac (300 

ha), is the largest wetland on Maui, and remains 

one of the most important sites in the Pacific for 

migratory shorebirds. It is part of Kealia Pond NWR 

and is a prime example of a coastal alkali marsh. 

Human modifications to the outlet have altered 

the hydrology and Refuge staff must now manage 

draining of the pond. These draw downs remain 

a critical management action needed to initiate 

nesting by Hawaiian Stilt and provide foraging 

habitat for stilts and migrant shorebirds. In early 

fall when small amounts of water sheet across this 

unvegetated pond, thousands of shorebirds can 

occur comprising as many as 14 species (plovers, 

turnstones, stilt, tattlers, Calidris sandpipers, 

dowitchers) (M. Nishimoto, USFWS pers. comm.). 

Nearly 50 percent of the world’s population of 

Hawaiian Stilt use Kealia during this period 

(USFWS 1999). Numerous ephemeral basins occur 

in Kihei and along West Maui’s southern shore, but 

most have been destroyed by development. Kanaha 

Pond, a deep-water habitat with some ephemeral 

habitat, is a State waterbird sanctuary surrounded 

by development on all sides. Despite this, the 

ephemeral basins are an important shorebird 

resource. Another small wetland, important for 

Hawaiian Stilt, is Nu`u Pond on Haleakala’s 

southeast coast (USFWS 1999). 

Most of Maui’s beaches and dunes have been 

developed or degraded due to human alterations. 

Volcanic benches on Maui are exposed during low 

tides and are used by tattler, turnstone, goldenplover, and Hawaiian Stilt. Tattler, turnstone, and 

Sanderling sometimes use the beach fronting Kealia 

Pond. Maui’s grasslands are diverse, ranging from 

golf courses to mid-altitude pasture, 3,000 to 6,000 

feet (914 - 1,829 m) up Haleakala’s slopes. Goldenplovers commonly use these grasslands throughout 

the winter.

Moloka`i’s shorebird habitats are located principally 

in wetlands and playas along the southern coast. 

Most are degraded and have lost their wetland 

function, but the Pala`au Flats comprise a 6-mile 

(11 km) long stretch of coastal wetlands which, when 

flooded, are some of the most diverse in the islands 

(Table 5). Pala`au Flats was recently identified as 

an overwintering site for Bristle-thighed Curlew (A. 

J. McCafferty and A. Engilis, Jr. pers obs). Active 

restoration at several sites on the Pala`au Flats 

has provided excellent habitat for large numbers 

of shorebirds, including Hawaiian Stilt (Ducks 

Unlimited 1996). At the Ohiapilo Wetland restoration 

project Hawaiian Stilt production went from zero 

successful nesting prior to restoration, to 20 - 30 

stilts fledged per year after restoration (K. Uyehara 

pers comm.).

Mo`omomi Dunes are remote and support a few 

curlews and golden-plovers. Moloka`i has large 

stretches of undeveloped dunes and coastal flats, but 

their importance remains unquantified. Mangrove 

invasion along the south shore has jeopardized most 

of these coastal flats. Grasslands are uncommon 

but some agricultural fields support golden-plovers. 

There are few parks or golf courses, and the latter 

are concentrated on Moloka`i’s west shore. They 

provide for a minimal number of golden-plovers.

L na`i has no natural wetlands, but the wastewater 

treatment ponds now support a small number of 

shorebirds. Parks of L na`i City, golf courses, and 

fallow agricultural lands provide habitat for goldenplovers. Coastal beaches are frequented by only a 

few shorebirds.

Kaho`olawe is the driest of the Main Islands, 

however small ephemeral playas exist in the 

craters in normal and wet years. Lua Ke`ali`alalo 

is the largest one at 2 ha (4 acres) (P. Higashino, 

pers comm.). Both Pacific Golden-Plover and 

Black-bellied Plover have been recorded at this 

site in past years (R.E. David pers. comm.). Open 

space and the few beaches of the island support 

only a few shorebirds. There is a potential for 

habitat restoration on Kaho`olawe, and introduced 

mammals are currently being eradicated. The latter 

action could prove important for wintering curlews. 
 26 U.S. Pacific Islands Shorebird Conservation Plan

Hawaiian Islands 

Hawai`i

Hawai`i is the youngest and largest of the Main 

Islands, and its wetlands are associated with the 

perched groundwater lenses along the Kona Coast 

and, to a lesser degree, several ponds along the 

windward coast. A few small lagoons occur as well. 

Two of the most important wetlands `Aimakapa 

and Opae`ula, are found on the Kona Coast. These 

two wetlands and several smaller ponds provide 

the only natural habitat for nesting Hawaiian Stilts 

on the island. Migratory shorebirds also use these 

wetlands. Windward coastal wetlands are deeper 

and heavily overgrown with emergent vegetation 

and provide limited habitat for shorebirds. The 

Kona Wastewater Treatment Plant and Cyanotech 

aquaculture facility are heavily used by stilts, 

golden-plovers, turnstones, tattlers, and Calidris 

sandpipers (Ducks Unlimited 2002)

Hawai`i has large tracts of short-grass pastures, 

the most extensive in the Pacific. These pastures are 

widely used by Pacific Golden-Plovers and Ruddy 

Turnstones. They range from sea level to 8,000 feet 

(0 – 2,440 m) elevation on Hawai`i’s mountains: 

Kohala, Mauna Kea, Mauna Loa, and Hualalai. The 

most important are those of windward Kohala and 

Mauna Kea (K.Uyehara pers obs.). Typically the 

best pastures for shorebirds are those that receive 

greater than 60 inches (152 cm) of rainfall per year, 

are regularly grazed, and have fairly flat topography 

(A. Engilis, Jr. pers. obs). An example is the pastures 

of the Kehena region of windward Kohala. These 

become increasingly wet as you proceed towards 

the summit ridge. At the 60 inch isocline, pastures 

remain wet and sedges and other wetland indicators 

are common plants. In these zones flocks of up to 

75 golden-plovers are recorded (K. Uyehara pers. 

obs). Lowland pastures also provide habitat for 

golden-plovers and turnstones, and are also used 

sparingly by Bristle-thighed Curlews (e.g., pastures 

on Hawai`i’s South Point).

Shorebird Species 

Forty-seven species of shorebirds have been 

recorded in the Hawaiian Islands (Appendix 4). These 

can be grouped into three categories – resident, 

winter visitors, and migrants. The Hawaiian 

Islands are of primary importance, for four species: 

Hawaiian Stilt, Pacific Golden-Plover, Bristlethighed Curlew, and Wandering Tattler. Only the 

Hawaiian Stilt is resident (and endemic). Other 

common winter visitors include Ruddy Turnstone 

and Sanderling. Winter visitors that occur annually 

in small numbers include Black-bellied Plover, 

Lesser Yellowlegs, Least Sandpiper, Pectoral 

Sandpiper, Sharp-tailed Sandpiper, Dunlin, and 

Long-billed Dowitcher. The remaining species are 

irregular or accidental. Pacific Golden-Plovers use 

the widest range of habitats and can be seen from 

sea level to 13,000 feet (3,960 m). They are most 

common in uplands, parks, pastures, and open 

wetlands. Ruddy Turnstones utilize high elevation 

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 Hawaiian Islands Subregion 27

Hawaiian Islands 

pastures, isolated beaches, flats and park lawns. 

Sanderlings are most faithful to mudflats, beaches, 

and open marshes. Bristle-thighed Curlews prefer 

undisturbed, predator-free habitats and most overwinter on secluded islands, beaches, and dunes. 

Small numbers winter on the Main Islands where 

dogs are controlled, or water is available for escape.

The Hawaiian Stilt is endangered, but at present 

the population is relatively stable, at low numbers. 

Limiting factors include habitat loss, predation by 

non-native vertebrates (e.g., mongoose, cattle egrets, 

and bullfrogs) and habitat degradation. Stilt share 

habitat with three other endangered waterbirds, 

Hawaiian Coot (Fulica alai), Hawaiian Moorhen 

(Gallinula chloropus sandvicensis), and Hawaiian 

Duck (Anas wyvilliana) and a draft recovery plan 

for these four Hawaiian waterbirds provides detailed 

information and recovery actions for this species 

(USFWS 1999, USFWS in prep.). The Hawaiian 

Stilt is coastal in its distribution and it is found on all 

the Main Islands except Kaho`olawe. Inter-island 

movements are common on a seasonal and perhaps 

even daily pattern (Reed et al. 1998). As with other 

recurvirostrids, the Hawaiian Stilt is a bird of open, 

early succession marshes and mudflats. Ephemeral 

wetlands, managed wetlands, and coastal playas are 

important habitats.

No comprehensive surveys of the entire archipelago 

are available to assess the status of migratory 

shorebirds in Hawai`i. Various surveys of specific 

habitats or individual islands are available but the 

trends indicated by these incomplete surveys are 

often contradictory. Engilis (1988) examined the 

Statewide waterbird surveys for trend data for a 

period of ten years and found the data set too limited 

to assess shorebird population trends (other than 

stilt). Other data sets include Audubon Christmas 

Bird Counts, field counts by agency biologists and 

birders, regular surveys of wildlife refuges (e.g., 

Kealia Pond NWR, Hanalei NWR, Hamakua Marsh 

Wildlife Sanctuary), surveys for wetland restoration 

projects (e.g. Ducks Unlimited), and O`ahu golf 

course surveys for golden-plovers (Johnson and 

Johnson 1993). Audubon Christmas count data 

provided the most comprehensive coverage of 

shorebird habitats, but these were also limited by 

years of coverage. For Pacific Golden-Plover, these 

data suggest an increase in the islands since the 

1940s. A significant action occurring at the beginning 

of the count (early 1940s) was the curtailment 

of golden-plover hunting in the islands in 1941 

(Schwartz and Schwartz 1949). 

The Statewide Waterbird Survey could provide 

a valuable data set once efforts to standardize 

protocol and enhance counts to cover shorebirds 

are implemented. Suggestions for strengthening 

the Statewide survey are listed in monitoring 

recommendations, below. In addition, the State of 

Hawai`i is working with the USFWS, the Hawai`i 

Natural Heritage Program, Tufts University, and 

the University of Hawai`i, Manoa to compile all 

data from State waterbird counts and analyze them 

using a GIS based framework. This data will provide 

a valuable means of assessing population status 

and trend for Hawaiian Stilt and other wetland 

associated shorebirds in the State.

Hawaiian Subregional Population Goals

- Support recovery actions in the Hawaiian 

Waterbird Recovery Plan (USFWS in prep.). 

Increase populations of Hawaiian Stilt to levels 

identified in the Recovery Plan for delisting and 

ensure multiple viable breeding populations on 

Kauai/Nihau, O`ahu, Maui/Molaka`i/L na`i and 

Hawai`i 

- Protect and enhance populations of Bristlethighed Curlews wintering in the Main Islands 

and maintain increasing or stable populations in 

the NWHI Islands

- Maintain or enhance populations of priority 

shorebirds species

- Accurately assess the population size and trends 

of over-wintering and migrating Pacific GoldenPlovers, Bristle-thighed Curlews, and Wandering 

Tattlers and coordinate with Alaska to develop 

quantitative population goals

Hawaiian Subregional Habitat Status,

Threats and Management Goals

The following are specific recommendations for the 

Hawaiian Subregion.

Tidal Flats and Estuaries

The primary threats to this habitat are the spread 

of red mangrove and contaminants. Restoration 

through eradication of mangrove, followed by 

maintenance has met with success in the Nu`upia 

Pond complex, O`ahu (Drigot 2001), but if 

maintenance does not follow removal, the flats 

quickly become overgrown again as in the West Loch 

Project, Pearl Harbor (A. Engilis, Jr. pers. obs.). 

Pearl Harbor has experienced countless fuel and 

chemical spills over the past half century and more 

can be expected in the future. Four hazardous 
 28 U.S. Pacific Islands Shorebird Conservation Plan

Hawaiian Islands 

waste sites at Pearl Harbor Naval Base have been 

identified by the U. S. Environmental Protection 

Agency (EPA) as superfund National Priorities. 

The Navy has identified 31 potential hazardous 

sources in Pearl Harbor alone. Hawai`i’s estuaries 

are also impacted by non-point source pollution and 

sedimentation of flats has accelerated as a result of 

land use in the watershed (USFWS 1996). Thus as a 

wetland habitat type, tidal flats are among the most 

degraded in the Islands. 

- Remove and control mangrove encroachment in

 tidal flats specifically in West Loch of Pearl

 Harbor, Kaneohe Bay, Kewalo Basin, Moloka`i’s

 south shore, and in smaller impacted areas on all

 islands 

- Continue mangrove control at Nu`upia Pond

 complex

- Protect remaining habitat from development and 

fill e.g., Kewalo Basin, Pearl Harbor, Kaneohe Bay, 

and other estuarine systems

- Monitor habitats and shorebirds for contaminants 

and coordinate with response teams for clean-up

 of hazardous spills 

Playas and Ephemeral Basins

The protection, restoration, and management of 

playa wetlands in the Hawaiian Islands is deemed 

crucial for the recovery of Hawaiian Stilt and 

maintenance of migratory shorebird populations 

(USFWS 1999). Major playas are still functional on 

Ni`ihau, O`ahu, Maui, and Moloka`i. On all islands, 

the main threat to playas has been the introduction 

of pickleweed and Indian fleabane. These aggressive 

plants have completely covered most coastal 

playas resulting in increased rates of siltation and 

accretion. In addition, accelerated sedimentation 

resulting from poor management of upland 

agricultural and ranch lands has heavily impacted 

playas (particularly on O`ahu and Moloka`i). The 

largest protected playa is Kealia Pond, but fleabane 

and pickleweed continue to encroach on the site. 

Annual drawdowns of Kealia Pond have created 

problems with the local community due to the stench 

of dead fish, midge (Chironamidae) blooms, and 

blowing dust (a natural deflation event characteristic 

of coastal playas), but this management action is 

critical for Hawaiian Stilt and migratory shorebirds. 

Wetland management should continue to investigate 

the manipulation of native and naturalized/exotic 

vegetation (moist-soil management) that provides 

important habitat for nesting, foraging, brooding, 

loafing, thermal/escape cover as well as minimizes 

impacts from human disturbance.

- Protect and restore degraded playa wetlands such 

as Mana Plains (Kaua`i), Pala`au Flats (Moloka`i), 

Kealia and Kihei wetlands (Maui) and Kahuku 

Point (O`ahu)

- Eradicate/control exotic plants (e.g., pickleweed 

and fleabane) and restore the natural hydrology to 

playa wetlands

- Work with landowners and the local communities 

to survey and assess the Ni`ihau playas, and 

develop management strategies as needed

- Work with private landowners to restore and 

manage wetlands through cooperative and 

incentive programs (WRP, WHIP, PIF, NAWCA)

Permanent, Semi-permanent Wetlands

Coastal permanent and semi-permanent wetlands 

are used with less frequency by shorebirds than 

coastal strands, tidal flats, ephemeral wetlands, 

and playas. Most are also hydologically linked to 

montane watersheds. They suffer the same threats 

as ephemeral wetlands, overgrowth with invasive 

plants, and loss to urban encroachment. Most 

of the large, remaining wetlands in Hawai`i are 

protected by agencies but most have limited value 

to shorebirds due to poor habitat quality. Habitat 

restoration, vegetative clearing, and long-term 

management are required on these wetlands. The 

reader is referred to the Hawaiian Endangered 

Waterbirds Recovery Plan (USFWS 1999) for 

detailed needs and actions related to Hawai`i’s 

wetlands.

Managed Water Projects (primary purpose is not 

wildlife related)

Managed water projects, whose primary purpose 

is not related to wildlife (e.g. taro, lotus, shrimp), 

include aquaculture, wastewater ponds, recreation 

areas, irrigation reservoirs, etc. These cultivated 

wetlands are most common on Kaua`i, O`ahu, 

Moloka`i, Maui, and Hawai`i. Cultivated wetlands 

are transient, in relation to long-term efforts to 

conserving habitats and maintaining populations of 

shorebirds. However, birds do become dependent 

upon them and local populations of Hawaiian 

Stilt and migratory shorebirds can be impacted 

if the practices are abandoned due to economic 

pressures, (e.g., collapse of the sugar cane industry 

in Hawai`i). Minimizing dependence on cultivated 

wetlands must be made a priority by agencies as 

part of the recovery actions needed for endangered 
 Hawaiian Islands Subregion 29

Hawaiian Islands 

Hawaiian waterbirds. These actions will also benefit 

migratory shorebirds. Balancing the restoration and 

management of wetlands dedicated for wildlife with 

reducing dependence on these habitats will remain a 

conservation challenge for some time to come.

- Identify standards for implementation of taro 

agricultural practices (drawdowns, weed control, 

fertilization) that avoid impacts to nesting, 

brooding and foraging shorebirds

- Minimize dependence on these habitats through

 improved shorebird habitat management on State

 and Federal refuges and reserves, particularly for

 Hawaiian Stilt

- Seek Safe Harbor Agreements or Habitat 

Conservation Plans for managed water projects to 

improve habitats for shorebirds

Sand Beach and Dunes

The most important beach and dune resources are 

located in the Northwestern Hawaiian Islands. 

These are critical habitat for wintering Bristlethighed Curlew and important for turnstone and 

Pacific Golden-Plover. The main threats include 

human generated trash, contaminants, oil spills, and 

tarballs that wash up on the beaches. There are few 

beach sanctuaries in the Main Islands; exceptions 

include Ka`ena Point, O`ahu and Mo`omomi Dunes, 

Moloka`i protected under the Natural Area Reserve 

System, and National Park Service lands on Hawai`i 

and Maui. Beach access is not fully restricted by 

these agencies although in most cases vehicles 

and other destructive uses are prohibited. The 

main threat to shorebirds on Main Island beaches 

continues to be human related disturbance. 

- Restore dunes on O`ahu, Moloka`i, and Maui and 

restrict ORV access to support native vegetation 

and habitat used by shorebirds, principally the 

Bristle-thighed Curlew

- Maintain secure beach and dune habitat in the 

Northwestern Hawaiian Islands

- Control introduced mammals in all Natural Area 

Reserves (State) and Federally protected beaches 

and maintain Northwestern Hawaiian Islands as 

mammal free 

- Monitor the Northwestern Hawaiian Islands 

for trash accumulation, and clean periodically to 

maintain suitable beach and strand habitat

- Monitor beaches for oil and other contaminant 

issues and participate in response teams for 

emergency actions

Grasslands

Open and grazed grasslands are important habitats 

for wintering shorebirds, particularly those 

associated with small upland stock and wildlife 

ponds. The largest tracts are on private ranch 

lands located on Hawai`i and Maui where current 

management restricts public access and human 

disturbance is low. The primary issue with these 

grasslands is the best long-term use of the land, 

both from an economic and ecological perspective. 

Reforestation of native forests (for native forest 

birds) has been initiated, as have plantations 

for commercial production of Koa (native) and 

Eucalyptus (non-native). As the cattle industry 

becomes less lucrative, private landowners may 

explore other uses of pastoral lands. Management 

of pastoral lands has been proposed on Hawai`i 

and Kaua`i to support Hawaiian Goose (Branta 

sandvicensis) recovery and migratory shorebirds 

could also benefit.

- Develop Safe Harbor Agreements with landowners 

to protect grazed pasture for shorebirds and 

coordinate with ongoing efforts to provide habitat 

for Hawaiian Duck and Goose

Maui Golf Course.

Photo by: Hawai`i 

Tourist Industry

Wastewater Pond, Hawai`i, Hawaiian Islands.

Photo by A. Engilis, Jr.
 30 U.S. Pacific Islands Shorebird Conservation Plan

Hawaiian Islands 

- Develop Regional Habitat Conservation Plans for 

wetland and grassland management, incorporating 

shorebird needs, in coordination with landowners 

and agencies targeting key grassland regions (e.g., 

upslope Maui, Kohala Mountains, and upslope 

Mauna Kea)

- Coordinate with reforestation efforts to 

incorporate grassland habitats to benefit a broad 

group of organisms

- Manage State and Federal protected, lowland 

grasslands in a state free from invasive plants 

such as Indian fleabane, fountain grass, and other 

invasive shrubs

- Seek to include grazing regimes in diversified 

farming operations by coordinating with 

landowners

- Promote integrated pest management practices of 

lawns and golf courses to minimize pesticide use

Rocky Shoreline/Offshore Islets

This habitat resource is relatively secure and is 

important for Wandering Tattlers, but provides 

limited habitat for other shorebirds. Uninhabited 

offshore rocks and islets are important as roost 

sites for shorebirds. Several offshore islets have 

been invaded by introduced mammals (rats, cats, 

and rabbits). There is an ongoing program by the 

Hawai`i Division of Forestry and Wildlife (DOFAW) 

to remove these predators. The re-colonization 

of islets by mammalian predators and human 

disturbance remain the principal threats to roost 

sites for shorebirds. Human access is currently 

restricted, but increased activity could pose a threat 

to shorebirds.

- Remove all introduced mammals from offshore 

islets and maintain predator free, relatively 

undisturbed roost habitats

- Restrict human access to minimize disturbance

Predator Control

Hawai`i has no living native, terrestrial mammals 

(except for a single species of bat). Introduced 

mammals, particularly Indian mongoose (Herpestes 

javanicus), rats (Rattus rattus, R. norveigicus, 

R. exulans), feral cats (Felis sylvestris) and dogs 

(Canis familiaris) depredate native shorebirds 

reducing their populations and limiting suitable 

habitat. Rats were recently eradicated from Midway 

and Kure Atolls and the only remaining introduced 

mammal in the Northwestern Hawaiian Islands 

is the house mouse at Midway Atoll. Additional, 

predator specific actions are restated in habitat 

sections (above).

- Develop and maintain a predator control program 

particularly on O`ahu, Moloka`i, Maui, and 

Hawai`i, to protect Hawaiian Stilt and Bristlethighed Curlews

- Monitor all islands and especially the 

Northwestern Hawaiian Islands to detect new 

predator introductions and initiate immediate 

eradication efforts

- Prevent introduction of brown tree snakes to the 

Hawaiian Islands

- Prevent spread of mongoose to mongoose free 

islands ( L na`i, Ni`ihau, Kaho`olawe, and 

Kaua`i)

Monitoring Priorities 

- Continue and fine-tune Statewide biannual 

monitoring of Hawaiian Stilt populations

- Monitor response of Hawaiian Stilt and migratory 

shorebirds to different management practices for 

managed wetlands

- Monitor shorebird response to habitat restoration 

to support an adaptive management approach 

to wetland and tidal flat conservation and 

management

- Develop a monitoring program for migratory 

shorebirds with initial emphasis on Pacific GoldenPlover, Bristle-thighed Curlew and Wandering 

Tattler. Assess and track changes in population 

size and habitat utilization

- Work with private landowners and local 

communities to monitor shorebird use of 

ephemeral playas, beaches, and dry grasslands on 

Ni`ihau

- Monitor trash accumulation (to target clean 

up efforts) on Northwest Hawaiian Islands to 

minimize impact on wintering shorebirds

Research Priorities 

- Investigate population dynamics and inter-island 

movements of Hawaiian Stilt and determine 

the importance of playa wetlands (especially on 

Ni`ihau) to the maintenance of stilt populations

- Analyze and summarize Hawai`i Statewide 

waterbird survey data for past 25 years. Modify 

the survey as needed to improve the applicability 

to shorebirds
 Hawaiian Islands Subregion 31

Hawaiian Islands 

- Investigate the migration routes of curlew, goldenplover, and tattler and determine Hawai`i’s role 

and linkages to Alaska and Asian populations. 

Identify important wintering sites, migratory 

stopover sites, and staging areas

- Analyze data from USFWS and DU restoration 

projects and initiate new studies to develop best 

management recommendations for shorebirds, 

especially Hawaiian Stilt, and distribute 

information to land managers 

- Evaluate the effects of different management 

techniques on vegetation, water levels, and 

shorebirds. Continue research to identify 

management strategies for control of native and 

naturalized/exotic vegetation to produce habitat 

for nesting, brooding, foraging, and loafing habitat 

for shorebirds

- Evaluate the effects of contaminants, including 

pesticides on shorebirds (e.g., golden-plovers 

utilizing managed grass lands: golf courses, lawns, 

pastures, etc.); shorebirds utilizing Pearl Harbor 

and other contaminated tidelands; shorebirds 

utilizing wastewater treatment ponds

- Identify important wintering sites, migratory 

stopover sites, and staging areas

- Study the ecology of Bristle-thighed Curlew on 

the wintering grounds including foraging habits, 

habitat requirements, population trends, and 

limiting factors

- Assess the incidence of disease in migratory 

birds, particularly the spread of West Nile Virus. 

Coordinate with animal disease specialists on the 

Mainland

- Assess Pacific Golden-Plover populations 

wintering and migrating through the region 

especially as it relates to habitat use and selection

- Research the removal and control of invasive 

plants including red mangrove, Indian fleabane, 

pickleweed, and California grass

- Investigate competition with Tilapia, design 

managed wetlands to control Tilapia invasions

- Quantify use of wastewater treatment ponds in 

relation to managed or natural wetlands

- Investigate the impacts of different grazing 

regimes on shorebird habitat use in pastures

- Investigate the implementation of a Statewide fall 

survey to capture the peak migration numbers, 

which will allow for comparison for over-wintering 

numbers as expressed by the mid-winter count

Education Priorities 

- Educate the public about migratory and resident 

shorebirds and shorebird habitats (wetlands, tidal 

flats, grasslands, beaches)

- Expand education curricula looking at bird 

migration for grade school students

- Maintain and expand Kolea Watch that involves 

schools and the public in monitoring golden-plover

- Establish Kolea, Pacific Golden-Plover, as a 

centerpiece for a wildlife festival. Seek support 

from Hawai`i Tourism Office

- Maintain and enhance the Shorebird Sister 

Schools’ Education Kit with region specific 

information, activities, games, books, etc. 

Implementation and Coordination

The conservation of shorebirds (endemic and 

migratory) must be undertaken as part of a broad, 

landscape approach from wetlands and beach 

strand to grassland and upland conservation. 

Recently the Pacific Coast Joint Venture expanded 

its area of coverage to include Hawai`i. A technical 

subcommittee for shorebirds should be formed to 

provide input to the Joint Venture. Partners in this 

effort could include such agencies as USFWS, State 

Department of Land and Natural Resources, NRCS, 

USEPA, NPS, NOAA Fisheries, USDOD, Hawai`i 

Department of Education, Hawai`i Department of 

Agriculture. Private Sector would include groups 

such as DU; TNC; HAS; Hawai`i Nature Center, 

and research universities. Coordination with private 

landowners, aquaculture and agriculture interests 

will be instrumental in applying a landscape 

approach to shorebird conservation. 

- Coordinate activities with Endangered Species 

Recovery efforts

- Encourage, on the ground, private and public 

partnerships to achieve habitat and population 

objectives
 Mariana Islands Subregion 33

Mariana Islands

Description of the Subregion

The Mariana Islands include the island of Guam 

(U.S. Territory) and the Commonwealth of the 

Northern Mariana Islands (CNMI) (15 islands) 

(Figure 7). The chain extends from 13 ̊ to 21 ̊ North 

Latitude and 144 ̊to 146 ̊ East Longitude in the 

western Pacific Ocean. Guam, Rota, Tinian, and 

Saipan are inhabited by humans, small settlements 

also occur on a few of the other islands. The entire 

landmass of the chain is approximately 1,015 km2, 

less than one tenth the size of the single island of 

Hawai`i. The largest island is Guam (554 km2). The 

Mariana Islands are comprised of a combination of 

volcanic and uplifted limestone rock. The northern 

islands are mostly steep rock islets with rocky 

coastlines that receive little rainfall. The southern 

islands (including Guam, Rota, Aguijan, Tinian, 

Saipan, and Farallon de Medinilla) are generally 

larger, forested, and support coastal plain woodlands 

and grasslands. These islands are characteristically 

flat: the highest peak is 1,506 ft (459 m) on Rota, 

highest elevations on Guam reach only 1330 ft (406 m).

The Mariana Islands provide limited resources for 

migrant shorebirds due to their small size, narrow 

intertidal zone, and lack of extensive mudflats 

(Parish et al. 1987). The best habitat is on Guam 

and Saipan, the largest islands, with intertidal 

beaches, mudflats, freshwater wetlands, and grassy 

areas (Stinson et al. 1997a, 1997b). During the wet 

season, approximately June through November, 

ephemeral basins with short grass, exposed mud, 

and shallow pools provide habitat for migratory 

shorebirds wintering in the islands. These basins 

are dry by December or January and migrant birds 

concentrate on the few remaining wet areas or 

depart the islands (Stinson et al. 1997b). Many of the 

seasonal freshwater wetlands are choked with reed 

thickets and other weedy species and are not used 

by shorebirds. Farming activities help to reopen 

some choked sites and farm fields provide habitat, 

especially in the wet season. Larger expanses of 

short grass habitats associated with military bases, 

airports, golf courses, fields, and residential parks 

are utilized by golden-plovers and, to a lesser extent, 

turnstones. As in Hawai`i, acreage of these latter 

habitats has increased over the last century due to 

removal of native forests.

Shorebird Habitats

Wetlands of Importance to Shorebirds 

Guam. Guam supports the most diverse setting of 

wetlands in the Marianas. Permanent wetlands are 

centered in four geographic regions (Talofofo River, 

Fena Valley, Atantano Marsh, and Agana Marsh). 

These wetlands are deep water habitats comprised 

of Pago tree swamps (Hibiscus tiliaceus) and are 

over grown by reeds (Phragmites) and California 

grass. Thus, they provide little available habitat for 

shorebirds. More important for shorebirds are the 

numerous depressions that fill as ephemeral ponds. 

Most are in agricultural settings and have degraded 

hydrology and support grasses and sedges. The 

importance of these wetlands is punctuated by the 

increase in acreage associated with seasonal rains. 

The base wetland 

Mariana Islands Subregion

Miles

Guam

Uracas

(Farallon de Pajaros)

Com

monwealth of the Northern Mariana Islands

Maug

Asuncion

Agrihan

Pagan

Alamagan

Guguan

Sarigan

Farallon

de Medinilla

Saipan

Tinian

Aguijan

Rota

Anatahan

Kilometers

0 50 100 150

0 50 100 150

FIGURE 7. 

Commonwealth of the Northern Mariana Islands
 34 U.S. Pacific Islands Shorebird Conservation Plan

Mariana Islands

acreage on Guam averages 316 ac (128 ha) during 

the dry season (USFWS 1996). These are expanded 

to greater than 740 ac (300 ha) during the wet 

season. Man-made wetlands such as Fena Reservoir 

have further altered the wetlands landscape on 

Guam. Guam’s western shore is lined with tidal 

flats and small estuaries that are used by wintering 

shorebirds. Over 170 ac (69 ha) of mangrove exist. 

Unlike Hawai`i, these mangrove forests are native 

and important for local fish and coastal species. They 

support some shorebirds, particularly tattlers.

Commonwealth of the Northern Mariana Islands. The 

islands of the CNMI have restricted wetlands used 

by shorebirds. Lake Susupe complex, located on 

Saipan, comprises over 60 percent of the wetland 

habitat. Lake Susupe, a brackish 42 ac (17 ha) pond, 

supports stands of Phragmites, Scirpus, sedges 

and water ferns along its shore and few shorebirds. 

Associated with Lake Susupe is a complex of semipermanent ponds approximately 458 ac (185ha) in 

size. More important for shorebirds are the small 

ephemeral basins scattered along Saipan’s western 

shore comprising approximately 90 ac (37 ha) of 

habitat. Many are overgrown with grasses, reeds, 

and sedges. The remaining wetlands of Saipan are 

seasonal in nature, filling during wet months and 

providing important foraging habitat for migrant 

shorebirds (turnstones, golden-plovers, tattlers, 

Tringa spp). Other significant habitats used by 

shorebirds are coastal flats, tidal estuaries and 

native mangrove swamps near Garapan. Limestone 

benches and exposed reefs dot Saipan’s western 

shoreline. Emergent surfaces of these support 

migrant shorebirds. Tinian is the only other island 

with semi-permanent wetlands. The most important 

is Lake Hagoi, at 10 ac (4 ha). It is surrounded 

by 48 ac (20 ha) of ephemeral pools. Today, only 

about 2.4 ac (1 ha) of Lake Hagoi remain in open 

water, the remaining is overgrown with Scirpus 

and Phragmites. Tinian was heavily bombed 

during WWII creating depressions that fill in 

the wet season. A cluster of potholes are located 

near Tinian’s northern, abandoned runway. Rota 

supports limited ephemeral wetlands but the runway 

seasonally accounts for most shorebirds observed 

(Figure 8). Wetlands that existed on Pagan were 

destroyed by a volcanic eruption in May 1981 

(USFWS 1996). 

Tidal Flats, Beaches, and Rocky Shoreline of 

Importance to Shorebirds 

The remote islands of the northern Marianas are 

uninhabited and support rocky shoreline and limited 

strand beaches used by shorebirds such as goldenplovers, turnstones, and tattlers (Lusk et al. 2000). 

Beaches with intertidal zones, mud or sand flats 

are preferred. Key among beach sites are Tanapag 

and Puerto Rico mudflats and beaches (Saipan) 

and Dungcas flats and Beach (Guam) (Stinson et 

al. 1997b). On the larger islands, beaches provide 

little habitat for migrant shorebirds, in part due to 

human recreation and resorts. Rocky shorelines 

are extensive, especially on the northern islands. 

This habitat is utilized by tattlers, but is extremely 

remote and difficult to survey.

FIGURE 8. Seasonal Variation in Wetland Sites on Rota, 2000 - 2002. (Source: Dept. of Fish and Wildlife, Saipan)

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 Mariana Islands Subregion 35

Mariana Islands

Grasslands and Open Spaces of Importance to 

Shorebirds

Guam and Saipan support the only pastoral lands 

that are used by migrant shorebirds. Urban parks, 

golf courses, antenna fields, and grass edges of 

runways are frequented by golden-plovers and 

turnstones. On Tinian, the large concrete runways, 

abandoned after WWII, are used as loafing sites by 

golden-plovers and a few other species. During rainy 

periods, concrete runways can flood and shorebirds 

congregate to bathe and loaf, some ancillary foraging 

may occur in pools on the tarmac. Interior grassy 

patches on Farallon de Medinilla are frequented 

by Whimbrel, golden-plover, and turnstone (Lusk 

et al. 2000). The golf course on Rota supports a few 

shorebirds annually.

Shorebird Species

Forty species of shorebirds have been recorded in 

the Mariana Islands, most breed predominately 

in Asia, but the islands also support some North 

American populations (Reichel and Glass 1991, Wiles 

et al. 1993) (Appendix 4). Of these only the Pacific 

Golden-Plover is abundant (Jenkins 1981, Stinson 

et al. 1997b). Asiatic Whimbrel, Ruddy Turnstone, 

Wandering Tattler, and Grey-tailed Tattler are 

common to uncommon (Table 6). Another four 

species, all Palearctic breeders, are regular in very 

small numbers (10 – 50 birds per year): Mongolian 

Plover, Wood Sandpiper, Common Sandpiper, and 

Red-necked Stint (Stinson et al. 1997b). There are 

no resident shorebirds in the Mariana Islands. 

Few estimates of shorebird numbers are available 

for the Marianas. Baker (1951) and Owen (1977) 

summarized early 20th century accounts. The most 

recent estimates of relative abundance are provided 

by Jenkins (1981) and Stinson et al. (1997b). Reichel 

and Glass (1991) and Stinson (1994) provide a 

checklist of birds of the Mariana Islands with 

general categorization of abundance. Stinson et al. 

(1997b) estimates between 5,000 and 20,000 goldenplovers pass through the islands and a few thousand 

over winter, and Ruddy Turnstone wintering 

numbers fluctuate at several hundred birds. They 

give no estimates for tattlers in the Marianas 

probably due to identification problems associated 

with separating the two species. All other species 

occur in low numbers (< 200 birds). Radar studies 

indicate that only a small percentage of migrants 

stop at the Marianas. Most over-fly, probably on 

non-stop flights from Asia to the South Pacific, but 

exact patterns are poorly understood (Williams 

and Williams 1988). Recent studies suggest that 

shorebird populations in the islands naturally 

fluctuate, probably as a result of movements of birds 

through the islands en route to southern wintering 

quarters; October - December support the highest 

numbers of birds (Figures 9, 10). According to 

Stinson et al. (1997b), shorebird abundance and 

variety in the Marianas is greatest from September 

to April. Autumn migration, enhanced by first-year 

young, occurs longer than spring migration and 

involves larger numbers of birds. 

TABLE 6. Shorebirds recorded on the 2000 Christmas Counts, Guam, Saipan, and Rota. 

 (Source: NAS 2000, 2001) 

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 36 U.S. Pacific Islands Shorebird Conservation Plan

Mariana Islands

FIGURE 9. Monthly Variation in Wetland/Wading Bird Counts on Siapan, 1999 -2002. (Source: CNMI Dept. of

 Fish and Wildlife, Saipan)

FIGURE 10. Seasonal Variation in Numbers of Shorebirds Along Saipan’s Coasts. (Source: CNMI Dept. of

 Fish and Wildlife, Saipan)

0

100

200

300

400

500

600

700

Oct-99

Dec-99

Feb-00

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Jun-00

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Oct-00

Dec-00

Feb-01

Apr-01

Jun-01

Aug-01

Oct-01

Dec-01

Feb-02

Apr-02

Jun-02

Aug-02

Oct-02

Month and Year

Birds Observed

0

20

40

60

80

100

120

Oct-99

Dec-99

Feb-00

Apr-00

Jun-00

Aug-00

Oct-00

Dec-00

Feb-01

Apr-01

Jun-01

Aug-01

Oct-01

Dec-01

Feb-02

Apr-02

Jun-02

Aug-02

Oct-02

MONTH AND YEAR

# of WADERS 1999-2002
 Mariana Islands Subregion 37

Mariana Islands

Marianas Subregional Population and 

Habitat Goals

The population status of migrant shorebirds in the 

Marianas is unknown. Several species wintering in 

the Marianas exploit a variety of habitats. Pacific 

Golden-Plovers over-winter in close association 

with humans. They forage on lawns, fields and 

other short-grass habitats, and roost on tarmacs 

of military fields, and rooftops. Without a better 

understanding of existing populations and trends, 

it is impossible to set population goals. Key in the 

Marianas is the protection and management of tidal 

flats, beaches, ephemeral wetlands and grassy areas 

utilized broadly by many species of shorebirds.

- Conduct island-wide shorebird surveys to

 quantify population levels and habitat 

 associations

- Manage existing wetlands, with emphasis on

 protection and restoration of wetlands and tidal

 flats 

- Develop a GIS system that identifies and ranks

 key shorebird habitats in the Mariana Islands

Marianas Subregional Habitat Status, 

Threats, and Management Goals

Wetlands

Impacts to wetlands in the Mariana Islands are 

generally divided into two categories: agriculture 

prior to WWII and urbanization and military 

development after WWII. Agricultural development 

has resulted in the loss of numerous ephemeral 

basins through land leveling and plowing. Larger 

wetlands were drained and diked to cultivate rice 

and taro, and for public health reasons (USFWS 

1992). During WWII, Japanese occupation expanded 

rice and taro production at the expense of wetlands 

on Guam, Saipan and Tinian. Forest clearing 

increased evapotranspiration drying ephemeral 

pools in forests (Nakajima 1944). Over the past 

two decades, the economies of the Mariana Islands 

have become more dependent on tourism and have 

moved away from subsistence-based lifestyle. The 

military continues to have a major presence in the 

Marianas. As the human population increases, so 

too will the need for more development. To support 

tourism, pressures have been placed on wetlands, 

estuaries, and beaches particularly on Guam and 

Saipan; the islands that support the highest numbers 

of shorebirds. No estimates as to the loss of wetlands 

on Guam are available, but nearly 65 percent of 

Saipan’s wetlands have been lost due to human 

actions (Stinson et al. 1991). Coastal wetlands can 

also be affected by well development, impacting 

aquifers, which support perched wetlands along 

the coast of larger islands. Little emphasis has 

been placed on the protection of ephemeral basins 

and they continue to be farmed and hydrologically 

altered. Most major wetlands are protected, but 

without active management these systems will 

become choked with vegetation. Although this 

degrades shorebird habitat, Phragmites and Scirpus 

thickets do provide habitat to a varying degree 

for the endangered Mariana Moorhen (Gallinula 

chloropus guami) and Nightingale Reed-Warbler 

(Acrocephalus luscinia) and thus a balance of 

open wetlands vs. vegetated wetlands must be 

maintained (USWFS 1992, USFWS 1995). Recovery 

actions recommended for the Mariana Moorhen 

and Nightingale Reed-Warbler address the need to 

restore and manage habitat and reduce predation 

by introduced mammals and brown tree snake 

(Boiga irregularis). As in Hawai`i and continental 

populations, Mariana Moorhens use ephemeral 

wetlands as dispersal and nesting habitat and these 

needs should be coordinated with shorebird habitat 

needs (Nagata 1983, Stinson et al. 1991a, Takano 

2003). The protection, restoration, and possibly 

even the creation of wetland complexes that support 

permanent wetlands associated with ephemeral 

basins should be developed on Guam, Tinian, and 

Saipan. 

- Incorporate habitat considerations for

 shorebirds into wetland management on Guam

 (Agana Marsh, Atantano Marsh) and CNMI

 (Lake Susupe, Lake Hagoi). Restore ephemeral

 marshes at key wetland complexes through

 vegetation removal or control

- Develop management strategies to maintain

 ephemeral wetlands free of invasive vegetation

- Coordinate habitat management for shorebirds

 with recovery actions for endangered wetland

 species (reed warbler and moorhen) 

- Coordinate mitigation wetlands to maximize

 complexes of ephemeral and permanent sites

Tidal Flats, Beaches, and Mangrove Estuaries

Historical loss of tidal habitats was accelerated 

by the USDOD between 1945-1950. During this 

period an estimated 1,200 ac (485 ha) that included 

mangroves and permanent wetlands were filled 

along the west-central coast of Guam (USFWS 

1996). The majority of tidal flats, beaches and 

mangrove estuaries that remain on Guam are owned 

by territorial or Federal agencies. Threats to these 

systems include pollution, contaminants, and fuel 

spills associated with increasing human populations 

and military activities, particularly on Guam and 

Saipan. Numerous oil spills, offshore of Saipan, 
 38 U.S. Pacific Islands Shorebird Conservation Plan

Mariana Islands

Guam, and Tinian, have been documented by the 

USFWS (1996). Increasing tourism will undoubtedly 

put pressures on developing prime beach locations 

on Saipan, Guam, and Tinian. Specific recommended 

actions include:

- Coordinate with USDOD to support habitat

 protection of tidal and beach habitats as part of

 overall land management strategy

- Seek protection status for key beach and tidal

 flat habitats, e.g., Tanapag and Puerto Rico

 (Saipan) and Dungcas (Guam)

- Address potential contamination of Puerto Rico

 Mudflat from the Saipan Dump and effect

 cleanup if needed

- Monitor habitats and shorebirds for contaminants

- Coordinate with response teams for damage

 assessments, contaminant clean-ups, or

 emergency response to spills

Agricultural Lands

 Agricultural lands on Guam and Saipan and the 

seasonally flooded basins are threatened from 

expanded human development and conversion to 

other uses. Easement programs through NRCS 

might serve to help establish land easements. 

 Cultivated wetlands are not a significant resource in 

the Mariana Islands.

- Identify and map key agricultural areas that

 support ephemeral wetlands and target for

 restoration and protection

- Expand opportunities for agricultural land,

 easements, or cooperative agreements to protect

 open space from development pressures (NRCS,

 USFWS programs)

Predator Control 

The extinction of most of Guam’s avifauna has been 

directly attributed to the spread of the introduced 

brown tree snake (Savidge 1987). The impact of the 

brown tree snake on migrant shorebirds is unknown, 

but should be addressed in any conservation plan 

involving migrant shorebirds. It could become 

a serious problem throughout the Pacific if 

accidentally introduced to other islands. Currently 

it is restricted to Guam, but records from Saipan 

and Hawai`i continue to occur as snakes stow-away 

on airplanes and boats. Introduction to islands 

that support Bristle-thighed Curlews or resident 

endangered species such as Hawai`ian Stilt or 

Tuamotu Sandpiper could be catastrophic for these 

and other endemic species. An international effort 

has been developed to prevent the spread of the 

brown tree snake to other Pacific Islands (USFWS 

1996). Introduced mammals, especially rats and feral 

dogs are a limiting factor in the survival of resident 

and migrant waterbirds. The impact on migrant 

shorebirds is undocumented.

- Control and ultimately eradicate brown tree snake

- Control introduced mammalian predators at key

 wetland complexes in the islands

- Eradicate introduced mammals and reptilian

 predators from islands where feasible

- Rigorously implement measures to ensure the

 brown tree snake does not spread to other

 Mariana Islands or other USPI

- Develop a response plan for quick detection and

 eradication in the event predators are introduced

Monitoring Priorities 

- Implement regular surveys to assess species,

 abundance, population trends and habitat

 utilization of migratory shorebirds

- Develop and standardize Guam and CNMI

 biannual waterbird monitoring program inclusive

 of migrant shorebirds

- Monitor shorebird response to habitat

 restoration to support adaptive management

 strategies as a component of wetland and tidal

 flat conservation

- Establish a monitoring program for the early

 detection of brown tree snake and introduced

 mammals on predator free islands

- Monitor for contaminants and spills on beaches,

 wetlands, and tidal flats that are important for

 shorebirds

Research Priorities

- Identify where wetlands can be created in an

 effort to balance shorebird habitat needs with

 urban growth (GIS coordinated)

- Investigate habitat use and shorebird occurrence 

 in the islands and quantify the importance of

 habitat type to maintenance of shorebird numbers

- Develop adaptive management strategies for

 ephemeral wetlands
 Mariana Islands Subregion 39

Mariana Islands

- Continue research of life history and

 effectiveness of control/eradication efforts on

 brown tree snake

Education Priorities 

- Educate the public about migratory shorebirds

 and the importance of shorebird habitats

 (wetlands, tidal flats, grasslands, beaches)

- Develop educational resources for USDOD

 personnel on shorebird ecology, threats

 (predators and disturbance) and important

 habitats: beaches, dunes, mudflats, wetlands, and 

 grassy areas

- Develop education curricula on migration to

 promote an understanding of the connectivity of

 the Mariana Islands to other regions of the globe

- Involve schools and the public in the monitoring

 program for golden-plover, expand Kolea Watch

 efforts

Implementation and Coordination

CNMI Division of Wildlife and USFWS (Guam, 

Rota) have expanded efforts to develop an islandwide ecosystem planning effort through the 

development of Habitat Conservation Plans (HCP) 

for each island. These HCPs address habitat 

fragmentation, important wetlands resources, and 

attempt to address conservation with economic 

growth and development within watersheds. 

They also attempt to link the recovery actions for 

endangered species in the islands. Two endangered 

species use wetland habitats in the Marianas, the 

Mariana Moorhen and Nightingale Reed-Warbler. 

Recovery plans call for protection of wetlands 

for both species. Although the conservation of 

migratory shorebirds in the Mariana Islands will not 

be of primary focus in the development of HCPs and 

other planning efforts, resource managers should 

integrate the maintenance of shorebird populations 

in the Marianas. The USFWS has developed a 

multi-agency partnership with the USDOD for the 

protection, development, and management of fish 

and wildlife resources on Guam and Tinian. Natural 

areas on public and private lands are protected by 

local and Federal regulations but are not under 

cooperative management. Key areas need to be 

prioritized by local governmental agencies and 

the USFWS. Coordination with development and 

economic plans for expanding tourism needs to be a 

continuing focus by resource agencies.

Ephemeral freshwater wetlands on Guam. Farmed wetland with overgrown wetland in near foreground (left). 

Unfarmed wetland basin (right). Photos by Andrew Engilis, Jr.
 American Samoa Subregion 41

American Samoa 

Description of the Subregion

American Samoa comprises five high volcanic islands 

(Tutuila, Aunu`u, Ta`u, Olosega, and Ofu) and two 

coral islands (Rose Atoll and Swains Island) (Figure 

11). This plan does not cover the independent nation 

of Samoa (Savai`i and `Upolu). American Samoa is 

located at 14 ̊ south Latitude and from 168 ̊ - 171 ̊ 

west Longitude. All of the high islands rise steeply 

from the ocean, supporting rugged interior forests 

and narrow coastal plains. The islands receive from 

125 – 300 inches (317 – 762 cm) of rainfall annually, 

most falling between October and March, with 

higher precipitation in the uplands. The islands 

range in size from 395 ac (1.6 km2) (Aunu`u) to 54.8 

mi2 (142 km2 ) (Tutuila) and the highest peak is 

3,166 ft (965 m) (Ta`u). Wetland acreage is limited, 

occurring primarily along the coastal plains. Swains 

Island and Rose Atoll are low coralline islands less 

than 10 m high. Swains Island is a small raised 

atoll enclosing a 259-acre (105 ha) central, brackish 

lagoon bordered by 4 acres (1.61 ha) of coastal 

marsh. Similar to Laysan Island, Hawai`i, this water 

body functions more as a lake than a true lagoon. 

Rose Atoll is a USFWS National Wildlife Refuge 

(part of the Pacific Remote Islands National Wildlife 

Refuge Complex) and is the world’s smallest atoll 

with two islets on a nearly circular reef. Rose Island 

is dominated by shrub vegetation and harbors a 

small Pu`avai (Pisonia grandis) forest. Sand Island 

is a sandy islet with no vegetation. The combined 

area of the two islets is approximately 24.7 ac (0.1 

km2).

Shorebird habitat in American Samoa is limited, 

and the migrant shorebird community is low in 

both species diversity and abundance. Habitats 

used by shorebirds include beaches and rocky 

shorelines, enclosed lagoons, mudflats, littoral and 

mangrove forests, and to a lesser degree, wetlands. 

The Pacific Golden-Plover is the most numerous 

species and uses a wide array of habitat including 

lawns, grasslands and other open spaces associated 

with human development in the Pacific. Wandering 

Tattlers are most common on rocky beaches but 

they also utilize a wide range of habitat from high 

mountains to grassy runways (Amerson, Jr. et al. 1982).

FIGURE 11. American Samoa

American Samoa Subregion

Western

Samoa

Swains Island

Tutuila

Ofu

Olosega

Taʻu

Rose Atoll

American Samoa

Aunuʻu

Maunuʻa Group
 42 U.S. Pacific Islands Shorebird Conservation Plan

American Samoa 

Shorebird Habitats

Wetlands and Enclosed Lagoons

American Samoa supports 495 wetland acres (200 

ha): 350 ac (142 ha) on Tutuila, 112 ac (45 ha) on 

Aunu`u, 20 ac (8 ha) on Ta`u, and smaller sites are 

scattered on other islands. Only 100 acres (40 ha) 

are freshwater wetlands and most harbor emergent 

stands of ferns (Cyclsorus interruptus and 

Acrostichum aureum) and spike rush (Eleocharis 

sp.). The majority of these acres are at Nu`u`uli 

Pala lagoon and on the small offshore island of 

Aunu`u. Along river bottoms, swamps predominate 

with a dense understory of ferns. Some ephemeral 

wetlands exist but to a lesser degree than in the 

Marianas and Hawai`i, a result of Samoa’s steep 

topography and narrow coastal plains. Except for 

Aunu`u, these wetlands are of limited importance 

for shorebirds, but habitat restoration and 

management could improve conditions for migrant 

birds.

Aquaculture is common in American Samoa; taro is 

the predominate crop. In 1989, taro covered 1,240 ac 

(495 ha) in American Samoa, mostly as small family 

farms and local commercial farms (Am. Samoa 

Comm. College web site 2002). Since then the taro 

blight affected numerous acres in production and 

hence has become a limited habitat for shorebirds. 

Dry land taro is now the predominate variety grown. 

Wetland taro is grown in limited acreage on Aunu`u 

and Ta`u. On these islands, taro fields are not 

flooded, as they are in Hawai`i. However, exposed 

mud and fallow ground during early growth stages 

of taro can support low numbers of shorebirds.

Beaches and Rocky Shorelines

Sandy beaches are a common feature of these 

eroded islands, especially along the south shores, 

and they are an important habitat type for curlews, 

golden-plovers, turnstones and, to a lesser degree, 

tattlers (Amerson, Jr. et al.1982). There are 

approximately 21 miles (53 km) of coralline beaches 

in American Samoa, and many remain undeveloped, 

although sand-mining has depleted natural beaches 

in some areas. These beaches also are important 

for nesting sea turtles. In particular, the beaches 

bordering lagoons at Rose Atoll and Swains Island 

are important wintering habitat for Bristle-thighed 

Curlews (Amerson, Jr. et al. 1982). Another 

important habitat is the rocky shoreline where most 

of American Samoa’s Wandering Tattlers overwinter. The use, distribution, and actual numbers 

of shorebirds in these habitats remains unclear 

and better quantitative data are needed to assess 

conservation needs. The beaches and dunes of 

Rose Atoll and Swains Island are known to support 

Bristle-thighed Curlews, but overall shorebird use 

on these remote islands is poorly documented. 

Estuaries, Littoral Forests, Mangroves, Flats

There are few estuaries in American Samoa and 

those that exist are small as a result of short, 

steep watersheds on the high islands. On Tutuila, 

Nu`uuli Pala Lagoon is an embayment with 

extensive mudflats near its upper end. This area 

provides important shorebird habitat. Other areas, 

notably the Leone Pala on Tutuila and the Aunu`u 

wetlands have mudflats that are used by shorebirds. 

Mangroves reach their eastern limit in American 

Samoa. Mangrove forests are found only on Tutuila 

and Aunu`u and are characterized by red mangrove, 

grasses and sedges. The largest mangrove forest 

remaining in American Samoa (100 acres [40 ha]) 

is located at Nu`uuli Pala. Amerson, Jr. et al. (1982) 

recorded good numbers of golden-plovers and 

tattlers in mangrove forests. Much of American 

Samoa’s mangrove forests have been degraded 

or destroyed by humans. The Nu`uuli Pala forest 

contains a unique plant community that has almost 

disappeared from American Samoa (Amerson, Jr. et 

al 1982). Protection of the remaining forests should 

be coupled with protection of surrounding wetlands 

and lagoon mudflats.

The littoral forests of American Samoa support a 

surprising number of shorebirds including goldenplovers and tattlers (Amerson, Jr. et al.1982). This 

forest type has been mostly cleared by humans 

for rural development and settlements, and as a 

result has become a threatened habitat. As with 

mangroves, the clearing of this forest type may have 

had detrimental impacts to shorebird numbers, but 

the impact remains undocumented. Littoral forests 

are dominated by lau fala (Pandanus), Pisonia,

or futu (Barrintonia). The dominant tree depends 

on the substrate and soils. Protection of remaining 

littoral forests and possible reforestation is an 

important conservation action. 

Grasslands of Importance to Shorebirds

Similar to other Pacific Islands, ornamental 

grasslands, grazed areas, lawns, runway edges, and 

parks support Pacific Golden-Plovers. Village lands 

are of particular importance for golden-plovers 

(Amerson, Jr. et al.1982). Large pastoral lands, such 

as those that occur in the Hawai`ian Islands, do not 

exist in American Samoa. 
 American Samoa Subregion 43

American Samoa 

Shorebird Species

Only seven species of shorebirds have been recorded 

in American Samoa, although undoubtedly others 

have occurred (Appendix 4). The most common are 

Pacific Golden-Plover, Wandering Tattler, and Ruddy 

Turnstone. Bristle-thighed Curlews are regular 

winter visitors on Rose Atoll and Swains Island, and 

have been recorded from Nu`uuli Pala Lagoon on 

Tutuila, and from Aunu`u. The golden-plover, tattler, 

and turnstone can be found in a variety of habitats. 

Amerson, Jr. et al. (1982) conducted an inventory 

and have provided the only estimates of these 

species in American Samoa. They estimated 4,500 

Pacific Golden-Plovers, 900 Wandering Tattlers, 

and 550 Ruddy Turnstones. These numbers are 

small relative to total USPI populations, except for 

Wandering Tattlers.

American Samoa Subregional 

Population and Habitat Goals

The population status of migrant shorebirds in 

American Samoa is poorly known. As with Hawai`i 

and the Marianas, common species wintering in the 

islands exploit a variety of habitats. 

- Determine the population size and trends in

 abundance of shorebirds and identify critical

 habitats for long-term protection and monitoring,

 emphasis on Pacific Golden-Plover, Wandering

 Tattler, and Bristle-thighed Curlew

- Determine, the breeding origin, migration

 routes and turnover rates for golden-plovers and

 Wandering Tattlers

Habitat Status, Threats, and 

Management Goals

A major issue facing America Samoa’s marine 

and coastal resources is non-point source 

pollution. Tutuila’s coastal environments and 

coral reefs have shown degradation as a result of 

landfill contamination, oil spills, pesticide runoff, 

industrial waste, and incineration (USFWS 1996). 

Human sewage disposal and waste disposal from 

piggeries contaminate nearshore resources and 

estuaries, including Nu`uuli Pala Lagoon. In 1993, 

a commercial fishing vessel (the Jin Shiang Fa) 

ran aground at Rose Atoll and dumped more than 

100,000 gallons (378,500 liters) of diesel fuel and 

2,500 lbs (1,134 kg) of ammonia onto the reef, causing 

widespread damage in the lagoon (USFWS 1996). 

Although oil spills of this nature are not common in 

Pacific atolls, a single occurrence can be catastrophic 

to the ecosystem. 

The USFWS estimates that nearly 25 percent 

of historic wetlands have been lost in American 

Samoa. The highest percentage of wetland loss has 

been in littoral and mangrove forests (Amerson, 

Jr. et al. 1982). Most of the losses are the result 

of reclamation projects in conjunction with the 

development of Pago Pago Harbor and human 

settlements. Protection of remaining habitats on 

Nu`uuli Pala Lagoon and the Aunu`u wetlands are 

important to conservation of wintering shorebirds in 

American Samoa. Habitat restoration efforts could 

be investigated on the high islands. The wetlands 

of American Samoa historically supported two rare 

species, the Spotless Crake (Porzana tabuensis), 

and the Pacific Black Duck (Anas superciliosa) 

rediscovered in the early 1990s (USFWS pers. 

comm.). The Spotless Crake was rediscovered 

in a coastal wetland in the mid-1980s (Engbring 

and Engilis 1988), but now is known to occur in 

American Samoa only on the summit of Ta`u Island. 

The Pacific Black Duck occurs in low numbers in 

wetlands on Manu`a and Aunu`u. The cultural 

importance of wetlands, both in maintaining the 

natural biota and cultivated wetland practices, 

should be built into agencies’ efforts to conserve 

wetlands. 

Introduced mammalian predators hinder 

conservation efforts in American Samoa. The 

Polynesian rat has been eradicated from Rose 

Atoll, but persists on Swains Island. Cats have 

been liberated on Swains Island to address the rat 

problem and their impact on nesting seabirds and 

migrant shorebirds is unknown. Cats, dogs, pigs, and 

rats occur on the high islands.

- Protect existing wetlands, placing an emphasis on

 Nu`uuli Pala, Aunu`u, and Swains lagoon

- Evaluate restoration potential for wetlands that

 support shorebirds

- Work with farmers to provide protection for

 wintering shorebirds that use aquaculture fields

- Identify important remaining littoral and

 mangrove forests and seek their protection

- Restore littoral and mangrove forests where

 feasible

- Eradicate all introduced mammals from Swains

 Island

- Establish a monitoring program for the early

 detection of introduced mammals on predator free 

 islands and a response plan for quick eradication

 in the event predators are introduced
 44 U.S. Pacific Islands Shorebird Conservation Plan

American Samoa 

Monitoring Priorities 

- Develop a standardized biannual waterbird

 monitoring program for American Samoa that

 includes migrant shorebirds, with initial emphasis

 on curlews, golden-plovers, and tattlers

- Monitor shorebird response to habitat restoration

 to support an adaptive management approach to

 wetland and tidal flat conservation

- Monitor for contaminants and spills on beaches,

 wetlands, and tidal flats that are important for

 shorebirds

- Work with local authorities to assess damage and

 outline restoration needs

Research Priorities

- Assess species richness, abundance, trends

 in abundance, and habitat use of migratory

 shorebirds (emphasis should be placed on

 variation in abundance and habitat use of golden-

 plovers, Bristle-thighed Curlews, and Wandering

 Tattlers)

- Determine if land crabs accumulate toxins

 harmful to humans when exposed directly or

 secondarily to rodenticides

- Examine limiting factors for shorebirds using

 lagoon systems

- Develop habitat-based GIS data layers to compare

 the distribution of important shorebird habitats

 with the distribution of human activities and

 conservation projects 

- Develop a coordinated strategy to create and 

 enhance habitats that can be used by migrant

 shorebird and resident waterbird species

Education Priorities 

- Educate developers, economic planners, and the 

public about the importance of littoral forests, 

mangroves, wetlands, and beaches in maintaining 

Samoan wildlife 

- Educate the public about migratory shorebirds

- Develop primary and secondary school curricula 

on shorebird migration, emphasize connectivity of 

American Samoa with Alaska, Siberia, and the rest 

of Oceania 

- Involve schools and the public in a monitoring 

program for golden-plover, e.g. expand Kolea 

Watch and the shorebird sister schools program 

Implementation and Coordination

Conservation and restoration of shorebird habitats 

in American Samoa requires close cooperation and 

coordination with the Government of American 

Samoa and the agencies and individuals responsible 

for environmental protection and planning for 

economic development in the territory. The USFWS 

has developed a multi-agency partnership with 

the Government of American Samoa to develop a 

coastal ecosystem restoration and enhancement 

program. Key to cooperative efforts on behalf 

of shorebirds is the improvement of information 

about wetlands, shorebird use, and other native 

wetland-dependent species. Protection of low 

coral islands and atolls is paramount not only for 

shorebirds but also breeding seabirds, sea turtles, 

and maintenance of coral reefs. Coastal conservation 

efforts have become established in American Samoa 

through the American Samoa Coastal Management 

Program, the Department of Marine and Wildlife 

Resources, and the American Samoa Environmental 

Protection Agency. Shorebird conservation should 

be incorporated into coastal conservation planning 

strategies.
 Central Pacific Islands Subregion 45

Central Pacific Islands 

Description of the Subregion

U.S. possessions in the Central Pacific are scattered 

across millions of square kilometers of ocean and 

include islands in three different archipelagos: 

Howland and Baker Islands (Phoenix Archipelago), 

Jarvis Island, Kingman Reef, and Palmyra 

Atoll (Line Archipelago), Wake Atoll (Marshall 

Archipelago), and Johnston Atoll (Figure 1). The 

combined land area of these islands is only 12.9 mi2

(33.4 km2) (Table 7). All are arid islands with low 

annual rainfall except Palmyra, which supports a 

dense rain forest. Human habitation is restricted to 

military installations on Johnston and Wake, and a 

small civilian population on Palmyra. The military 

base at Johnston is closing and USDOD is currently 

working with contractors and USFWS to remove 

buildings and contaminants from the atoll. The 

USFWS manages Howland, Baker, Jarvis, Kingman 

Reef, Johnston, and Palmyra NWRs as part of the 

Pacific Remote Islands National Wildlife Refuge 

Complex. The largest island at Palmyra is not 

included in the NWR and it is owned and managed 

by The Nature Conservancy; USFWS manages the 

submerged lands and the rest of Palmyra’s emergent 

lands. 

Shorebird Habitats 

Wetlands of Importance to shorebirds 

There are no natural wetlands in this subregion.

Beaches of Importance to Shorebirds 

Beaches, especially on uninhabited islands, are 

an important resource for shorebirds. Most of 

these islands are so small that they consist almost 

entirely of beach strands with associated dunes. 

Only Palmyra has dense littoral forests (comprised 

of Pisonia trees), which are used by shorebirds. 

The other islands support short grasses and sparse 

shrubs.

Margins of Lagoons 

Atoll lagoons are a common feature in this subregion 

and their margins offer habitat for migrant 

shorebirds, particularly curlews and golden-plovers. 

Those of noted importance for shorebirds include 

the lagoon margins and intertidal flats at Palmyra 

and lagoon margins at Wake and Johnston.

Central Pacific Islands Subregion 

Johnston Atoll. USFWS Photo

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 46 U.S. Pacific Islands Shorebird Conservation Plan

Central Pacific Islands 

Shorebird Species 

Thirty-five species of shorebirds have been recorded 

in this subregion, and it is of primary importance 

for the Bristle-thighed Curlew and Pacific GoldenPlover. Other species occurring regularly include 

Ruddy Turnstone, Sanderling, Wandering Tattler, 

Gray-tailed Tattler, and Bar-tailed Godwit. Few 

estimates of shorebird abundance exist because 

these islands are extremely isolated and visited only 

rarely by biologists. More than 200 Bristle-thighed 

Curlews have been recorded at Palmyra (USFWS 

1992), and fewer than 50 have been observed at 

Howland and Baker (Marks and Redmond 1994). 

Eleven curlews were counted on Johnston Island 

during the 1999 Christmas Count conducted by 

the USFWS (NAS 2000, 2001). Although the total 

wintering population of Bristle-thighed Curlews 

in the Central Pacific Islands remains virtually 

unknown, the limited data from this region indicate 

that these islands provide important habitat for 

this species. The Tuamotu Sandpiper has not 

been recorded from the USPI in this region, but 

the type specimen was collected at Kiritimati 

Island (Kiribati), in the Line Islands. Palmyra and 

Jarvis are also located in the Line Islands and 

these two islands, along with other Central Pacific 

Islands, should be evaluated as potential sites for 

establishing additional populations of this rare 

shorebird. 

Central Pacific Islands Subregional 

Population and Habitat Goals 

The population status of migrant shorebirds in the 

Central Pacific Islands is unknown. The abundance 

and distribution of shorebirds, and their habitat use, 

in the region should be documented. Of particular 

interest is the status and distribution of the Bristlethighed Curlew. 

- Determine the population size and trends of 

wintering Bristle-thighed Curlews and identify 

important habitats for long-term protection and 

monitoring

- Assess population size and trends of other 

regularly wintering species of shorebirds

Habitat Status, Threats, and 

Management Goals 

Similar to other subregions covered in this plan, 

the Central Pacific Islands provide a variety of 

habitats used by wintering shorebird species. Pacific 

Golden-Plovers forage in anthropogenic habitat 

on lawns, tarmacs of military fields, and they roost 

on rooftops. They also use beaches, wetlands, and 

other natural habitats. Upland and beach habitats 

are priorities for protection on developed islands. 

Protection of beaches and lagoon edges that support 

wintering Bristle-thighed Curlews (e.g., Wake and 

Palmyra) should be emphasized. Many islands in 

this subregion have experienced major alterations 

of their natural environments as a result of military 

activities during and since World War II. Nuclear 

tests, military dumping, munitions storage and 

removal remain a concern, particularly on Johnston 

and Wake islands. Groundwater and nearshore 

pollution from these storage facilities is suspected 

but not documented. Daily sewage discharges are a 

regular occurrence on Johnston and Wake islands, 

despite modernization of facilities in the early 

1990s (USFWS 1996). Sources of contamination 

on Howland and Baker have been linked to WWII 

and post-war military activities. Chemical weapons 

and nuclear materials were stored at Johnston 

Atoll. These munitions at Johnston have recently 

been destroyed and cleanup is underway. Ground 

contamination by dioxins and PCB-containing fuel 

is high in places, and three aborted thermonuclear 

warheads resulted in plutonium contamination of the 

entire atoll (USFWS 1996). 

Introduced species are a major problem in this 

subregion. Over the past 25 years, USFWS has 

eradicated rats and cats from all islands in the 

subregion, except for Wake and Palmyra. In 

2004, a collaborative effort by the Endangered 

Species Recovery Council, Wildlife Management 

International of New Zealand, and Marine 

Endeavors, completed a project to eradicate cats 

from Wake. Initial surveys are very promising, 

and follow-up surveys over the next few years will 

determine if all of the cats were removed. Complete 

eradication of rats and cats at Wake and rats at 

Palmyra are high priorities. Introduced scale insects 

and ants at Palmyra are attacking the Pisonia 

forest on Palmyra and the effects on shorebirds are 

unknown.

- Remove introduced mammals from Wake and

 Palmyra

- Develop interdiction programs to prevent 

reintroduction of predators
 Central Pacific Islands Subregion 47

Central Pacific Islands 

- Eliminate or control introduced scale insects at 

Palmyra and limit the potential for introduction to 

other islands in the region

- Eliminate contaminant sources from military/

 island base resources

Monitoring Priorities 

- Monitoring priorities are similar to those in 

American Samoa. Lack of knowledge about 

shorebird numbers, habitat use, and threats limit 

our ability to develop conservation priorities

- Develop a monitoring program to assess shorebird 

species diversity, abundance and variation in 

abundance, distribution, population trends, and 

habitat use. Focus on Pacific Golden-Plover and 

Bristle-thighed Curlew 

- Monitor for contaminants on beaches, in lagoons, 

and on tidal flats 

- Monitor the response of curlews to predator 

eradication at Wake and Palmyra

Research Priorities 

- Work with the international shorebird community 

to collect basic information on the ecology of the 

Tuamotu Sandpiper in Polynesia and determine if 

suitable habitat exists on U.S. Islands to establish 

and sustain Tuamotu Sandpiper populations

- Work with the international shorebird community 

to collect basic information on the ecology of the 

Tuamotu Sandpiper in Polynesia and determine if 

suitable habitat exists on U.S. Islands to establish 

and sustain Tuamotu Sandpiper populations

- Study the ecology of the Bristle-thighed Curlew on 

low and coral islands and atolls with emphasis on 

Palmyra

- Investigate the effects of introduced scale insects 

on the habitat and shorebird populations at 

Palmyra.

- Develop strategies to control or eradicate 

introduced invertebrates with initial emphasis on 

scale insects and ants

Education Priorities 

- Education of USDOD personnel on shorebird 

ecology, threats (predators and disturbance) and 

important habitats: beaches, dunes, and lagoons

- Work with The Nature Conservancy to develop 

an education and outreach program regarding 

shorebirds, their ecology, and importance of 

predator free islands

Implementation and Coordination 

Howland, Baker, and Jarvis Islands; Johnston and 

Palmyra Atolls; and Kingman Reef are part of the 

Pacific Remote Islands NWR Complex. Wake Atoll 

is a military installation. USFWS and The Nature 

Conservancy jointly own Palmyra Atoll. Efforts to 

clean contaminated sites are being addressed by the 

USFWS and USDOD. Removal of rats and cats is 

a priority for nesting seabirds as well as wintering 

shorebirds. USGS is working with the USFWS to 

investigate control of scale insects at Palmyra.