Polynesian-Introduced Species

Polynesian-Introduced Species

Geckos and other Reptiles

Hawaiian Name: Mo‘o ‘Alā

[Illustration: Gecko]

They scurry up walls and across the ceiling upside down. They make strange noises at night. Most people think they’re cute, and appreciate them for catching undesirable bugs. These are the geckos...and other reptilian inhabitants of the Hawaiian Islands.

Mo‘o is the Hawaiian word lizards and other reptiles. An ancient proverb states, “Mai kolohe i ka mo‘o o lele i ka pali.” (“Do not bother lizards or you’ll fall off a cliff,”), which was “...a warning not to bother lizards lest someday the mo‘o cause a madness that makes one leap off a cliff and die.”[i]

Reptiles in the Hawaiian Islands

Reptiles have been on Earth for about 300 million years. There are currently about 7,000 known reptile species, including more than 3,850 lizard species and about 3,500 snake species worldwide.

When Captain Cook established Western contact with the Hawaiian Islands in 1778, there were already seven terrestrial reptile species established in the Hawaiian Islands, including three skink species and four gecko species.

The seven terrestrial reptile species in the Hawaiian Islands before Western contact was established in 1778 likely came to the Hawaiian Islands as stowaways on the voyaging canoes of the Polynesian settlers.

These seven species include the: Indo-Pacific Gecko (Hemidactylus garnotii); Mourning Gecko (Lepidodactylus lugubris); Stump-Toed Gecko (Gehyra mutilata); Tree Gecko (Hemiphyllodactylus typus); Azure-Tailed Skink (Emoia impar); Moth Skink (Lipinia noctua noctua); and Snake-Eyed Skink (Cryptoblepharus poecilopleurus).

All seven species are considered Polynesian introductions, not native to the Hawaiian Islands. There is a possibility, however, that some of these gecko and skink species are native to the Hawaiian Islands, having arrived before the Polynesian settlers, and without the help of humans (perhaps on a floating log or a raft of debris).

An ancient Hawaiian proverb states, “He mo‘o, he pili pōhaku, he pili lā‘au a he pili lepo” (“It is a lizard, for it clings to rocks, clings to trees, clings to the earth,”), which is “...said in derision of one who spies, hiding behind rocks, trees, and so forth. Also said of one who likes climbing over rocks and trees like a lizard.”[ii]

When assessing reptiles of the Hawaiian Islands, one must also consider sea turtles and snakes. In offshore waters of the Hawaiian Islands, five sea turtles come near the Hawaiian Islands, though only two come ashore in the Hawaiian Islands to lay their eggs. (See Hawaiian Sea Turtles, Chapter 6.)

Another marine reptile occasionally seen in Hawaiian waters (and thus considered native) is the Yellow-bellied sea snake (Pelamis platurus), a venomous yellow and black sea snake that is about 29 inches (74 cm) long.

A distant relative of the cobra, the Yellow-bellied sea snake is the only truly pelagic (open-ocean) sea snake of 55 known sea snake species. No terrestrial reptiles (e.g., snakes) are considered native to the Hawaiian Islands.

One non-native snake species, the island blind snake (Ramphotyphlops braminus), has now become established in the Hawaiian Islands. A burrowing snake about 6½ inches (16.5 cm) long, the Island blind snake is native to southeastern Asia and probably arrived in the Hawaiian Islands some time around 1930 in the soil in potted palm trees imported to the Hawaiian Islands from the Philippines for landscaping. The Island blind snake feeds on insects and small invertebrates, and lives mostly underground.

As of 2002, at least 21 lizard species have been found in the wild in the Hawaiian Islands, including geckos, skinks, anolis lizards, chameleons, horned lizards, and iguanas.

The Azure-tailed skink (Emoia impar) has not been documented since the 1950s. The Coast horned lizard (Phrynosoma coronatum) was released on O‘ahu around 1900, and the Texas horned lizard (Phrynosoma cornutum) was established at two O‘ahu locations in the 1960s, but neither of these species has survived in the wild in the Hawaiian Islands.

A veiled chameleon was found in the wild on Maui in 2002 (see below), but it remains uncertain whether a wild population has become established.

At least 17 lizard species may be found in the wild in the Hawaiian Islands today. Some of these species, such as the Green iguana (Iguana iguana) and Tokay gecko (Gekko gecko) exist only in very small areas on particular islands.

[Illustration: Tokay gecko (Gekko gecko)]

Lizards in the Hawaiian Islands

Geckos (Gekkonidae)

Gecko Physiology

How Geckos Walk Upside-Down


Gecko Species in the Hawaiian Islands—An Overview

Gold Dust Day Gecko (Phelsuma laticauda laticauda)

House Gecko (Hemidactylus frenatus)

Indo-Pacific Gecko (Hemidactylus garnotii)

Mourning Gecko (Lepidodactylus lugubris)

Orange-Spotted Day Gecko (Phelsuma guimbeaui guimbeaui)

Stump-Toed Gecko (Gehyra mutilata)

Tokay Gecko (Gekko gecko)

Tree Gecko (Hemiphyllodactylus typus)

Chameleons (Chamaeleo)

Jackson’s Chameleon (Chamaeleo jacksonii xantholophus)

Veiled Chameleon (Chamealeo calyptratus)

Anoles (Anolis)

Green anole (Anolis carolinensis)

Brown anole (Anolis sagrei)

Knight anole (Anolis equestris equestris)

Skinks (Scincidae)

Azure-Tailed Skink (Emoia impar)

Copper-Tailed Skink (Emoia cyanura)

Metallic Skink (Lampropholis delicata)

Moth Skink (Lipinia noctua noctua)

Snake-Eyed Skink (Cryptoblepharus poecilopleurus)

Iguanas (Iguanidae

Green Iguana (Iguana iguana)

Geckos (Gekkonidae) 

The scientific family Gekkonidae is found worldwide, and includes at least 900 species in tropical and subtropical regions. Four of these species came to the Hawaiian Islands as stowaways aboard the voyaging canoes of the early Polynesian settlers of the Hawaiian Islands.

Gecko Physiology

Geckos are nocturnal (active mostly at night), feeding primarily on insects. Geckos are usually less than 6 inches (15 cm) long and live for five to seven years, though larger varieties may live up to 20 years.

Geckos have clear, fixed eyelids similar to contact lenses. The gecko’s eyes are always open, and its immovable eyelids distinguish it from many other lizard species. To protect against bright light, the gecko merely closes its vertical pupil, and to clean its eyes the gecko uses its long tongue.

Unlike most other types of lizards, the gecko has a voice. Sounds emanating from geckos have been described as barks, croaks, clicks, squeaks and groans. The gecko produces these sounds (which are often surprisingly loud), by vibrating its tongue against the roof of its mouth.

Some species of gecko that are native to Asia and Africa make a sound similar to the pronunciation of their common name, “gecko.” Specific vocalizations may be used during courtship or for defining territory, or as an exclamation of surprise or alarm.

The gecko’s tail is detachable, and may unhook from the body if grabbed by a predator. The detached tail continues to wriggle, distracting the predator as the gecko escapes.

Geckos in the genus Gehyra, such as the Stump-toed gecko (Gehyra mutilata), may shed their skin when grabbed by a predator (e.g., an owl or a bird), allowing the gecko to slip away from the predator’s grasp.

Another technique geckos use to avoid predators is cryptic coloring, the ability to change the coloration of their body. The gecko may do this automatically in order to better match its background or as a response to environmental conditions (e.g., sunlight).

All gecko species in the Hawaiian Islands are arboreal (tree-dwelling), and have specialized (enlarged) toe pads that allow them to climb trees and other vertical surfaces. The pads beneath each toe digit are known as lamellae, and are composed of many tiny hairs known as setae (see below).

How Geckos Walk Upside-Down

Scientists recently used new mini-machines and ultra-tiny sensors to measure the small forces exerted by gecko feet. This allowed researchers to finally find the answer to a puzzling question: how is it that geckos are able to walk upside down on the ceiling?

Researchers had ruled out suction (geckos can walk upside down in a vacuum), they ruled out friction (they can walk upside-down on smooth surfaces), and they ruled out electrostatic attraction (antistatic guns do not deter the gecko’s upside-down abilities).

So how do geckos walk upside down? It turns out that each gecko toe contains more than 100,000 tiny hairs, called setae, and each setae is one-tenth as thick as a human hair and only about twice as long as a human hair’s diameter. The end of the setae is split into hundreds of parts, each with a spatula-shaped tip, which can only be seen with an electron microscope.

The gecko’s sheer number of surface contact points—literally millions—collectively generates the same type of force that holds molecules together. It is this intermolecular force, known as VanderWaals force, that creates the adhesive bond that allows geckos to walk upside down on the ceiling.

The tips of the hairs are so fine that they go into even the slightest depressions on sheets of glass or other surfaces. Geckos roll their toes as they step, changing the angle of the hairs just enough to release the surface tension.

Scientists learning how to use this adhesive intermolecular force are now considering a variety of new ideas, from reusable tape to climbing gloves and Department of Defense geckobots.

Researchers estimate that one million gecko toe hairs may hold up to 45 pounds (20 kg). There are many possibilities for future applications of this scientific principle that allows geckos to cling to surfaces.

[Photograph: Gecko upside down on ceiling]


Geckos lay two porcelain-colored eggs, each about the size of a pea. The eggs hatch in one to three months, and two egg-teeth attached to the hatchling’s nose allow it to break out of the shell.

Then after one or two days the teeth fall off. Within one to three years the gecko is full-grown, about 3½ to 5 inches (9 to 13 cm) long on average, with half of that being its tail.

Gecko Species in the Hawaiian IslandsAn Overview

For many centuries there were just four types of geckos on the Hawaiian Islands: the Stump-toed gecko (Gehyra mutilata), the Indo-Pacific gecko (Hemidactylus garnotii), the Mourning gecko (Lepidodactylus lugubris), and the Tree gecko (Hemiphyllodactylus typus).

In the 1940s, a slightly larger and more aggressive type of gecko, called the House gecko (Hemidactylus frenatus) took hold in the Hawaiian Islands, and is now the most common gecko in the Hawaiian Islands. Another gecko now naturalized in the Hawaiian Islands, the Gold-dust day gecko (Phelsuma laticauda laticauda), was released in the wild in 1974.

There are currently at least eight species of gecko established in the Hawaiian Islands, and six of these are relatively common. The other two species that are now established in the Hawaiian Islands are the Orange-spotted day gecko (Phelsuma guimbeaui guimbeaui) and the Tokay gecko (Gekko gecko).

All of these gecko species are insect-eaters, and usually have a very specific feeding area. Geckos consume moths, flies, ants, mosquitoes, cockroaches and various other insects and other arthropods. Tokay geckos sometimes eat mice and small birds.

[Photograph: Gold-dust day gecko]

Gold-Dust Day Gecko (Phelsuma laticauda laticauda)

The Gold-dust day gecko is bright green to yellowish-green in color, and is about 4¾ inches (12 cm) long on average. The top of the gecko on the neck area is spotted with bright yellow (resembling gold dust), and there are also reddish to brownish bars on the gecko’s back in the area above the back legs, as well as on the head region in front of and behind the eyes.

Released in the wild in the Hawaiian Islands in 1974, the Gold-dust day gecko is now established in several areas on O‘ahu and on the Kona side of the island of Hawai‘i, and less commonly near Hilo and in West Maui. Gold-dust day geckos are native to Madagascar and nearby regions.

The Gold-dust day gecko is active during the day (diurnal) feeding on insects as well as beetles, spiders and other arthropods (mostly introduced species) and also sometimes seen feeding on flower pollen or lapping up fruit nectar. It may be seen in trees, on the ground and in houses as well as other areas inhabited by humans.

[Photograph: House gecko]

House Gecko (Hemidactylus frenatus)

As the name implies the House gecko is frequently seen around human dwellings, and is the most common gecko in the Hawaiian Islands. House geckos may be seen in all areas of houses as well as in piles of rocks or lumber, and also in forested areas.

Native to the Indian region of Asia, the House gecko is brown to beige or grayish in color (sometimes whitish), and covered with small spots or marks. Light colored undulating stripes may run from the gecko’s tail to its head.

The belly (ventral surface) is lighter in color than the upper region of the body. The gecko’s coloration is generally lighter (sometimes pinkish) at night when feeding near lighted areas. Enlarged rows of scales line the gecko’s tail.

Also known as the Leaf-toed gecko, the House gecko is slightly bigger and also more aggressive than the Polynesian-introduced gecko species. The House gecko measures about 4¾ inches (12 cm) long on average.

House geckos sometimes prey on juvenile geckos, but mainly feed on various insects as well as spiders and other arthropods. House geckos are territorial, and very vocal, commonly emanating loud sequences of chirps. Established in the Hawaiian Islands in the 1940s, House geckos are now found on all of the main Hawaiian Islands.

[Photograph: Indo-Pacific gecko]

Indo-Pacific Gecko (Hemidactylus garnotii)

Inhabiting low and middle elevations on all the main Hawaiian Islands, Indo-Pacific geckos are often seen in houses and near human dwellings. The Indo-Pacific gecko varies in color from gray to charcoal black, light brown to tan, or even whitish.

Covered with numerous dark or light marks, the underside of the gecko’s slightly flattened tail may be tinted with an orange to pink color. Along the lateral edge of the tail is a single row of spine-like scales.

Indo-Pacific geckos are about 4½ inches (11 cm) long. Mostly nocturnal, Indo-Pacific geckos feed on mosquitoes, spiders, and other invertebrates. The Indo-Pacific gecko is also called the Fox gecko because its snout is said to resemble a fox’s snout.

Indo-Pacific geckos likely arrived in the Hawaiian Islands aboard the voyaging canoes of the early Polynesian settlers of the Hawaiian Islands. The Indo-Pacific gecko was quite common around homes in the 1940s but has now been largely displaced by the House gecko.

[Photograph: Mourning gecko]

Mourning Gecko (Lepidodactylus lugubris)

The Mourning gecko is creamy to brownish in color (lighter on the belly) with a darker bar through the eye region to the tip of the snout, and inverted, V-shaped dark bars (or paired spots) along its back.

Tooth-like scales line the side of the gecko’s moderately flattened tail, and its smooth skin may feel silky if touched. The gecko’s length is about 3¼ inches (8 cm), making it the second smallest of the geckos established in the Hawaiian Islands.

Generally the slowest moving of all geckos in the Hawaiian Islands, the Mourning gecko is sometimes seen licking the sap off fruits, such as papayas and mangoes, but also feeds on insects, and may be seen at night near lighted areas where insects gather.

Mourning geckos may be seen in trees as well as on the ground, and also inhabit houses where they are sometimes quite friendly in the kitchen area.

The notably loud chirping vocalizations of the Mourning gecko are often repeated up to ten times in rapid succession. Also called the Scaly-toed gecko, the Mourning gecko likely arrived in the Hawaiian Islands aboard the voyaging canoes of the early Polynesian settlers of the Hawaiian Islands. The life span of Mourning gecko is about five years.

Today the Mourning gecko is quite common in the Hawaiian Islands, second only to the House gecko. Mourning geckos were the most common geckos in the island until about 1950, when the larger and more aggressive House gecko was introduced.

Mourning geckos are found on all of the main Hawaiian Islands, as well as on many other Pacific Islands.

[Photograph: Orange-spotted day gecko]

Orange-Spotted Day Gecko (Phelsuma guimbeaui guimbeaui)

The Orange-spotted day gecko has a relatively thick body that is bright green in color with bright orange to orangish-red markings on its back (dorsal surface). On the gecko’s head and neck is a powder blue patch, and the tip of the tail may also show some powder blue color.

When the Orange-spotted day gecko is inactive or when the temperature is cool, the gecko’s color may become gray or black. The belly (ventral surface) is pale yellow with some brown spotting and V-shaped marks.

Orange-spotted day geckos feed on various insects and other arthropods, and sometimes lick pollen and juices from fruit and flowers. Established on O‘ahu at least since the 1980s, Orange-spotted day geckos inhabit tall trees such as coconut palms in Kane‘ohe, Kailua, and other areas.

Orange-spotted day geckos are native to the island of Mauritius (east of Madagascar off the African coast east) and other islands in the Indian Ocean.

[Photograph: Stump-toed gecko]

Stump-Toed Gecko (Gehyra mutilata)

Also called the Stump-toed Dtella, the Stump-toed gecko is about 3½ to 4 inches (9 to 10 cm) long with a stout body that is gray to dark brownish or black in color on the dorsal surface, and covered with numerous dark and light spots. The gecko’s belly is cream to yellow in color.

A dark horizontal line may be seen through the eye area of the Stump-toed gecko, and the snout is relatively short. The gecko’s dorsal surface is generally dark during the day, but becomes lighter in color at night or against light backgrounds, and sometimes shows a whitish tint.

The Stump-toed gecko was seen near houses more often before the arrival of the House gecko in the 1940s. A territorial gecko, it is often seen beneath or in large trees, including monkeypods, banyans, and palms. It also may be seen climbing around in piles of rocks or lumber.

The Stump-toed gecko may shed large pieces of skin in order to squirm away from predators or humans trying to pick them up.

The Stump-toed gecko likely arrived in the Hawaiian Islands aboard the voyaging canoes of the early Polynesian settlers of the Hawaiian Islands, and is a common species on many South Pacific Islands throughout Polynesia and Micronesia. The Stump-toed gecko is notable for its broad toe pads that have a width exceeded only by the toe pads of the Tree gecko.

[Photograph: Tokay gecko]

Tokay Gecko (Gekko gecko)

The Tokay gecko is one of the largest gecko species, averaging about 11 inches (28 cm) long. Males are bluish-gray, with large, bright red or orange-red to purple spots.

The markings on females are not as light and the background color is more of a greenish-gray. The belly (ventral surface) of the Tokay gecko is whitish with flecks of orange-red. The top of the body (but not the tail) is also covered with tubercles, or small bumps.

Tokay geckos are territorial and arboreal (tree-dwelling), and feed on a variety of insects and other arthropods as well as other lizard species and even mice. The Tokay gecko is nocturnal (active at night), and if grabbed by a predator the gecko’s tail may break off as a defensive mechanism that helps the gecko escape from predators.

Tokay geckos are found in Lanikai and above Kāne‘ohe in O‘ahu’s Ko‘olau Mountains. They inhabit large trees such as coconut palms, banyans, and figs. Tokay geckos also live in houses, often taking up residence in the attic area. After mating with a male, the female lays one to two eggs that hatch in 2½ to 6 months, depending on temperature.

Tokay geckos are native to Southeast Asia, where it is considered good luck to have one residing in your home. It is also considered good luck to hear the gecko’s loud, bark-like vocalization repeated seven times in succession. The vocalization is said to sound like “gecko” and also “Tokay,” leading to those two names.

[Photograph: Tree gecko]

Tree Gecko (Hemiphyllodactylus typus)

Tree geckos are the smallest geckos in the Hawaiian Islands, measuring just over 3¾ inches (9.5 cm) on average. They are nocturnal insect-eaters, and are not seen around human dwellings as often as some other geckos. They are also not as vocal.

The dorsal surface of this slender, little gecko is gray to brown or blackish, with white specks. A dark horizontal stripe on each side of the gecko’s head runs from the shoulder forward to the eye region. The ventral surface is light in color. Tree geckos are seen in the forest climbing trees as well as on the ground and in piles of debris.

The Tree gecko has vertical eye pupils and no eyelids, and uses its tongue to keep its eyes clean. The pupils expand open at night but in bright light are seen only as narrow vertical slits. At the base of the Tree gecko’s narrow tail are two distinctive, dark spots. Elongated, dark bars may also line the tail’s lateral surface. The ventral surface of the tail is orange.

Like the Stump-toed gecko, the Tree gecko may become lighter in color at night, sometimes even showing a whitish tint that allows body organs to be seen through the transparent skin.

Also called the Waif gecko, the Tree gecko likely arrived in the Hawaiian Islands aboard the voyaging canoes of the early Polynesian settlers of the Hawaiian Islands. Today Tree geckos are found on all of the Hawaiian Islands as well as many tropical islands in the Western Pacific.


Chameleons (Chamaeleo) 

Chameleons belong to the genus Chamaeleo in the scientific family Chamaeleonidae, which includes more than 130 arboreal (tree-dwelling) insect-eating species native to the island of Madagascar or the continent of Africa.

Chameleons are known for their ability to change their colors and patterns to match their surroundings. They are also known for their prehensile tails and long projectile tongues that, when unfurled, may stretch longer than their entire body. Another significant trait of chameleons is their independently moving eyes.

[Photograph: Jackson’s chameleon]

Jackson’s Chameleon (Chamaeleo jacksonii xantholophus)

The Jackson’s chameleon is quite common in some O‘ahu forests, including the Ko‘olau Range where it is seen at middle elevations between Kailua and Kāne‘ohe, and near Makawao, Maui, as well as near Kona on the island of Hawai‘i.

Averaging about 10 inches (25 cm) in length, this unusual lizard has eyes that swivel independently for better depth perception and may also work together to provide binocular vision.

The Jackson’s chameleon has a dinosaur-like body and the male has three horn-like head projections. Some females also have horns, though they are smaller than the male’s horns.

Male Jackson’s chameleons sometimes fight over territory, using their horns as weapons. The winner is the one who pushes his opponent off the branch. This sparring may also be done to establish mating rights with females.

With opposable toes on all its feet, the Jackson’s chameleon is well adapted to tree climbing, and sometimes uses its prehensile tail as a fifth foot while climbing in tree branches.

The projectile tongue of the Jackson’s chameleon unfurls at speeds of more than 16 feet (4.9 m) per second to make contact with the prey, which may include a variety of insects and other arthropods, such as crickets, flies, butterflies, bees, and spiders. The chameleon’s long, hollow tongue, with a suction-cup tip, shoots out in less than 1/100th of a second to grab the prey.

The color of the Jackson’s chameleon may range from blackish, to gray, brown, green, yellow, or even bluish. The Jackson’s chameleon is adept at changing its color, which is generally done not to match its background but instead as a response to certain emotional states (e.g., fear), or environmental conditions (e.g., temperature, or light intensity), or particular activities (e.g., courtship behaviors).

A male signaling its intent to mate with a female will bob its head laterally and show blue and yellow colors. These body color changes may act as a signal to other Jackson’s chameleons or to predators, and may also serve to camouflage the chameleon.

The Jackson’s chameleon originally became established in the Hawaiian Islands in 1972 when some pets were released on O‘ahu, where they now inhabit several locations in the Ko‘olau Range.

A January 2002 search of a Makawao residential area on Maui by State of Hawai‘i workers looking for veiled chameleons (see below) led also to the capture of 102 Jackson’s chameleons.

Veiled Chameleon

The veiled chameleon is a larger relative of the Jackson’s chameleon. Veiled chameleons may reach 2 feet (61 cm) in length, nearly twice the size of the Jackson’s chameleon.

The color of the veiled chameleon varies from white to yellow, red, orange, green, brown, gray or black (usually striped).

The veiled chameleon is recognized by its large head shield that is bony and shaped like a shark fin. The shield measures about 3 inches (8 cm).

A 16½-inch (42 cm) veiled chameleon was found in March of 2002 in an agricultural field above Kā‘anapali, Maui. Six more veiled chameleons were found in Maui by December of 2002, and eight more in January, 2003.

In all, more than 20 veiled chameleons were caught or turned in to authorities between March of 2002 and February of 2003, raising fears among state agencies that a population of the reptiles is now established in Maui.

Native to Saudi Arabia and Yemen, the veiled chameleon is considered a greater threat to Hawaiian ecosystem than the Jackson’s chameleon. Unlike the Jackson’s chameleon, which is an insect eater, the veiled chameleon may feed on plants and birds as well as insects. Veiled chameleons may lay up to 70 eggs, which incubate for 70 to 200 days before hatching.

Though illegal in the Hawaiian Islands, the veiled chameleon is currently highly valued in the international pet industry, and may have been deliberately introduced to the Hawaiian Islands by traders hoping to establish a population.

Anolis Lizards (Anolis) 

The genus Anolis includes at least 250 species commonly known as anolis lizards, or anoles. Anoles are native to the American continent and Caribbean islands. They are Anoles have long tails and may be green, gray or brownish in color.

The extra skin on the anolis lizard’s throat is known as a dewlap, or throat fan, and may be reddish, yellowish, or whitish in color. The male often extends the throat fan when engaged in a territorial battle with another male and also during the courtship process. Anole species reproduce by laying eggs (oviparous), and most are at least partly arboreal (tree-dwelling).

Anoles were first introduced to the Hawaiian Islands around 1950. There are now at least three species of anoles established in the Hawaiian Islands, including the Green anole (Anolis carolinensis), Brown anole (Anolis sagrei), and Knight anole (Anolis equestris equestris). These lizards actively feed during the day, unlike the geckos, which are mostly nocturnal.

Anoles are ardent defenders of their small territories, which may also be home to as many as three female anoles. The male anole may appear to be doing push-ups as it bobs up and down and extends its throat sac to intimidate other males, which may be chased away and even bitten if they persist in encroaching upon the territory.

Like chameleons, anoles may rapidly change their body color. Chemical messages sent from the anole’s brain trigger the cell pigmentation reactions that cause the color changes.

Anoles may quickly change from an olive color to bright green. These body coloration changes help the lizard camouflage itself from predators, and may serve as an adaptation to external conditions (e.g., darker colors provide better heat absorption from the sun).

Kilioe wahine i uka.

Kiloe, woman of the upland.

Kilioe was a wahine mo‘o (lizard woman) famed in chants and songs of the ali‘i. She belonged to Kaua‘i and it was she who tried to prevent Hi‘iaka from taking the body of Lohi‘au from a cave at Hā‘ena.

(Pukui: 1799-193)

[Photograph: Green Anole]

Green Anole (Anolis carolinensis)

The Green anole has a pointed snout, and may be bright green, grayish, tan, or brown in color. The Green anole’s color variations result from changes in skin pigment cells, and these changes may be caused by particular activities or emotional states as well as temperature and humidity levels.

Green anoles measure about 7 inches (18 cm) long on average, including the tail, which may break off allowing the anole to escape from predators. Male Green anoles are generally bigger than females. Often visible on the male is the pinkish-colored dewlap (throat fan).

The Green anole is an arboreal (tree-dwelling) lizard. The Green anole’s toe pads are elongated and each toe is tipped with a claw that helps the anole climb tree trunks and other vertical surfaces. Active during the day (diurnal), the Green anole is territorial and feeds on insects.

The Green anole male will engage in battles to defend its territory, extending its pink dewlap (throat fan) and turning bright green, often locking jaws with the opponent until the loser is pushed from the area. Green anoles are found on all of the main Hawaiian Islands, with the possible exceptions of Lāna‘i and Ni‘ihau.

Female Green anoles bury one or two small eggs beneath soil or leaf material, and about one month later the eggs hatch. Green anoles became established in the Hawaiian Islands around 1950, when they were available in local pet stores and some of these pets either escaped or were released into the wild.

[Photograph: Brown Anole]

Brown Anole (Anolis sagrei)

Brown anoles range in color from tan to light brown, dark brown, or even black. While Green anoles are slender, the Brown anole is distinctively more robust (plump), and also a bit shorter.

The male Brown anole’s dewlap (throat fan) is red to orange in color and bordered with yellow or white. The throat fan is not always visible. The male Brown anole also has a crest on its head and back. Some female Brown anoles have a row of light marks along their back.

Both the Green anole and Brown anole may be found in shrubs and trees as well as in and around houses, but the Brown anole is less arboreal (tree-dwelling) and doesn’t usually climb higher than about 6 feet (1.8 m). The Brown anole often positions itself head down on vertical (or nearly vertical) surface, such as the trunk of a tree, and in this position a male may display its dewlap.

Brown anoles are territorial, and feed on a variety of insects and other invertebrates, particularly ground dwelling species such as ants and spiders. Brown anoles measure about 6¾ inches (17 cm) long on average, with males usually slightly bigger than females.

The Brown anole took hold in the Hawaiian Islands in the 1980s. Native to the Bahamas, Jamaica, and Cuba, Brown anoles are now well established in several areas of O‘ahu.

[Photograph: Knight Anole]

Knight Anole (Anolis equestris equestris)

The Knight anole is usually greenish in color (sometimes brownish or black) with a whitish or yellow mark on its shoulders and beneath its eyes. The Knight anole measures about 16 inches (41 cm) long on average, and has a wedge-shaped head.

The Knight anole male has a small crest on its neck, and a relatively large dewlap (throat fan) that extends from beneath the anole’s chin back toward the chest area. The dewlap is light pink in color (not spotted as in some other Hawaiian lizards).

Knight anoles are not widespread, and are found only in certain small areas of windward O‘ahu forests (e.g., Lanikai and Kāne‘ohe) and possibly a few other isolated island locations. They are native to Cuba and first became established in the Hawaiian Islands around 1980 or earlier.

Active during the day (diurnal), Knight anoles are also arboreal (tree-dwelling), inhabiting coconut palms and other large trees. They feed on a variety of insects, spiders, and other arthropods as well as small lizards and berries. Large Knight anoles have also been known to eat small rodents and frogs.

Like the Brown anole, Knight anoles often position themselves head down on a tree trunk or other nearly vertical surface. The Knight anole is generally slower moving than the other anoles in the Hawaiian Islands.

Skinks (Scincidae) 

Skinks belong to the family Scincidae, which includes more than 1,300 species worldwide. Four species of skinks are now established in the Hawaiian Islands, including the Copper-tailed skink (Emoia cyanura), which is found only on southern Kaua‘i.

A fifth skink species, the Azure-tailed skink (Emoia impar), was relatively common in the Hawaiian Islands in the early 1900s, but no sightings have been documented since about 1950.

The three most common species of skinks in the Hawaiian Islands are the Moth skink (Lipinia noctua noctua), the Snake-eyed skink (Cryptoblepharus poecilopleurus) and the Metallic skink (Lampropholis delicata).

The skink may exceed 8 inches (20 cm) including the tail. Recognized by its conical head, short limbs, and slender, cylindrical-shaped body, the skink has smooth scales that give it a shiny appearance.

Skinks are diurnal (active during the day), and may be found near the edges of forests at low and middle elevations feeding primarily on insects and other arthropods. They are also commonly seen in rock piles and among forest debris.

Skinks are more terrestrial than anoles, and like to hide under logs and rocks, particularly in moist areas (e.g., near streams). Skinks are active mainly in the morning hours before the midday heat. When attempting to move fast, skinks wriggle in a snake-like fashion, hardly using their legs at all.

Like geckos, skinks have what is known as tail autonomy. The tail may detach from the body, and then a new tail regenerates. This adaptive mechanism helps the skink escape predators. Unlike geckos, skinks do not have the ability to change their color.

Following are detailed descriptions and information about skink species of the Hawaiian Islands.

[Photograph: Azure-tailed skink]

Azure-Tailed Skink (Emoia impar)

The Azure-tailed skink is about 4½ inches (11 cm) long on average, with smooth scales and a conical head. The back (dorsal surface) is brownish to bronze colored and the bluish tail is more than 1½ times as long as the skink’s head and body. The belly (ventral surface) is whitish-gray.

A slender and attractive, striped skink, the Azure-tailed skink is rare or perhaps extinct in the Hawaiian Islands, though it is found on other Pacific Islands.

The Azure-tailed skink likely arrived in the Hawaiian Islands aboard the voyaging canoes of the early Polynesian settlers and was common in the Hawaiian Islands around 1900, but was has not been documented in the Hawaiian Islands since the 1950s.

Primary factors in the demise of the Azure-tailed skink in the Hawaiian Islands are competition from the Metallic skink and predation by other introduced species, such as the mongoose (Herpestes auropunctatus).

[Photograph: Copper-tailed skink]

Copper-Tailed Skink (Emoia cyanura)

The Copper-tailed skink is brownish in color with three white stripes that run from the tip of the skink’s nose to its tail.

The dorsal surface of the skink’s body is a lighter brown color than its head, and the tail’s color may be copper or greenish. The belly (ventral surface) is white. Copper-tailed skinks measure about 4½ inches (11 cm) long on average.

The Copper-tailed skink’s eyelids are movable, and the transparent lower lids allow the skink to see even when the lids are closed.

Copper-tailed skinks are found only in southern Kaua‘i, and the population bears a close resemblance to Copper-tailed skinks on the Cook Islands and in Fiji. Cattle egrets pose a threat to the species in the Hawaiian Islands.

[Photograph: Metallic skink]

Metallic Skink (Lampropholis delicata)

The Metallic skink is the most common skink in the Hawaiian Islands. It is brown to grayish-brown in color, often with a wide, dark brown side stripe and small, dark spots or flecks.

The scales are shiny and smooth, giving the skink a metallic, glossy look. The skink’s head is often rust-brown in color, and the ventral surface is lighter in color. The grayish tail may have a bluish (azure) tint to it, and is reddish-brown at the tip.

Also called the Delicate skink or the Rainbow skink, the Metallic skink is relatively slender and averages about 4¼ inches (10.8 cm) in length. Not often seen in densely covered forest areas, the Metallic skin is more commonly seen on the forest’s edge and underneath large trees with protruding roots, such as figs and banyans, where it feeds on a variety of small insects, including mosquitoes, ants, beetles, and moths.

The wedge-shaped head of the Metallic skink is well adapted to burrowing in dirt. Metallic skinks also feed on worms. The Metallic skink is not native to the Hawaiian Islands nor is it a Polynesian introduction, having instead arrived in the Hawaiian Islands some time after Western contact, probably around 1900.

Native to Australia, Metallic skinks are now found on all of the large Hawaiian Islands. They are seen at middle elevations down to sea level. At some locations on Kaua‘i and the island of Hawai‘i they inhabit higher elevations, up to about 4,000 feet (1,220 m).

[Photograph: Moth skink]

Moth Skink (Lipinia noctua noctua)

The Moth skink is light brownish in color, darker on the sides, with a tail that is tan on the upper side but white to grey underneath. On the back of its head is a distinct yellow spot that extends into a light-colored stripe along its back to the beginning of the tail. The Moth skink measures about 3½ inches (9 cm) long on average, and prefers low elevation habitats.

Active in the morning and evening, Moth skinks may be seen in and around homes, often in crevices on rock walls and beneath large trees. If grabbed by a predator, the Moth skink’s tail may detach and continue to wriggle, distracting the predator and allowing the skink to escape.

During the next two to three months, the skink will grow a new (though shorter and less colorful) tail. The Moth skink is the only skink in the Hawaiian Islands that gives birth to live offspring instead of laying eggs.

Moth skinks were established in the Hawaiian Islands before Western contact, probably arriving in the Hawaiian Islands as stowaways aboard the voyaging canoes of the early Polynesian settlers.

The Moth skink was long thought to be extremely rare due to predation by other introduced species and competition for habitat with newly introduced species.

The Metallic skink occupies many of the same habitats as the Moth skink. When the Metallic skink was introduced to the Hawaiian Islands around 1900, it began to displace the Moth skink in many areas.

Recent surveys, however, have shown that the Moth skink’s distribution remains widespread. The species is well established in various O‘ahu locations as well as on Kaua‘i, Maui, Moloka‘i, and the island of Hawai‘i.

[Photograph: Snake-eyed skink]

Snake-Eyed Skink (Cryptoblepharus poecilopleurus)

The Snake-eyed skink ranges in color from shiny brown to grayish, being a bit darker on the sides, and flecked with white. Along the length of the Snake-eyed skink’s back from its head to its rear legs are two thin, metallic-gold stripes. Its ventral surface (belly) is yellow.

The Snake-eyed skink is about 4½ inches (11.5 cm) long on average, and is found on all the main Hawaiian Islands (though it is not too common), preferring low elevation habitats. The snake-eyed skinks is often seen near shorelines and on lava flow areas.

The Snake-eyed skink gets its name from the fact that it is the only skink in the Hawaiian Islands that has immovable eyelids. It is often seen in lava areas near the ocean or hiding among the crevices in rock walls or debris piles.

Snake-eyed skinks are active during the day (diurnal), and often venture below the high tide line where they feed on beach flies, sand fleas, butterflies, and other insects and arthropods.

Snake-eyed skinks were established in the Hawaiian Islands before Western contact, probably arriving in the Hawaiian Islands as stowaways aboard the voyaging canoes of the early Polynesian settlers.

Populations of Snake-eyed skinks in the Hawaiian Islands have diminished significantly since the early 1900s, possibly as a result of coastal developments.

Green Iguana (Iguana iguana)

The Green iguana is the largest lizard found in the Hawaiian Islands, and may exceed 6.5 feet (2 m) in length, with two-thirds of that being tail. Green iguanas are green to brown or gray in color, and may have gray or brown bars.

A row of spines extends the length of the back along the crest. The Green iguana also has a relatively large dewlap (throat fan) and a subtympanic plate (shield) beneath each ear.

The family Iguanidae previously included most lizard species native to the American continent, but this changed in 1989 when the scientific family was split into nine different families.

One of these nine families is still referred to as Iguanidae, and now includes about 25 lizard species, including the Green iguana. Another one of the nine reclassified families (formerly all known as Iguanidae) is Polychridae, which includes the genus Anolis (see above).

The Green iguana is native to Central and South America as well as Mexico, and is now found in some forest areas on O‘ahu. The Green iguana is a good climber and a good swimmer, and may be seen in trees near streams.

The iguana may escape from predators by diving into the water and using its tail as a paddle to glide through the water while streamlining its body by holding its limbs against its sides.

The Green iguana feeds mainly on flowers (including brightly-colored flowers, such as hibiscus), fruit and leaves of trees and shrubs, though juveniles may also feed on insects.

Male green iguanas have a bigger dewlap than females. The male also has large jowls and extends his dewlap when engaging in courtship and territorial displays, which often involve head bobbing.

The Green iguana has been seen in the Hawaiian Islands since at least the 1950s. On O‘ahu populations have become established in numerous areas, including Nu‘uanu, Mānoa, and Waimānalo Valleys.

State agriculture officials have acknowledged that the iguana is established in some windward areas of O‘ahu. Five iguanas were found in five months on O‘ahu from December, 2001 to April, 2002.

Though the species is generally harmless, iguanas may be harmful to native plants and birds, and potentially also dangerous to humans, particularly if confronted. Anyone spotting an iguana should report it to officials at 808-586-PEST (7378).

[Photograph: Green iguana]

The Wild Boar (Sus scrofa)

Hawaiian Name: Pua‘a

[Illustration: Boar]

A jogger running along a Hawaiian mountain trail jumps over a small log lying across the path, and suddenly all heck breaks loose. Several wild boars jump up from their resting place amidst a chorus of honks and squeals.

The startled jogger is infused with adrenalin and takes off like an Olympic sprinter. Fortunately the boars are not aggressive toward humans, and they quickly disappear into the forest.

An ancient Hawaiian proverb states: “‘Inā paha he pua‘a, pau i kālua.” (If a pig, [you] would have been roasted.”), which is “said with laughter when a person forgets to come home on time. A straying pig can end up roasted in an imu. A common saying in Puna and eastern Ka‘ū.”[iii]

Origins of Wild Boars in the Hawaiian Islands

When Captain Cook first visited Kaua‘i in 1778, he noted the abundance of boars, also called pigs, which ran around freely amongst the villages of the native Hawaiians.

The pigs were not native to the Hawaiian Islands, however, but were brought to the Hawaiian Islands on the voyaging canoes of the Polynesians. These pigs were descendants of a Southeast Asian wild boar, and weighed up to about 60 pounds (27 kg).

Cook introduced a larger variety of boar to the Hawaiian Islands in 1778. This was the domestic swine that eventually led to the feral boars that inhabit Hawaiian forests today.

These larger boars may be up to 300 pounds (136 kg), and there have been numerous reports of pigs topping 500 pounds (227 kg). A giant boar that has repeatedly been sighted atop Kaua‘i’s Mt. Wai‘ale‘ale is estimated by local hunters and helicopter pilots to weigh upwards of 800 pounds (363 kg)!

Boar Anatomy and Habitat

The wild boars now inhabiting Hawaiian forests are long-bristled, with a straight little tuft of a tail and pointed ears. They are usually black in color, though they sometimes have a calico pattern and may be bronze or red-colored. The boars have sharp, curved tusks.

On the boar’s shoulders are humps of skin known as shields. The shields are about 1 inch (2.5 cm) thick, and may serve as protection in fights.

Wild boars in the Hawaiian Islands are found on all of the main Hawaiian Islands except Kaho‘olawe and Lāna‘i. While they mostly inhabit remote and mountainous areas, they are sometimes seen in the more inhabited parts of the Hawaiian Islands. Residents may occasionally see one running across a road at night.

Though wild boars in the Hawaiian Islands are most active at night, they are sometimes they are seen during the day. Boars can’t see very well, but they do have a good sense of smell.

Feral boars in the Hawaiian Islands are sought after by local hunters who often use dogs to assist them in their hunting efforts.

Encountering a Wild Boar

If you encounter wild boars on a Hawaiian trail, the animal will probably flee unless it is protecting its young ones. In the worst case, you should climb a tree if you startle the boar and it charges you.

More likely, the boar will probably take just a few steps in your direction to scare you, and then turn away (as you flee also, undoubtedly).

The Boar’s Effect on Native Hawaiian Ecosystems

Boars chew away at the trunks of the native tree ferns, hāpu‘u (Cibotium species) and ‘ama‘u (Sadleria species), to get at the starchy stems. Boars also eat other starchy trunks, as well as fallen fruit, roots, and the three native orchid species.

The massive soil rooting done by the boars upsets the fragile forest ecology and leads to various problems that continue to threaten endangered Hawaiian bird species in the higher native forests. Boars also snout up and eat grubs and earthworms.

Digging and rooting done by boars also creates wallows that fill with water and provide places for mosquitoes to breed. Mosquitoes allow avian malaria and pox a chance to take hold, to the great detriment of native species.

Recently boars and other feral ungulates (cloven hoof creatures such as sheep and deer) have been fenced out of some ecologically sensitive areas in an effort to protect extremely endangered native species.

Despite their harmful effects on native habitats, wild boars are a significant part of modern as well as ancient Hawaiian culture. Boars are hunted in remote forest areas, and then traditionally cooked in an imu (underground earthen oven) for a lū‘au (Hawaiian feast).

E mānalo ka hala o ke kanaka i ka imu o ka pua‘a.

The wrongs done by man are atoned for by a pig in the imu.

When a person has committed a wrong against others or against the gods, he makes an offering of a hog with prayers of forgiveness.

[i] p. 225, Pukui, Mary Kawena. ‘Ōlelo No‘eau: Hawaiian Proverbs & Poetical Sayings. Honolulu: Bishop Museum Press, 1983. Proverb 2074.

[ii] p. 90, Pukui, Mary Kawena. ‘Ōlelo No‘eau: Hawaiian Proverbs & Poetical Sayings. Honolulu: Bishop Museum Press, 1983. Proverb 828.

[iii] p. 134, Pukui, Mary Kawena. ‘Ōlelo No‘eau: Hawaiian Proverbs & Poetical Sayings. Honolulu: Bishop Museum Press, 1983. Proverb 1241.