The pueo (''Asio flammeus sandwichensis'') is a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the

short-eared owl The short-eared owl (''Asio flammeus'') is a widespread grassland species in the family Strigidae. Owls belonging to genus ''Asio'' are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or ...

and is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

. The pueo is one of the more famous of the various physical forms assumed by '' aumākua'' (ancestor spirits) in Hawaiian culture.

Taxonomy

This

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

was first named by

Andrew Bloxam Andrew Bloxam (22 September 1801 – 2 February 1878) was an English clergyman and naturalist; in his later life he had a particular interest in botany. He was the naturalist on board during its voyage around South America and the Pacific in 18 ...

(as the species ''Strix sandwichensis''). He saw it, although did not collect a specimen, while in the

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

in 1825 as the naturalist on board HMS ''Blonde''. It is now considered to be a subspecies of the

, ''Asio flammeus'', although

Storrs Olson Storrs Lovejoy Olson (April 3, 1944 – January 20, 2021) was an American biologist and ornithologist who spent his career at the Smithsonian Institution, retiring in 2008. One of the world's foremost avian paleontologists, he was best known ...

did not consider it to be distinct from ''Asio flammeus flammeus''.

Distribution and population

The pueo inhabits forests and grasslands throughout the Hawai’i archipelago. However, recent surveys suggest that their population is declining, specifically on Oʻahu, an island where they were once quite common. O’ahu is the most densely human-populated island, and the most consistently-developed area, in Hawai’i. Additionally, the island is also the location of the state capital (and largest city in Hawai’i). Thus, O’ahu is consequentially the most-visited part of Hawai’i by foreigners and tourists, as well—all factors that potentially affect the pueo’s natural range and behaviors. The pueo is recognized as an

subspecies of

by the state of Hawai’i; on the island of O’ahu, the state currently lists it as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

. Nevertheless, the pueo’s presence in Hawai’i is the result of prehistoric human activities, not solely natural evolution or avian migration, thus blurring the concept of a true

native species In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equi ...

. The pueo is thought to have somehow colonized Hawai’i after the arrival of the

Polynesians Polynesians are an ethnolinguistic group comprising closely related ethnic groups native to Polynesia, which encompasses the islands within the Polynesian Triangle in the Pacific Ocean. They trace their early prehistoric origins to Island Sout ...

. This relatively recent arrival of the pueo in Hawai’i may be linked to Polynesian rats (''Rattus exulans''), which were brought to the islands by humans. The only truly native land (non-aquatic) mammals in Hawai’i are two species of bat—the Hawaiian hoary bat and the (extinct) ''

Synemporion keana ''Synemporion keana'' is an extinct species of bat which lived in what is now Hawaii from at least 320,000 years ago to around 2,100 years ago. It is the only species in the genus ''Synemporion''.'' A further seven raptor species formerly inhabited prehistoric Hawai’i—the

Hawaiian hawk The Hawaiian hawk or ''io'' (''Buteo solitarius'') is a raptor in the genus '' Buteo'' endemic to Hawaii, currently restricted to the Big Island. The ''io'' is one of two extant birds of prey that are native to Hawaii, the other being the '' pu ...

, the wood harrier, the

white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla''), sometimes known as the 'sea eagle', is a large bird of prey, widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which also ...

(or a very close relative of), and four species of stilt-owls. Much like the related, continental short-eared owls, pueo primarily consume small

mammals A mammal () is a vertebrate animal of the class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle e ...

, which they can expertly detect from far distances with their large eyes, an adaptation for superb

night vision Night vision is the ability to see in low-light conditions, either naturally with scotopic vision or through a night-vision device. Night vision requires both sufficient spectral range and sufficient intensity range. Humans have poor night v ...

and hunting after-dark. Their incredibly advanced nocturnal vision also enables them to fly through densely wooded areas with ease, deftly navigating between trees. Strigiformes (owls), as a whole, are well-known for flying silently, and without overly flapping their wings; this ensures their prey does not escape, as they cannot hear or suspect a predator approaching from above. As soon as a choice prey animal is spotted by the pueo, the owl intently glides-over and lands directly on top of it, killing it instantly before flying away, without a sound.

Threats to survival

Pueo nest on the ground, which makes their eggs and young susceptible to

predation Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

by the introduced

small Indian mongoose The small Indian mongoose (''Urva auropunctata'') is a mongoose species native to Iraq and northern India; it has also been introduced to several Caribbean and Pacific islands. Taxonomy ''Mangusta auropunctata'' was the scientific name proposed ...

and other predators. Pueo are strongly affected by

light pollution Light pollution is the presence of any unwanted, inappropriate, or excessive artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting sources, during the ...

. They are often killed in vehicular accidents in which they dive toward the headlights of cars, possibly in an attempt to hunt. Many such collisions have been reported on Interstate H-3 and other newly built roadways in areas which once held high populations of pueo. Pueo appear to be somewhat resistant to the avian malaria that has devastated many other endemic bird populations in Hawaii; however, they have recently become victim to an unknown mysterious " sick owl syndrome", or SOS, in which large numbers of pueo have been found walking dazedly on roads, leading to death by collision. The cause of sick owl syndrome is unknown; it is suspected that

pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

toxicity may be responsible, particularly through secondary

rodenticide Rodenticides are chemicals made and sold for the purpose of killing rodents. While commonly referred to as "rat poison", rodenticides are also used to kill mice, woodchucks, chipmunks, porcupines, nutria, beavers, and voles. Some rodenticides ...

poisoning. However, it has also been hypothesized that the cause may be an infectious agent, seizure-like confusion due to

, or a variety of other causes.

References

External links

More information with sounds produced by the pueo
{{Taxonbar, from=Q7258519 Asio Endemic birds of Hawaii Birds described in 1827 Hawaiian words and phrases