Pueo inhabit forests and grasslands throughout the islands of Hawaii, although their numbers are declining rapidly, particularly in the last two decades, and especially on the island of Oahu, upon which they were at one time very prevalent. Pueo are now listed as an endangered species.
This taxon was first named by Andrew Bloxam (as the species Strix sandwichensis). He saw it, although did not collect a specimen, while in the Hawaiian Islands in 1825 as the naturalist on board HMS Blonde. It is now considered to be a subspecies of the Short-eared Owl, Asio flammeus, although Storrs Olson does not consider it to be distinct from Asio flammeus flammeus.
Threats to survival
Pueo nest on the ground, which makes their eggs and young susceptible to predation by the introduced Small Asian Mongoose and other predators, as well as by bulldozers.
Pueo are strongly affected by light pollution. 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 decimated many other endemic bird populations in Hawaii; however, they have recently become victim to a 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 toxicity may be responsible, particularly through secondary rodenticide poisoning. However, it has also been hypothesized that the cause may be an infectious agent, seizure-like confusion due to light pollution, or a variety of other causes.
- "Asio flammeus sandwichensis". ITIS Report. Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=687200. Retrieved 2009-02-16.
- Olson, Storrs L. (1996), "The contribution of the voyage of H.M.S. Blonde to Hawaiin ornithology", Archives of Natural History 23 (1): 1–42, http://si-pddr.si.edu/dspace/bitstream/10088/8385/1/VZ_269_Blonde_in_Hawaii.pdf