The Hawaiʻi ʻelepaio (Chasiempis sandwichensis), also Hawaiian ʻelepaio, is a
monarch flycatcher found on the Big Island of
Hawaii. Until 2010, all three ʻelepaio species, the
Kauaʻi ʻelepaio (Chasiempis sclateri), the
Oʻahu ʻelepaio (Chasiempis ibidis) and this species were considered
conspecific.
Taxonomy and systematics
The Hawaiʻi ʻelepaio was
formally described in 1789 by the German naturalist
Johann Friedrich Gmelin in his revised and expanded edition of
Carl Linnaeus's Systema Naturae. He placed it with the flycatchers in the
genusMuscicapa and coined the
binomial nameMuscicapa sandwichensis.[2][3] Gmelin based his description on the "sandwich flycatcher" that had been described in 1783 by the English ornithologist
John Latham in his book A General Synopsis of Birds. Latham had examined a specimen from the Sandwich Islands (now the Hawaiian Islands) in the collection of the naturalist
Joseph Banks.[4] The specimen would have been collected between 17 January and 22 February 1779 near
Kealakekua Bay on the
island of Hawaii during
James Cook's
third voyage to the Pacific Ocean.[5] The Hawaiʻi ʻelepaio is now placed in the genus Chasiempis that was introduced in 1847 by the German ornithologist
Jean Cabanis. The species was formerly considered to be
conspecific with the
Kauaʻi ʻelepaio (Chasiempis sclateri) and the
Oʻahu ʻelepaio (Chasiempis ibidis).[6] The genus name is derived from
Ancient Greekkhaskō meaning "to gape" and empis meaning "mosquito" or "gnat".[7]
Subspecies
Three subspecies are recognised which differ in their ecological requirements and head coloration (see also
Gloger's Rule):[6][8]
C. s. sandwichensis - (
Gmelin, 1789): The
Kona ʻelepaio. It differs from the volcano subspecies by having the forehead and the
supercilium whitish with some rusty feathers. It inhabits
mesic forest characterized by koa (Acacia koa) and ʻōhiʻa lehua (Metrosideros polymorpha); its population seems to be stable at about 60,000–65,000.
C. s. ridgwayi -
Stejneger, 1887: The
volcano ʻelepaio. Originally described as a separate species. This is the most common subspecies today, with a population of around 100,000–150,000, or more than half of the total number of ʻelepaio. It is a bird of the
rainforest, which on Hawaiʻi are characterized by ʻōhiʻa lehua and hāpuʻu (Cibotiumtree ferns).
C. s. bryani -
Pratt, 1979: The
Mauna Kea ʻelepaio. It is only found in the
māmane (Sophora chrysophylla ) – naio (Myoporum sandwicense)
dry forest on the
leeward slopes of Mauna Kea. It has the entire head heavily washed with white. Due to destruction of most of its habitat, it is the rarest Big Island subspecies, with a population of 2,000–2,500 birds.
^
abGill, Frank; Donsker, David;
Rasmussen, Pamela, eds. (January 2023).
"Monarchs". IOC World Bird List Version 13.1. International Ornithologists' Union. Retrieved 15 April 2023.