The San Benedicto rock wren (''Salpinctes obsoletus exsul'') is a small
extinct passerine
A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...
which was endemic to
San Benedicto Island
San Benedicto, formerly Isla de los Innocentes, is an uninhabited island, and third largest island of the Revillagigedo Islands, located in the Pacific Ocean.
It is 4.8 km by 2.4 km in size, with an area 10 km². It is of volcanic ...
in the
Revillagigedo Islands
The Revillagigedo Islands ( es, Islas Revillagigedo, ) or Revillagigedo Archipelago are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem. They lie approximately from Socorro Island south and southwest of C ...
off
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
. It was a subspecies of the
rock wren.
Extinction
San Benedicto is a
volcano
A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface.
On Ear ...
, like all the Revillagigedo group. Unlike, for example,
Roca Partida
Roca Partida ( en, Split Rock) ranks as the smallest of the four Revillagigedo Islands, part of the Free and Sovereign State of Colima in Mexico. The uninhabited island (Latitude 19° 0'2.53"N, Longitude 112° 4'5.35"W) encompasses an extremely sm ...
, it was still active in recent times. On August 1, 1952, lava fountains started to break out of the Boquerón vent, located in a rift between the two older volcano cones. By around 8:45,
ejecta were thrown up for several km in a severe
vulcanian eruption
A Vulcanian eruption is a type of volcanic eruption characterized by a dense cloud of ash-laden gas exploding from the crater and rising high above the peak. They usually commence with phreatomagmatic eruptions which can be extremely noisy due t ...
of magnitude 3 on the
Volcanic Explosivity Index scale;
pyroclastic flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...
s rolled over the island.
[
Two weeks later, the entire island was covered in ash and ]pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular v ...
up to 10 ft (3 m) deep. Bárcena crater, nearly 1100 ft high (over 300 m), rose where the wren's habitat had previously existed. The birds were never seen again.[
This rock wren was the only endemic terrestrial bird on San Benedicto. It was one of but two landbirds on San Benedicto, sharing the island with ]western raven
The common raven (''Corvus corax'') is a large all-black passerine bird. It is the most widely distributed of all corvids, found across the Northern Hemisphere. It is a raven known by many names at the subspecies level; there are at least e ...
s, which were wiped out by the eruption as well.
References
External links
Biogeography of the Islas Revillagigedo, MexicoThe changing status of marine birds breeding at San Benedicto Island, Mexico
San Benedicto rock wren
Endemic birds of Western Mexico
Extinct animals of Mexico
Extinct birds of North America
Natural history of the Revillagigedo Islands
Bird extinctions since 1500
San Benedicto rock wren
Taxa named by Robert Ridgway
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