Islas San Benito

The Islas San Benito lie in the Pacific Ocean off the west coast of the Mexican state of Baja California, 25 km west of Cedros Island. They are part of the Cedros Island delegación, a subdivision of Ensenada (municipality), Baja California.

The group consists of three barren islands, with a total area of 3.899 km2, and is surrounded by rocks and patches of kelp. The census of 2001 recorded a population of two on Benito del Oeste (West Benito); the other islands are uninhabited.[1]

Cedros BC
Location of Cedros Island and Islas San Benito in
Baja California
Cedros
annotated Space Shuttle photo of Cedros Island,
with Islas San Benito in the upper left

Geography and ecology

Benito del Oeste (West Benito, 2.6 km2) is the westernmost and largest island of the group. It appears as a plateau with a mound rising 600 ft (202 m) high near the center. A lighthouse tower, 4 m high, stands in the southern part of the island. The main lighthouse, a prominent, 17 m high tower with a dwelling, stands near the northwest extremity of the island. Rocas Pinaculo, two steep-to rocks, lie 1.6 km west of Benito del Oeste.[2]

Benito del Centro (Central Benito, 0.4 km2) 28°18′30″N 115°33′54″W / 28.30833°N 115.56500°W and Benito del Este (East Benito, 0.9 km2) 28°18′03″N 115°32′25″W / 28.30083°N 115.54028°W, the other two islands, lie close east of Benito del Oeste and are separated by Canal de Peck, a deep passage just 200 ft (c. 65 m) wide.[2] Benito del Este is characterized by four well-defined hills up to 421 ft (c.140 m) high. Benito del Centro is low and flat with a hill 82 ft (25 m) high rising near its eastern end.

The vegetation consists mainly of low shrubs and herbs as well as some large cacti (Cylindropuntia prolifera, C. ramosissima[3]). There are few land animals and no native mammals. Birds are moderately abundant due to the islands' barrenness, but Cassin's auklet is rather plentiful at breeding time.

Endemism

Due to the islands' remoteness, several endemic taxa have evolved here:

Animals:[4]

Disappeared c. the 1940s, mainly due to overhunting by biological specimen collectors.

Plants:[3]

  • Cryptantha patula – only on West Benito
  • Dudleya linearis – only on West Benito
  • Hemizonia streetsii – West and East Benito
  • Lavatera venosa – all islands
  • Mammillaria neopalmeri – West and East Benito
  • Senecio benedictus – only on West Benito

References

  1. ^ Instituto Nacional de Estadística, Geografía e Informática (2007): Principales resultados por localidad 2005 (ITER) Archived 2010-01-18 at WebCite ["Principal results of the 2005 census by locality"] [in Spanish]. Retrieved 2007-OCT-10.
  2. ^ a b National Geospatial-Intelligence Agency (2004): Sector 2 – West coast of Baja California. In: PUB153 Sailing Directions (Enroute): West Coasts of Mexico & Central America (10th ed.): 9–18. ProStar Publications, Inc. ISBN 1-57785-559-0
  3. ^ a b California/Mexico Island Conservation Database (2007): Plant accounts: Guadalupe Island Archived 2007-12-08 at the Wayback Machine. Retrieved 2007-OCT-10.
  4. ^ Thayer, John E.; Bangs, Outram (1907). "Birds Collected by W. W. Brown, Jr., on Cerros, San Benito and Natividad Islands in the Spring of 1906, with Notes on the Biota of the Islands" (PDF). Condor. 9 (3): 77–81. doi:10.2307/1361136.

Coordinates: 28°18′12″N 115°35′24″W / 28.30333°N 115.59000°W

Black-vented shearwater

The black-vented shearwater (Puffinus opisthomelas) is a species of seabird. The bird is 30–38 cm in size, with a 76–89 cm wingspan. Formerly considered a subspecies of the Manx shearwater, its actual relationships are unresolved.This species is pelagic, occurring in the Pacific Ocean and the Gulf of California. It comes closer to land than most other shearwaters, so it sometimes can be seen from shore. It predominantly nests on offshore islands off north and western Baja California, namely Isla de Guadalupe, Islas San Benito and Isla Natividad. It is fairly common off the United States coast of central and southern California during the country's colder months.

The black-vented shearwater is thought to feed on mainly small fish. This bird nests in burrows and caves; it is a colonial nester.

In the past, this bird had been threatened by feral cats and other predators on its breeding islands, but the problem seems to have been largely eliminated. There is some loss of birds from commercial gill netting, and the species is classified as near threatened by the IUCN mainly due to the uncertain impact on it by the expanding fishing industry.

C. ramosissima

C. ramosissima may refer to:

Coleogyne ramosissima, the blackbrush, a thorny aromatic shrub species native to the deserts of the southwestern United States

Cylindropuntia ramosissima, the diamond cholla or branched pencil cholla, a cactus species native to the Mojave and Sonoran Deserts of the Southwestern United States, California, and Northwestern Mexico, and to Baja California and its Islas San Benito

Cedros Island

Cedros Island (Isla de Cedros, "island of cedars" in Spanish) is an island in the Pacific Ocean belonging to the state of Baja California, Mexico. The dry and rocky island had a population of 1,350 in 2005 and has an area of 348 square kilometres (134 sq mi) which includes the area of several small nearby islands. Cedros Island is mountainous, reaching a maximum elevation of 1,205 metres (3,953 ft). The economy is based on commercial fishing and salt mining. Cedros has a distinctive flora and the traces of some of the earliest human beings in the New World. The ocean around the island is popular with sports fishermen.

The American Indian inhabitants when the island was first visited by Spanish explorers in the 16th century called it Huamalgua, the "Island of Fogs." The Indian inhabitants have been given the name Huamalgueños by modern day scholars. They were relocated to the mainland of Baja California by Jesuit missionaries in 1732 and ceased to exist as an identifiable people.

Cylindropuntia ramosissima

Cylindropuntia ramosissima is a species of cactus known by the common names diamond cholla and branched pencil cholla.

List of islands of Mexico

This is an incomplete list of islands of Mexico.

List of lighthouses in Mexico

This is a list of lighthouses in Mexico. They are located along the Pacific, Gulf of Mexico, and Caribbean coastlines of the country. These are named landfall lights, or those with a range of over fifteen nautical miles.

Punta Eugenia

Punta Eugenia is a headland in the Mulegé Municipality, and is the westernmost point on the mainland of the state of Baja California Sur. To its north west lie Isla Natividad, Cedros Island and the Islas San Benito.

The pattern of ocean currents and eddies around Punta Eugenia has been shown to be a significant phylogeographic break in the distribution of fish species.

Savannah sparrow

The Savannah sparrow (Passerculus sandwichensis) is a small American sparrow. It was the only member of the genus Passerculus and is typically the only widely accepted member. Comparison of mtDNA NADH dehydrogenase subunit 2 and 3 sequences indicates that the Ipswich sparrow, formerly usually considered a valid species (as Passerculus princeps), is a well-marked subspecies of the Savannah sparrow, whereas the southwestern large-billed sparrow should be recognized as a distinct species (Passerculus rostratus).The common name comes from Savannah, Georgia, where one of the first specimens of this bird was collected.

Vermilacinia paleoderma

Vermilacinia paleoderma is a pale yellow-green fruticose lichen that occurs commonly along the fog zone of the Pacific Coast of Northern Vizcaíno Desert region of Baja Californica and occasionally in the Chaparral Islands of California.

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