This reserve is located between 26o 29' 20" and 28o N and 112o 15' 45" and 115o 15' W in the Peninsula of Baja California. The protected area is in the municipality of Mulege, which is part of the state of Baja California Sur (Southern Baja). Its boundaries include a 5 km-wide strip running along the beach into the Pacific Ocean and the Gulf of California (also known as the Sea of Cortés). Vizcaíno's total area is 2,546,790 hectares. The low elevations of the central and western parts of the reserve receive constant coastal winds and intense solar radiation. Altitudes range from 0 at the coast to 1985 meters above sea level at the highest peaks in the mountains. Median annual daily temperatures range from 18o to 22 oC, and during the night temperatures plunge. Average yearly precipitation is usually below 80 mm; although precipitation can drop to 0 mm per year for up to four years at a time, or jump to a few hundred mm in a single year (INE 2000; Arriaga et al. 2000).
These extreme climatic conditions result in high evaporation rates; river and stream waters do not reach the ocean. Constant transversal winds continually form dunes. The reserve's mountainous sector is found in the east, where elevations reach over 1600 m, temperatures are cooler, and peaks are occasionally covered with snow during the winter. These mountains are made up of sedimentary and extrusive volcanic rocks. Las Vírgenes, Partido and Azufre volcanoes are located in the San Francisco Range (Sierra de San Francisco). Azufre Volcano is active and possesses important geothermic energy sources. There are 16 islands and islets included in the reserve--the largest are Isla Natividad, Isla Asunción and Isla San Roque.
According to Dinerstein et al. (1995), the reserve belongs to the following terrestrial ecoregions: Xeric scrublands of Baja California and Mexico and Xeric scrublands of Sonora, Mexico and the US. The most representative habitats include xeric microphyll scrublands and xeric shrubs and cacti. There are also marine portions included in the reserve, because they are conservation priorities (Sealey and Bustamante 1999; Arriaga et al. 2000) within the following ecoregions: the Mexican Temperate Pacific and Gulf of Cortés.
Physical characteristics of the marine environments on both coasts are distinct and determine the specific biological diversity and richness present in each. The eastern coast, Gulf Coast, is a transitional area of temperate and tropical species. This partially closed bay contributed to speciation, influenced the formation of endemic species and helped create very diverse biota (Brusca 1980).
The western Pacific Coast is less diverse; but, because the environment is more temperate with permanent emergences, valuable species with high economic potential abound.
There are many archeological remains in the region, including cave paintings, petroglyphs and shellfish fossils . The most important cave art in North America is found in the eastern San Franscisco Range. There are more than 200 caves with paintings of huge men, pronghorns (Antilocapra americana peninsularis), sheep, pumas, birds, whales, turtles, snakes and what appears to be stars, in addition to other images (Hambletón 1979). The ancient Californians' paintings are approximately 10,000 years old. Many of the caves within and around the reserve contain cave paintings showing men and wildlife.
In addition to these archeological remains, the colonial legacy continues in surviving architecture. For example, one important colonial architectural structure is the mission of San Ignacio de Loyola, founded in 1728. The most exquisite adornments in the entire peninsula are found within the mission and include a carved, gold-plated wood altar, and oil paintings, among others (CIBNOR 1995).
Historical monuments include the city of Santa Rosalía, because it is the only town in the region with French-colonial influenced architecture. The National Institute of Anthropology and History (INAH) has cataloged 20 monuments such as the Central Hotel, the Boleo Store, the French Hotel, the Nuestra Se~nora del Carmen Church, and two works by Gustave Eiffel, among others.
Flora of the Vizcaíno Desert Region includes many species that live in harmony with the arid landscape. Thus far, 469 species have been identified, a third of which have shrub-like forms. A majority of the others are annual and perennial herbaceous plants. There are 39 endemic floral species in the protected area (León de la Luz et al. 1995; INE 2000; WWF and IUCN. 1994-1997). Threatened species include fan palms (Erythea armata, Washingtonia filifera, W. robusta) and tree yucca (Yucca valida) (INE 2000). The following vegetation types are found in the area:
o Sarcocaul (Mattoral sarcocaule) shrubland: Thick-stemmed trees and shrubs are characteristic of this vegetative type. Its plants grow in rocky soils from 500 m in the plains to 1200 m in the mountains. Representative species include: Bursera microphyla, B. cerasifolia, Agave sebastiana, Opuntia invicta, Yucca valida, and Ephedra aspera.
o Sarcocrasicaul (Mattoral sarco-crasicaule) Scrublands: Species in this classification are mostly cacti, many of which have candelabra forms and tall stalks, such as Pachycerus pringlei, Stenocereus gummosus, Ferocactus chrysacantus, and F. peninsulae; these last two species are threatened (D.O.F. 2002).
o Halophytic Vegetation: Species in this vegetative group are tolerant of high salinity and alkalinity soils. Representative species include Ambrosia magdalenae, Agave vizcainoensis, Euphorbia misera, Frankenia grandifolia, and Opuntia cholla.
o Dune Scrublands: Vegetation grows on coastal dunes and helps stabilize the dunes. Representative species include Abronia carterae, Asclepios subulata, Chaenactis lacera, and Proboscidea altheaefolia.
o Spineless Scrublands: This vegetation is found between the Halophytic and Dune Scrublands and it is more densely vegetated. Characteristic species include Asclepias subulata, Encelia californica, Jatropha cinerea, Larrea tridentate, and Rhus microphylla.
o Microphyllous (Matorral desertico microfilo) Scrublands: This group is made up of Dune and Halophytic vegetation and has sandy and rocky soils. Herbaceous and semi-shrub species are most common. The shrub species has non-spiny, deciduous plants. Representative species include Acacia farnesiana, Ambrosia dumosa, Prosopis glandulosa, Euphorbia misera, and Stegnosperma halimifolium.
o Coastal Dune Vegetation: This vegetation is next to Halophytic Vegetation and grows along the littoral zone. Characteristic species include Abronia gracilis, Atriplex canescens, Dalea maritima, Plantado insulares, and Mesembryanthemum cristallinum.
o Eriales: These are located close to bays, such as Ojo de Liebre and San Ignacio. Species' abundance is low and there are few individuals. Species growing here are tolerant of the saline and alkaline soils, constant winds, and elevated solar radiation. Genera include Atriplex, Salicornia, Allenrolfea, Suaeda, and Limonium.
o Aquatic vegetation: This category consists of mangrove species that have small trunks immersed in the water. Species include Rhizophora mangle, with special protection status, and Laguncularia racemosa (Delgadillo et al. 1992). Submerged species include Zostera marina, Phyllospadix scouleri, and Ruppia maritima.
Marine vegetation in the Sea of Cortes is of tropical origin and is less abundant than the vegetation off the western coast. There are 85 species of macro-algae reported for Ojo de Liebre Bay, including Sargassum spp., Neogardhiella sp., Laurencia irieii, L. pacifica, Zostera marina, Chondria californica, Colpomenia sp., Gigartina tedii, Asparagopsis taxiformis, and Euchema unicinatum. It has been found that Euchema unicinatum has biotechnological applications.
Not including fish, there are 308 species of terrestrial and marine vertebrates present in the reserve. There are 4 amphibian, 43 reptile, 192 bird, and 69 mammal species (Alvarez-Casta~neda and Patton. 2000; CIBNOR 1991a; INE 2000). According to Official Mexican Ecological Norm 059 published in the Federation's Official Registry (NOM-059-ECOL-2001), within the reserve there are 17 threatened species, including four endangered, six under special protection and one rare species (DOF 2002). There are only two endemic species within the protected area: Baja California rock squirrel (Spermophilus atricapillus) and the agile kangaroo rat (Dipodomys peninsulares).
Within the herpetofauna, the reptiles and lizards are best represented. Notable species include one terrestrial turtle (Chrysemys scritpa), the Baja worm lizard (Bipes biporus) and five marine turtles in danger of extinction: Dermochelys coriacea, Caretta caretta, Chelonia mydas, Eretmochelys imbricata, Lepidochelys olivacea (IUCN 2003). Seven of Baja California's endemics are found within the reserve: Bipes biporus, the lizards Petrosaurus thalassinus, Cnemidophorus labialis, Elgaria paucicarinata; and the snakes Eridiphas slevini, Crotalus enyo, Crotalus exsul (Flores-Villela 1993).
Of a total 120 bird species, the majority are aquatic, some terrestrial. Best-represented families include Anatidae with 23 species, and Scolopacidae and Laridae with 22 species each.
The habitat diversity found in the reserve's bays and along its coast is an important resource for thousands of migratory birds that arrive every year. The bays of Guarrero Negro, Ojo de Liebre, and San Ignacio are the most important wintering grounds for the Pacific black brant (Branta bernicla nigricans), whose flocks number in the thousands. Other important migrant species arriving in lesser numbers include lesser scaup (Aythya affinis), red-breasted merganser (Mergus serrator), and northern pintail (Anas acuta). The reserve's wetlands are considered extremely important wintering grounds for coastal birds. There are estimates that more than 500,000 individuals winter along the Peninsula's western Pacific coast (Carmona and Danemann 1998).
Some species that nest in the reserve include the osprey (Pandion haliaetus), which has a large population, the brown pelican (Pelecanus occidentalis), the reddish egret (Egretta rufescens), terns (Sterna maximus, S. antillarum, S. caspia), and snowy plover (Charadrius alexandrinus), among others (Salinas-Zavala et al 1991).
Several terrestrial birds are listed as threatened to some degree in NOM-059-ECOL-2001. Golden eagles (Aquila chrysaetos), the peregrine falcon (Falco pereginus), and the prairie falcon (Falco mexicanus) are listed as threatened; the bald eagle (Haliaeetus leucocephalus) is listed as endangered (D.O.F. 2002; IUCN 2003).
There are 44 terrestrial mammals under special protection (D.O.F. 2002), including the peninsular pronghorn (Antilocapra americana peninsularis) (which is considered endangered [Castellanos and Holland 2001; Conde 2003; CIBNOR 2004] ), mule deer (Odocoileus hemionus), and bighorn sheep (Ovis canadensis). Among the large predators, the reserve has pumas (Puma concolor), bobcat (Lynx rufus), and coyotes, which are the most abundant and widely distributed in the zone. The kit fox (Vulpes macrotis) needs open soils in order to excavate its dens, and is therefore an example of a threatened species whose distribution is limited (CIBNOR 1991).
The magnitude of marine biodiversity in the reserve is not entirely known, however the principal invertebrate groups include: sponges, cnidarias (stinging cells like jellyfish, anemones, and corals), platyhelminthes (flatworms), pelecypod (bivalves), opisthobranchia (sea slugs), chitons, cephalopods (nautilus, squid, cuttlefish, and octopus), barnacles, gastropods, shrimp, crabs, and echinoderms (starfish, sea urchins, sea cucumbers). Notable species include the California spiny lobster (Panulirus interruptus) because of its high economic value, and the kelp (Macrocystis pyrifera) community because it is the main prey for other species like abalone (Haliotis spp.) and lobsters (Panulirus spp.).
There is approximately 113 species of ichthyofauna, but most likely this is an understatement--more research is needed to identify these species more thoroughly. Species off the western coast include spotted sandbass (Paralabrax maculatofasciatus), and fringed flounder (Etropus crossotus) (Miller and Lea 1972; Leija Tristán et al. 1991; Acevedo 1997). Important pelagic species supporting the fishing industry include: Pacific sardine (Sardinops sagax), Pacific anchoveta (Cetengraulis mysticetus) and California anchovy (Engraulis mordax), milkfish (Chanos chanos), Panama hake (Merluccius angustimanus), yellowtail jack (Seriola dorsalis), common dolphinfish (Coryphaena hippurus) and Spanish mackerel (Scomber japonicus). Other species include Hippocampus ingens, Signathus auliscus, Fistularia commersonii, Paralabrax clathrathus, Calamos brachisomus, and Diodon holocanthus (De La Cruz-Aguero et al. 1996; Leija Tristán et al. 1991).
Off of the eastern coast, the most representative species include groupers Mycteroperca rosacea, M. jordani and Epinephelus labriformis-which are very valuable. The mesopelagics, that is, mid-depth dwelling fish, are also common off of the eastern coast. The most important species include 18 shark species, and 14 manta ray species that are also important to the fishing industry.
Charismatic marine mammals such as the gray whale (Eschrichtius robustus) are under special protection (IPN. 1986; Taylor 1990; Álvarez and Granados 1992; D.O.F. 2002). This large mammal is found off of both coasts and uses the Ojo de Liebre and San Ignacio Bays to reproduce. Another captivating mammal is the California sea lion (Zalophus californianus), also found on both coasts. Its largest congregations are on large islands like Natividad, Asunción, and San Roque. The common seal (Phoca vitulina) also inhabits deserted beaches and islands like San Roque (INE 2000).