San Bruno Mountain
San Bruno Mountain is located in northern San Mateo County, with some slopes of the mountain crossing over into southern San Francisco. Most of the mountain lies within the 2,326-acre San Bruno Mountain State Park. Next to the state park is the 83-acre state San Bruno Mountain Ecological Reserve on the north slope, it is near the southern boundary of San Francisco, surrounded by the cities of South San Francisco, Daly City and Brisbane. San Bruno Mountain is topped by a four mile long ridge. Trails to the summit afford expansive views of the San Francisco Bay Area. Radio Peak is the highest point, hosting several radio broadcast towers, KTSF7 television, ION's KKPX television and NBC's KNTV television, serving a huge area that would otherwise have poor service in the hilly Bay Area region; the mountain provides habitat for several species of butterflies. The endangered San Bruno elfin butterfly inhabits a few other locations; the distinct Franciscan fog zone plants of San Bruno Mountain set it apart from other California coastal areas.
The Portola expedition visited San Francisco Bay in 1769. The expedition is considered the first European presence in the area. Five years Fernando Rivera and four soldiers climbed the mountain and watched sunrise across the bay; the mountain was named by Bruno de Heceta for his patron saint. San Bruno Mountain consists of portions of five Mexican land grants. Jose Antonio Sanchez, who rode by mule as a child from Sonora, was given Rancho Buri Buri in 1827, with confirmation in 1835. Rancho Buri Buri extended from the bay salt flats to San Andreas Valley and from Colma to Burlingame. Rancho Canada de Guadalupe la Visitacion y Rodeo Viejo contained most of the present day San Bruno Mountain. In 1835 this rancho was granted to Jacob P. Leese. In 1884 banker Charles Crocker acquired core holdings of this rancho amounting to 3,997 acres from Leese's successors, that land devolved to the Crocker Estate Company, who are the present day owners of San Bruno Mountain. Three other ranchos held minor portions of the northern flank of San Bruno Mountain.
The cities that have grown up around the mountain are San Francisco to the north, Brisbane to the east, South San Francisco to the south and both Daly City and Colma to the west. Nossaman attorney Robert D. Thornton pioneered the Habitat Conservation Plan concept creating the first such plan for the area around San Bruno Mountain. KRON was the first television station to place a transmitter tower on Radio Peak, in 1949, followed by KQED and KTVU, though these tenants moved their transmitters to Sutro Tower in the 1970s. A number of FM stations built transmitter towers on the mountain, in 2005, KNTV moved its transmitter to the mountain, on the former KCSM-TV tower. KTSF occupies the former KRON site. In 1965, Westbay Community Associates announced a plan to level a portion of the mountain to fill 27 square miles of San Francisco Bay north of Sierra Point with landfill; the proposal intended to create housing developments in the "Saddle" just north of Guadalupe Canyon Road and in the landfill zone.
In order to remove 250 million cubic yards of earth from the ridge, Westbay proposed using a conveyor belt system to transport the fill across Bayshore Boulevard and Bayshore Freeway to offshore barges, which would deposit the material along the shores of the Bay. Opposition by organizations such as Save The Bay and the residents of Brisbane led to the defeat of Westbay's conveyor plan in June 1967 and the ceasing of all landfill operations at Sierra Point by December 1972; the Terra Bay project was approved in the mid-1980s for development at the south and southeast base of San Bruno Mountain. Terra Bay was constructed in three phases: the first phase constructed townhomes and detached houses; the original developer, W. W. Dean & Associates, was unable to complete the project, SunChase Holdings acquired the project in 1992, completing site preparation before selling the parcels for Phase I to Centex Homes; the Terra Bay site was known to include habitat for the Mission blue and Callippe silverspot butterflies.
Under the terms established by the 1982 amendment to the Endangered Species Act, the nation's first-ever Habitat Conservation Plan was agreed upon, allowing developers to destroy the habitat of endangered species if substitute lands were made available. SunChase agreed to fund ecological restoration to mitigate the impact of Terra Bay during the development of Phase I under the terms of the San Bruno HCP. SunChase entered a joint venture with Myers Development for the development of Phases II and III. Although the shellmound had been noted as early as 1909, a sample of 22 cubic metres of the shellmound conducted in 1989 by Holman & Associates revealed the massive shellmound contained human remains, further, that the shellmound site is eligibl
Nectar is a sugar-rich liquid produced by plants in glands called nectaries, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide antiherbivore protection. Common nectar-consuming pollinators include mosquitoes, wasps, bees and moths, hummingbirds and bats. Nectar plays an important role in the foraging economics and overall evolution of nectar-eating species. Nectar is the sugar source for honey, it is useful in agriculture and horticulture because the adult stages of some predatory insects feed on nectar. For example, the social wasp species Apoica flavissima relies on nectar as a primary food source. In turn, these wasps hunt agricultural pest insects as food for their young. For example, thread-waisted wasps are known for hunting caterpillars. Caterpillars however, do become butterflies and moths, which are important pollinators. Nectar secretion increases as the flower is visited by pollinators.
After pollination, the nectar is reabsorbed into the plant. Nectar is derived from the fabled drink of Greek gods; the word is derived as a compound of nek, meaning death, tar, meaning the ability to overcome. The common use of nectar refers to the "sweet liquid in flowers", first recorded in AD 1600. A nectary is floral tissue found in different locations in the flower; the different types of floral nectaries include sepal nectaries, petal nectaries, staminal nectaries found on the stamen, gynoecial nectaries found on the ovary tissue. The nectaries may vary in color and symmetry. Nectaries can be categorized as structural or non-structural. Structural nectaries refer to specific areas of tissue that exude nectar, such as the types of floral nectaries listed. Non-structural nectaries secrete nectar infrequently from non-differentiated tissues; the different types of floral nectaries coevolved depending on the pollinator that feeds on the plant's nectar. Nectar is secreted from epidermal cells of the nectaries by means of modified stomata.
The nectar comes from phloem with additional sugars that are secreted from the cells through vesicles packaged by the endoplasmic reticulum. Flowers that have longer nectaries sometimes have a vascular strand in the nectary to assist in transport over a longer distance.. Floral nectaries are used by plants to attract pollinators such as insects and other vertebrates; the pollinators feed on the nectar and depending on the location of the nectary the pollinator assists in fertilization and outcrossing of the plant as they brush against the reproductive organs, the stamen and pistil, of the plant and pick up or deposit pollen. Nectar from floral nectaries is sometimes used as a reward to insects, such as ants, that protect the plant from predators. Many floral families have evolved a nectar spur; these spurs are projections of various lengths formed from different tissues, such as the petals or sepals. They allow for pollinators to land on the elongated tissue and more reach the nectaries and obtain the nectar reward.
Different characteristics of the spur, such as its length or position in the flower, may determine the type of pollinator that visits the flower. Defense from herbivory is one of the roles of extrafloral nectaries. Floral nectaries can be involved in defense. In addition to the sugars found in nectar, certain proteins may be found in nectar secreted by floral nectaries. In tobacco plants, these proteins have antimicrobial and antifungal properties and can be secreted to defend the gynoecium from certain pathogens. Floral nectaries have evolved and diverged into the different types of nectaries due to the various pollinators that visit the flowers. In Melastomataceae, different types of floral nectaries have been lost many times. Flowers that ancestrally produced nectar and had nectaries may have lost their ability to produce nectar due to a lack of nectar consumption by pollinators, such as certain species of bees. Instead they focused on energy allocation to pollen production. Species of angiosperms that have nectaries use the nectar to attract pollinators that consume the nectar, such as birds and butterflies.
In Bromeliaceae, septal nectaries are common in species that are bird pollinated. In species that are wind pollinated, nectaries are absent because there is no pollinator to provide a reward for. In flowers that are pollinated by long-tongued organism such as certain flies, moths and birds, nectaries in the ovaries are common because they are able to reach the nectar reward when pollinating. Sepal and petal nectaries are more common in species that are pollinated by short-tongued insects that cannot reach so far into the flower. Extrafloral nectaries are nectar-secreting plant glands that develop outside of flowers and are not involved in pollination, they are diverse in form, location and mechanism. They have been described in all above-ground plant parts—including leaves, stipules, cotyledons and stems, among others, they range from single-celled trichomes to complex cup-like structures that may or may not be vascularized. In contrast to floral nectaries, nectar produced outside the flower have a defensive function.
The nectar attracts predatory insects whic
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which includes moths. Adult butterflies have large brightly coloured wings, conspicuous, fluttering flight; the group comprises the large superfamily Papilionoidea, which contains at least one former group, the skippers, the most recent analyses suggest it contains the moth-butterflies. Butterfly fossils date to the Paleocene, about 56 million years ago. Butterflies have the typical four-stage insect life cycle. Winged adults lay eggs on the food plant; the caterpillars grow, sometimes rapidly, when developed, pupate in a chrysalis. When metamorphosis is complete, the pupal skin splits, the adult insect climbs out, after its wings have expanded and dried, it flies off; some butterflies in the tropics, have several generations in a year, while others have a single generation, a few in cold locations may take several years to pass through their entire life cycle. Butterflies are polymorphic, many species make use of camouflage and aposematism to evade their predators.
Some, like the monarch and the painted lady, migrate over long distances. Many butterflies are attacked by parasites or parasitoids, including wasps, protozoans and other invertebrates, or are preyed upon by other organisms; some species are pests because in their larval stages they can damage domestic trees. Larvae of a few butterflies eat harmful insects, a few are predators of ants, while others live as mutualists in association with ants. Culturally, butterflies are a popular motif in the literary arts; the Oxford English Dictionary derives the word straightforwardly from Old English butorflēoge, butter-fly. A possible source of the name is the bright yellow male of the brimstone; the earliest Lepidoptera fossils are of a small moth, Archaeolepis mane, of Jurassic age, around 190 million years ago. Butterflies evolved from moths, so while the butterflies are monophyletic, the moths are not; the oldest butterflies are from the Palaeocene MoClay or Fur Formation of Denmark 55 million years old.
The oldest American butterfly is the Late Eocene Prodryas persephone from the Florissant Fossil Beds 34 million years old. Traditionally, the butterflies have been divided into the superfamily Papilionoidea excluding the smaller groups of the Hesperiidae and the more moth-like Hedylidae of America. Phylogenetic analysis suggests that the traditional Papilionoidea is paraphyletic with respect to the other two groups, so they should both be included within Papilionoidea, to form a single butterfly group, thereby synonymous with the clade Rhopalocera. Butterfly adults are characterized by their four scale-covered wings, which give the Lepidoptera their name; these scales give butterfly wings their colour: they are pigmented with melanins that give them blacks and browns, as well as uric acid derivatives and flavones that give them yellows, but many of the blues, greens and iridescent colours are created by structural coloration produced by the micro-structures of the scales and hairs. As in all insects, the body is divided into three sections: the head and abdomen.
The thorax is composed of each with a pair of legs. In most families of butterfly the antennae are clubbed, unlike those of moths which may be threadlike or feathery; the long proboscis can be coiled. Nearly all butterflies are diurnal, have bright colours, hold their wings vertically above their bodies when at rest, unlike the majority of moths which fly by night, are cryptically coloured, either hold their wings flat or fold them over their bodies; some day-flying moths, such as the hummingbird hawk-moth, are exceptions to these rules. Butterfly larvae, have a hard head with strong mandibles used for cutting their food, most leaves, they have cylindrical bodies, with ten segments to the abdomen with short prolegs on segments 3–6 and 10. Many are well camouflaged; the pupa or chrysalis, unlike that of moths, is not wrapped in a cocoon. Many butterflies are sexually dimorphic. Most butterflies have the ZW sex-determination system where females are the heterogametic sex and males homogametic. Butterflies are distributed worldwide except Antarctica.
Of these, 775 are Nearctic. The monarch butterfly is native to the Americas, but in the nineteenth century or before, spread across the world, is now found in Australia, New Zealand, other parts of Oceania, the Iberian Peninsula, it is not clear.
Off-roading is the activity of driving or riding a vehicle on unsurfaced roads or tracks, made of materials such as sand, riverbeds, snow and other natural terrain. Types of off-roading range in intensity, from leisure drives with unmodified vehicles to competitions with customized vehicles and professional drivers. Off-roaders have been met with criticism for the environmental damage caused by their vehicles. There have been extensive debates over the role of government in regulating the sport, including a Supreme Court case brought against the Bureau of Land Management. Travelling on off-road terrains require vehicles capable of accommodating off-road driving such as ATVs; these vehicles accommodate off-road conditions with extended ground clearance, off-road tires and drive-train. Some manufacturers offer vehicles meant for off-road use; some examples of recreational off-roading include the following: Dune bashing is a form of off-roading on sand dunes. A Large sport utility vehicle such as the Toyota Land Cruiser is an example of vehicle used.
Vehicles driven on dunes may be equipped with a roll cage in case of an overturn. Before entering the desert in an everyday-use SUV or pickup, it is essential to reduce the tire pressure; this is done to gain more traction by increasing the footprint of the tire and, reducing the ground pressure of the vehicle on the sand as there is a greater surface area. For example, tires with a recommended pressure of 35 psi would be reduced to 12-14 psi. A common modification is to fit beadlock rims, which allow tire pressure to be lowered further, without risking tire and rim separation. Upon entering the desert, it is common to meet with a pack of vehicles and a group leader before proceeding; the group leader leads the pack through the stunts in single file. The main reason for this technique is to prevent vehicles from losing track of direction and getting lost. High speed racing in the open desert includes chases and racing on a rough desert terrain with numerous pots and bumps at the maximum speed.
Drivers use RWD and 4WD trucks with long travel suspension, wide stance on the front and large tires which allows to maintain optimal stability at the high speed. This type of trucks is called Prerunner. Rock Racing is similar to rock crawling in the fact that the vehicles are driven over rocks, the difference is that there are no penalties for hitting cones, backing up or winching as is done in rock crawling. Rock racing involves a degree of high-speed racing not seen in typical rock crawling. Unlike stationary dune bashing that tends to revolve around a single star dune or one obstacle, cross-country off-roading is an activity that lasts several days on routes with desert or other terrains. Routes in Africa have obstacles in uninhabited and uncharted terrain; these circuit routes are over 50 km and around 300 km long This is a type of travel undertaken with a 4x4 that goes over tracks and contains some bits of off-roading. Traditionally these trips are going through uninhabited areas. Popular are the deserts in Tunisia and other North African countries, continent crossing trips through Africa, trips through Mongolia or Northern Scandinavia.
Typical modifications to vehicles for this kind of travel are the addition of extra fuel tanks, roof rack tents, elaborate storage systems in the back for food, water/drinking, spare parts and other cargo. Due to the extra weight the suspension is reinforced with stronger springs, shock absorbers etc... Green laning is a leisure pursuit suitable for any four-wheel-drive vehicle those without modifications or additional equipment; the term green lane refers to the fact that the routes are predominantly along unsurfaced tracks, forest tracks, or older roadways that may have fallen into disuse. In the UK they are roads which are not maintained in any way and will include fords. Mudding is off-roading through an area of wet clay; the goal is to drive through as far as possible without becoming stuck. There are many types of tires; some tires are mud-terrain tires and paddle tires. This activity is popular in the United States, although it is illegal on public land due to the environmental impact. Rock crawling is a category of off-roading.
Vehicles used for rock crawling are modified with different tires, suspension components that allow greater axle articulation, changes in the differential gear ratio in order to obtain characteristics suitable for low speed operation for traversing obstacles. It is common for a rock crawler to have a "spotter", an assistant on foot by the vehicle to provide information to the driver about the areas out of sight to the driver. All progress is made at low speed and the emphasis is on skill, rather than finishing first although trialing can be competitive. There are three traditional forms of off-road trailing. RTV trialing is the most common form of trialing; as the name suggests, it is for vehicles. This excludes vehicles that are modified or specially built. RTV-class vehicles can carry a wide range of suspension modifications, as well as off-road tires, recovery winches, raised air intakes etc. Vehicles on RTV trials are usually
In scientific nomenclature, a synonym is a scientific name that applies to a taxon that goes by a different scientific name, although the term is used somewhat differently in the zoological code of nomenclature. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies; this name is no longer in use: it is now a synonym of the current scientific name, Picea abies. Unlike synonyms in other contexts, in taxonomy a synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms have a different status. For any taxon with a particular circumscription and rank, only one scientific name is considered to be the correct one at any given time. A synonym cannot exist in isolation: it is always an alternative to a different scientific name. Given that the correct name of a taxon depends on the taxonomic viewpoint used a name, one taxonomist's synonym may be another taxonomist's correct name. Synonyms may arise whenever the same taxon is named more than once, independently.
They may arise when existing taxa are changed, as when two taxa are joined to become one, a species is moved to a different genus, a variety is moved to a different species, etc. Synonyms come about when the codes of nomenclature change, so that older names are no longer acceptable. To the general user of scientific names, in fields such as agriculture, ecology, general science, etc. A synonym is a name, used as the correct scientific name but, displaced by another scientific name, now regarded as correct, thus Oxford Dictionaries Online defines the term as "a taxonomic name which has the same application as another one, superseded and is no longer valid." In handbooks and general texts, it is useful to have synonyms mentioned as such after the current scientific name, so as to avoid confusion. For example, if the much advertised name change should go through and the scientific name of the fruit fly were changed to Sophophora melanogaster, it would be helpful if any mention of this name was accompanied by "".
Synonyms used in this way may not always meet the strict definitions of the term "synonym" in the formal rules of nomenclature which govern scientific names. Changes of scientific name have two causes: they may be taxonomic or nomenclatural. A name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight. A name change may be due to purely nomenclatural reasons, that is, based on the rules of nomenclature. Speaking in general, name changes for nomenclatural reasons have become less frequent over time as the rules of nomenclature allow for names to be conserved, so as to promote stability of scientific names. In zoological nomenclature, codified in the International Code of Zoological Nomenclature, synonyms are different scientific names of the same taxonomic rank that pertain to that same taxon. For example, a particular species could, over time, have had two or more species-rank names published for it, while the same is applicable at higher ranks such as genera, orders, etc.
In each case, the earliest published name is called the senior synonym, while the name is the junior synonym. In the case where two names for the same taxon have been published the valid name is selected accorded to the principle of the first reviser such that, for example, of the names Strix scandiaca and Strix noctua, both published by Linnaeus in the same work at the same date for the taxon now determined to be the snowy owl, the epithet scandiaca has been selected as the valid name, with noctua becoming the junior synonym. One basic principle of zoological nomenclature is that the earliest published name, the senior synonym, by default takes precedence in naming rights and therefore, unless other restrictions interfere, must be used for the taxon. However, junior synonyms are still important to document, because if the earliest name cannot be used the next available junior synonym must be used for the taxon. For other purposes, if a researcher is interested in consulting or compiling all known information regarding a taxon, some of this may well have been published under names now regarded as outdated and so it is again useful to know a list of historic synonyms which may have been used for a given current taxon name.
Objective synonyms refer to taxa with same rank. This may be species-group taxa of the same rank with the same type specimen, genus-group taxa of the same rank with the same type species or if their type species are themselves objective synonyms, of family-group taxa with the same type genus, etc. In the case of subjective synonyms, there is no such shared type, so the synonymy is open to taxonomic judgement, meaning that th
Sedum is a large genus of flowering plants in the family Crassulaceae, members of which are known as stonecrops. The genus has been described as containing up to 600 species updated to 470, they are leaf succulents found in the Northern Hemisphere, but extending into the southern hemisphere in Africa and South America. The plants vary from creeping herbs to shrubs; the plants have water-storing leaves. The flowers have five petals four or six. There are twice as many stamens as petals. Various species classified as Sedum are now in the segregate genera Hylotelephium and Rhodiola. Well-known European species of Sedum are Sedum acre, Sedum album, Sedum dasyphyllum, Sedum reflexum and Sedum hispanicum. Sedum demonstrates a wide variation in chromosome numbers, polyploidy is common. Chromosome number is an important taxonomic feature. Linnaeus described 16 species of European Sedum. There are now thought to be 55 European species. Now in Dudleya: Dudleya caespitosa Dudleya edulis Now in Hylotelephium: Hylotelephium spectabile Hylotelephium telephioides Now in Rhodiola: Rhodiola rhodantha Rhodiola rosea Rhodiola pachyclados Sedum species are used as food plants by the larvae of some Lepidoptera species including Grey Chi.
In particular, Sedum spathulifolium is the host plant of the endangered San Bruno elfin butterfly of San Mateo County, California. Sedum lanceolatum is the host plant of the more common Parnassius smintheus found in the Rocky Mountains; as well as Sedum spathulifolium, many other species of Sedum serve the environmental role of host plants for butterflies. For example, the butterfly Callophrys xami uses several species of Sedum, such as Sedum allantoides, for suitable host plants. Many sedums are cultivated as garden plants, due to their interesting and attractive appearance and hardiness; the various species differ in their requirements. Numerous hybrid cultivars have been developed, of which the following have gained the Royal Horticultural Society's Award of Garden Merit:-'Herbstfreude"Bertram Anderson"Matrona"Ruby Glow' The leaves of most stonecrops are edible, excepting Sedum rubrotinctum, although toxicity has been reported in some other species. Sedum reflexum, known as "prickmadam", "stone orpine", or "crooked yellow stonecrop", is used as a salad leaf or herb in Europe, including the United Kingdom.
It has a astringent sour taste. Sedum divergens, known as "spreading stonecrop", was eaten by First Nations people in Northwest British Columbia; the plant is used as a salad herb by the Nisga'a people. It is common in the Nass Valley of British Columbia. Biting Stonecrop contains high quantities of piperidine alkaloids, which give it a sharp, acrid taste and make it somewhat toxic. Sedum can be used to provide a roof covering in green roofs. Ford's Dearborn Truck Plant's living roof has 454,000 square feet of sedum. Rolls-Royce Motor Cars plant in Goodwood, has a 242,000 square feet roof complex covered in Sedum, the largest in the United Kingdom. Nintendo of America's roof is covered in some 75,000 square feet of Sedum; the Javits Center in New York City is covered with 292,000 square feet of Sedum. Media related to Sedum at Wikimedia Commons Data related to Sedum at Wikispecies "Sedum". Encyclopædia Britannica. 1911. Drought Smart Plants Sedum Society Sedum Yellow Stonecrop
Pacifica is a city in San Mateo County, California, on the coast of the Pacific Ocean between San Francisco and Half Moon Bay. The City of Pacifica is spread along a six-mile stretch of coastal beaches and hills in north central California; the city comprises several small valleys spread between Sweeney Ridge in the east, Montara Mountain to the south, the Pacific Ocean's rocky bluffs to the west. Pacifica is well known regionally as a popular surfing destination. Surfers and families visit Linda Mar Beach. Rockaway Beach is a scenic location and offers recreation and dining. 2005 marked. Pacifica is a popular mountain biking destination, with many trails crossing the hillsides that surround the city, including Pedro Mountain Road, Sweeney Ridge, areas of the Golden Gate National Recreation Area. Fishermen frequent the local beaches and the Pacifica Pier catching striped bass and salmon. Pacifica is a popular place to hike, with many trails that wind along the beaches and bluffs, including Mori Point, San Pedro Valley County Park, the Sanchez Adobe, Milagra Ridge, the owned Pacifica quarry.
For live local theater and performing arts, Pacifica Spindrift Players is a local and popular favorite, in addition to Pacifica Performances which provides both musical presentations and performing arts as well. Pacifica is home to the Sharp Park Golf Course, designed in 1931 by architect Alister MacKenzie; the world class bromeliad nursery, Shelldance Orchid Gardens is located just off Highway 1 in Pacifica, adjacent to the Sweeney Ridge hiking trailhead. Pacifica is divided into eleven districts from north to south: Fairmont Westview Pacific Manor Edgemar Sharp Park Fairway Park Vallemar Rockaway Beach Pedro Point and Shelter Cove in the south west, Linda Mar, Linda Mar Valley, in the south. Park Pacifica in south east portions of the city; the 2010 United States Census reported that Pacifica had a population of 37,234. The population density was 2,941.1 people per square mile. The racial makeup of Pacifica was 55.6% white, 16.8% Hispanic or Latino of any race, 976 African American, 206 Native American, 7,230 Asian, 315 Pacific Islander, 1,703 from other races, 2,638 from two or more races.
The Census reported that 37,052 people lived in households, 64 lived in non-institutionalized group quarters, 118 were institutionalized. There were 13,967 households, out of which 4,511 had children under the age of 18 living in them, 7,385 were opposite-sex married couples living together, 1,592 had a female householder with no husband present, 709 had a male householder with no wife present. There were 869 unmarried opposite-sex partnerships, 237 same-sex married couples or partnerships. 3,126 households were made up of individuals and 1,098 had someone living alone, 65 years of age or older. The average household size was 2.65. There were 9,686 families; the population was spread out with 7,707 people under the age of 18, 2,842 people aged 18 to 24, 10,011 people aged 25 to 44, 12,155 people aged 45 to 64, 4,519 people who were 65 years of age or older. The median age was 41.5 years. For every 100 females, there were 95.6 males. For every 100 females age 18 and over, there were 93.4 males. There were 14,523 housing units at an average density of 1,147.2 per square mile, of which 9,545 were owner-occupied, 4,422 were occupied by renters.
The homeowner vacancy rate was 0.9%. 26,567 people lived in owner-occupied housing units and 10,485 people lived in rental housing units. As of the census of 2000, there were 38,390 people, 13,994 households, 9,655 families residing in the city; the population density was 3,038.9 people per square mile. There were 14,245 housing units at an average density of 1,127.6 per square mile. There were 13,994 households out of which 32.0% had children under the age of 18 living with them, 53.5% were married couples living together, 11.0% had a female householder with no husband present, 31.0% were non-families. 21.2% of all households were made up of individuals and 6.4% had someone living alone, 65 years of age or older. The average household size was 2.73 and the average family size was 3.21. In the city, the population was spread out with 23.2% under the age of 18, 7.7% from 18 to 24, 32.8% from 25 to 44, 26.6% from 45 to 64, 9.7% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 97.2 males.
For every 100 females age 18 and over, there were 95.2 males. The median income for a household in the city was $31,737, the median income for a family was $48,361. Males had a median income of $50,761 versus $40,261 for females; the per capita income for the city was $30,183. About 1.2% of families and 2.9% of the population were below the poverty line, including 1.2% of those under age 18 and 4.9% of those age 65 or over. The oldest person to live in Pacifica is Rose G. Rosenthal, born on April 8, 1901, died December 27, 2008; the Reverend Herschell Harkins Memorial pier was constructed in 1973 and was designed to carry sewage piping out to sea. It was closed in 1992 due to corrosion of some of the structure. Since the pier h