The California Least Tern, Sterna antillarum browni, is a subspecies of Least Tern that breeds in bays of the Pacific Ocean within a very limited range in Orange County, San Diego County and extreme northern Mexico. It is a U.S. federally listed endangered species. The total population of the species amounted to 582 breeding pairs in the year 1974, when census work on this bird began. While population numbers have gradually increased with its protected status, the species is still vulnerable to natural disasters or further disturbance of man. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anenomes) Placozoa (trichoplax) Subregnum Bilateria (bilateral symmetry) Acoelomorpha (basal) Orthonectida (parasitic to flatworms, echinoderms, etc. ... Typical Classes Subphylum Urochordata - Tunicatas Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Aves redirects here. ... Families Thinocoridae Pedionomidae Scolopacidae Rostratulidae Jacanidae Chionididae Burhinidae Haematopodidae Recurvirostridae Ibidorhynchidae Charadriidae Pluvianellidae Dromadidae Glareolidae Stercorariidae Rhynchopidae Laridae Sternidae Alcidae Charadriiformes is a diverse order of small to medium-large birds. ... Genera Sterna (Gelochelidon) (Hydroprogne) (Thalasseus) Chlidonias Phaetusa Anous Procelsterna Gygis Larosterna Terns are seabirds in the family Sternidae, previously considered a subfamily Sterninae of the gull family Laridae. ... Genera Sterna (Gelochelidon) (Hydroprogne) (Thalasseus) Chlidonias Phaetusa Anous Procelsterna Gygis Larosterna Terns are seabirds in the family Sternidae, previously considered a subfamily Sterninae of the gull family Laridae. ... Trinomial nomenclature is a taxonomic naming system that extends the standard system of binomial nomenclature by adding a third taxon. ... Binomial name Sterna albifrons Pallas, 1764 The Little Tern (Sterna albifrons) is a seabird of the tern family Sternidae. ... Orange County is the name of several counties in the United States of America: Orange County, California: probably named for the city of Orange, California, which in turn may have been named after the orange groves that used to exist there. ... San Diego County is a county located on the Pacific Ocean in the far southwest of California, along the border with Mexico. ... The American bison there are as few as 750 in 1890 due to extreme overhunting. ...

Nesting and breeding behavior

Wintering locations are actually unknown, but suspected to include the South American Pacific Coast. South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ...

Batiquitos Lagoon, San Diego County

The California least tern arrives at its Southern California/ Northern Mexico breeding grounds in late April. Courtship typically takes place removed from the nesting colony site, usually on an exposed tidal flat or beach. Only after courtship has confirmed mate selection does nesting begin by mid-May and is usually complete by mid-June. Nests are situated on barren to sparsely vegetated places near water, normally on sandy or gravelly substrates. Where the surace is hard, this species may use an artificial indentation (such as a deep dried footprint) to form the nest basin. The breeding colonies are not dense and may appear along marine or estuarine shores in areas free from humans or predators. San Diego County is a county located on the Pacific Ocean in the far southwest of California, along the border with Mexico. ... Courtship or dating is the process of selecting and attracting a mate for companionship, sex, marriage and sexual reproduction. ... Courtship or dating is the process of selecting and attracting a mate for companionship, sex, marriage and sexual reproduction. ...

The nest density may be as low as several per acre, but in San Diego County, densities of 70 nests per acre have been observed. Most commonly the clutch size is two or three, but it is not rare to consist of either one or four eggs. Both female and male incubate the eggs for a period of about three weeks, and both parents tend the semiprecocial young. Young birds can fly at age four weeks. After formation of the new families, groupings of birds may appear at lacustrine settings in proximity to the coast. Late season nesting may be renests or late season arrival activity. In any case, the bulk of the population has left California by the end of August. San Diego County is a county located on the Pacific Ocean in the far southwest of California, along the border with Mexico. ... A clutch is a subcomponent of an engines transmission designed to allow engagement or disengagement of the engine to the gearbox or whatever apparatus is being driven. ... The word incubate in the context of birds refers to the development of the chick (embryo) within the egg and the constant temperature required for the development of it over a specific period. ... Lacustrine is derived from the Latin word lacus, which means lake. ...

Least terns and Snowy plovers nesting at Batiquitos Lagoon

Binomial name Charadrius alexandrinus Linnaeus, 1758 The Kentish Plover, Charadrius alexandrinus, is a small wader in the plover bird family. ...

Feeding and roosting characteristics

The California least tern hunts primarily in shallow estuaries and lagoons, where smaller fishes are abundant. They hover until spotting prey, and then plunge into the water without full submersion to extract dinner. In the bays and lagoons of Southern California and northern Mexico, the favored prey include anchovy,smelt, shiner perch and small crustaceans. Not infrequently they will feed near shore in the open ocean, especially in proximity to lagoons or bay mouths. An estuary is a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water mixes with fresh water. ... See lagoon (disambiguation) for other possible meanings. ... Prey can refer to: Look up Prey in Wiktionary, the free dictionary A prey animal eaten by a predator in an act called predation. ... Southern California Downtown Los Angeles Skyline Southern California, sometimes abbreviated SoCal or colloquially, the Southland, is an informal name for the megalopolis and nearby desert that occupies the southern-most quarter of the state of California. ... Genera Amazonsprattus Anchoa Anchovia Anchiovella Cetengraulis Coilia Encrasicholina Engraulis Jurengraulis Lycengraulis Lycothrissa Papuengraulis Pterengraulis Setipinna Stolephorus Thryssa The anchovies are a family (Engraulidae) of small but common schooling saltwater plankton-feeding fish. ... See smelting for the chemical process. ... Species Perca flavescens (Yellow perch) Perca fluviatilis (European perch) Perca schrenkii (Balkhash perch) A perch is a freshwater bony fish belonging to the family Osteichthyes. ... Classes Remipedia Cephalocarida Branchiopoda Ostracoda Maxillopoda Malacostraca The crustaceans (Crustacea) are a large group of arthropods (55,000 species), usually treated as a subphylum. ...

Adults do not require cover, so that they commonly roost on the open ground. After young chicks are three days old, they are brooded less frequently by parents and require wind blocks and shade.

Relation to other least terns

The California Least Tern is closely related to the Common Least Tern (Sterna antillarum) that breeds on the Pacific coast from Tomales Bay to northern Mexico and on the Atlantic coast from Maine to Florida and Texas. Sterna antillarum is also found in breeding grounds along rivers in the midwest and Great Plains of the United States. Both the California and Common Least Tern are approximately 23 centimeters in length. Both of these species have conspicuous black markings on their outermost primaries and fly over water with a distinctive hunchback appearance, will bills pointing slightly downward. Binomial name Sterna albifrons Pallas, 1764 The Little Tern (Sterna albifrons) is a seabird of the tern family Sternidae. ... Tomales Bay Tomales Bay is a long narrow inlet of the Pacific Ocean in Marin County in northern California in the United States. ... The Atlantic Ocean is Earths second-largest ocean, covering approximately one_fifth of its surface. ... Official language(s) None Capital Augusta Largest city Portland Area  - Total  - Width  - Length  - % water  - Latitude  - Longitude Ranked 39th 86,542 km² 305 km 515 km 13. ... Official language(s) English Capital Tallahassee Largest city Jacksonville Area  - Total  - Width  - Length  - % water  - Latitude  - Longitude Ranked 22nd 170 451 km² 260 km 800 km 17. ... Official language(s) None. ... The Great Plains is the broad expanse of prairie which lies east of the Rocky Mountains in the United States of America and Canada, covering all or parts of the U.S. states of New Mexico, Texas, Oklahoma, Colorado, Kansas, Nebraska, Wyoming, Montana, South Dakota and North Dakota and the...

Bibliography

• Audubon Handbook: Western Birds, McGraw Hill Book Company (1988) ISBN 0-07-019977-9
• B. Massey, Breeding Biology of the California least tern, Proceedings Linn. Society, New York 72:1-24 (1974)
• Gary Deghi and C. Michael Hogan, Biological Assessment for the Proposed Tijuana/San Diego Joint Innternational Wastewater Treatment Plant, Publication of the U.S. Environmental Protection Agency Region IX, Earth Metrics Incorporated, Burlingame, CA with Harvey and Stanley, Alviso, CA