(DRAFT) - Taxonomy
                           Species TERN, LEAST, CALIFORNIA
                                Species Id ESIS101005
                                   Date 14 MAR 96



TAXONOMY

NAME - TERN, LEAST, CALIFORNIA OTHER COMMON NAMES - TERN, LEAST, CALIFORNIA;TERN and LEAST ELEMENT CODE - CATEGORY - Birds PHYLUM AND SUBPHYLUM - CHORDATA, CLASS AND SUBCLASS - AVES, ORDER AND SUBORDER - CHARADRIIFORMES, FAMILY AND SUBFAMILY - LARIDAE, GENUS AND SUBGENUS - STERNA, SPECIES AND SSP - ANTILLARUM, BROWNI SCIENTIFIC NAME - STERNA ANTILLARUM BROWNI AUTHORITY - TAXONOMY REFERENCES - COMMENTS ON TAXONOMY - California Least Tern Sterna antillarum browni Mearns, 1916 KINGDOM: Animal GROUP: Bird PHYLUM: Chordata CLASS: Aves ORDER: Charadriiformes FAMILY: Laridae The California least tern is a small seabird ca. 21.5 - 24 cm in length with a 51 cm wingspread (11). In breeding plumage, it has a white forehead, black nape and crown extending forward through the eye and lores to the base of the upper mandible. The back, scapulars, tertials and rump are pale gray; the outer rectrices are mainly white, the rest uniformly pale gray. The outer 2-3 primaries are mainly black with a white edge to the inner web; the inner primaries, secondaries, alula and wing coverts are pale gray. Underparts are white. Bill is yellow with a varying amount of black at the tip. Legs and feet are reddish-orange (26). The American least tern was first described from the West Indies by Lesson in 1847 (20). It was considered specifically distinct from the little tern of Europe, Sterna albifrons Pallas (34), and named Sternula antillarum. In 1921 Hartert combined the two species and the California least tern became the subspecies S. albifrons browni (19). Taxonomy - 1 (DRAFT) - Taxonomy Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 The common name, however, continued in use. In 1983 the taxonomy was again revised, and the least tern was restored to the status of a full species (02) based on research that documented differences in vocalizations and morphology (24). The scientific name is now Sterna antillarum. Three subspecies of the least tern have been recognized in the U.S. - antillarum on the east and gulf coasts, athalassos in the Mississippi drainage system, and browni on the west coast (01). The west coast subspecies was first described by Mearns in 1916; the type specimen is in the U.S. National Museum, #134773 (29). Several synonyms in use before Hartert revised the taxonomy in 1921 were listed by him (19): Sternula melanorhynchus Lesson 1847 (an error - a juvenile mistaken for an adult form) Sterna frenata Gambel 1848 Sterna minuta americana Sundevall 1869 For a complete description of plumages, both adult and juvenile, see reference 26. Color photographs can be found in Natural History 90:62-72, 1981, and Western Birds 14:71-72 & cover, 1983. The Los Angeles County Museum of Natural History has a good collection of study skins of California least terns. The California least tern is also referred to simply as the least tern. Taxonomy - 2
                                  (DRAFT) - Status
                           Species TERN, LEAST, CALIFORNIA
                                Species Id ESIS101005
                                   Date 14 MAR 96



STATUS

Coded Status E: Federal Endangered Federal Migratory Non-consumptive recreational COMMENTS ON STATUS - U.S. STATUSES AND LAWS: The California least tern, Sterna antillarum browni, is listed as Endangered in California and Mexico pursuant to the Endangered Species Act of 1973, as amended (50 CFR 17.11) and is protected wherever found. The California least tern is also listed on the Migratory Bird Treaty Act (50 CFR 10.13) at the specific level, Sterna antillarum. This subspecies is protected by the Lacey Act (P.L. 97-79, as amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import, export, transport, sell, receive, acquire, or purchase any wild animal (alive or dead including parts, products, eggs, or offspring): (1) in interstate or foreign commerce if taken, possessed, transported or sold in violation of any State law or regulation; or (2) if taken or possessed in violation of any U.S. law, treaty, or regulation or in violation of Indian tribal law. It is also unlawful to possess any wild animal (alive or dead including parts, products, eggs, and offspring) within the U.S. territorial or special maritime jurisdiction (as defined in 18 U.S.C. 7) that is taken, possessed, transported, or sold in violation of any State law or regulation, foreign law, or Indian tribal law. RESPONSIBLE FEDERAL AGENCIES: USFWS - is responsible for the management/recovery, listing, and law enforcement/protection of this species. DOD - is responsible for cooperation in the management/recovery and protection of this tern where it occurs on DOD lands. STATE STATUSES AND LAWS: STATE: California DESIGNATED STATUS: Endangered ADMINISTRATIVE AGENCY: California Department of Fish and Game STATE STATUTE: California Endangered Species Act; Fish and Game Code, Chapter 1.5, Article 1, Sec. 2050. Status - 1 (DRAFT) - Status Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS: The IUCN Red Data Book lists the California least tern as Endangered. The California least tern (S. albifrons browni) is listed by the U.S. in the Convention on Nature Protection and Wilife Preservation in the Western Hemisphere Annex (1970). ECONOMIC STATUSES: California least terns are important in non-consumptive recreational pursuits by bird enthusiasts. 70/06/02:35 FR 08491/08498 - Listed Endangered, US list foreign wildl. 70/08/25:35 FR 13519/13520 - Proposed rule, add US list native wildl. 70/10/13:35 FR 16047/ - Listed Endangered, US list native wildl. 79/05/21:44 FR 29566/29577 - Five year review 85/07/22:50 FR 29901/29909 - Five year review Status - 2
     

HABITAT ASSOCIATIONS

HABITAT - TERRESTRIAL COASTAL OCEANIC LAND USE - Industrial Transportation, communications, and Util Mixed Urban or Built-up Land Lakes Reservoirs Bays and Estuaries Nonforested Wetland Dry Salt Flats Beaches Sandy Areas other than Beaches Transitional Areas NATIONAL WETLAND INVENTORY CODES NWI NWICLS NWIMOD NWISPEC Lacustrine, limnetic OW0 Lacustrine, limnetic Riverine, lower perennial UB3 Riverine, lower perennial UB2 Riverine, lower perennial UB1 Riverine, lower perennial UB Riverine, lower perennial 1UB Riverine, tidal UB2 Riverine, tidal UB1 Riverine, tidal UB Riverine, tidal Estuarine, subtidal OW0 Marine, intertidal FL2 Marine, intertidal FL1 Marine, intertidal BB2 Marine, intertidal BB1 Marine, intertidal BB Marine, subtidal OW0 COMMENTS ON HABITAT ASSOCIATIONS - Beaches, dunes, sand bars and spits on the ocean shore are the typical and preferred nesting habitat for the California least tern (08,09). Colonies have often been located close to estuaries (23), even long after the estuary has been destroyed. Saltflats in saltmarshes are also used (14,32). The mouths of rivers, particularly those with estuaries, were (and are) favored nesting locations. Few estuaries remain in southern California: Most have been dredged, filled or otherwise altered beyond recognition, for example Marina del Rey, Alamitos Bay, Santa Ana River mouth, and Mission Bay, but there are least tern nesting colonies at each of these places (09). Habitat not only includes open expanses of sand, but also mud or dumped rubbish near a lagoon or estuary, including land fills, spoil banks and parking lots. At one time sandy open beaches were used. But, all colonies in such situations have been abandoned due to human activities and developments along the California coast, with the Habitat Associations - 1 concomitant disturbance, roads and pollution. The tern is, nevertheless, remarkably tolerant of human interference and now nests in highly modified areas adjacent to mixed urban, residential and industrial areas. However, the absence of good feeding grounds in the vicinity may well be a limiting factor (35). (See field N-OCCURRENCE for specific areas and associations.) The species also occurs adjacent to transportation facilities (airports) and county parks. Foraging habitat encompasses any waters within 5 km of a nesting site where small fish may be caught. The ocean (particularly near-shore waters), river mouths, saltmarshes, marinas, river channels, lakes and ponds are all used for foraging (06,09). There are several post-breeding areas used regularly for foraging and flocking by adults and juveniles before migration. Among these are both natural lakes and reservoirs. Habitat Associations - 2
                                (DRAFT) - Food Habits
                           Species TERN, LEAST, CALIFORNIA
                                Species Id ESIS101005
                                   Date 14 MAR 96



FOOD HABITS

TROPHIC LEVEL - CARNIVORE LIFESTAGE FOOD FOOD PART General Fish Food Habits - 1
                         (DRAFT) - Environment Associations
                           Species TERN, LEAST, CALIFORNIA
                                Species Id ESIS101005
                                   Date 14 MAR 96



ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult LIM = Limiting RA = Resting Adult J = Juvenile FA = Feeding Adult RJ = Resting Juvenile BA = Breeding Adult FJ = Feeding Juvenile P = Pupae L = Larvae E = Egg RL = Resting Larvae FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS G Coastal Wetlands: Mangrove swamps G Coastal Features: Sandy offshore islands G Environment Associations - 1
                               (DRAFT) - Life History
                           Species TERN, LEAST, CALIFORNIA
                                Species Id ESIS101005
                                   Date 14 MAR 96



LIFE HISTORY

FOOD HABITS: The staple diet of the California least tern is small fish (05, 22,32), usually <5.0 cm in length (05). The birds have not been observed eating any other food. Many species of fish are consumed - only those with pre-opercular or fin spines or whose body depth exceeds the birds' gape are apparently unsuitable (05). The species most commonly eaten are the northern anchovy (Engraulis mordax) (05,22,32), topsmelt (Atherinops affinis) (05,22,32), shiner perch (Cymatogaster aggregata) (22), California killifish (Fundulus parvipinnis) (32), deepbody anchovy (Anchoa compress) (32), and jacksmelt (Atherinops californiensis) (05). Atwood and Kelly, in a study of fish dropped at nesting colonies, found 19 species they considered suitable for least tern consumption (05). Chicks are fed smaller specimens than their parents eat (22) but not different species (05). Least terns nesting on beaches and foraging mostly in the ocean (in near-shore waters) eat more northern anchovies than any other species of fish, while those nesting and foraging in estuaries feed more on topsmelt and California killifish (05). HOME RANGE/TERRITORY: Least terns are colonial but do not nest in as dense a concentration as other tern species. Although nests have been found as close together as 0.8 m (16), usual minimum distances between nests are 3.0 - 4.6 m, and average distances are much greater (23,36). In northern Santa Barbara County, where nesting occurs in vast expanses of coastal dune habitat, as few as 15 nesting pairs can be widely scattered in colonies with a 1.6 km perimeter or more (04). The area around the nest is defended during incubation. Aggressive behavior is observed when an intruding bird lands too close to the nest; the intruder is scolded and driven off, but fighting rarely ensues (21, 36). Davis calculated the minimum territory size around the nest as ca. 40 cm (16). After hatching, the chicks leave the nest scrape within 1-2 days (23) and nest defense ceases. The terns flock together amicably before the nesting season, at night roosts during the nesting season, and at fishing sites after the nesting season (21). There is no indication that feeding is territorial (21). PERIODICITY: During the nesting season, peaks of foraging activity are observed in the early morning and pre-dusk hours (13). MIGRATION PATTERNS: The California least tern is a migratory species. The route in California is along the coast in both spring and fall. The terns arrive in coastal San Diego County 2 - 3 weeks before they appear in Los Angeles County (04,14,21,30). Concentations of migrating birds are seen in the coastal lagoons in August - color bands have identified them as nesting at more northern colonies in Los Angeles and Orange Counties (04,14,21). The first arrivals in California Life History - 1 (DRAFT) - Life History Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 occur usually in early to mid-April. Fall migration usually begins by August (21). Late-lingering fall migrants have been observed into October (04), but usually the terns have left California by the 15th of September (21). South of the California border, the migratory route is not known, but is assumed to be coastal. From wintering grounds in Mexico and south it is believed they travel along the coast of mainland Mexico, cross the Gulf of California to the tip of the Baja California peninsula, and then head north along the west coast of Baja. This assumption is based on sightings of least terns in March and April in Colima, Mexico (04), in the Gulf (03), and in the large lagoons in western Baja California (03,17). COVER/SHELTER REQUIREMENTS: Least terns nest preferentially on sandy beaches and need no vegetative cover. However, they frequently choose a spot next to a piece of flotsam or other landmark, as if to facilitate nest recognition (04,14,21,30). They will nest in places with sparse vegetation (natural or weedy) but avoid those where the cover has become too dense (04,14,21,30). A small amount of vegetative cover is desireable for the chicks to hide in after they become mobile. Natural dune plants and halophytes at the edges of the saltmarsh are commonly used, but so are weedy invaders (04,14,21,30). REPRODUCTIVE SITE REQUIREMENTS: Least terns make a simple scrape in the sand in which to lay their eggs (23). Nests are sometimes lined later with shell fragments, small stones and occasionally sticks (14,21,30) but may be left unadorned. When nesting in dunes or even small hillocks of sand, the birds usually choose heights rather than valleys, where sightlines are good (16). This is presumably a predator defense. REPRODUCTIVE CHARACTERISTICS: Early in the breeding season, least terns engage in aerial courtship displays (fish flights and aerial glides). After the pair bond is formed, it is reinforced by courtship feeding, with the male bringing fish to the waiting female (24,36). Copulation is usually preceded by a "parade", then vigorous head wagging (with the male holding and flicking a fish), and at the moment of cloacal contact the female grabs and eats the fish (23,36). Minimum breeding age is 2 years, these young birds arrive later than the older ones and nest in late June and July (27). Only a small portion of the 2-year old population breeds, most of the birds are 3 or 4 years of age at first breeding (27). There is one breeding season, from May through August (25), and only one brood is raised. However, the birds will renest if eggs or chicks are lost (27). The pair bond is maintained through the breeding season (unless one of the pair dies) and sometimes for several years. However, many birds "divorce" from one season to the next, some of them more than once (21). The incubation period is 20-25 days (usually 22); the average Life History - 2 (DRAFT) - Life History Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 clutch size is two with a range of 1-3 (23). Smaller clutches are layed by late nesting birds, including renesting birds and first time breeders (2 years of age) (27). PARENTAL CARE: Least tern chicks are precocial (in terms of mobility), leaving the nest scrape 1 - 2 days after hatching (23). However, they are totally dependent on their parents for food until well after fledging (25). During the 18-20 day period before fledging, when the chicks range freely around the nesting area, one parent usually stands guard while the mate is foraging (21). For several weeks after fledging the juveniles practice fishing and continue to be fed by their parents at favored roosting and fishing sites that are used every year (21). Parents continue to feed their offspring during migration and perhaps even on the wintering grounds (33). POPULATION BIOLOGY: Current limiting factors include lack of suitable nesting areas in parts of the birds' range, severe predation at certain colonies, and periodic food shortages. Although new breeding sites have been developed in the past 10 years, none have been on beaches, the traditional preferred nesting habitat of the least tern. Nest sites in saltmarshes (e.g., Cerritos Lagoon, Anaheim Bay, Bolsa Chica) are subject to severe predation, and and require elaborate protective devices and constant monitoring to be successful (04,21,30). There are long stretches of beach that once hosted least tern colonies where new nesting sites should be established. However, there is not a single beach nesting site between Venice in Los Angeles County and Huntington Beach State Park in Orange County (09). Predators have caused heavy chicks mortality at Bolsa Chica, Huntington Beach, Santa Margarita River, Mission Bay and Chula Vista Wildlife Reserve for the past several years (14,30). The food supply is a third limiting factor. In 1982 there was a dearth of the small fish that comprise the least tern's diet. The number of successful fledglings was reduced considerably that season (09,14,26,30). In 1984 the number of breeding pairs that arrived in the spring dropped for the first time since 1973. The reduction was apparent throughout the breeding range (12) and the most plausible explanation was a dearth of food in the wintering area. Survival rate, recovery potential and other parameters are under study as part of a long-term research program (25). The recovery plan calls for a population increase to 1200 breeding pairs distributed in at least 20 secure coastal ecosystems throughout the 1982 breeding range before delisting can be considered (08,09). SPECIES INTERRELATIONSHIPS: The least tern's diet is fish. The species most commonly eaten are listed above under Food Habits. A shortage of these fish directly impacts the tern's breeding success. In 1982 a food shortage resulted in a much reduced crop of fledglings (See Population Biology, above). Life History - 3 (DRAFT) - Life History Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 OTHER LIFE HISTORY DESCRIPTORS: None. Life History - 4
                           (DRAFT) - Management Practices
                           Species TERN, LEAST, CALIFORNIA
                                Species Id ESIS101005
                                   Date 14 MAR 96



MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE Beneficial Restricting/regulating human disturbance of populations Beneficial Developing/maintaining stream structures Beneficial Maintaining/Controlling Water Flow Beneficial Developing/maintaining/protecting wetlands Beneficial Land Acquisition Beneficial Controlling/Restricting Herbicide Use Beneficial Creating Artificial Habitat/Nesting Structure Beneficial Reforestation Beneficial Controlling/Removing Native Vegetation Beneficial Controlling/Removing Native Vertebrates Beneficial Controlling/Removing Exotic Vertebrates Beneficial Controlling/Removing Feral Animals Beneficial Controlling/Removing Domestic Animals Adverse Harassment/Vandalism/Indiscriminate Killing Existing Harassment/Vandalism/Indiscriminate Killing Adverse Off Road Vehicles Existing Off Road Vehicles Adverse Food Supply Reduction Existing Food Supply Reduction Adverse Predation Existing Predation Adverse Recreational development Existing Recreational development Adverse Highway/Railroads Existing Highway/Railroads Adverse Soil compaction by heavy equipment in mine areas Existing Soil compaction by heavy equipment in mine areas Adverse Siltation Existing Siltation Adverse Draining wetlands, marshes, ponds, lakes Existing Draining wetlands, marshes, ponds, lakes Adverse Dredging Existing Dredging Adverse Developing/maintaining stream bank vegetation Existing Developing/maintaining stream bank vegetation Adverse Shoreline modification/development Existing Shoreline modification/development Adverse Erosion Existing Erosion Adverse Existing COMMENTS ON MANAGEMENT PRACTICES - The decline in numbers of the California least tern was apparently a gradual one (35). There are no reliable records for numbers of pairs early in the century, but the construction of the railroad and Pacific Coast Highway, both along previously undisturbed beaches in southern California, increased human disturbance and began Management Practices - 1 (DRAFT) - Management Practices Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 a steady erosion of the secluded beach-nesting habitat the terns require (35). Because the birds lay their eggs on the sand, preferably on ocean-fronting beaches, they are extremely vulnerable to disturbance, and freedom from disturbance is one of the requisites for successful nesting. Adults incubating eggs fly up in alarm at any intruder into the colony; parents feeding chicks will not do so if there is a disturbance in the colony (21). By the 1940's most tern colonies were gone from the beaches of L.A. and Orange Counties (10), and they were considered sparse everywhere (18). The post-war boom in housing in the late 1950's put still more pressure on the dwindling tern colonies, as the beaches became more crowded and disturbance from recreational activities, including off-road vehicle use, increased. Shoreline/beach modification and wetland filling for development further reduced habitat and increased disturbance. Estuaries, which serve as feeding grounds for this tern, have been and are being altered, at least in part, by the effects of jettys and by the channel modification and siltation that dredging and agricultural practices cause. The mouths of rivers, particularly those with estuaries, were (and are) favored nesting locations. Few estuaries remain in southern California, most have been dredged, filled or otherwise altered beyond recognition, for example Marina del Rey, Alamitos Bay, Santa Ana River mouth, and Mission Bay, but there are least tern nesting colonies at each of these places (09). In the early 1960's a small fenced enclosure was erected at Huntington Beach State Park for the few remaining pairs of a colony that once numbered at least 600 pairs (31). This was the first protective measure taken (21). Since 1973, when the California Least Tern Recovery Team began to function, protection has been achieved at many more nesting sites, and some new nesting areas have been created (08,09). In 1973, the first year a census was taken of the breeding population in California, 600 pairs were estimated (07). The numbers increased slowly but steadily from 1976 on, reaching 1,200 pairs in 1983 (09), but then dropped suddenly and sharply in 1984 to 1,000 pairs. The cause of this setback is unknown, but is probably related to the wintering grounds in Mexico and south. The problem of human disturbance at nest sites is under reasonable control, but a new concern has arisen in conjunction with the increase in colony size. Predators have found the eggs and chicks a good food source; American kestrels, feral cats, red foxes, American crows, coyotes and Norway rats are some of the major predators (09,28, 30). Another problem appeared in 1982 when there was a shortage of the small fish the terns eat. The cause of this shortage is unknown. The diminished food supply resulted in delayed nesting, smaller clutch size, lagging chick growth rate, emaciated and dead chicks and, ultimately, a reduced crop of fledglings (05,12,28). Despite these problems, the California least tern is doing quite well at present, thanks to good management and annual monitoring. APPROVED PLAN: U.S. Fish and Wildlife Service. 1980. Recovery Plan for the Management Practices - 2 (DRAFT) - Management Practices Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 California Least Tern. U.S. Fish and Wildlife Service, Portland, OR. 58 pp. A revised recovery plan is being prepared (September 1986). The primary objective of the recovery plan for the California least tern is to restore and maintain the breeding population at self-sustaining levels of at least 1,200 pairs distributed in 20 colonies. Delisting of the species may be considered if the 1,200 breeding pair population is attained and if each of 20 wetland ecosystems have sufficiently secure habitat to support at least one colony of terns. No criteria was formulated for reclassifying to Threatened. The recovery activities necessary to achieve the primary objective are: 1. Provide adequate breeding habitat by: a. Implementing habitat management plans at existing colonies; b. Securing nesting habitat (currently privately owned) through acquisition, easements, MOU or other means; c. Identifying special site protection needs; d. Securing alternate nesting areas for vulnerable colonies; e. Securing at least five nesting sites in Mission Bay; f. Restoring or creating habitat through removal of native vegetation, creating artificial shelters for chicks, restoring historic sites, constructing alternate nesting sites, and limiting human access and activities (e.g., horseback riding, and off-road vehicle use); g. Minimizing mortality through fencing and signs to limit access by humans and domestic animals, and h. minimizing predation. Predators may include coyote, Norway rat, striped skunk, longtail weasel, common raven, American crow, gulls and domestic (and possibly feral) dogs. 2. Provide adequate feeding habitat by: a. Maintaining high water quality, preventing fill and drainage projects; b. Restoring/improving tidal flow in wetlands; and c. Increasing food fish populations in degraded or potential feeding areas. 3. Protect important non-nesting, feeding and roosting habitats from detrimental land or water use changes. Maintain high water quality (controlling agricultural runoff, sewage effluent and herbicide use), minimize tideland fill and drainage projects, and restore or improve tidal flow in wetlands (stream channel modification) to provide the needed protection. 4. Encourage protection of habitat and populations in Mexico. 5. Monitor populations to determine status, distribution, and progress of species management. 6. Designate "Critical Habitat". Management Practices - 3 (DRAFT) - Management Practices Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 7. Determine effects of pollutants and conduct basic research on life history. 8. Enforce Federal and State laws and regulations (e.g., to protect terns from harassment or indiscriminant killing), and 9. Develop and implement a public information and education program. Management Practices - 4
                                   (DRAFT) - References
                             Species TERN, LEAST, CALIFORNIA
                                  Species Id ESIS101005
                                      Date 14 MAR 96



     

References

***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE ***** 01 American Ornithologists' Union. 1957. Check-list of North American birds, 5th ed. 691 pp. 02 American Ornithologists' Union. 1983. Check-list of North American birds, 6th ed. 877 pp. 03 Anderson, Daniel W. 1985. Personal communication. Div. Wildlife/Fisheries, Univ. of California, Davis, CA 95616. 04 Atwood, Jonathan L. 1985. Personal communication. Dept. of Biology, Univ. of California, Los Angeles, CA 90024. 05 Atwood, J.L. and P.R. Kelly. 1984. Fish dropped on breeding colonies as indicators of least tern food habits. Wilson Bull. 96:34-47. 06 Atwood, J.L. and D.E. Minsky. 1983. Least tern foraging ecology at three major California breeding colonies. Western Birds 14:57-72. 07 Bender, K. 1972. California least tern census and nesting survey, 1973. (Avail. from: State of Calif., The Resources Agency, Calif. Dept. Fish Game, Sacramento, CA.) 08 U.S. Fish and Wildlife Service. 1980. California Least Tern Recovery Plan. U.S. Fish and Wildlife Service, Portland, OR. 58 pp. 09 U.S. Fish and Wildlife Service. In prep. Revised California Least Tern Recovery Plan. U.S. Fish and Wildlife Service. Sacramento, CA. 10 Cogswell, H.L. 1947. Southern California Region. Aud. Field Notes 1:188-190. 11 Cogswell, H.L. 1977. Waterbirds of California. Univ. Calif. Press, Berkeley. 12 Collins, Charles T. 1985. Personal communication. Dept. of Biology, Cal. State Univ., Long Beach, CA 90804. 13 Collins, C.T., K.E. Bender, and D.D. Rypka. 1979. Report of the feeding and nesting habits of the California least tern in the Santa Ana River marsh area, Orange County, CA. (Avail. from: U.S. Army Corps of Engineers, Los Angeles Dist.) 14 Cooper, Elizabeth. 1985. Pers. comm. Coronado, CA 92118. 15 Craig, A. 1971. Survey of California least tern nesting sites. (Avail. from: State of Calif., The Resources Agency, Dept. Calif. Fish Game, Sacramento, CA.) 16 Davis, M.E. 1974. Experiments on the nesting behavior of the least tern. Proc. Linn. Soc. N.Y. 72:25-43. 17 Flanagan, Patricia. Pers. comm. Julian, CA 92036. 18 Grinnell, J. and A. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna 27:1-608. 19 Hartert, E. 1921. Die Vogel der Palaarktischen Fauna. Bd. II und Erganzungsband, Berlin. 1715 pp. 20 Lesson, R. 1847. IN: Compl. Ouevres Buffon 20:256. 21 Massey, Barbara W. Field notes. Long Beach, CA 90815. 22 Massey, B.W. 1972. Breeding biology of the California least tern. M.A. Thesis, Cal. State Univ., Long Beach, CA 90840. 23 Massey, B.W. 1974. Breeding biology of the California least Tern. References - 1 (DRAFT) - References Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 Proc. Linn. Soc. N.Y. 72:1-24. 24 Massey, B.W. 1976. Vocal differences between American least terns and the European little tern. Auk 93:760-773. 25 Massey, B.W. 1981. A least tern makes a right turn. Nat. Hist. 90:62-72. 26 Massey, B.W. and J.L. Atwood. 1978. Plumages of the least tern. J. Field Ornith. 49:360-371. 27 Massey, B.W. and J.L. Atwood. 1981. Second-wave nesting of the California least tern: Age composition and reproductive success. Auk 98:596-605. 28 Massey, B.W. and J.L. Atwood. 1982. Application of ecological information to habitat management for the California least tern. U.S. Fish & Wildl. Serv., Laguna Niguel, CA. 29 Mearns, E.A. 1916. Description of a new subspecies of the American least tern. Proc. Biol. Soc. Washington 24:71-72. 30 Minsky, Dennis E. Pers. comm. Dept. of Biol., Cal. State Univ., Long Beach, CA 90840. 31 Shepardson, D.I. 1909. Notes on the least tern. Oologist 26:152. 32 Swickard, D. 1971. Mimeographed manuscript. The status of the California least tern at Camp Pendleton, 1971. Camp Pendleton Marine Corps Base. 30 pp. 33 Tompkins, I.R. 1959. Life history notes on the least tern. Wilson Bull. 71:313-322. 34 Vroegs Cat. Verzam. 1764. Vogelen, Adumbratiuncula. 6 pp. 35 Wilbur, S.R. 1974. The literature of the California least tern. Patuxent Wildlife Research Center, Bureau of Sport Fisheries and Wildlife Special Sci. Rep. - Wildlife No. 175. Washington, D.C. 36 Wolk, R.G. 1974. Reproductive behavior of the least tern. Proc. Linn. Soc. N.Y. 72:63-76. ***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY ***** 01 Allen, A. 1933. The season: San Francisco Region. Bird-Lore 35:336-337. 02 Allen, A. 1934. The season: San Francisco Region. Bird-Lore 36:316. 03 American Ornithologists Union. 1957. Check-list of North American birds, 5th ed. 691 pp. 04 Anderson, Daniel W. 1985. Personal communication. Div. Wildlife/Fisheries, Univ. of California, Davis, CA 95616. 05 Anderson W. 1970. The California least tern breeding in Alameda and San Mateo Counties. Cal. Fish and Game 56:136-137. 06 Atwood, Jonathan L. 1985. Personal communication. Dept. of Biology, Univ. of California, Los Angeles, CA 90024. 07 Atwood, J.L. and D.E. Minsky. 1983. Least tern foraging ecology at three major California breeding colonies. Western Birds 14:57-72. 08 Bancroft, G. 1927. Breeding birds of Scammons Lagoon, lower California. Condor 29:29-57. 09 Bevier, Louis. Personal communication. Box 3874, Santa Barbara, CA 93105. 10 U.S. Fish and Wildlife Service. 1980. California Least Tern References - 2 (DRAFT) - References Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 Recovery Plan. U.S. Fish and Wildlife Service, Portland, OR. 58 pp. 11 U.S. Fish and Wildlife Service. In prep. Revised California Least Tern Recovery Plan. U.S. Fish and Wildlife Service. Sacramento, CA. 12 Chandik, T. and A. Baldridge. 1967. Nesting season, Middle Pacific Coast Region. Aud. Field Notes 21:600-603. 13 Chase, T. and R.O. Paxton. 1965. Middle Pacific Coast Region. Aud. Field Notes 19:574-576. 14 Collins, C.T. In prep. California least tern field study, 1983 field season. Report for Cal. Dept. Fish Game. 15 Collins, L.D. and S.F. Bailey. 1981. California least tern nesting season at Alameda Naval Air Station - 1981. Report to Cal. Dept. Fish Game, Sacramento. 16 Cooper, Elizabeth. 1985. Personal communication. 227 F Ave., Coronado, CA 92118. 17 Craig, Alan. 1983. Personal communication. Cal. Dept. Fish Game, P.O. Box 374, Lakeview, CA 92353. 18 Dawson, W.L. 1924. The birds of California. South Moulton Co., San Diego, CA. 19 DeBenedictis, P. and T. Chase, Jr. 1963. Middle Pacific Coast Region. American Birds 26:801-807. 20 Goldwasser, S. 1980. Least tern breeding season from San Luis Obispo County to Santa Barbara County. Report to Cal. Dept. Fish Game, Sacramento. 21 Grinnell, J. 1928. A distributional summation of the ornithology of lower California. Univ. of Calif. Publ. in Zool. 32:1-300. 22 Grinnell, J. and A. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna 27:1-608. 23 Grinnell, J. and M.W. Wythe. 1927. Directory of the bird-life of the San Francisco Bay Region. Pacific Coast Avifauna 18:1-160. 24 Heilbrun, L.H. 1980. The eightieth Audubon Christmas Bird Count. American Birds 34:327-681. 25 Heilbrun, L.H. 1982. The eighty-second Audubon Christmas bird count. American Birds 36:369-778. 26 Jorgensen, Paul. 1980. Personal communication. 2727 Congress St., San Diego, CA 92110. 27 Jorgensen, P. 1981. The least tern nest season on NAS North Island, 1981 and proposed management for 1982. Report to North Island Naval Air Station, San Diego, CA 92135. 28 Lamb, C.C. 1927. Notes on some birds of the southern extremity of lower California. Condor 29:155-157. 29 Massey, B.W. 1974. Breeding biology of the California least Tern. Proc. Linn. Soc. N.Y. 72:1-24. 30 Massey, B.W. 1977. Occurrence and nesting of the least tern and other Endangered species in Baja California, Mexico. Western Birds 8:67-70. 31 Massey, Barbara W. Field notes and personal correspondence. 1825 Knoxville Ave., Long Beach, CA 90815. 32 Minsky, Dennis E. Personal communication. Dept. of Biology, Cal. State Univ., Long Beach, CA 90840. 33 Pray, R.H. 1954. Middle Pacific Coast Region. Aud. Field Notes 8:326-327. References - 3 (DRAFT) - References Species TERN, LEAST, CALIFORNIA Species Id ESIS101005 Date 14 MAR 96 34 Sechrist, E.E. 1915. Least tern. Oologist 32:18. 35 Sibley, C.G. 1952. The birds of the South San Francisco Bay Region. Manuscript at Oakland Public Museum. 42 pp. 36 Sowls, A.L., A.R. DeGrange, J.W. Nelson, and G.S. Lester. 1980. Catalog of California seabird colonies. Coastas Ecosystems Project, Office of Biological Services, U.S. Fish and Wildlife Service, Washington, D.C. 37 Western Foundation for Vertebrage Zoology (egg collections). 1100 Glendon Ave., Los Angeles, CA 90024. 38 Wilbur, S.R. 1974. The literature of the California least tern. Patuxent Wildlife Research Center, Bureau of Sport Fisheries and Wildlife Special Sci. Rep. - Wildlife No. 175. Washington, D.C. References - 4